L: linux-kernel@vger.kernel.org
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/vdso
S: Maintained
-F: arch/x86/vdso/
+F: arch/x86/entry/vdso/
XC2028/3028 TUNER DRIVER
M: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
obj-y += mm/
obj-y += crypto/
-obj-y += vdso/
+
obj-$(CONFIG_IA32_EMULATION) += ia32/
obj-y += platform/
PHONY += vdso_install
vdso_install:
- $(Q)$(MAKE) $(build)=arch/x86/vdso $@
+ $(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
archclean:
$(Q)rm -rf $(objtree)/arch/i386
#
obj-y := entry_$(BITS).o
+obj-y += vdso/
+
obj-$(CONFIG_IA32_EMULATION) += ia32entry.o
--- /dev/null
+vdso.lds
+vdsox32.lds
+vdso32-syscall-syms.lds
+vdso32-sysenter-syms.lds
+vdso32-int80-syms.lds
+vdso-image-*.c
+vdso2c
--- /dev/null
+#
+# Building vDSO images for x86.
+#
+
+KBUILD_CFLAGS += $(DISABLE_LTO)
+KASAN_SANITIZE := n
+
+VDSO64-$(CONFIG_X86_64) := y
+VDSOX32-$(CONFIG_X86_X32_ABI) := y
+VDSO32-$(CONFIG_X86_32) := y
+VDSO32-$(CONFIG_COMPAT) := y
+
+# files to link into the vdso
+vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
+
+# files to link into kernel
+obj-y += vma.o
+
+# vDSO images to build
+vdso_img-$(VDSO64-y) += 64
+vdso_img-$(VDSOX32-y) += x32
+vdso_img-$(VDSO32-y) += 32-int80
+vdso_img-$(CONFIG_COMPAT) += 32-syscall
+vdso_img-$(VDSO32-y) += 32-sysenter
+
+obj-$(VDSO32-y) += vdso32-setup.o
+
+vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
+
+$(obj)/vdso.o: $(obj)/vdso.so
+
+targets += vdso.lds $(vobjs-y)
+
+# Build the vDSO image C files and link them in.
+vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
+vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
+vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
+obj-y += $(vdso_img_objs)
+targets += $(vdso_img_cfiles)
+targets += $(vdso_img_sodbg)
+.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \
+ $(vdso_img-y:%=$(obj)/vdso%.so)
+
+export CPPFLAGS_vdso.lds += -P -C
+
+VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
+ -Wl,--no-undefined \
+ -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
+ $(DISABLE_LTO)
+
+$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
+ $(call if_changed,vdso)
+
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/x86/include/uapi
+hostprogs-y += vdso2c
+
+quiet_cmd_vdso2c = VDSO2C $@
+define cmd_vdso2c
+ $(obj)/vdso2c $< $(<:%.dbg=%) $@
+endef
+
+$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
+ $(call if_changed,vdso2c)
+
+#
+# Don't omit frame pointers for ease of userspace debugging, but do
+# optimize sibling calls.
+#
+CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
+ $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
+ -fno-omit-frame-pointer -foptimize-sibling-calls \
+ -DDISABLE_BRANCH_PROFILING
+
+$(vobjs): KBUILD_CFLAGS += $(CFL)
+
+#
+# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
+#
+CFLAGS_REMOVE_vdso-note.o = -pg
+CFLAGS_REMOVE_vclock_gettime.o = -pg
+CFLAGS_REMOVE_vgetcpu.o = -pg
+CFLAGS_REMOVE_vvar.o = -pg
+
+#
+# X32 processes use x32 vDSO to access 64bit kernel data.
+#
+# Build x32 vDSO image:
+# 1. Compile x32 vDSO as 64bit.
+# 2. Convert object files to x32.
+# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
+# so that it can reach 64bit address space with 64bit pointers.
+#
+
+CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
+VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
+ -Wl,-soname=linux-vdso.so.1 \
+ -Wl,-z,max-page-size=4096 \
+ -Wl,-z,common-page-size=4096
+
+# 64-bit objects to re-brand as x32
+vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))
+
+# x32-rebranded versions
+vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)
+
+# same thing, but in the output directory
+vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
+
+# Convert 64bit object file to x32 for x32 vDSO.
+quiet_cmd_x32 = X32 $@
+ cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
+
+$(obj)/%-x32.o: $(obj)/%.o FORCE
+ $(call if_changed,x32)
+
+targets += vdsox32.lds $(vobjx32s-y)
+
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg
+ $(call if_changed,objcopy)
+
+$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
+ $(call if_changed,vdso)
+
+#
+# Build multiple 32-bit vDSO images to choose from at boot time.
+#
+vdso32.so-$(VDSO32-y) += int80
+vdso32.so-$(CONFIG_COMPAT) += syscall
+vdso32.so-$(VDSO32-y) += sysenter
+
+vdso32-images = $(vdso32.so-y:%=vdso32-%.so)
+
+CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
+VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
+
+# This makes sure the $(obj) subdirectory exists even though vdso32/
+# is not a kbuild sub-make subdirectory.
+override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
+
+targets += vdso32/vdso32.lds
+targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
+targets += vdso32/vclock_gettime.o
+
+$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
+
+KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
+$(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
+$(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
+
+KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
+KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
+KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
+KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
+KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
+KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
+$(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
+
+$(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
+ $(obj)/vdso32/vdso32.lds \
+ $(obj)/vdso32/vclock_gettime.o \
+ $(obj)/vdso32/note.o \
+ $(obj)/vdso32/%.o
+ $(call if_changed,vdso)
+
+#
+# The DSO images are built using a special linker script.
+#
+quiet_cmd_vdso = VDSO $@
+ cmd_vdso = $(CC) -nostdlib -o $@ \
+ $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
+ -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
+ sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
+
+VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
+ $(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
+GCOV_PROFILE := n
+
+#
+# Install the unstripped copies of vdso*.so. If our toolchain supports
+# build-id, install .build-id links as well.
+#
+quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
+define cmd_vdso_install
+ cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
+ if readelf -n $< |grep -q 'Build ID'; then \
+ buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
+ first=`echo $$buildid | cut -b-2`; \
+ last=`echo $$buildid | cut -b3-`; \
+ mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
+ ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
+ fi
+endef
+
+vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
+
+$(MODLIB)/vdso: FORCE
+ @mkdir -p $(MODLIB)/vdso
+
+$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
+ $(call cmd,vdso_install)
+
+PHONY += vdso_install $(vdso_img_insttargets)
+vdso_install: $(vdso_img_insttargets) FORCE
+
+clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80* vdso64* vdso-image-*.c vdsox32.so*
--- /dev/null
+#!/bin/sh
+nm="$1"
+file="$2"
+$nm "$file" | grep '^ *U' > /dev/null 2>&1
+if [ $? -eq 1 ]; then
+ exit 0
+else
+ echo "$file: undefined symbols found" >&2
+ exit 1
+fi
--- /dev/null
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ * Subject to the GNU Public License, v.2
+ *
+ * Fast user context implementation of clock_gettime, gettimeofday, and time.
+ *
+ * 32 Bit compat layer by Stefani Seibold <stefani@seibold.net>
+ * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
+ *
+ * The code should have no internal unresolved relocations.
+ * Check with readelf after changing.
+ */
+
+#include <uapi/linux/time.h>
+#include <asm/vgtod.h>
+#include <asm/hpet.h>
+#include <asm/vvar.h>
+#include <asm/unistd.h>
+#include <asm/msr.h>
+#include <linux/math64.h>
+#include <linux/time.h>
+
+#define gtod (&VVAR(vsyscall_gtod_data))
+
+extern int __vdso_clock_gettime(clockid_t clock, struct timespec *ts);
+extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz);
+extern time_t __vdso_time(time_t *t);
+
+#ifdef CONFIG_HPET_TIMER
+extern u8 hpet_page
+ __attribute__((visibility("hidden")));
+
+static notrace cycle_t vread_hpet(void)
+{
+ return *(const volatile u32 *)(&hpet_page + HPET_COUNTER);
+}
+#endif
+
+#ifndef BUILD_VDSO32
+
+#include <linux/kernel.h>
+#include <asm/vsyscall.h>
+#include <asm/fixmap.h>
+#include <asm/pvclock.h>
+
+notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
+{
+ long ret;
+ asm("syscall" : "=a" (ret) :
+ "0" (__NR_clock_gettime), "D" (clock), "S" (ts) : "memory");
+ return ret;
+}
+
+notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
+{
+ long ret;
+
+ asm("syscall" : "=a" (ret) :
+ "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
+ return ret;
+}
+
+#ifdef CONFIG_PARAVIRT_CLOCK
+
+static notrace const struct pvclock_vsyscall_time_info *get_pvti(int cpu)
+{
+ const struct pvclock_vsyscall_time_info *pvti_base;
+ int idx = cpu / (PAGE_SIZE/PVTI_SIZE);
+ int offset = cpu % (PAGE_SIZE/PVTI_SIZE);
+
+ BUG_ON(PVCLOCK_FIXMAP_BEGIN + idx > PVCLOCK_FIXMAP_END);
+
+ pvti_base = (struct pvclock_vsyscall_time_info *)
+ __fix_to_virt(PVCLOCK_FIXMAP_BEGIN+idx);
+
+ return &pvti_base[offset];
+}
+
+static notrace cycle_t vread_pvclock(int *mode)
+{
+ const struct pvclock_vsyscall_time_info *pvti;
+ cycle_t ret;
+ u64 last;
+ u32 version;
+ u8 flags;
+ unsigned cpu, cpu1;
+
+
+ /*
+ * Note: hypervisor must guarantee that:
+ * 1. cpu ID number maps 1:1 to per-CPU pvclock time info.
+ * 2. that per-CPU pvclock time info is updated if the
+ * underlying CPU changes.
+ * 3. that version is increased whenever underlying CPU
+ * changes.
+ *
+ */
+ do {
+ cpu = __getcpu() & VGETCPU_CPU_MASK;
+ /* TODO: We can put vcpu id into higher bits of pvti.version.
+ * This will save a couple of cycles by getting rid of
+ * __getcpu() calls (Gleb).
+ */
+
+ pvti = get_pvti(cpu);
+
+ version = __pvclock_read_cycles(&pvti->pvti, &ret, &flags);
+
+ /*
+ * Test we're still on the cpu as well as the version.
+ * We could have been migrated just after the first
+ * vgetcpu but before fetching the version, so we
+ * wouldn't notice a version change.
+ */
+ cpu1 = __getcpu() & VGETCPU_CPU_MASK;
+ } while (unlikely(cpu != cpu1 ||
+ (pvti->pvti.version & 1) ||
+ pvti->pvti.version != version));
+
+ if (unlikely(!(flags & PVCLOCK_TSC_STABLE_BIT)))
+ *mode = VCLOCK_NONE;
+
+ /* refer to tsc.c read_tsc() comment for rationale */
+ last = gtod->cycle_last;
+
+ if (likely(ret >= last))
+ return ret;
+
+ return last;
+}
+#endif
+
+#else
+
+notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
+{
+ long ret;
+
+ asm(
+ "mov %%ebx, %%edx \n"
+ "mov %2, %%ebx \n"
+ "call __kernel_vsyscall \n"
+ "mov %%edx, %%ebx \n"
+ : "=a" (ret)
+ : "0" (__NR_clock_gettime), "g" (clock), "c" (ts)
+ : "memory", "edx");
+ return ret;
+}
+
+notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
+{
+ long ret;
+
+ asm(
+ "mov %%ebx, %%edx \n"
+ "mov %2, %%ebx \n"
+ "call __kernel_vsyscall \n"
+ "mov %%edx, %%ebx \n"
+ : "=a" (ret)
+ : "0" (__NR_gettimeofday), "g" (tv), "c" (tz)
+ : "memory", "edx");
+ return ret;
+}
+
+#ifdef CONFIG_PARAVIRT_CLOCK
+
+static notrace cycle_t vread_pvclock(int *mode)
+{
+ *mode = VCLOCK_NONE;
+ return 0;
+}
+#endif
+
+#endif
+
+notrace static cycle_t vread_tsc(void)
+{
+ cycle_t ret;
+ u64 last;
+
+ /*
+ * Empirically, a fence (of type that depends on the CPU)
+ * before rdtsc is enough to ensure that rdtsc is ordered
+ * with respect to loads. The various CPU manuals are unclear
+ * as to whether rdtsc can be reordered with later loads,
+ * but no one has ever seen it happen.
+ */
+ rdtsc_barrier();
+ ret = (cycle_t)__native_read_tsc();
+
+ last = gtod->cycle_last;
+
+ if (likely(ret >= last))
+ return ret;
+
+ /*
+ * GCC likes to generate cmov here, but this branch is extremely
+ * predictable (it's just a funciton of time and the likely is
+ * very likely) and there's a data dependence, so force GCC
+ * to generate a branch instead. I don't barrier() because
+ * we don't actually need a barrier, and if this function
+ * ever gets inlined it will generate worse code.
+ */
+ asm volatile ("");
+ return last;
+}
+
+notrace static inline u64 vgetsns(int *mode)
+{
+ u64 v;
+ cycles_t cycles;
+
+ if (gtod->vclock_mode == VCLOCK_TSC)
+ cycles = vread_tsc();
+#ifdef CONFIG_HPET_TIMER
+ else if (gtod->vclock_mode == VCLOCK_HPET)
+ cycles = vread_hpet();
+#endif
+#ifdef CONFIG_PARAVIRT_CLOCK
+ else if (gtod->vclock_mode == VCLOCK_PVCLOCK)
+ cycles = vread_pvclock(mode);
+#endif
+ else
+ return 0;
+ v = (cycles - gtod->cycle_last) & gtod->mask;
+ return v * gtod->mult;
+}
+
+/* Code size doesn't matter (vdso is 4k anyway) and this is faster. */
+notrace static int __always_inline do_realtime(struct timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+ int mode;
+
+ do {
+ seq = gtod_read_begin(gtod);
+ mode = gtod->vclock_mode;
+ ts->tv_sec = gtod->wall_time_sec;
+ ns = gtod->wall_time_snsec;
+ ns += vgetsns(&mode);
+ ns >>= gtod->shift;
+ } while (unlikely(gtod_read_retry(gtod, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return mode;
+}
+
+notrace static int __always_inline do_monotonic(struct timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+ int mode;
+
+ do {
+ seq = gtod_read_begin(gtod);
+ mode = gtod->vclock_mode;
+ ts->tv_sec = gtod->monotonic_time_sec;
+ ns = gtod->monotonic_time_snsec;
+ ns += vgetsns(&mode);
+ ns >>= gtod->shift;
+ } while (unlikely(gtod_read_retry(gtod, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return mode;
+}
+
+notrace static void do_realtime_coarse(struct timespec *ts)
+{
+ unsigned long seq;
+ do {
+ seq = gtod_read_begin(gtod);
+ ts->tv_sec = gtod->wall_time_coarse_sec;
+ ts->tv_nsec = gtod->wall_time_coarse_nsec;
+ } while (unlikely(gtod_read_retry(gtod, seq)));
+}
+
+notrace static void do_monotonic_coarse(struct timespec *ts)
+{
+ unsigned long seq;
+ do {
+ seq = gtod_read_begin(gtod);
+ ts->tv_sec = gtod->monotonic_time_coarse_sec;
+ ts->tv_nsec = gtod->monotonic_time_coarse_nsec;
+ } while (unlikely(gtod_read_retry(gtod, seq)));
+}
+
+notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
+{
+ switch (clock) {
+ case CLOCK_REALTIME:
+ if (do_realtime(ts) == VCLOCK_NONE)
+ goto fallback;
+ break;
+ case CLOCK_MONOTONIC:
+ if (do_monotonic(ts) == VCLOCK_NONE)
+ goto fallback;
+ break;
+ case CLOCK_REALTIME_COARSE:
+ do_realtime_coarse(ts);
+ break;
+ case CLOCK_MONOTONIC_COARSE:
+ do_monotonic_coarse(ts);
+ break;
+ default:
+ goto fallback;
+ }
+
+ return 0;
+fallback:
+ return vdso_fallback_gettime(clock, ts);
+}
+int clock_gettime(clockid_t, struct timespec *)
+ __attribute__((weak, alias("__vdso_clock_gettime")));
+
+notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+ if (likely(tv != NULL)) {
+ if (unlikely(do_realtime((struct timespec *)tv) == VCLOCK_NONE))
+ return vdso_fallback_gtod(tv, tz);
+ tv->tv_usec /= 1000;
+ }
+ if (unlikely(tz != NULL)) {
+ tz->tz_minuteswest = gtod->tz_minuteswest;
+ tz->tz_dsttime = gtod->tz_dsttime;
+ }
+
+ return 0;
+}
+int gettimeofday(struct timeval *, struct timezone *)
+ __attribute__((weak, alias("__vdso_gettimeofday")));
+
+/*
+ * This will break when the xtime seconds get inaccurate, but that is
+ * unlikely
+ */
+notrace time_t __vdso_time(time_t *t)
+{
+ /* This is atomic on x86 so we don't need any locks. */
+ time_t result = ACCESS_ONCE(gtod->wall_time_sec);
+
+ if (t)
+ *t = result;
+ return result;
+}
+int time(time_t *t)
+ __attribute__((weak, alias("__vdso_time")));
--- /dev/null
+#include <asm/vdso.h>
+
+/*
+ * Linker script for vDSO. This is an ELF shared object prelinked to
+ * its virtual address, and with only one read-only segment.
