Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
authorLinus Torvalds <torvalds@linux-foundation.org>
Wed, 16 Dec 2015 18:57:24 +0000 (10:57 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 16 Dec 2015 18:57:24 +0000 (10:57 -0800)
Pull ARM fixes from Russell King:
 "Further ARM fixes:
   - Anson Huang noticed that we were corrupting a register we shouldn't
     be during suspend on some CPUs.
   - Shengjiu Wang spotted a bug in the 'swp' instruction emulation.
   - Will Deacon fixed a bug in the ASID allocator.
   - Laura Abbott fixed the kernel permission protection to apply to all
     threads running in the system.
   - I've fixed two bugs with the domain access control register
     handling, one to do with printing an appropriate value at oops
     time, and the other to further fix the uaccess_with_memcpy code"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8475/1: SWP emulation: Restore original *data when failed
  ARM: 8471/1: need to save/restore arm register(r11) when it is corrupted
  ARM: fix uaccess_with_memcpy() with SW_DOMAIN_PAN
  ARM: report proper DACR value in oops dumps
  ARM: 8464/1: Update all mm structures with section adjustments
  ARM: 8465/1: mm: keep reserved ASIDs in sync with mm after multiple rollovers

arch/arm/include/asm/uaccess.h
arch/arm/kernel/process.c
arch/arm/kernel/swp_emulate.c
arch/arm/lib/uaccess_with_memcpy.c
arch/arm/mm/context.c
arch/arm/mm/init.c
arch/arm/mm/proc-v7.S

index 8cc85a4ebec20a1223f966bb868e5def5f70928e..35c9db857ebe9c7d53715ec42518a6e9fbe1dc6e 100644 (file)
@@ -510,10 +510,14 @@ __copy_to_user_std(void __user *to, const void *from, unsigned long n);
 static inline unsigned long __must_check
 __copy_to_user(void __user *to, const void *from, unsigned long n)
 {
+#ifndef CONFIG_UACCESS_WITH_MEMCPY
        unsigned int __ua_flags = uaccess_save_and_enable();
        n = arm_copy_to_user(to, from, n);
        uaccess_restore(__ua_flags);
        return n;
+#else
+       return arm_copy_to_user(to, from, n);
+#endif
 }
 
 extern unsigned long __must_check
index 7a7c4cea55231b1c793982ab63d6c5598004b14b..4adfb46e3ee93276ea506b723eb11e33c57459f4 100644 (file)
@@ -95,6 +95,22 @@ void __show_regs(struct pt_regs *regs)
 {
        unsigned long flags;
        char buf[64];
+#ifndef CONFIG_CPU_V7M
+       unsigned int domain;
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+       /*
+        * Get the domain register for the parent context. In user
+        * mode, we don't save the DACR, so lets use what it should
+        * be. For other modes, we place it after the pt_regs struct.
+        */
+       if (user_mode(regs))
+               domain = DACR_UACCESS_ENABLE;
+       else
+               domain = *(unsigned int *)(regs + 1);
+#else
+       domain = get_domain();
+#endif
+#endif
 
        show_regs_print_info(KERN_DEFAULT);
 
@@ -123,21 +139,8 @@ void __show_regs(struct pt_regs *regs)
 
 #ifndef CONFIG_CPU_V7M
        {
-               unsigned int domain = get_domain();
                const char *segment;
 
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
-               /*
-                * Get the domain register for the parent context. In user
-                * mode, we don't save the DACR, so lets use what it should
-                * be. For other modes, we place it after the pt_regs struct.
-                */
-               if (user_mode(regs))
-                       domain = DACR_UACCESS_ENABLE;
-               else
-                       domain = *(unsigned int *)(regs + 1);