+ * This script controls its layout.
+ */
+
+#if defined(BUILD_VDSO64)
+# define SHDR_SIZE 64
+#elif defined(BUILD_VDSO32) || defined(BUILD_VDSOX32)
+# define SHDR_SIZE 40
+#else
+# error unknown VDSO target
+#endif
+
+#define NUM_FAKE_SHDRS 13
+
+SECTIONS
+{
+ /*
+ * User/kernel shared data is before the vDSO. This may be a little
+ * uglier than putting it after the vDSO, but it avoids issues with
+ * non-allocatable things that dangle past the end of the PT_LOAD
+ * segment.
+ */
+
+ vvar_start = . - 2 * PAGE_SIZE;
+ vvar_page = vvar_start;
+
+ /* Place all vvars at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
+#define __VVAR_KERNEL_LDS
+#include <asm/vvar.h>
+#undef __VVAR_KERNEL_LDS
+#undef EMIT_VVAR
+
+ hpet_page = vvar_start + PAGE_SIZE;
+
+ . = SIZEOF_HEADERS;
+
+ .hash : { *(.hash) } :text
+ .gnu.hash : { *(.gnu.hash) }
+ .dynsym : { *(.dynsym) }
+ .dynstr : { *(.dynstr) }
+ .gnu.version : { *(.gnu.version) }
+ .gnu.version_d : { *(.gnu.version_d) }
+ .gnu.version_r : { *(.gnu.version_r) }
+
+ .dynamic : { *(.dynamic) } :text :dynamic
+
+ .rodata : {
+ *(.rodata*)
+ *(.data*)
+ *(.sdata*)
+ *(.got.plt) *(.got)
+ *(.gnu.linkonce.d.*)
+ *(.bss*)
+ *(.dynbss*)
+ *(.gnu.linkonce.b.*)
+
+ /*
+ * Ideally this would live in a C file, but that won't
+ * work cleanly for x32 until we start building the x32
+ * C code using an x32 toolchain.
+ */
+ VDSO_FAKE_SECTION_TABLE_START = .;
+ . = . + NUM_FAKE_SHDRS * SHDR_SIZE;
+ VDSO_FAKE_SECTION_TABLE_END = .;
+ } :text
+
+ .fake_shstrtab : { *(.fake_shstrtab) } :text
+
+
+ .note : { *(.note.*) } :text :note
+
+ .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
+ .eh_frame : { KEEP (*(.eh_frame)) } :text
+
+
+ /*
+ * Text is well-separated from actual data: there's plenty of
+ * stuff that isn't used at runtime in between.
+ */
+
+ .text : { *(.text*) } :text =0x90909090,
+
+ /*
+ * At the end so that eu-elflint stays happy when vdso2c strips
+ * these. A better implementation would avoid allocating space
+ * for these.
+ */
+ .altinstructions : { *(.altinstructions) } :text
+ .altinstr_replacement : { *(.altinstr_replacement) } :text
+
+ /DISCARD/ : {
+ *(.discard)
+ *(.discard.*)
+ *(__bug_table)
+ }
+}
+
+/*
+ * Very old versions of ld do not recognize this name token; use the constant.
+ */
+#define PT_GNU_EH_FRAME 0x6474e550
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+ text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
+ dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
+ note PT_NOTE FLAGS(4); /* PF_R */
+ eh_frame_hdr PT_GNU_EH_FRAME;
+}
--- /dev/null
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/uts.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+ELFNOTE_START(Linux, 0, "a")
+ .long LINUX_VERSION_CODE
+ELFNOTE_END
--- /dev/null
+/*
+ * Linker script for 64-bit vDSO.
+ * We #include the file to define the layout details.
+ *
+ * This file defines the version script giving the user-exported symbols in
+ * the DSO.
+ */
+
+#define BUILD_VDSO64
+
+#include "vdso-layout.lds.S"
+
+/*
+ * This controls what userland symbols we export from the vDSO.
+ */
+VERSION {
+ LINUX_2.6 {
+ global:
+ clock_gettime;
+ __vdso_clock_gettime;
+ gettimeofday;
+ __vdso_gettimeofday;
+ getcpu;
+ __vdso_getcpu;
+ time;
+ __vdso_time;
+ local: *;
+ };
+}
--- /dev/null
+/*
+ * vdso2c - A vdso image preparation tool
+ * Copyright (c) 2014 Andy Lutomirski and others
+ * Licensed under the GPL v2
+ *
+ * vdso2c requires stripped and unstripped input. It would be trivial
+ * to fully strip the input in here, but, for reasons described below,
+ * we need to write a section table. Doing this is more or less
+ * equivalent to dropping all non-allocatable sections, but it's
+ * easier to let objcopy handle that instead of doing it ourselves.
+ * If we ever need to do something fancier than what objcopy provides,
+ * it would be straightforward to add here.
+ *
+ * We're keep a section table for a few reasons:
+ *
+ * The Go runtime had a couple of bugs: it would read the section
+ * table to try to figure out how many dynamic symbols there were (it
+ * shouldn't have looked at the section table at all) and, if there
+ * were no SHT_SYNDYM section table entry, it would use an
+ * uninitialized value for the number of symbols. An empty DYNSYM
+ * table would work, but I see no reason not to write a valid one (and
+ * keep full performance for old Go programs). This hack is only
+ * needed on x86_64.
+ *
+ * The bug was introduced on 2012-08-31 by:
+ * https://code.google.com/p/go/source/detail?r=56ea40aac72b
+ * and was fixed on 2014-06-13 by:
+ * https://code.google.com/p/go/source/detail?r=fc1cd5e12595
+ *
+ * Binutils has issues debugging the vDSO: it reads the section table to
+ * find SHT_NOTE; it won't look at PT_NOTE for the in-memory vDSO, which
+ * would break build-id if we removed the section table. Binutils
+ * also requires that shstrndx != 0. See:
+ * https://sourceware.org/bugzilla/show_bug.cgi?id=17064
+ *
+ * elfutils might not look for PT_NOTE if there is a section table at
+ * all. I don't know whether this matters for any practical purpose.
+ *
+ * For simplicity, rather than hacking up a partial section table, we
+ * just write a mostly complete one. We omit non-dynamic symbols,
+ * though, since they're rather large.
+ *
+ * Once binutils gets fixed, we might be able to drop this for all but
+ * the 64-bit vdso, since build-id only works in kernel RPMs, and
+ * systems that update to new enough kernel RPMs will likely update
+ * binutils in sync. build-id has never worked for home-built kernel
+ * RPMs without manual symlinking, and I suspect that no one ever does
+ * that.
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <err.h>
+
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#include <tools/le_byteshift.h>
+
+#include <linux/elf.h>
+#include <linux/types.h>
+
+const char *outfilename;
+
+/* Symbols that we need in vdso2c. */
+enum {
+ sym_vvar_start,
+ sym_vvar_page,
+ sym_hpet_page,
+ sym_VDSO_FAKE_SECTION_TABLE_START,
+ sym_VDSO_FAKE_SECTION_TABLE_END,
+};
+
+const int special_pages[] = {
+ sym_vvar_page,
+ sym_hpet_page,
+};
+
+struct vdso_sym {
+ const char *name;
+ bool export;
+};
+
+struct vdso_sym required_syms[] = {
+ [sym_vvar_start] = {"vvar_start", true},
+ [sym_vvar_page] = {"vvar_page", true},
+ [sym_hpet_page] = {"hpet_page", true},
+ [sym_VDSO_FAKE_SECTION_TABLE_START] = {
+ "VDSO_FAKE_SECTION_TABLE_START", false
+ },
+ [sym_VDSO_FAKE_SECTION_TABLE_END] = {
+ "VDSO_FAKE_SECTION_TABLE_END", false
+ },
+ {"VDSO32_NOTE_MASK", true},
+ {"VDSO32_SYSENTER_RETURN", true},
+ {"__kernel_vsyscall", true},
+ {"__kernel_sigreturn", true},
+ {"__kernel_rt_sigreturn", true},
+};
+
+__attribute__((format(printf, 1, 2))) __attribute__((noreturn))
+static void fail(const char *format, ...)
+{
+ va_list ap;
+ va_start(ap, format);
+ fprintf(stderr, "Error: ");
+ vfprintf(stderr, format, ap);
+ if (outfilename)
+ unlink(outfilename);
+ exit(1);
+ va_end(ap);
+}
+
+/*
+ * Evil macros for little-endian reads and writes
+ */
+#define GLE(x, bits, ifnot) \
+ __builtin_choose_expr( \
+ (sizeof(*(x)) == bits/8), \
+ (__typeof__(*(x)))get_unaligned_le##bits(x), ifnot)
+
+extern void bad_get_le(void);
+#define LAST_GLE(x) \
+ __builtin_choose_expr(sizeof(*(x)) == 1, *(x), bad_get_le())
+
+#define GET_LE(x) \
+ GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_GLE(x))))
+
+#define PLE(x, val, bits, ifnot) \
+ __builtin_choose_expr( \
+ (sizeof(*(x)) == bits/8), \
+ put_unaligned_le##bits((val), (x)), ifnot)
+
+extern void bad_put_le(void);
+#define LAST_PLE(x, val) \
+ __builtin_choose_expr(sizeof(*(x)) == 1, *(x) = (val), bad_put_le())
+
+#define PUT_LE(x, val) \
+ PLE(x, val, 64, PLE(x, val, 32, PLE(x, val, 16, LAST_PLE(x, val))))
+
+
+#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
+
+#define BITSFUNC3(name, bits, suffix) name##bits##suffix
+#define BITSFUNC2(name, bits, suffix) BITSFUNC3(name, bits, suffix)
+#define BITSFUNC(name) BITSFUNC2(name, ELF_BITS, )
+
+#define INT_BITS BITSFUNC2(int, ELF_BITS, _t)
+
+#define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
+#define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
+#define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
+
+#define ELF_BITS 64
+#include "vdso2c.h"
+#undef ELF_BITS
+
+#define ELF_BITS 32
+#include "vdso2c.h"
+#undef ELF_BITS
+
+static void go(void *raw_addr, size_t raw_len,
+ void *stripped_addr, size_t stripped_len,
+ FILE *outfile, const char *name)
+{
+ Elf64_Ehdr *hdr = (Elf64_Ehdr *)raw_addr;
+
+ if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
+ go64(raw_addr, raw_len, stripped_addr, stripped_len,
+ outfile, name);
+ } else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
+ go32(raw_addr, raw_len, stripped_addr, stripped_len,
+ outfile, name);
+ } else {
+ fail("unknown ELF class\n");
+ }
+}
+
+static void map_input(const char *name, void **addr, size_t *len, int prot)
+{
+ off_t tmp_len;
+
+ int fd = open(name, O_RDONLY);
+ if (fd == -1)
+ err(1, "%s", name);
+
+ tmp_len = lseek(fd, 0, SEEK_END);
+ if (tmp_len == (off_t)-1)
+ err(1, "lseek");
+ *len = (size_t)tmp_len;
+
+ *addr = mmap(NULL, tmp_len, prot, MAP_PRIVATE, fd, 0);
+ if (*addr == MAP_FAILED)
+ err(1, "mmap");
+
+ close(fd);
+}
+
+int main(int argc, char **argv)
+{
+ size_t raw_len, stripped_len;
+ void *raw_addr, *stripped_addr;
+ FILE *outfile;
+ char *name, *tmp;
+ int namelen;
+
+ if (argc != 4) {
+ printf("Usage: vdso2c RAW_INPUT STRIPPED_INPUT OUTPUT\n");
+ return 1;
+ }
+
+ /*
+ * Figure out the struct name. If we're writing to a .so file,
+ * generate raw output insted.
+ */
+ name = strdup(argv[3]);
+ namelen = strlen(name);
+ if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
+ name = NULL;
+ } else {
+ tmp = strrchr(name, '/');
+ if (tmp)
+ name = tmp + 1;
+ tmp = strchr(name, '.');
+ if (tmp)
+ *tmp = '\0';
+ for (tmp = name; *tmp; tmp++)
+ if (*tmp == '-')
+ *tmp = '_';
+ }
+
+ map_input(argv[1], &raw_addr, &raw_len, PROT_READ);
+ map_input(argv[2], &stripped_addr, &stripped_len, PROT_READ);
+
+ outfilename = argv[3];
+ outfile = fopen(outfilename, "w");
+ if (!outfile)
+ err(1, "%s", argv[2]);
+
+ go(raw_addr, raw_len, stripped_addr, stripped_len, outfile, name);
+
+ munmap(raw_addr, raw_len);
+ munmap(stripped_addr, stripped_len);
+ fclose(outfile);
+
+ return 0;
+}
--- /dev/null
+/*
+ * This file is included twice from vdso2c.c. It generates code for 32-bit
+ * and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs
+ * are built for 32-bit userspace.
+ */
+
+static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
+ void *stripped_addr, size_t stripped_len,
+ FILE *outfile, const char *name)
+{
+ int found_load = 0;
+ unsigned long load_size = -1; /* Work around bogus warning */
+ unsigned long mapping_size;
+ ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
+ int i;
+ unsigned long j;
+ ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
+ *alt_sec = NULL;
+ ELF(Dyn) *dyn = 0, *dyn_end = 0;
+ const char *secstrings;
+ INT_BITS syms[NSYMS] = {};
+
+ ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_LE(&hdr->e_phoff));
+
+ /* Walk the segment table. */
+ for (i = 0; i < GET_LE(&hdr->e_phnum); i++) {
+ if (GET_LE(&pt[i].p_type) == PT_LOAD) {
+ if (found_load)
+ fail("multiple PT_LOAD segs\n");
+
+ if (GET_LE(&pt[i].p_offset) != 0 ||
+ GET_LE(&pt[i].p_vaddr) != 0)
+ fail("PT_LOAD in wrong place\n");
+
+ if (GET_LE(&pt[i].p_memsz) != GET_LE(&pt[i].p_filesz))
+ fail("cannot handle memsz != filesz\n");
+
+ load_size = GET_LE(&pt[i].p_memsz);
+ found_load = 1;
+ } else if (GET_LE(&pt[i].p_type) == PT_DYNAMIC) {
+ dyn = raw_addr + GET_LE(&pt[i].p_offset);
+ dyn_end = raw_addr + GET_LE(&pt[i].p_offset) +
+ GET_LE(&pt[i].p_memsz);
+ }
+ }
+ if (!found_load)
+ fail("no PT_LOAD seg\n");
+
+ if (stripped_len < load_size)
+ fail("stripped input is too short\n");
+
+ /* Walk the dynamic table */
+ for (i = 0; dyn + i < dyn_end &&
+ GET_LE(&dyn[i].d_tag) != DT_NULL; i++) {
+ typeof(dyn[i].d_tag) tag = GET_LE(&dyn[i].d_tag);
+ if (tag == DT_REL || tag == DT_RELSZ || tag == DT_RELA ||
+ tag == DT_RELENT || tag == DT_TEXTREL)
+ fail("vdso image contains dynamic relocations\n");
+ }
+
+ /* Walk the section table */
+ secstrings_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
+ GET_LE(&hdr->e_shentsize)*GET_LE(&hdr->e_shstrndx);
+ secstrings = raw_addr + GET_LE(&secstrings_hdr->sh_offset);
+ for (i = 0; i < GET_LE(&hdr->e_shnum); i++) {
+ ELF(Shdr) *sh = raw_addr + GET_LE(&hdr->e_shoff) +
+ GET_LE(&hdr->e_shentsize) * i;
+ if (GET_LE(&sh->sh_type) == SHT_SYMTAB)
+ symtab_hdr = sh;
+
+ if (!strcmp(secstrings + GET_LE(&sh->sh_name),
+ ".altinstructions"))
+ alt_sec = sh;
+ }
+
+ if (!symtab_hdr)
+ fail("no symbol table\n");
+
+ strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
+ GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
+
+ /* Walk the symbol table */
+ for (i = 0;
+ i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
+ i++) {
+ int k;
+ ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
+ GET_LE(&symtab_hdr->sh_entsize) * i;
+ const char *name = raw_addr + GET_LE(&strtab_hdr->sh_offset) +
+ GET_LE(&sym->st_name);
+
+ for (k = 0; k < NSYMS; k++) {
+ if (!strcmp(name, required_syms[k].name)) {
+ if (syms[k]) {
+ fail("duplicate symbol %s\n",
+ required_syms[k].name);
+ }
+
+ /*
+ * Careful: we use negative addresses, but
+ * st_value is unsigned, so we rely
+ * on syms[k] being a signed type of the
+ * correct width.
+ */
+ syms[k] = GET_LE(&sym->st_value);
+ }
+ }
+ }
+
+ /* Validate mapping addresses. */
+ for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
+ INT_BITS symval = syms[special_pages[i]];
+
+ if (!symval)
+ continue; /* The mapping isn't used; ignore it. */
+
+ if (symval % 4096)
+ fail("%s must be a multiple of 4096\n",
+ required_syms[i].name);
+ if (symval + 4096 < syms[sym_vvar_start])
+ fail("%s underruns vvar_start\n",
+ required_syms[i].name);
+ if (symval + 4096 > 0)
+ fail("%s is on the wrong side of the vdso text\n",
+ required_syms[i].name);
+ }
+ if (syms[sym_vvar_start] % 4096)
+ fail("vvar_begin must be a multiple of 4096\n");
+
+ if (!name) {
+ fwrite(stripped_addr, stripped_len, 1, outfile);
+ return;
+ }
+
+ mapping_size = (stripped_len + 4095) / 4096 * 4096;
+
+ fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
+ fprintf(outfile, "#include <linux/linkage.h>\n");
+ fprintf(outfile, "#include <asm/page_types.h>\n");
+ fprintf(outfile, "#include <asm/vdso.h>\n");
+ fprintf(outfile, "\n");
+ fprintf(outfile,
+ "static unsigned char raw_data[%lu] __page_aligned_data = {",
+ mapping_size);
+ for (j = 0; j < stripped_len; j++) {
+ if (j % 10 == 0)
+ fprintf(outfile, "\n\t");
+ fprintf(outfile, "0x%02X, ",
+ (int)((unsigned char *)stripped_addr)[j]);
+ }
+ fprintf(outfile, "\n};\n\n");
+
+ fprintf(outfile, "static struct page *pages[%lu];\n\n",
+ mapping_size / 4096);
+
+ fprintf(outfile, "const struct vdso_image %s = {\n", name);
+ fprintf(outfile, "\t.data = raw_data,\n");
+ fprintf(outfile, "\t.size = %lu,\n", mapping_size);
+ fprintf(outfile, "\t.text_mapping = {\n");
+ fprintf(outfile, "\t\t.name = \"[vdso]\",\n");
+ fprintf(outfile, "\t\t.pages = pages,\n");
+ fprintf(outfile, "\t},\n");
+ if (alt_sec) {
+ fprintf(outfile, "\t.alt = %lu,\n",
+ (unsigned long)GET_LE(&alt_sec->sh_offset));
+ fprintf(outfile, "\t.alt_len = %lu,\n",
+ (unsigned long)GET_LE(&alt_sec->sh_size));
+ }
+ for (i = 0; i < NSYMS; i++) {
+ if (required_syms[i].export && syms[i])
+ fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
+ required_syms[i].name, (int64_t)syms[i]);
+ }
+ fprintf(outfile, "};\n");
+}
--- /dev/null
+/*
+ * (C) Copyright 2002 Linus Torvalds
+ * Portions based on the vdso-randomization code from exec-shield:
+ * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
+ *
+ * This file contains the needed initializations to support sysenter.
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/mm_types.h>
+
+#include <asm/cpufeature.h>
+#include <asm/processor.h>
+#include <asm/vdso.h>
+
+#ifdef CONFIG_COMPAT_VDSO
+#define VDSO_DEFAULT 0
+#else
+#define VDSO_DEFAULT 1
+#endif
+
+/*
+ * Should the kernel map a VDSO page into processes and pass its
+ * address down to glibc upon exec()?
+ */
+unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
+
+static int __init vdso32_setup(char *s)
+{
+ vdso32_enabled = simple_strtoul(s, NULL, 0);
+
+ if (vdso32_enabled > 1)
+ pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
+
+ return 1;
+}
+
+/*
+ * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
+ * behavior on both 64-bit and 32-bit kernels.
+ * On 32-bit kernels, vdso=[012] means the same thing.
+ */
+__setup("vdso32=", vdso32_setup);
+
+#ifdef CONFIG_X86_32
+__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
+#endif
+
+#ifdef CONFIG_X86_64
+
+#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
+#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
+
+#else /* CONFIG_X86_32 */
+
+#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
+#define vdso32_syscall() (0)
+
+#endif /* CONFIG_X86_64 */
+
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+const struct vdso_image *selected_vdso32;
+#endif
+
+int __init sysenter_setup(void)
+{
+#ifdef CONFIG_COMPAT
+ if (vdso32_syscall())
+ selected_vdso32 = &vdso_image_32_syscall;
+ else
+#endif
+ if (vdso32_sysenter())
+ selected_vdso32 = &vdso_image_32_sysenter;
+ else
+ selected_vdso32 = &vdso_image_32_int80;
+
+ init_vdso_image(selected_vdso32);
+
+ return 0;
+}
+
+#ifdef CONFIG_X86_64
+
+subsys_initcall(sysenter_setup);
+
+#ifdef CONFIG_SYSCTL
+/* Register vsyscall32 into the ABI table */
+#include <linux/sysctl.h>
+
+static struct ctl_table abi_table2[] = {
+ {
+ .procname = "vsyscall32",
+ .data = &vdso32_enabled,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {}
+};
+
+static struct ctl_table abi_root_table2[] = {
+ {
+ .procname = "abi",
+ .mode = 0555,
+ .child = abi_table2
+ },
+ {}
+};
+
+static __init int ia32_binfmt_init(void)
+{
+ register_sysctl_table(abi_root_table2);
+ return 0;
+}
+__initcall(ia32_binfmt_init);
+#endif /* CONFIG_SYSCTL */
+
+#endif /* CONFIG_X86_64 */
--- /dev/null
+vdso32.lds
--- /dev/null
+/*
+ * Code for the vDSO. This version uses the old int $0x80 method.
+ *
+ * First get the common code for the sigreturn entry points.
+ * This must come first.
+ */
+#include "sigreturn.S"
+
+ .text
+ .globl __kernel_vsyscall
+ .type __kernel_vsyscall,@function
+ ALIGN
+__kernel_vsyscall:
+.LSTART_vsyscall:
+ int $0x80
+ ret
+.LEND_vsyscall:
+ .size __kernel_vsyscall,.-.LSTART_vsyscall
+ .previous
+
+ .section .eh_frame,"a",@progbits
+.LSTARTFRAMEDLSI:
+ .long .LENDCIEDLSI-.LSTARTCIEDLSI
+.LSTARTCIEDLSI:
+ .long 0 /* CIE ID */
+ .byte 1 /* Version number */
+ .string "zR" /* NUL-terminated augmentation string */
+ .uleb128 1 /* Code alignment factor */
+ .sleb128 -4 /* Data alignment factor */
+ .byte 8 /* Return address register column */
+ .uleb128 1 /* Augmentation value length */
+ .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
+ .byte 0x0c /* DW_CFA_def_cfa */
+ .uleb128 4
+ .uleb128 4
+ .byte 0x88 /* DW_CFA_offset, column 0x8 */
+ .uleb128 1
+ .align 4
+.LENDCIEDLSI:
+ .long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
+.LSTARTFDEDLSI:
+ .long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
+ .long .LSTART_vsyscall-. /* PC-relative start address */
+ .long .LEND_vsyscall-.LSTART_vsyscall
+ .uleb128 0
+ .align 4
+.LENDFDEDLSI:
+ .previous
+
+ /*
+ * Pad out the segment to match the size of the sysenter.S version.
+ */
+VDSO32_vsyscall_eh_frame_size = 0x40
+ .section .data,"aw",@progbits
+ .space VDSO32_vsyscall_eh_frame_size-(.LENDFDEDLSI-.LSTARTFRAMEDLSI), 0
+ .previous
--- /dev/null
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+/* Ideally this would use UTS_NAME, but using a quoted string here
+ doesn't work. Remember to change this when changing the
+ kernel's name. */
+ELFNOTE_START(Linux, 0, "a")
+ .long LINUX_VERSION_CODE
+ELFNOTE_END
+
+#ifdef CONFIG_XEN
+/*
+ * Add a special note telling glibc's dynamic linker a fake hardware
+ * flavor that it will use to choose the search path for libraries in the
+ * same way it uses real hardware capabilities like "mmx".
+ * We supply "nosegneg" as the fake capability, to indicate that we
+ * do not like negative offsets in instructions using segment overrides,
+ * since we implement those inefficiently. This makes it possible to
+ * install libraries optimized to avoid those access patterns in someplace
+ * like /lib/i686/tls/nosegneg. Note that an /etc/ld.so.conf.d/file
+ * corresponding to the bits here is needed to make ldconfig work right.
+ * It should contain:
+ * hwcap 1 nosegneg
+ * to match the mapping of bit to name that we give here.
+ *
+ * At runtime, the fake hardware feature will be considered to be present
+ * if its bit is set in the mask word. So, we start with the mask 0, and
+ * at boot time we set VDSO_NOTE_NONEGSEG_BIT if running under Xen.
+ */
+
+#include "../../xen/vdso.h" /* Defines VDSO_NOTE_NONEGSEG_BIT. */
+
+ELFNOTE_START(GNU, 2, "a")
+ .long 1 /* ncaps */
+VDSO32_NOTE_MASK: /* Symbol used by arch/x86/xen/setup.c */
+ .long 0 /* mask */
+ .byte VDSO_NOTE_NONEGSEG_BIT; .asciz "nosegneg" /* bit, name */
+ELFNOTE_END
+#endif
--- /dev/null
+/*
+ * Common code for the sigreturn entry points in vDSO images.
+ * So far this code is the same for both int80 and sysenter versions.
+ * This file is #include'd by int80.S et al to define them first thing.
+ * The kernel assumes that the addresses of these routines are constant
+ * for all vDSO implementations.
+ */
+
+#include <linux/linkage.h>
+#include <asm/unistd_32.h>
+#include <asm/asm-offsets.h>
+
+#ifndef SYSCALL_ENTER_KERNEL
+#define SYSCALL_ENTER_KERNEL int $0x80
+#endif
+
+ .text
+ .globl __kernel_sigreturn
+ .type __kernel_sigreturn,@function
+ nop /* this guy is needed for .LSTARTFDEDLSI1 below (watch for HACK) */
+ ALIGN
+__kernel_sigreturn:
+.LSTART_sigreturn:
+ popl %eax /* XXX does this mean it needs unwind info? */
+ movl $__NR_sigreturn, %eax
+ SYSCALL_ENTER_KERNEL
+.LEND_sigreturn:
+ nop
+ .size __kernel_sigreturn,.-.LSTART_sigreturn
+
+ .globl __kernel_rt_sigreturn
+ .type __kernel_rt_sigreturn,@function
+ ALIGN
+__kernel_rt_sigreturn:
+.LSTART_rt_sigreturn:
+ movl $__NR_rt_sigreturn, %eax
+ SYSCALL_ENTER_KERNEL
+.LEND_rt_sigreturn:
+ nop
+ .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn
+ .previous
+
+ .section .eh_frame,"a",@progbits
+.LSTARTFRAMEDLSI1:
+ .long .LENDCIEDLSI1-.LSTARTCIEDLSI1
+.LSTARTCIEDLSI1:
+ .long 0 /* CIE ID */
+ .byte 1 /* Version number */
+ .string "zRS" /* NUL-terminated augmentation string */
+ .uleb128 1 /* Code alignment factor */
+ .sleb128 -4 /* Data alignment factor */
+ .byte 8 /* Return address register column */
+ .uleb128 1 /* Augmentation value length */
+ .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
+ .byte 0 /* DW_CFA_nop */
+ .align 4
+.LENDCIEDLSI1:
+ .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */
+.LSTARTFDEDLSI1:
+ .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */
+ /* HACK: The dwarf2 unwind routines will subtract 1 from the
+ return address to get an address in the middle of the
+ presumed call instruction. Since we didn't get here via
+ a call, we need to include the nop before the real start
+ to make up for it. */
+ .long .LSTART_sigreturn-1-. /* PC-relative start address */
+ .long .LEND_sigreturn-.LSTART_sigreturn+1
+ .uleb128 0 /* Augmentation */
+ /* What follows are the instructions for the table generation.
+ We record the locations of each register saved. This is
+ complicated by the fact that the "CFA" is always assumed to
+ be the value of the stack pointer in the caller. This means
+ that we must define the CFA of this body of code to be the
+ saved value of the stack pointer in the sigcontext. Which
+ also means that there is no fixed relation to the other
+ saved registers, which means that we must use DW_CFA_expression
+ to compute their addresses. It also means that when we
+ adjust the stack with the popl, we have to do it all over again. */
+
+#define do_cfa_expr(offset) \
+ .byte 0x0f; /* DW_CFA_def_cfa_expression */ \
+ .uleb128 1f-0f; /* length */ \
+0: .byte 0x74; /* DW_OP_breg4 */ \
+ .sleb128 offset; /* offset */ \
+ .byte 0x06; /* DW_OP_deref */ \
+1:
+
+#define do_expr(regno, offset) \
+ .byte 0x10; /* DW_CFA_expression */ \
+ .uleb128 regno; /* regno */ \
+ .uleb128 1f-0f; /* length */ \
+0: .byte 0x74; /* DW_OP_breg4 */ \
+ .sleb128 offset; /* offset */ \
+1:
+
+ do_cfa_expr(IA32_SIGCONTEXT_sp+4)
+ do_expr(0, IA32_SIGCONTEXT_ax+4)
+ do_expr(1, IA32_SIGCONTEXT_cx+4)
+ do_expr(2, IA32_SIGCONTEXT_dx+4)
+ do_expr(3, IA32_SIGCONTEXT_bx+4)
+ do_expr(5, IA32_SIGCONTEXT_bp+4)
+ do_expr(6, IA32_SIGCONTEXT_si+4)
+ do_expr(7, IA32_SIGCONTEXT_di+4)
+ do_expr(8, IA32_SIGCONTEXT_ip+4)
+
+ .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */
+
+ do_cfa_expr(IA32_SIGCONTEXT_sp)
+ do_expr(0, IA32_SIGCONTEXT_ax)
+ do_expr(1, IA32_SIGCONTEXT_cx)
+ do_expr(2, IA32_SIGCONTEXT_dx)
+ do_expr(3, IA32_SIGCONTEXT_bx)
+ do_expr(5, IA32_SIGCONTEXT_bp)
+ do_expr(6, IA32_SIGCONTEXT_si)
+ do_expr(7, IA32_SIGCONTEXT_di)
+ do_expr(8, IA32_SIGCONTEXT_ip)
+
+ .align 4
+.LENDFDEDLSI1:
+
+ .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */
+.LSTARTFDEDLSI2:
+ .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */
+ /* HACK: See above wrt unwind library assumptions. */
+ .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */
+ .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1
+ .uleb128 0 /* Augmentation */
+ /* What follows are the instructions for the table generation.
+ We record the locations of each register saved. This is
+ slightly less complicated than the above, since we don't
+ modify the stack pointer in the process. */
+
+ do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_sp)
+ do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ax)
+ do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_cx)
+ do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_dx)
+ do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bx)
+ do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bp)
+ do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_si)
+ do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_di)
+ do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ip)
+
+ .align 4
+.LENDFDEDLSI2:
+ .previous
--- /dev/null
+/*
+ * Code for the vDSO. This version uses the syscall instruction.
+ *
+ * First get the common code for the sigreturn entry points.
+ * This must come first.
+ */
+#define SYSCALL_ENTER_KERNEL syscall
+#include "sigreturn.S"
+
+#include <asm/segment.h>
+
+ .text
+ .globl __kernel_vsyscall
+ .type __kernel_vsyscall,@function
+ ALIGN
+__kernel_vsyscall:
+.LSTART_vsyscall:
+ push %ebp
+.Lpush_ebp:
+ movl %ecx, %ebp
+ syscall
+ movl %ebp, %ecx
+ popl %ebp
+.Lpop_ebp:
+ ret
+.LEND_vsyscall:
+ .size __kernel_vsyscall,.-.LSTART_vsyscall
+
+ .section .eh_frame,"a",@progbits
+.LSTARTFRAME:
+ .long .LENDCIE-.LSTARTCIE
+.LSTARTCIE:
+ .long 0 /* CIE ID */
+ .byte 1 /* Version number */
+ .string "zR" /* NUL-terminated augmentation string */
+ .uleb128 1 /* Code alignment factor */
+ .sleb128 -4 /* Data alignment factor */
+ .byte 8 /* Return address register column */
+ .uleb128 1 /* Augmentation value length */
+ .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
+ .byte 0x0c /* DW_CFA_def_cfa */
+ .uleb128 4
+ .uleb128 4
+ .byte 0x88 /* DW_CFA_offset, column 0x8 */
+ .uleb128 1
+ .align 4
+.LENDCIE:
+
+ .long .LENDFDE1-.LSTARTFDE1 /* Length FDE */
+.LSTARTFDE1:
+ .long .LSTARTFDE1-.LSTARTFRAME /* CIE pointer */
+ .long .LSTART_vsyscall-. /* PC-relative start address */
+ .long .LEND_vsyscall-.LSTART_vsyscall
+ .uleb128 0 /* Augmentation length */
+ /* What follows are the instructions for the table generation.
+ We have to record all changes of the stack pointer. */
+ .byte 0x40 + .Lpush_ebp-.LSTART_vsyscall /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .uleb128 8
+ .byte 0x85, 0x02 /* DW_CFA_offset %ebp -8 */
+ .byte 0x40 + .Lpop_ebp-.Lpush_ebp /* DW_CFA_advance_loc */
+ .byte 0xc5 /* DW_CFA_restore %ebp */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .uleb128 4
+ .align 4
+.LENDFDE1:
+ .previous
+
+ /*
+ * Pad out the segment to match the size of the sysenter.S version.
+ */
+VDSO32_vsyscall_eh_frame_size = 0x40
+ .section .data,"aw",@progbits
+ .space VDSO32_vsyscall_eh_frame_size-(.LENDFDE1-.LSTARTFRAME), 0
+ .previous
--- /dev/null
+/*
+ * Code for the vDSO. This version uses the sysenter instruction.
+ *
+ * First get the common code for the sigreturn entry points.
+ * This must come first.
+ */
+#include "sigreturn.S"
+
+/*
+ * The caller puts arg2 in %ecx, which gets pushed. The kernel will use
+ * %ecx itself for arg2. The pushing is because the sysexit instruction
+ * (found in entry.S) requires that we clobber %ecx with the desired %esp.
+ * User code might expect that %ecx is unclobbered though, as it would be
+ * for returning via the iret instruction, so we must push and pop.
+ *
+ * The caller puts arg3 in %edx, which the sysexit instruction requires
+ * for %eip. Thus, exactly as for arg2, we must push and pop.
+ *
+ * Arg6 is different. The caller puts arg6 in %ebp. Since the sysenter
+ * instruction clobbers %esp, the user's %esp won't even survive entry
+ * into the kernel. We store %esp in %ebp. Code in entry.S must fetch
+ * arg6 from the stack.
+ *
+ * You can not use this vsyscall for the clone() syscall because the
+ * three words on the parent stack do not get copied to the child.
+ */
+ .text
+ .globl __kernel_vsyscall
+ .type __kernel_vsyscall,@function
+ ALIGN
+__kernel_vsyscall:
+.LSTART_vsyscall:
+ push %ecx
+.Lpush_ecx:
+ push %edx
+.Lpush_edx:
+ push %ebp
+.Lenter_kernel:
+ movl %esp,%ebp
+ sysenter
+
+ /* 7: align return point with nop's to make disassembly easier */
+ .space 7,0x90
+
+ /* 14: System call restart point is here! (SYSENTER_RETURN-2) */
+ int $0x80
+ /* 16: System call normal return point is here! */
+VDSO32_SYSENTER_RETURN: /* Symbol used by sysenter.c via vdso32-syms.h */
+ pop %ebp
+.Lpop_ebp:
+ pop %edx
+.Lpop_edx:
+ pop %ecx
+.Lpop_ecx:
+ ret
+.LEND_vsyscall:
+ .size __kernel_vsyscall,.-.LSTART_vsyscall
+ .previous
+
+ .section .eh_frame,"a",@progbits
+.LSTARTFRAMEDLSI:
+ .long .LENDCIEDLSI-.LSTARTCIEDLSI
+.LSTARTCIEDLSI:
+ .long 0 /* CIE ID */
+ .byte 1 /* Version number */
+ .string "zR" /* NUL-terminated augmentation string */
+ .uleb128 1 /* Code alignment factor */
+ .sleb128 -4 /* Data alignment factor */
+ .byte 8 /* Return address register column */
+ .uleb128 1 /* Augmentation value length */
+ .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
+ .byte 0x0c /* DW_CFA_def_cfa */
+ .uleb128 4
+ .uleb128 4
+ .byte 0x88 /* DW_CFA_offset, column 0x8 */
+ .uleb128 1
+ .align 4
+.LENDCIEDLSI:
+ .long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
+.LSTARTFDEDLSI:
+ .long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
+ .long .LSTART_vsyscall-. /* PC-relative start address */
+ .long .LEND_vsyscall-.LSTART_vsyscall
+ .uleb128 0
+ /* What follows are the instructions for the table generation.
+ We have to record all changes of the stack pointer. */
+ .byte 0x40 + (.Lpush_ecx-.LSTART_vsyscall) /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x08 /* RA at offset 8 now */
+ .byte 0x40 + (.Lpush_edx-.Lpush_ecx) /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x0c /* RA at offset 12 now */
+ .byte 0x40 + (.Lenter_kernel-.Lpush_edx) /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x10 /* RA at offset 16 now */
+ .byte 0x85, 0x04 /* DW_CFA_offset %ebp -16 */
+ /* Finally the epilogue. */
+ .byte 0x40 + (.Lpop_ebp-.Lenter_kernel) /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x0c /* RA at offset 12 now */
+ .byte 0xc5 /* DW_CFA_restore %ebp */
+ .byte 0x40 + (.Lpop_edx-.Lpop_ebp) /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x08 /* RA at offset 8 now */
+ .byte 0x40 + (.Lpop_ecx-.Lpop_edx) /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x04 /* RA at offset 4 now */
+ .align 4
+.LENDFDEDLSI:
+ .previous
+
+ /*
+ * Emit a symbol with the size of this .eh_frame data,
+ * to verify it matches the other versions.
+ */
+VDSO32_vsyscall_eh_frame_size = (.LENDFDEDLSI-.LSTARTFRAMEDLSI)
--- /dev/null
+#define BUILD_VDSO32
+
+#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
+#undef CONFIG_OPTIMIZE_INLINING
+#endif
+
+#undef CONFIG_X86_PPRO_FENCE
+
+#ifdef CONFIG_X86_64
+
+/*
+ * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
+ * configuration
+ */
+#undef CONFIG_64BIT
+#undef CONFIG_X86_64
+#undef CONFIG_ILLEGAL_POINTER_VALUE
+#undef CONFIG_SPARSEMEM_VMEMMAP
+#undef CONFIG_NR_CPUS
+
+#define CONFIG_X86_32 1
+#define CONFIG_PAGE_OFFSET 0
+#define CONFIG_ILLEGAL_POINTER_VALUE 0
+#define CONFIG_NR_CPUS 1
+
+#define BUILD_VDSO32_64
+
+#endif
+
+#include "../vclock_gettime.c"
--- /dev/null
+#include "../vdso-fakesections.c"
--- /dev/null
+/*
+ * Linker script for 32-bit vDSO.
+ * We #include the file to define the layout details.
+ *
+ * This file defines the version script giving the user-exported symbols in
+ * the DSO.
+ */
+
+#include <asm/page.h>
+
+#define BUILD_VDSO32
+
+#include "../vdso-layout.lds.S"
+
+/* The ELF entry point can be used to set the AT_SYSINFO value. */
+ENTRY(__kernel_vsyscall);
+
+/*
+ * This controls what userland symbols we export from the vDSO.
+ */
+VERSION
+{
+ LINUX_2.6 {
+ global:
+ __vdso_clock_gettime;
+ __vdso_gettimeofday;
+ __vdso_time;
+ };
+
+ LINUX_2.5 {
+ global:
+ __kernel_vsyscall;
+ __kernel_sigreturn;
+ __kernel_rt_sigreturn;
+ local: *;
+ };
+}
--- /dev/null
+/*
+ * Linker script for x32 vDSO.
+ * We #include the file to define the layout details.
+ *
+ * This file defines the version script giving the user-exported symbols in
+ * the DSO.
+ */
+
+#define BUILD_VDSOX32
+
+#include "vdso-layout.lds.S"
+
+/*
+ * This controls what userland symbols we export from the vDSO.
+ */
+VERSION {
+ LINUX_2.6 {
+ global:
+ __vdso_clock_gettime;
+ __vdso_gettimeofday;
+ __vdso_getcpu;
+ __vdso_time;
+ local: *;
+ };
+}
--- /dev/null
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ * Subject to the GNU Public License, v.2
+ *
+ * Fast user context implementation of getcpu()
+ */
+
+#include <linux/kernel.h>
+#include <linux/getcpu.h>
+#include <linux/time.h>
+#include <asm/vgtod.h>
+
+notrace long
+__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
+{
+ unsigned int p;
+
+ p = __getcpu();
+
+ if (cpu)
+ *cpu = p & VGETCPU_CPU_MASK;
+ if (node)
+ *node = p >> 12;
+ return 0;
+}
+
+long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
+ __attribute__((weak, alias("__vdso_getcpu")));
--- /dev/null
+/*
+ * Copyright 2007 Andi Kleen, SUSE Labs.
+ * Subject to the GPL, v.2
+ *
+ * This contains most of the x86 vDSO kernel-side code.
+ */
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/random.h>
+#include <linux/elf.h>
+#include <linux/cpu.h>
+#include <asm/vgtod.h>
+#include <asm/proto.h>
+#include <asm/vdso.h>
+#include <asm/vvar.h>
+#include <asm/page.h>
+#include <asm/hpet.h>
+#include <asm/desc.h>
+
+#if defined(CONFIG_X86_64)
+unsigned int __read_mostly vdso64_enabled = 1;
+#endif
+
+void __init init_vdso_image(const struct vdso_image *image)
+{
+ int i;
+ int npages = (image->size) / PAGE_SIZE;
+
+ BUG_ON(image->size % PAGE_SIZE != 0);
+ for (i = 0; i < npages; i++)
+ image->text_mapping.pages[i] =
+ virt_to_page(image->data + i*PAGE_SIZE);
+
+ apply_alternatives((struct alt_instr *)(image->data + image->alt),
+ (struct alt_instr *)(image->data + image->alt +
+ image->alt_len));
+}
+
+struct linux_binprm;
+
+/*
+ * Put the vdso above the (randomized) stack with another randomized
+ * offset. This way there is no hole in the middle of address space.
+ * To save memory make sure it is still in the same PTE as the stack
+ * top. This doesn't give that many random bits.
+ *
+ * Note that this algorithm is imperfect: the distribution of the vdso
+ * start address within a PMD is biased toward the end.
+ *
+ * Only used for the 64-bit and x32 vdsos.
+ */
+static unsigned long vdso_addr(unsigned long start, unsigned len)
+{
+#ifdef CONFIG_X86_32
+ return 0;
+#else
+ unsigned long addr, end;
+ unsigned offset;
+
+ /*
+ * Round up the start address. It can start out unaligned as a result
+ * of stack start randomization.
+ */
+ start = PAGE_ALIGN(start);
+
+ /* Round the lowest possible end address up to a PMD boundary. */
+ end = (start + len + PMD_SIZE - 1) & PMD_MASK;
+ if (end >= TASK_SIZE_MAX)
+ end = TASK_SIZE_MAX;
+ end -= len;
+
+ if (end > start) {
+ offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
+ addr = start + (offset << PAGE_SHIFT);
+ } else {
+ addr = start;
+ }
+
+ /*
+ * Forcibly align the final address in case we have a hardware
+ * issue that requires alignment for performance reasons.
+ */
+ addr = align_vdso_addr(addr);
+
+ return addr;
+#endif
+}
+
+static int map_vdso(const struct vdso_image *image, bool calculate_addr)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long addr, text_start;
+ int ret = 0;
+ static struct page *no_pages[] = {NULL};
+ static struct vm_special_mapping vvar_mapping = {
+ .name = "[vvar]",
+ .pages = no_pages,
+ };
+
+ if (calculate_addr) {
+ addr = vdso_addr(current->mm->start_stack,
+ image->size - image->sym_vvar_start);
+ } else {
+ addr = 0;
+ }
+
+ down_write(&mm->mmap_sem);
+
+ addr = get_unmapped_area(NULL, addr,
+ image->size - image->sym_vvar_start, 0, 0);
+ if (IS_ERR_VALUE(addr)) {
+ ret = addr;
+ goto up_fail;
+ }
+
+ text_start = addr - image->sym_vvar_start;
+ current->mm->context.vdso = (void __user *)text_start;
+
+ /*
+ * MAYWRITE to allow gdb to COW and set breakpoints
+ */
+ vma = _install_special_mapping(mm,
+ text_start,
+ image->size,
+ VM_READ|VM_EXEC|
+ VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+ &image->text_mapping);
+
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto up_fail;
+ }
+
+ vma = _install_special_mapping(mm,
+ addr,
+ -image->sym_vvar_start,
+ VM_READ|VM_MAYREAD,
+ &vvar_mapping);
+
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto up_fail;
+ }
+
+ if (image->sym_vvar_page)
+ ret = remap_pfn_range(vma,
+ text_start + image->sym_vvar_page,
+ __pa_symbol(&__vvar_page) >> PAGE_SHIFT,
+ PAGE_SIZE,
+ PAGE_READONLY);
+
+ if (ret)
+ goto up_fail;
+
+#ifdef CONFIG_HPET_TIMER
+ if (hpet_address && image->sym_hpet_page) {
+ ret = io_remap_pfn_range(vma,
+ text_start + image->sym_hpet_page,
+ hpet_address >> PAGE_SHIFT,
+ PAGE_SIZE,
+ pgprot_noncached(PAGE_READONLY));
+
+ if (ret)
+ goto up_fail;
+ }
+#endif
+
+up_fail:
+ if (ret)
+ current->mm->context.vdso = NULL;
+
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+static int load_vdso32(void)
+{
+ int ret;
+
+ if (vdso32_enabled != 1) /* Other values all mean "disabled" */
+ return 0;
+
+ ret = map_vdso(selected_vdso32, false);
+ if (ret)
+ return ret;
+
+ if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
+ current_thread_info()->sysenter_return =
+ current->mm->context.vdso +
+ selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
+
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_X86_64
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+ if (!vdso64_enabled)
+ return 0;
+
+ return map_vdso(&vdso_image_64, true);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+ int uses_interp)
+{
+#ifdef CONFIG_X86_X32_ABI
+ if (test_thread_flag(TIF_X32)) {
+ if (!vdso64_enabled)
+ return 0;
+
+ return map_vdso(&vdso_image_x32, true);
+ }
+#endif
+
+ return load_vdso32();
+}
+#endif
+#else
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+ return load_vdso32();
+}
+#endif
+
+#ifdef CONFIG_X86_64
+static __init int vdso_setup(char *s)
+{
+ vdso64_enabled = simple_strtoul(s, NULL, 0);
+ return 0;
+}
+__setup("vdso=", vdso_setup);
+#endif
+
+#ifdef CONFIG_X86_64
+static void vgetcpu_cpu_init(void *arg)
+{
+ int cpu = smp_processor_id();
+ struct desc_struct d = { };
+ unsigned long node = 0;
+#ifdef CONFIG_NUMA
+ node = cpu_to_node(cpu);
+#endif
+ if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP))
+ write_rdtscp_aux((node << 12) | cpu);
+
+ /*
+ * Store cpu number in limit so that it can be loaded
+ * quickly in user space in vgetcpu. (12 bits for the CPU
+ * and 8 bits for the node)
+ */
+ d.limit0 = cpu | ((node & 0xf) << 12);
+ d.limit = node >> 4;
+ d.type = 5; /* RO data, expand down, accessed */
+ d.dpl = 3; /* Visible to user code */
+ d.s = 1; /* Not a system segment */
+ d.p = 1; /* Present */
+ d.d = 1; /* 32-bit */
+
+ write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);
+}
+
+static int
+vgetcpu_cpu_notifier(struct notifier_block *n, unsigned long action, void *arg)
+{
+ long cpu = (long)arg;
+
+ if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
+ smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1);
+
+ return NOTIFY_DONE;
+}
+
+static int __init init_vdso(void)
+{
+ init_vdso_image(&vdso_image_64);
+
+#ifdef CONFIG_X86_X32_ABI
+ init_vdso_image(&vdso_image_x32);
+#endif
+
+ cpu_notifier_register_begin();
+
+ on_each_cpu(vgetcpu_cpu_init, NULL, 1);
+ /* notifier priority > KVM */
+ __hotcpu_notifier(vgetcpu_cpu_notifier, 30);
+
+ cpu_notifier_register_done();
+
+ return 0;
+}
+subsys_initcall(init_vdso);
+#endif /* CONFIG_X86_64 */
+++ /dev/null
-vdso.lds
-vdsox32.lds
-vdso32-syscall-syms.lds
-vdso32-sysenter-syms.lds
-vdso32-int80-syms.lds
-vdso-image-*.c
-vdso2c
+++ /dev/null
-#
-# Building vDSO images for x86.
-#
-
-KBUILD_CFLAGS += $(DISABLE_LTO)
-KASAN_SANITIZE := n
-
-VDSO64-$(CONFIG_X86_64) := y
-VDSOX32-$(CONFIG_X86_X32_ABI) := y
-VDSO32-$(CONFIG_X86_32) := y
-VDSO32-$(CONFIG_COMPAT) := y
-
-# files to link into the vdso
-vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
-
-# files to link into kernel
-obj-y += vma.o
-
-# vDSO images to build
-vdso_img-$(VDSO64-y) += 64
-vdso_img-$(VDSOX32-y) += x32
-vdso_img-$(VDSO32-y) += 32-int80
-vdso_img-$(CONFIG_COMPAT) += 32-syscall
-vdso_img-$(VDSO32-y) += 32-sysenter
-
-obj-$(VDSO32-y) += vdso32-setup.o
-
-vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
-
-$(obj)/vdso.o: $(obj)/vdso.so
-
-targets += vdso.lds $(vobjs-y)
-
-# Build the vDSO image C files and link them in.
-vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
-vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
-vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
-obj-y += $(vdso_img_objs)
-targets += $(vdso_img_cfiles)
-targets += $(vdso_img_sodbg)
-.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \
- $(vdso_img-y:%=$(obj)/vdso%.so)
-
-export CPPFLAGS_vdso.lds += -P -C
-
-VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
- -Wl,--no-undefined \
- -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
- $(DISABLE_LTO)
-
-$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
- $(call if_changed,vdso)
-
-HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/x86/include/uapi
-hostprogs-y += vdso2c
-
-quiet_cmd_vdso2c = VDSO2C $@
-define cmd_vdso2c
- $(obj)/vdso2c $< $(<:%.dbg=%) $@
-endef
-
-$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
- $(call if_changed,vdso2c)
-
-#
-# Don't omit frame pointers for ease of userspace debugging, but do
-# optimize sibling calls.
-#
-CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
- $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
- -fno-omit-frame-pointer -foptimize-sibling-calls \
- -DDISABLE_BRANCH_PROFILING
-
-$(vobjs): KBUILD_CFLAGS += $(CFL)
-
-#
-# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
-#
-CFLAGS_REMOVE_vdso-note.o = -pg
-CFLAGS_REMOVE_vclock_gettime.o = -pg
-CFLAGS_REMOVE_vgetcpu.o = -pg
-CFLAGS_REMOVE_vvar.o = -pg
-
-#
-# X32 processes use x32 vDSO to access 64bit kernel data.
-#
-# Build x32 vDSO image:
-# 1. Compile x32 vDSO as 64bit.
-# 2. Convert object files to x32.
-# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
-# so that it can reach 64bit address space with 64bit pointers.
-#
-
-CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
-VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
- -Wl,-soname=linux-vdso.so.1 \
- -Wl,-z,max-page-size=4096 \
- -Wl,-z,common-page-size=4096
-
-# 64-bit objects to re-brand as x32
-vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))
-
-# x32-rebranded versions
-vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)
-
-# same thing, but in the output directory
-vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
-
-# Convert 64bit object file to x32 for x32 vDSO.
-quiet_cmd_x32 = X32 $@
- cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
-
-$(obj)/%-x32.o: $(obj)/%.o FORCE
- $(call if_changed,x32)
-
-targets += vdsox32.lds $(vobjx32s-y)
-
-$(obj)/%.so: OBJCOPYFLAGS := -S
-$(obj)/%.so: $(obj)/%.so.dbg
- $(call if_changed,objcopy)
-
-$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
- $(call if_changed,vdso)
-
-#
-# Build multiple 32-bit vDSO images to choose from at boot time.
-#
-vdso32.so-$(VDSO32-y) += int80
-vdso32.so-$(CONFIG_COMPAT) += syscall
-vdso32.so-$(VDSO32-y) += sysenter
-
-vdso32-images = $(vdso32.so-y:%=vdso32-%.so)
-
-CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
-VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
-
-# This makes sure the $(obj) subdirectory exists even though vdso32/
-# is not a kbuild sub-make subdirectory.
-override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
-
-targets += vdso32/vdso32.lds
-targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
-targets += vdso32/vclock_gettime.o
-
-$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
-
-KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
-$(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
-$(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
-
-KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
-KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
-KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
-KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
-KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
-KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
-$(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
-
-$(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
- $(obj)/vdso32/vdso32.lds \
- $(obj)/vdso32/vclock_gettime.o \
- $(obj)/vdso32/note.o \
- $(obj)/vdso32/%.o
- $(call if_changed,vdso)
-
-#
-# The DSO images are built using a special linker script.
-#
-quiet_cmd_vdso = VDSO $@
- cmd_vdso = $(CC) -nostdlib -o $@ \
- $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
- -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
- sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
-
-VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
- $(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
-GCOV_PROFILE := n
-
-#
-# Install the unstripped copies of vdso*.so. If our toolchain supports
-# build-id, install .build-id links as well.
-#
-quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
-define cmd_vdso_install
- cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
- if readelf -n $< |grep -q 'Build ID'; then \
- buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
- first=`echo $$buildid | cut -b-2`; \
- last=`echo $$buildid | cut -b3-`; \
- mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
- ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
- fi
-endef
-
-vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
-
-$(MODLIB)/vdso: FORCE
- @mkdir -p $(MODLIB)/vdso
-
-$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
- $(call cmd,vdso_install)
-
-PHONY += vdso_install $(vdso_img_insttargets)
-vdso_install: $(vdso_img_insttargets) FORCE
-
-clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80* vdso64* vdso-image-*.c vdsox32.so*
+++ /dev/null
-#!/bin/sh
-nm="$1"
-file="$2"
-$nm "$file" | grep '^ *U' > /dev/null 2>&1
-if [ $? -eq 1 ]; then
- exit 0
-else
- echo "$file: undefined symbols found" >&2
- exit 1
-fi
+++ /dev/null
-/*
- * Copyright 2006 Andi Kleen, SUSE Labs.
- * Subject to the GNU Public License, v.2
- *
- * Fast user context implementation of clock_gettime, gettimeofday, and time.
- *
- * 32 Bit compat layer by Stefani Seibold <stefani@seibold.net>
- * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
- *
- * The code should have no internal unresolved relocations.
- * Check with readelf after changing.
- */
-
-#include <uapi/linux/time.h>
-#include <asm/vgtod.h>
-#include <asm/hpet.h>
-#include <asm/vvar.h>
-#include <asm/unistd.h>
-#include <asm/msr.h>
-#include <linux/math64.h>
-#include <linux/time.h>
-
-#define gtod (&VVAR(vsyscall_gtod_data))
-
-extern int __vdso_clock_gettime(clockid_t clock, struct timespec *ts);
-extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz);
-extern time_t __vdso_time(time_t *t);
-
-#ifdef CONFIG_HPET_TIMER
-extern u8 hpet_page
- __attribute__((visibility("hidden")));
-
-static notrace cycle_t vread_hpet(void)
-{
- return *(const volatile u32 *)(&hpet_page + HPET_COUNTER);
-}
-#endif
-
-#ifndef BUILD_VDSO32
-
-#include <linux/kernel.h>
-#include <asm/vsyscall.h>
-#include <asm/fixmap.h>
-#include <asm/pvclock.h>
-
-notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
-{
- long ret;
- asm("syscall" : "=a" (ret) :
- "0" (__NR_clock_gettime), "D" (clock), "S" (ts) : "memory");
- return ret;
-}
-
-notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
-{
- long ret;
-
- asm("syscall" : "=a" (ret) :
- "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
- return ret;
-}
-
-#ifdef CONFIG_PARAVIRT_CLOCK
-
-static notrace const struct pvclock_vsyscall_time_info *get_pvti(int cpu)
-{
- const struct pvclock_vsyscall_time_info *pvti_base;
- int idx = cpu / (PAGE_SIZE/PVTI_SIZE);
- int offset = cpu % (PAGE_SIZE/PVTI_SIZE);
-
- BUG_ON(PVCLOCK_FIXMAP_BEGIN + idx > PVCLOCK_FIXMAP_END);
-
- pvti_base = (struct pvclock_vsyscall_time_info *)
- __fix_to_virt(PVCLOCK_FIXMAP_BEGIN+idx);
-
- return &pvti_base[offset];
-}
-
-static notrace cycle_t vread_pvclock(int *mode)
-{
- const struct pvclock_vsyscall_time_info *pvti;
- cycle_t ret;
- u64 last;
- u32 version;
- u8 flags;
- unsigned cpu, cpu1;
-
-
- /*
- * Note: hypervisor must guarantee that:
- * 1. cpu ID number maps 1:1 to per-CPU pvclock time info.
- * 2. that per-CPU pvclock time info is updated if the
- * underlying CPU changes.
- * 3. that version is increased whenever underlying CPU
- * changes.
- *
- */
- do {
- cpu = __getcpu() & VGETCPU_CPU_MASK;
- /* TODO: We can put vcpu id into higher bits of pvti.version.
- * This will save a couple of cycles by getting rid of
- * __getcpu() calls (Gleb).
- */
-
- pvti = get_pvti(cpu);
-
- version = __pvclock_read_cycles(&pvti->pvti, &ret, &flags);
-
- /*
- * Test we're still on the cpu as well as the version.
- * We could have been migrated just after the first
- * vgetcpu but before fetching the version, so we
- * wouldn't notice a version change.
- */
- cpu1 = __getcpu() & VGETCPU_CPU_MASK;
- } while (unlikely(cpu != cpu1 ||
- (pvti->pvti.version & 1) ||
- pvti->pvti.version != version));
-
- if (unlikely(!(flags & PVCLOCK_TSC_STABLE_BIT)))
- *mode = VCLOCK_NONE;
-
- /* refer to tsc.c read_tsc() comment for rationale */
- last = gtod->cycle_last;
-
- if (likely(ret >= last))
- return ret;
-
- return last;
-}
-#endif
-
-#else
-
-notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
-{
- long ret;
-
- asm(
- "mov %%ebx, %%edx \n"
- "mov %2, %%ebx \n"
- "call __kernel_vsyscall \n"
- "mov %%edx, %%ebx \n"
- : "=a" (ret)
- : "0" (__NR_clock_gettime), "g" (clock), "c" (ts)
- : "memory", "edx");
- return ret;
-}
-
-notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
-{
- long ret;
-
- asm(
- "mov %%ebx, %%edx \n"
- "mov %2, %%ebx \n"
- "call __kernel_vsyscall \n"
- "mov %%edx, %%ebx \n"
- : "=a" (ret)
- : "0" (__NR_gettimeofday), "g" (tv), "c" (tz)
- : "memory", "edx");
- return ret;
-}
-
-#ifdef CONFIG_PARAVIRT_CLOCK
-
-static notrace cycle_t vread_pvclock(int *mode)
-{
- *mode = VCLOCK_NONE;
- return 0;
-}
-#endif
-
-#endif
-
-notrace static cycle_t vread_tsc(void)
-{
- cycle_t ret;
- u64 last;
-
- /*
- * Empirically, a fence (of type that depends on the CPU)
- * before rdtsc is enough to ensure that rdtsc is ordered
- * with respect to loads. The various CPU manuals are unclear
- * as to whether rdtsc can be reordered with later loads,
- * but no one has ever seen it happen.
- */
- rdtsc_barrier();
- ret = (cycle_t)__native_read_tsc();
-
- last = gtod->cycle_last;
-
- if (likely(ret >= last))
- return ret;
-
- /*
- * GCC likes to generate cmov here, but this branch is extremely
- * predictable (it's just a funciton of time and the likely is
- * very likely) and there's a data dependence, so force GCC
- * to generate a branch instead. I don't barrier() because
- * we don't actually need a barrier, and if this function
- * ever gets inlined it will generate worse code.
- */
- asm volatile ("");
- return last;
-}
-
-notrace static inline u64 vgetsns(int *mode)
-{
- u64 v;
- cycles_t cycles;
-
- if (gtod->vclock_mode == VCLOCK_TSC)
- cycles = vread_tsc();
-#ifdef CONFIG_HPET_TIMER
- else if (gtod->vclock_mode == VCLOCK_HPET)
- cycles = vread_hpet();
-#endif
-#ifdef CONFIG_PARAVIRT_CLOCK
- else if (gtod->vclock_mode == VCLOCK_PVCLOCK)
- cycles = vread_pvclock(mode);
-#endif
- else
- return 0;
- v = (cycles - gtod->cycle_last) & gtod->mask;
- return v * gtod->mult;
-}
-
-/* Code size doesn't matter (vdso is 4k anyway) and this is faster. */
-notrace static int __always_inline do_realtime(struct timespec *ts)
-{
- unsigned long seq;
- u64 ns;
- int mode;
-
- do {
- seq = gtod_read_begin(gtod);
- mode = gtod->vclock_mode;
- ts->tv_sec = gtod->wall_time_sec;
- ns = gtod->wall_time_snsec;
- ns += vgetsns(&mode);
- ns >>= gtod->shift;
- } while (unlikely(gtod_read_retry(gtod, seq)));
-
- ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
- ts->tv_nsec = ns;
-
- return mode;
-}
-
-notrace static int __always_inline do_monotonic(struct timespec *ts)
-{
- unsigned long seq;
- u64 ns;
- int mode;
-
- do {
- seq = gtod_read_begin(gtod);
- mode = gtod->vclock_mode;
- ts->tv_sec = gtod->monotonic_time_sec;
- ns = gtod->monotonic_time_snsec;
- ns += vgetsns(&mode);
- ns >>= gtod->shift;
- } while (unlikely(gtod_read_retry(gtod, seq)));
-
- ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
- ts->tv_nsec = ns;
-
- return mode;
-}
-
-notrace static void do_realtime_coarse(struct timespec *ts)
-{
- unsigned long seq;
- do {
- seq = gtod_read_begin(gtod);
- ts->tv_sec = gtod->wall_time_coarse_sec;
- ts->tv_nsec = gtod->wall_time_coarse_nsec;
- } while (unlikely(gtod_read_retry(gtod, seq)));
-}
-
-notrace static void do_monotonic_coarse(struct timespec *ts)
-{
- unsigned long seq;
- do {
- seq = gtod_read_begin(gtod);
- ts->tv_sec = gtod->monotonic_time_coarse_sec;
- ts->tv_nsec = gtod->monotonic_time_coarse_nsec;
- } while (unlikely(gtod_read_retry(gtod, seq)));
-}
-
-notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
-{
- switch (clock) {
- case CLOCK_REALTIME:
- if (do_realtime(ts) == VCLOCK_NONE)
- goto fallback;
- break;
- case CLOCK_MONOTONIC:
- if (do_monotonic(ts) == VCLOCK_NONE)
- goto fallback;
- break;
- case CLOCK_REALTIME_COARSE:
- do_realtime_coarse(ts);
- break;
- case CLOCK_MONOTONIC_COARSE:
- do_monotonic_coarse(ts);
- break;
- default:
- goto fallback;
- }
-
- return 0;
-fallback:
- return vdso_fallback_gettime(clock, ts);
-}
-int clock_gettime(clockid_t, struct timespec *)
- __attribute__((weak, alias("__vdso_clock_gettime")));
-
-notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
-{
- if (likely(tv != NULL)) {
- if (unlikely(do_realtime((struct timespec *)tv) == VCLOCK_NONE))
- return vdso_fallback_gtod(tv, tz);
- tv->tv_usec /= 1000;
- }
- if (unlikely(tz != NULL)) {
- tz->tz_minuteswest = gtod->tz_minuteswest;
- tz->tz_dsttime = gtod->tz_dsttime;
- }
-
- return 0;
-}
-int gettimeofday(struct timeval *, struct timezone *)
- __attribute__((weak, alias("__vdso_gettimeofday")));
-
-/*
- * This will break when the xtime seconds get inaccurate, but that is
- * unlikely
- */
-notrace time_t __vdso_time(time_t *t)
-{
- /* This is atomic on x86 so we don't need any locks. */
- time_t result = ACCESS_ONCE(gtod->wall_time_sec);
-
- if (t)
- *t = result;
- return result;
-}
-int time(time_t *t)
- __attribute__((weak, alias("__vdso_time")));
+++ /dev/null
-#include <asm/vdso.h>
-
-/*
- * Linker script for vDSO. This is an ELF shared object prelinked to
- * its virtual address, and with only one read-only segment.
- * This script controls its layout.
- */
-
-#if defined(BUILD_VDSO64)
-# define SHDR_SIZE 64
-#elif defined(BUILD_VDSO32) || defined(BUILD_VDSOX32)
-# define SHDR_SIZE 40
-#else
-# error unknown VDSO target
-#endif
-
-#define NUM_FAKE_SHDRS 13
-
-SECTIONS
-{
- /*
- * User/kernel shared data is before the vDSO. This may be a little
- * uglier than putting it after the vDSO, but it avoids issues with
- * non-allocatable things that dangle past the end of the PT_LOAD
- * segment.
- */
-
- vvar_start = . - 2 * PAGE_SIZE;
- vvar_page = vvar_start;
-
- /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
-#define __VVAR_KERNEL_LDS
-#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
-#undef EMIT_VVAR
-
- hpet_page = vvar_start + PAGE_SIZE;
-
- . = SIZEOF_HEADERS;
-
- .hash : { *(.hash) } :text
- .gnu.hash : { *(.gnu.hash) }
- .dynsym : { *(.dynsym) }
- .dynstr : { *(.dynstr) }
- .gnu.version : { *(.gnu.version) }
- .gnu.version_d : { *(.gnu.version_d) }
- .gnu.version_r : { *(.gnu.version_r) }
-
- .dynamic : { *(.dynamic) } :text :dynamic
-
- .rodata : {
- *(.rodata*)
- *(.data*)
- *(.sdata*)
- *(.got.plt) *(.got)
- *(.gnu.linkonce.d.*)
- *(.bss*)
- *(.dynbss*)
- *(.gnu.linkonce.b.*)
-
- /*
- * Ideally this would live in a C file, but that won't
- * work cleanly for x32 until we start building the x32
- * C code using an x32 toolchain.
- */
- VDSO_FAKE_SECTION_TABLE_START = .;
- . = . + NUM_FAKE_SHDRS * SHDR_SIZE;
- VDSO_FAKE_SECTION_TABLE_END = .;
- } :text
-
- .fake_shstrtab : { *(.fake_shstrtab) } :text
-
-
- .note : { *(.note.*) } :text :note
-
- .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
- .eh_frame : { KEEP (*(.eh_frame)) } :text
-
-
- /*
- * Text is well-separated from actual data: there's plenty of
- * stuff that isn't used at runtime in between.
- */
-
- .text : { *(.text*) } :text =0x90909090,
-
- /*
- * At the end so that eu-elflint stays happy when vdso2c strips
- * these. A better implementation would avoid allocating space
- * for these.
- */
- .altinstructions : { *(.altinstructions) } :text
- .altinstr_replacement : { *(.altinstr_replacement) } :text
-
- /DISCARD/ : {
- *(.discard)
- *(.discard.*)
- *(__bug_table)
- }
-}
-
-/*
- * Very old versions of ld do not recognize this name token; use the constant.
- */
-#define PT_GNU_EH_FRAME 0x6474e550
-
-/*
- * We must supply the ELF program headers explicitly to get just one
- * PT_LOAD segment, and set the flags explicitly to make segments read-only.
- */
-PHDRS
-{
- text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
- dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
- note PT_NOTE FLAGS(4); /* PF_R */
- eh_frame_hdr PT_GNU_EH_FRAME;
-}
+++ /dev/null
-/*
- * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
- * Here we can supply some information useful to userland.
- */
-
-#include <linux/uts.h>
-#include <linux/version.h>
-#include <linux/elfnote.h>
-
-ELFNOTE_START(Linux, 0, "a")
- .long LINUX_VERSION_CODE
-ELFNOTE_END
+++ /dev/null
-/*
- * Linker script for 64-bit vDSO.
- * We #include the file to define the layout details.
- *
- * This file defines the version script giving the user-exported symbols in
- * the DSO.
- */
-
-#define BUILD_VDSO64
-
-#include "vdso-layout.lds.S"
-
-/*
- * This controls what userland symbols we export from the vDSO.
- */
-VERSION {
- LINUX_2.6 {
- global:
- clock_gettime;
- __vdso_clock_gettime;
- gettimeofday;
- __vdso_gettimeofday;
- getcpu;
- __vdso_getcpu;
- time;
- __vdso_time;
- local: *;
- };
-}
+++ /dev/null
-/*
- * vdso2c - A vdso image preparation tool
- * Copyright (c) 2014 Andy Lutomirski and others
- * Licensed under the GPL v2
- *
- * vdso2c requires stripped and unstripped input. It would be trivial
- * to fully strip the input in here, but, for reasons described below,
- * we need to write a section table. Doing this is more or less
- * equivalent to dropping all non-allocatable sections, but it's
- * easier to let objcopy handle that instead of doing it ourselves.
- * If we ever need to do something fancier than what objcopy provides,
- * it would be straightforward to add here.
- *
- * We're keep a section table for a few reasons:
- *
- * The Go runtime had a couple of bugs: it would read the section
- * table to try to figure out how many dynamic symbols there were (it
- * shouldn't have looked at the section table at all) and, if there
- * were no SHT_SYNDYM section table entry, it would use an
- * uninitialized value for the number of symbols. An empty DYNSYM
- * table would work, but I see no reason not to write a valid one (and
- * keep full performance for old Go programs). This hack is only
- * needed on x86_64.
- *
- * The bug was introduced on 2012-08-31 by:
- * https://code.google.com/p/go/source/detail?r=56ea40aac72b
- * and was fixed on 2014-06-13 by:
- * https://code.google.com/p/go/source/detail?r=fc1cd5e12595
- *
- * Binutils has issues debugging the vDSO: it reads the section table to
- * find SHT_NOTE; it won't look at PT_NOTE for the in-memory vDSO, which
- * would break build-id if we removed the section table. Binutils
- * also requires that shstrndx != 0. See:
- * https://sourceware.org/bugzilla/show_bug.cgi?id=17064
- *
- * elfutils might not look for PT_NOTE if there is a section table at
- * all. I don't know whether this matters for any practical purpose.
- *
- * For simplicity, rather than hacking up a partial section table, we
- * just write a mostly complete one. We omit non-dynamic symbols,
- * though, since they're rather large.
- *
- * Once binutils gets fixed, we might be able to drop this for all but
- * the 64-bit vdso, since build-id only works in kernel RPMs, and
- * systems that update to new enough kernel RPMs will likely update
- * binutils in sync. build-id has never worked for home-built kernel
- * RPMs without manual symlinking, and I suspect that no one ever does
- * that.
- */
-
-#include <inttypes.h>
-#include <stdint.h>
-#include <unistd.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <fcntl.h>
-#include <err.h>
-
-#include <sys/mman.h>
-#include <sys/types.h>
-
-#include <tools/le_byteshift.h>
-
-#include <linux/elf.h>
-#include <linux/types.h>
-
-const char *outfilename;
-
-/* Symbols that we need in vdso2c. */
-enum {
- sym_vvar_start,
- sym_vvar_page,
- sym_hpet_page,
- sym_VDSO_FAKE_SECTION_TABLE_START,
- sym_VDSO_FAKE_SECTION_TABLE_END,
-};
-
-const int special_pages[] = {
- sym_vvar_page,
- sym_hpet_page,
-};
-
-struct vdso_sym {
- const char *name;
- bool export;
-};
-
-struct vdso_sym required_syms[] = {
- [sym_vvar_start] = {"vvar_start", true},
- [sym_vvar_page] = {"vvar_page", true},
- [sym_hpet_page] = {"hpet_page", true},
- [sym_VDSO_FAKE_SECTION_TABLE_START] = {
- "VDSO_FAKE_SECTION_TABLE_START", false
- },
- [sym_VDSO_FAKE_SECTION_TABLE_END] = {
- "VDSO_FAKE_SECTION_TABLE_END", false
- },
- {"VDSO32_NOTE_MASK", true},
- {"VDSO32_SYSENTER_RETURN", true},
- {"__kernel_vsyscall", true},
- {"__kernel_sigreturn", true},
- {"__kernel_rt_sigreturn", true},
-};
-
-__attribute__((format(printf, 1, 2))) __attribute__((noreturn))
-static void fail(const char *format, ...)
-{
- va_list ap;
- va_start(ap, format);
- fprintf(stderr, "Error: ");
- vfprintf(stderr, format, ap);
- if (outfilename)
- unlink(outfilename);
- exit(1);
- va_end(ap);
-}
-
-/*
- * Evil macros for little-endian reads and writes
- */
-#define GLE(x, bits, ifnot) \
- __builtin_choose_expr( \
- (sizeof(*(x)) == bits/8), \
- (__typeof__(*(x)))get_unaligned_le##bits(x), ifnot)
-
-extern void bad_get_le(void);
-#define LAST_GLE(x) \
- __builtin_choose_expr(sizeof(*(x)) == 1, *(x), bad_get_le())
-
-#define GET_LE(x) \
- GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_GLE(x))))
-
-#define PLE(x, val, bits, ifnot) \
- __builtin_choose_expr( \
- (sizeof(*(x)) == bits/8), \
- put_unaligned_le##bits((val), (x)), ifnot)
-
-extern void bad_put_le(void);
-#define LAST_PLE(x, val) \
- __builtin_choose_expr(sizeof(*(x)) == 1, *(x) = (val), bad_put_le())
-
-#define PUT_LE(x, val) \
- PLE(x, val, 64, PLE(x, val, 32, PLE(x, val, 16, LAST_PLE(x, val))))
-
-
-#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
-
-#define BITSFUNC3(name, bits, suffix) name##bits##suffix
-#define BITSFUNC2(name, bits, suffix) BITSFUNC3(name, bits, suffix)
-#define BITSFUNC(name) BITSFUNC2(name, ELF_BITS, )
-
-#define INT_BITS BITSFUNC2(int, ELF_BITS, _t)
-
-#define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
-#define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
-#define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
-
-#define ELF_BITS 64
-#include "vdso2c.h"
-#undef ELF_BITS
-
-#define ELF_BITS 32
-#include "vdso2c.h"
-#undef ELF_BITS
-
-static void go(void *raw_addr, size_t raw_len,
- void *stripped_addr, size_t stripped_len,
- FILE *outfile, const char *name)
-{
- Elf64_Ehdr *hdr = (Elf64_Ehdr *)raw_addr;
-
- if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
- go64(raw_addr, raw_len, stripped_addr, stripped_len,
- outfile, name);
- } else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
- go32(raw_addr, raw_len, stripped_addr, stripped_len,
- outfile, name);
- } else {
- fail("unknown ELF class\n");
- }
-}
-
-static void map_input(const char *name, void **addr, size_t *len, int prot)
-{
- off_t tmp_len;
-
- int fd = open(name, O_RDONLY);
- if (fd == -1)
- err(1, "%s", name);
-
- tmp_len = lseek(fd, 0, SEEK_END);
- if (tmp_len == (off_t)-1)
- err(1, "lseek");
- *len = (size_t)tmp_len;
-
- *addr = mmap(NULL, tmp_len, prot, MAP_PRIVATE, fd, 0);
- if (*addr == MAP_FAILED)
- err(1, "mmap");
-
- close(fd);
-}
-
-int main(int argc, char **argv)
-{
- size_t raw_len, stripped_len;
- void *raw_addr, *stripped_addr;
- FILE *outfile;
- char *name, *tmp;
- int namelen;
-
- if (argc != 4) {
- printf("Usage: vdso2c RAW_INPUT STRIPPED_INPUT OUTPUT\n");
- return 1;
- }
-
- /*
- * Figure out the struct name. If we're writing to a .so file,
- * generate raw output insted.
- */
- name = strdup(argv[3]);
- namelen = strlen(name);
- if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
- name = NULL;
- } else {
- tmp = strrchr(name, '/');
- if (tmp)
- name = tmp + 1;
- tmp = strchr(name, '.');
- if (tmp)
- *tmp = '\0';
- for (tmp = name; *tmp; tmp++)
- if (*tmp == '-')
- *tmp = '_';
- }
-
- map_input(argv[1], &raw_addr, &raw_len, PROT_READ);
- map_input(argv[2], &stripped_addr, &stripped_len, PROT_READ);
-
- outfilename = argv[3];
- outfile = fopen(outfilename, "w");
- if (!outfile)
- err(1, "%s", argv[2]);
-
- go(raw_addr, raw_len, stripped_addr, stripped_len, outfile, name);
-
- munmap(raw_addr, raw_len);
- munmap(stripped_addr, stripped_len);
- fclose(outfile);
-
- return 0;
-}
+++ /dev/null
-/*
- * This file is included twice from vdso2c.c. It generates code for 32-bit
- * and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs
- * are built for 32-bit userspace.
- */
-
-static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
- void *stripped_addr, size_t stripped_len,
- FILE *outfile, const char *name)
-{
- int found_load = 0;
- unsigned long load_size = -1; /* Work around bogus warning */
- unsigned long mapping_size;
- ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
- int i;
- unsigned long j;
- ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
- *alt_sec = NULL;
- ELF(Dyn) *dyn = 0, *dyn_end = 0;
- const char *secstrings;
- INT_BITS syms[NSYMS] = {};
-
- ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_LE(&hdr->e_phoff));
-
- /* Walk the segment table. */
- for (i = 0; i < GET_LE(&hdr->e_phnum); i++) {
- if (GET_LE(&pt[i].p_type) == PT_LOAD) {
- if (found_load)
- fail("multiple PT_LOAD segs\n");
-
- if (GET_LE(&pt[i].p_offset) != 0 ||
- GET_LE(&pt[i].p_vaddr) != 0)
- fail("PT_LOAD in wrong place\n");
-
- if (GET_LE(&pt[i].p_memsz) != GET_LE(&pt[i].p_filesz))
- fail("cannot handle memsz != filesz\n");
-
- load_size = GET_LE(&pt[i].p_memsz);
- found_load = 1;
- } else if (GET_LE(&pt[i].p_type) == PT_DYNAMIC) {
- dyn = raw_addr + GET_LE(&pt[i].p_offset);
- dyn_end = raw_addr + GET_LE(&pt[i].p_offset) +
- GET_LE(&pt[i].p_memsz);
- }
- }
- if (!found_load)
- fail("no PT_LOAD seg\n");
-
- if (stripped_len < load_size)
- fail("stripped input is too short\n");
-
- /* Walk the dynamic table */
- for (i = 0; dyn + i < dyn_end &&
- GET_LE(&dyn[i].d_tag) != DT_NULL; i++) {
- typeof(dyn[i].d_tag) tag = GET_LE(&dyn[i].d_tag);
- if (tag == DT_REL || tag == DT_RELSZ || tag == DT_RELA ||
- tag == DT_RELENT || tag == DT_TEXTREL)
- fail("vdso image contains dynamic relocations\n");
- }
-
- /* Walk the section table */
- secstrings_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
- GET_LE(&hdr->e_shentsize)*GET_LE(&hdr->e_shstrndx);
- secstrings = raw_addr + GET_LE(&secstrings_hdr->sh_offset);
- for (i = 0; i < GET_LE(&hdr->e_shnum); i++) {
- ELF(Shdr) *sh = raw_addr + GET_LE(&hdr->e_shoff) +
- GET_LE(&hdr->e_shentsize) * i;
- if (GET_LE(&sh->sh_type) == SHT_SYMTAB)
- symtab_hdr = sh;
-
- if (!strcmp(secstrings + GET_LE(&sh->sh_name),
- ".altinstructions"))
- alt_sec = sh;
- }
-
- if (!symtab_hdr)
- fail("no symbol table\n");
-
- strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
- GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
-
- /* Walk the symbol table */
- for (i = 0;
- i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
- i++) {
- int k;
- ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
- GET_LE(&symtab_hdr->sh_entsize) * i;
- const char *name = raw_addr + GET_LE(&strtab_hdr->sh_offset) +
- GET_LE(&sym->st_name);
-
- for (k = 0; k < NSYMS; k++) {
- if (!strcmp(name, required_syms[k].name)) {
- if (syms[k]) {
- fail("duplicate symbol %s\n",
- required_syms[k].name);
- }
-
- /*
- * Careful: we use negative addresses, but
- * st_value is unsigned, so we rely
- * on syms[k] being a signed type of the
- * correct width.
- */
- syms[k] = GET_LE(&sym->st_value);
- }
- }
- }
-
- /* Validate mapping addresses. */
- for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
- INT_BITS symval = syms[special_pages[i]];
-
- if (!symval)
- continue; /* The mapping isn't used; ignore it. */
-
- if (symval % 4096)
- fail("%s must be a multiple of 4096\n",
- required_syms[i].name);
- if (symval + 4096 < syms[sym_vvar_start])
- fail("%s underruns vvar_start\n",
- required_syms[i].name);
- if (symval + 4096 > 0)
- fail("%s is on the wrong side of the vdso text\n",
- required_syms[i].name);
- }
- if (syms[sym_vvar_start] % 4096)
- fail("vvar_begin must be a multiple of 4096\n");
-
- if (!name) {
- fwrite(stripped_addr, stripped_len, 1, outfile);
- return;
- }
-
- mapping_size = (stripped_len + 4095) / 4096 * 4096;
-
- fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
- fprintf(outfile, "#include <linux/linkage.h>\n");
- fprintf(outfile, "#include <asm/page_types.h>\n");
- fprintf(outfile, "#include <asm/vdso.h>\n");
- fprintf(outfile, "\n");
- fprintf(outfile,
- "static unsigned char raw_data[%lu] __page_aligned_data = {",
- mapping_size);
- for (j = 0; j < stripped_len; j++) {
- if (j % 10 == 0)
- fprintf(outfile, "\n\t");
- fprintf(outfile, "0x%02X, ",
- (int)((unsigned char *)stripped_addr)[j]);
- }
- fprintf(outfile, "\n};\n\n");
-
- fprintf(outfile, "static struct page *pages[%lu];\n\n",
- mapping_size / 4096);
-
- fprintf(outfile, "const struct vdso_image %s = {\n", name);
- fprintf(outfile, "\t.data = raw_data,\n");
- fprintf(outfile, "\t.size = %lu,\n", mapping_size);
- fprintf(outfile, "\t.text_mapping = {\n");
- fprintf(outfile, "\t\t.name = \"[vdso]\",\n");
- fprintf(outfile, "\t\t.pages = pages,\n");
- fprintf(outfile, "\t},\n");
- if (alt_sec) {
- fprintf(outfile, "\t.alt = %lu,\n",
- (unsigned long)GET_LE(&alt_sec->sh_offset));
- fprintf(outfile, "\t.alt_len = %lu,\n",
- (unsigned long)GET_LE(&alt_sec->sh_size));
- }
- for (i = 0; i < NSYMS; i++) {
- if (required_syms[i].export && syms[i])
- fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
- required_syms[i].name, (int64_t)syms[i]);
- }
- fprintf(outfile, "};\n");
-}
+++ /dev/null
-/*
- * (C) Copyright 2002 Linus Torvalds
- * Portions based on the vdso-randomization code from exec-shield:
- * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
- *
- * This file contains the needed initializations to support sysenter.
- */
-
-#include <linux/init.h>
-#include <linux/smp.h>
-#include <linux/kernel.h>
-#include <linux/mm_types.h>
-
-#include <asm/cpufeature.h>
-#include <asm/processor.h>
-#include <asm/vdso.h>
-
-#ifdef CONFIG_COMPAT_VDSO
-#define VDSO_DEFAULT 0
-#else
-#define VDSO_DEFAULT 1
-#endif
-
-/*
- * Should the kernel map a VDSO page into processes and pass its
- * address down to glibc upon exec()?
- */
-unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
-
-static int __init vdso32_setup(char *s)
-{
- vdso32_enabled = simple_strtoul(s, NULL, 0);
-
- if (vdso32_enabled > 1)
- pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
-
- return 1;
-}
-
-/*
- * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
- * behavior on both 64-bit and 32-bit kernels.
- * On 32-bit kernels, vdso=[012] means the same thing.
- */
-__setup("vdso32=", vdso32_setup);
-
-#ifdef CONFIG_X86_32
-__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
-#endif
-
-#ifdef CONFIG_X86_64
-
-#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
-#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
-
-#else /* CONFIG_X86_32 */
-
-#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
-#define vdso32_syscall() (0)
-
-#endif /* CONFIG_X86_64 */
-
-#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
-const struct vdso_image *selected_vdso32;
-#endif
-
-int __init sysenter_setup(void)
-{
-#ifdef CONFIG_COMPAT
- if (vdso32_syscall())
- selected_vdso32 = &vdso_image_32_syscall;
- else
-#endif
- if (vdso32_sysenter())
- selected_vdso32 = &vdso_image_32_sysenter;
- else
- selected_vdso32 = &vdso_image_32_int80;
-
- init_vdso_image(selected_vdso32);
-
- return 0;
-}
-
-#ifdef CONFIG_X86_64
-
-subsys_initcall(sysenter_setup);
-
-#ifdef CONFIG_SYSCTL
-/* Register vsyscall32 into the ABI table */
-#include <linux/sysctl.h>
-
-static struct ctl_table abi_table2[] = {
- {
- .procname = "vsyscall32",
- .data = &vdso32_enabled,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec
- },
- {}
-};
-
-static struct ctl_table abi_root_table2[] = {
- {
- .procname = "abi",
- .mode = 0555,
- .child = abi_table2
- },
- {}
-};
-
-static __init int ia32_binfmt_init(void)
-{
- register_sysctl_table(abi_root_table2);
- return 0;
-}
-__initcall(ia32_binfmt_init);
-#endif /* CONFIG_SYSCTL */
-
-#endif /* CONFIG_X86_64 */
+++ /dev/null
-vdso32.lds
+++ /dev/null
-/*
- * Code for the vDSO. This version uses the old int $0x80 method.
- *
- * First get the common code for the sigreturn entry points.
- * This must come first.
- */
-#include "sigreturn.S"
-
- .text
- .globl __kernel_vsyscall
- .type __kernel_vsyscall,@function
- ALIGN
-__kernel_vsyscall:
-.LSTART_vsyscall:
- int $0x80
- ret
-.LEND_vsyscall:
- .size __kernel_vsyscall,.-.LSTART_vsyscall
- .previous
-
- .section .eh_frame,"a",@progbits
-.LSTARTFRAMEDLSI:
- .long .LENDCIEDLSI-.LSTARTCIEDLSI
-.LSTARTCIEDLSI:
- .long 0 /* CIE ID */
- .byte 1 /* Version number */
- .string "zR" /* NUL-terminated augmentation string */
- .uleb128 1 /* Code alignment factor */
- .sleb128 -4 /* Data alignment factor */
- .byte 8 /* Return address register column */
- .uleb128 1 /* Augmentation value length */
- .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
- .byte 0x0c /* DW_CFA_def_cfa */
- .uleb128 4
- .uleb128 4
- .byte 0x88 /* DW_CFA_offset, column 0x8 */
- .uleb128 1
- .align 4
-.LENDCIEDLSI:
- .long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
-.LSTARTFDEDLSI:
- .long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
- .long .LSTART_vsyscall-. /* PC-relative start address */
- .long .LEND_vsyscall-.LSTART_vsyscall
- .uleb128 0
- .align 4
-.LENDFDEDLSI:
- .previous
-
- /*
- * Pad out the segment to match the size of the sysenter.S version.
- */
-VDSO32_vsyscall_eh_frame_size = 0x40
- .section .data,"aw",@progbits
- .space VDSO32_vsyscall_eh_frame_size-(.LENDFDEDLSI-.LSTARTFRAMEDLSI), 0
- .previous
+++ /dev/null
-/*
- * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
- * Here we can supply some information useful to userland.
- */
-
-#include <linux/version.h>
-#include <linux/elfnote.h>
-
-/* Ideally this would use UTS_NAME, but using a quoted string here
- doesn't work. Remember to change this when changing the
- kernel's name. */
-ELFNOTE_START(Linux, 0, "a")
- .long LINUX_VERSION_CODE
-ELFNOTE_END
-
-#ifdef CONFIG_XEN
-/*
- * Add a special note telling glibc's dynamic linker a fake hardware
- * flavor that it will use to choose the search path for libraries in the
- * same way it uses real hardware capabilities like "mmx".
- * We supply "nosegneg" as the fake capability, to indicate that we
- * do not like negative offsets in instructions using segment overrides,
- * since we implement those inefficiently. This makes it possible to
- * install libraries optimized to avoid those access patterns in someplace
- * like /lib/i686/tls/nosegneg. Note that an /etc/ld.so.conf.d/file
- * corresponding to the bits here is needed to make ldconfig work right.
- * It should contain:
- * hwcap 1 nosegneg
- * to match the mapping of bit to name that we give here.
- *
- * At runtime, the fake hardware feature will be considered to be present
- * if its bit is set in the mask word. So, we start with the mask 0, and
- * at boot time we set VDSO_NOTE_NONEGSEG_BIT if running under Xen.
- */
-
-#include "../../xen/vdso.h" /* Defines VDSO_NOTE_NONEGSEG_BIT. */
-
-ELFNOTE_START(GNU, 2, "a")
- .long 1 /* ncaps */
-VDSO32_NOTE_MASK: /* Symbol used by arch/x86/xen/setup.c */
- .long 0 /* mask */
- .byte VDSO_NOTE_NONEGSEG_BIT; .asciz "nosegneg" /* bit, name */
-ELFNOTE_END
-#endif
+++ /dev/null
-/*
- * Common code for the sigreturn entry points in vDSO images.
- * So far this code is the same for both int80 and sysenter versions.
- * This file is #include'd by int80.S et al to define them first thing.
- * The kernel assumes that the addresses of these routines are constant
- * for all vDSO implementations.
- */
-
-#include <linux/linkage.h>
-#include <asm/unistd_32.h>
-#include <asm/asm-offsets.h>
-
-#ifndef SYSCALL_ENTER_KERNEL
-#define SYSCALL_ENTER_KERNEL int $0x80
-#endif
-
- .text
- .globl __kernel_sigreturn
- .type __kernel_sigreturn,@function
- nop /* this guy is needed for .LSTARTFDEDLSI1 below (watch for HACK) */
- ALIGN
-__kernel_sigreturn:
-.LSTART_sigreturn:
- popl %eax /* XXX does this mean it needs unwind info? */
- movl $__NR_sigreturn, %eax
- SYSCALL_ENTER_KERNEL
-.LEND_sigreturn:
- nop
- .size __kernel_sigreturn,.-.LSTART_sigreturn
-
- .globl __kernel_rt_sigreturn
- .type __kernel_rt_sigreturn,@function
- ALIGN
-__kernel_rt_sigreturn:
-.LSTART_rt_sigreturn:
- movl $__NR_rt_sigreturn, %eax
- SYSCALL_ENTER_KERNEL
-.LEND_rt_sigreturn:
- nop
- .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn
- .previous
-
- .section .eh_frame,"a",@progbits
-.LSTARTFRAMEDLSI1:
- .long .LENDCIEDLSI1-.LSTARTCIEDLSI1
-.LSTARTCIEDLSI1:
- .long 0 /* CIE ID */
- .byte 1 /* Version number */
- .string "zRS" /* NUL-terminated augmentation string */
- .uleb128 1 /* Code alignment factor */
- .sleb128 -4 /* Data alignment factor */
- .byte 8 /* Return address register column */
- .uleb128 1 /* Augmentation value length */
- .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
- .byte 0 /* DW_CFA_nop */
- .align 4
-.LENDCIEDLSI1:
- .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */
-.LSTARTFDEDLSI1:
- .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */
- /* HACK: The dwarf2 unwind routines will subtract 1 from the
- return address to get an address in the middle of the
- presumed call instruction. Since we didn't get here via
- a call, we need to include the nop before the real start
- to make up for it. */
- .long .LSTART_sigreturn-1-. /* PC-relative start address */
- .long .LEND_sigreturn-.LSTART_sigreturn+1
- .uleb128 0 /* Augmentation */
- /* What follows are the instructions for the table generation.
- We record the locations of each register saved. This is
- complicated by the fact that the "CFA" is always assumed to
- be the value of the stack pointer in the caller. This means
- that we must define the CFA of this body of code to be the
- saved value of the stack pointer in the sigcontext. Which
- also means that there is no fixed relation to the other
- saved registers, which means that we must use DW_CFA_expression
- to compute their addresses. It also means that when we
- adjust the stack with the popl, we have to do it all over again. */
-
-#define do_cfa_expr(offset) \
- .byte 0x0f; /* DW_CFA_def_cfa_expression */ \
- .uleb128 1f-0f; /* length */ \
-0: .byte 0x74; /* DW_OP_breg4 */ \
- .sleb128 offset; /* offset */ \
- .byte 0x06; /* DW_OP_deref */ \
-1:
-
-#define do_expr(regno, offset) \
- .byte 0x10; /* DW_CFA_expression */ \
- .uleb128 regno; /* regno */ \
- .uleb128 1f-0f; /* length */ \
-0: .byte 0x74; /* DW_OP_breg4 */ \
- .sleb128 offset; /* offset */ \
-1:
-
- do_cfa_expr(IA32_SIGCONTEXT_sp+4)
- do_expr(0, IA32_SIGCONTEXT_ax+4)
- do_expr(1, IA32_SIGCONTEXT_cx+4)
- do_expr(2, IA32_SIGCONTEXT_dx+4)
- do_expr(3, IA32_SIGCONTEXT_bx+4)
- do_expr(5, IA32_SIGCONTEXT_bp+4)
- do_expr(6, IA32_SIGCONTEXT_si+4)
- do_expr(7, IA32_SIGCONTEXT_di+4)
- do_expr(8, IA32_SIGCONTEXT_ip+4)
-
- .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */
-
- do_cfa_expr(IA32_SIGCONTEXT_sp)
- do_expr(0, IA32_SIGCONTEXT_ax)
- do_expr(1, IA32_SIGCONTEXT_cx)
- do_expr(2, IA32_SIGCONTEXT_dx)
- do_expr(3, IA32_SIGCONTEXT_bx)
- do_expr(5, IA32_SIGCONTEXT_bp)
- do_expr(6, IA32_SIGCONTEXT_si)
- do_expr(7, IA32_SIGCONTEXT_di)
- do_expr(8, IA32_SIGCONTEXT_ip)
-
- .align 4
-.LENDFDEDLSI1:
-
- .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */
-.LSTARTFDEDLSI2:
- .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */
- /* HACK: See above wrt unwind library assumptions. */
- .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */
- .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1
- .uleb128 0 /* Augmentation */
- /* What follows are the instructions for the table generation.
- We record the locations of each register saved. This is
- slightly less complicated than the above, since we don't
- modify the stack pointer in the process. */
-
- do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_sp)
- do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ax)
- do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_cx)
- do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_dx)
- do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bx)
- do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bp)
- do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_si)
- do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_di)
- do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ip)
-
- .align 4
-.LENDFDEDLSI2:
- .previous
+++ /dev/null
-/*
- * Code for the vDSO. This version uses the syscall instruction.
- *
- * First get the common code for the sigreturn entry points.
- * This must come first.
- */
-#define SYSCALL_ENTER_KERNEL syscall
-#include "sigreturn.S"
-
-#include <asm/segment.h>
-
- .text
- .globl __kernel_vsyscall
- .type __kernel_vsyscall,@function
- ALIGN
-__kernel_vsyscall:
-.LSTART_vsyscall:
- push %ebp
-.Lpush_ebp:
- movl %ecx, %ebp
- syscall
- movl %ebp, %ecx
- popl %ebp
-.Lpop_ebp:
- ret
-.LEND_vsyscall:
- .size __kernel_vsyscall,.-.LSTART_vsyscall
-
- .section .eh_frame,"a",@progbits
-.LSTARTFRAME:
- .long .LENDCIE-.LSTARTCIE
-.LSTARTCIE:
- .long 0 /* CIE ID */
- .byte 1 /* Version number */
- .string "zR" /* NUL-terminated augmentation string */
- .uleb128 1 /* Code alignment factor */
- .sleb128 -4 /* Data alignment factor */
- .byte 8 /* Return address register column */
- .uleb128 1 /* Augmentation value length */
- .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
- .byte 0x0c /* DW_CFA_def_cfa */
- .uleb128 4
- .uleb128 4
- .byte 0x88 /* DW_CFA_offset, column 0x8 */
- .uleb128 1
- .align 4
-.LENDCIE:
-
- .long .LENDFDE1-.LSTARTFDE1 /* Length FDE */
-.LSTARTFDE1:
- .long .LSTARTFDE1-.LSTARTFRAME /* CIE pointer */
- .long .LSTART_vsyscall-. /* PC-relative start address */
- .long .LEND_vsyscall-.LSTART_vsyscall
- .uleb128 0 /* Augmentation length */
- /* What follows are the instructions for the table generation.
- We have to record all changes of the stack pointer. */
- .byte 0x40 + .Lpush_ebp-.LSTART_vsyscall /* DW_CFA_advance_loc */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .uleb128 8
- .byte 0x85, 0x02 /* DW_CFA_offset %ebp -8 */
- .byte 0x40 + .Lpop_ebp-.Lpush_ebp /* DW_CFA_advance_loc */
- .byte 0xc5 /* DW_CFA_restore %ebp */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .uleb128 4
- .align 4
-.LENDFDE1:
- .previous
-
- /*
- * Pad out the segment to match the size of the sysenter.S version.
- */
-VDSO32_vsyscall_eh_frame_size = 0x40
- .section .data,"aw",@progbits
- .space VDSO32_vsyscall_eh_frame_size-(.LENDFDE1-.LSTARTFRAME), 0
- .previous
+++ /dev/null
-/*
- * Code for the vDSO. This version uses the sysenter instruction.
- *
- * First get the common code for the sigreturn entry points.
- * This must come first.
- */
-#include "sigreturn.S"
-
-/*
- * The caller puts arg2 in %ecx, which gets pushed. The kernel will use
- * %ecx itself for arg2. The pushing is because the sysexit instruction
- * (found in entry.S) requires that we clobber %ecx with the desired %esp.
- * User code might expect that %ecx is unclobbered though, as it would be
- * for returning via the iret instruction, so we must push and pop.
- *
- * The caller puts arg3 in %edx, which the sysexit instruction requires
- * for %eip. Thus, exactly as for arg2, we must push and pop.
- *
- * Arg6 is different. The caller puts arg6 in %ebp. Since the sysenter
- * instruction clobbers %esp, the user's %esp won't even survive entry
- * into the kernel. We store %esp in %ebp. Code in entry.S must fetch
- * arg6 from the stack.
- *
- * You can not use this vsyscall for the clone() syscall because the
- * three words on the parent stack do not get copied to the child.
- */
- .text
- .globl __kernel_vsyscall
- .type __kernel_vsyscall,@function
- ALIGN
-__kernel_vsyscall:
-.LSTART_vsyscall:
- push %ecx
-.Lpush_ecx:
- push %edx
-.Lpush_edx:
- push %ebp
-.Lenter_kernel:
- movl %esp,%ebp
- sysenter
-
- /* 7: align return point with nop's to make disassembly easier */
- .space 7,0x90
-
- /* 14: System call restart point is here! (SYSENTER_RETURN-2) */
- int $0x80
- /* 16: System call normal return point is here! */
-VDSO32_SYSENTER_RETURN: /* Symbol used by sysenter.c via vdso32-syms.h */
- pop %ebp
-.Lpop_ebp:
- pop %edx
-.Lpop_edx:
- pop %ecx
-.Lpop_ecx:
- ret
-.LEND_vsyscall:
- .size __kernel_vsyscall,.-.LSTART_vsyscall
- .previous
-
- .section .eh_frame,"a",@progbits
-.LSTARTFRAMEDLSI:
- .long .LENDCIEDLSI-.LSTARTCIEDLSI
-.LSTARTCIEDLSI:
- .long 0 /* CIE ID */
- .byte 1 /* Version number */
- .string "zR" /* NUL-terminated augmentation string */
- .uleb128 1 /* Code alignment factor */
- .sleb128 -4 /* Data alignment factor */
- .byte 8 /* Return address register column */
- .uleb128 1 /* Augmentation value length */
- .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
- .byte 0x0c /* DW_CFA_def_cfa */
- .uleb128 4
- .uleb128 4
- .byte 0x88 /* DW_CFA_offset, column 0x8 */
- .uleb128 1
- .align 4
-.LENDCIEDLSI:
- .long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
-.LSTARTFDEDLSI:
- .long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
- .long .LSTART_vsyscall-. /* PC-relative start address */
- .long .LEND_vsyscall-.LSTART_vsyscall
- .uleb128 0
- /* What follows are the instructions for the table generation.
- We have to record all changes of the stack pointer. */
- .byte 0x40 + (.Lpush_ecx-.LSTART_vsyscall) /* DW_CFA_advance_loc */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .byte 0x08 /* RA at offset 8 now */
- .byte 0x40 + (.Lpush_edx-.Lpush_ecx) /* DW_CFA_advance_loc */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .byte 0x0c /* RA at offset 12 now */
- .byte 0x40 + (.Lenter_kernel-.Lpush_edx) /* DW_CFA_advance_loc */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .byte 0x10 /* RA at offset 16 now */
- .byte 0x85, 0x04 /* DW_CFA_offset %ebp -16 */
- /* Finally the epilogue. */
- .byte 0x40 + (.Lpop_ebp-.Lenter_kernel) /* DW_CFA_advance_loc */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .byte 0x0c /* RA at offset 12 now */
- .byte 0xc5 /* DW_CFA_restore %ebp */
- .byte 0x40 + (.Lpop_edx-.Lpop_ebp) /* DW_CFA_advance_loc */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .byte 0x08 /* RA at offset 8 now */
- .byte 0x40 + (.Lpop_ecx-.Lpop_edx) /* DW_CFA_advance_loc */
- .byte 0x0e /* DW_CFA_def_cfa_offset */
- .byte 0x04 /* RA at offset 4 now */
- .align 4
-.LENDFDEDLSI:
- .previous
-
- /*
- * Emit a symbol with the size of this .eh_frame data,
- * to verify it matches the other versions.
- */
-VDSO32_vsyscall_eh_frame_size = (.LENDFDEDLSI-.LSTARTFRAMEDLSI)
+++ /dev/null
-#define BUILD_VDSO32
-
-#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
-#undef CONFIG_OPTIMIZE_INLINING
-#endif
-
-#undef CONFIG_X86_PPRO_FENCE
-
-#ifdef CONFIG_X86_64
-
-/*
- * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
- * configuration
- */
-#undef CONFIG_64BIT
-#undef CONFIG_X86_64
-#undef CONFIG_ILLEGAL_POINTER_VALUE
-#undef CONFIG_SPARSEMEM_VMEMMAP
-#undef CONFIG_NR_CPUS
-
-#define CONFIG_X86_32 1
-#define CONFIG_PAGE_OFFSET 0
-#define CONFIG_ILLEGAL_POINTER_VALUE 0
-#define CONFIG_NR_CPUS 1
-
-#define BUILD_VDSO32_64
-
-#endif
-
-#include "../vclock_gettime.c"
+++ /dev/null
-#include "../vdso-fakesections.c"
+++ /dev/null
-/*
- * Linker script for 32-bit vDSO.
- * We #include the file to define the layout details.
- *
- * This file defines the version script giving the user-exported symbols in
- * the DSO.
- */
-
-#include <asm/page.h>
-
-#define BUILD_VDSO32
-
-#include "../vdso-layout.lds.S"
-
-/* The ELF entry point can be used to set the AT_SYSINFO value. */
-ENTRY(__kernel_vsyscall);
-
-/*
- * This controls what userland symbols we export from the vDSO.
- */
-VERSION
-{
- LINUX_2.6 {
- global:
- __vdso_clock_gettime;
- __vdso_gettimeofday;
- __vdso_time;
- };
-
- LINUX_2.5 {
- global:
- __kernel_vsyscall;
- __kernel_sigreturn;
- __kernel_rt_sigreturn;
- local: *;
- };
-}
+++ /dev/null
-/*
- * Linker script for x32 vDSO.
- * We #include the file to define the layout details.
- *
- * This file defines the version script giving the user-exported symbols in
- * the DSO.
- */
-
-#define BUILD_VDSOX32
-
-#include "vdso-layout.lds.S"
-
-/*
- * This controls what userland symbols we export from the vDSO.
- */
-VERSION {
- LINUX_2.6 {
- global:
- __vdso_clock_gettime;
- __vdso_gettimeofday;
- __vdso_getcpu;
- __vdso_time;
- local: *;
- };
-}
+++ /dev/null
-/*
- * Copyright 2006 Andi Kleen, SUSE Labs.
- * Subject to the GNU Public License, v.2
- *
- * Fast user context implementation of getcpu()
- */
-
-#include <linux/kernel.h>
-#include <linux/getcpu.h>
-#include <linux/time.h>
-#include <asm/vgtod.h>
-
-notrace long
-__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
-{
- unsigned int p;
-
- p = __getcpu();
-
- if (cpu)
- *cpu = p & VGETCPU_CPU_MASK;
- if (node)
- *node = p >> 12;
- return 0;
-}
-
-long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
- __attribute__((weak, alias("__vdso_getcpu")));
+++ /dev/null
-/*
- * Copyright 2007 Andi Kleen, SUSE Labs.
- * Subject to the GPL, v.2
- *
- * This contains most of the x86 vDSO kernel-side code.
- */
-#include <linux/mm.h>
-#include <linux/err.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/random.h>
-#include <linux/elf.h>
-#include <linux/cpu.h>
-#include <asm/vgtod.h>
-#include <asm/proto.h>
-#include <asm/vdso.h>
-#include <asm/vvar.h>
-#include <asm/page.h>
-#include <asm/hpet.h>
-#include <asm/desc.h>
-
-#if defined(CONFIG_X86_64)
-unsigned int __read_mostly vdso64_enabled = 1;
-#endif
-
-void __init init_vdso_image(const struct vdso_image *image)
-{
- int i;
- int npages = (image->size) / PAGE_SIZE;
-
- BUG_ON(image->size % PAGE_SIZE != 0);
- for (i = 0; i < npages; i++)
- image->text_mapping.pages[i] =
- virt_to_page(image->data + i*PAGE_SIZE);
-
- apply_alternatives((struct alt_instr *)(image->data + image->alt),
- (struct alt_instr *)(image->data + image->alt +
- image->alt_len));
-}
-
-struct linux_binprm;
-
-/*
- * Put the vdso above the (randomized) stack with another randomized
- * offset. This way there is no hole in the middle of address space.
- * To save memory make sure it is still in the same PTE as the stack
- * top. This doesn't give that many random bits.
- *
- * Note that this algorithm is imperfect: the distribution of the vdso
- * start address within a PMD is biased toward the end.
- *
- * Only used for the 64-bit and x32 vdsos.
- */
-static unsigned long vdso_addr(unsigned long start, unsigned len)
-{
-#ifdef CONFIG_X86_32
- return 0;
-#else
- unsigned long addr, end;
- unsigned offset;
-
- /*
- * Round up the start address. It can start out unaligned as a result
- * of stack start randomization.
- */
- start = PAGE_ALIGN(start);
-
- /* Round the lowest possible end address up to a PMD boundary. */
- end = (start + len + PMD_SIZE - 1) & PMD_MASK;
- if (end >= TASK_SIZE_MAX)
- end = TASK_SIZE_MAX;
- end -= len;
-
- if (end > start) {
- offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
- addr = start + (offset << PAGE_SHIFT);
- } else {
- addr = start;
- }
-
- /*
- * Forcibly align the final address in case we have a hardware
- * issue that requires alignment for performance reasons.
- */
- addr = align_vdso_addr(addr);
-
- return addr;
-#endif
-}
-
-static int map_vdso(const struct vdso_image *image, bool calculate_addr)
-{
- struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
- unsigned long addr, text_start;
- int ret = 0;
- static struct page *no_pages[] = {NULL};
- static struct vm_special_mapping vvar_mapping = {
- .name = "[vvar]",
- .pages = no_pages,
- };
-
- if (calculate_addr) {
- addr = vdso_addr(current->mm->start_stack,
- image->size - image->sym_vvar_start);
- } else {
- addr = 0;
- }
-
- down_write(&mm->mmap_sem);
-
- addr = get_unmapped_area(NULL, addr,
- image->size - image->sym_vvar_start, 0, 0);
- if (IS_ERR_VALUE(addr)) {
- ret = addr;
- goto up_fail;
- }
-
- text_start = addr - image->sym_vvar_start;
- current->mm->context.vdso = (void __user *)text_start;
-
- /*
- * MAYWRITE to allow gdb to COW and set breakpoints
- */
- vma = _install_special_mapping(mm,
- text_start,
- image->size,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- &image->text_mapping);
-
- if (IS_ERR(vma)) {
- ret = PTR_ERR(vma);
- goto up_fail;
- }
-
- vma = _install_special_mapping(mm,
- addr,
- -image->sym_vvar_start,
- VM_READ|VM_MAYREAD,
- &vvar_mapping);
-
- if (IS_ERR(vma)) {
- ret = PTR_ERR(vma);
- goto up_fail;
- }
-
- if (image->sym_vvar_page)
- ret = remap_pfn_range(vma,
- text_start + image->sym_vvar_page,
- __pa_symbol(&__vvar_page) >> PAGE_SHIFT,
- PAGE_SIZE,
- PAGE_READONLY);
-
- if (ret)
- goto up_fail;
-
-#ifdef CONFIG_HPET_TIMER
- if (hpet_address && image->sym_hpet_page) {
- ret = io_remap_pfn_range(vma,
- text_start + image->sym_hpet_page,
- hpet_address >> PAGE_SHIFT,
- PAGE_SIZE,
- pgprot_noncached(PAGE_READONLY));
-
- if (ret)
- goto up_fail;
- }
-#endif
-
-up_fail:
- if (ret)
- current->mm->context.vdso = NULL;
-
- up_write(&mm->mmap_sem);
- return ret;
-}
-
-#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
-static int load_vdso32(void)
-{
- int ret;
-
- if (vdso32_enabled != 1) /* Other values all mean "disabled" */
- return 0;
-
- ret = map_vdso(selected_vdso32, false);
- if (ret)
- return ret;
-
- if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
- current_thread_info()->sysenter_return =
- current->mm->context.vdso +
- selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
-
- return 0;
-}
-#endif
-
-#ifdef CONFIG_X86_64
-int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
-{
- if (!vdso64_enabled)
- return 0;
-
- return map_vdso(&vdso_image_64, true);
-}
-
-#ifdef CONFIG_COMPAT
-int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
- int uses_interp)
-{
-#ifdef CONFIG_X86_X32_ABI
- if (test_thread_flag(TIF_X32)) {
- if (!vdso64_enabled)
- return 0;
-
- return map_vdso(&vdso_image_x32, true);
- }
-#endif
-
- return load_vdso32();
-}
-#endif
-#else
-int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
-{
- return load_vdso32();
-}
-#endif
-
-#ifdef CONFIG_X86_64
-static __init int vdso_setup(char *s)
-{
- vdso64_enabled = simple_strtoul(s, NULL, 0);
- return 0;
-}
-__setup("vdso=", vdso_setup);
-#endif
-
-#ifdef CONFIG_X86_64
-static void vgetcpu_cpu_init(void *arg)
-{
- int cpu = smp_processor_id();
- struct desc_struct d = { };
- unsigned long node = 0;
-#ifdef CONFIG_NUMA
- node = cpu_to_node(cpu);
-#endif
- if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP))
- write_rdtscp_aux((node << 12) | cpu);
-
- /*
- * Store cpu number in limit so that it can be loaded
- * quickly in user space in vgetcpu. (12 bits for the CPU
- * and 8 bits for the node)
- */
- d.limit0 = cpu | ((node & 0xf) << 12);
- d.limit = node >> 4;
- d.type = 5; /* RO data, expand down, accessed */
- d.dpl = 3; /* Visible to user code */
- d.s = 1; /* Not a system segment */
- d.p = 1; /* Present */
- d.d = 1; /* 32-bit */
-
- write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);
-}
-
-static int
-vgetcpu_cpu_notifier(struct notifier_block *n, unsigned long action, void *arg)
-{
- long cpu = (long)arg;
-
- if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
- smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1);
-
- return NOTIFY_DONE;
-}
-
-static int __init init_vdso(void)
-{
- init_vdso_image(&vdso_image_64);
-
-#ifdef CONFIG_X86_X32_ABI
- init_vdso_image(&vdso_image_x32);
-#endif
-
- cpu_notifier_register_begin();
-
- on_each_cpu(vgetcpu_cpu_init, NULL, 1);
- /* notifier priority > KVM */
- __hotcpu_notifier(vgetcpu_cpu_notifier, 30);
-
- cpu_notifier_register_done();
-
- return 0;
-}
-subsys_initcall(init_vdso);
-#endif /* CONFIG_X86_64 */
projects / firefly-linux-kernel-4.4.55.git / commitdiff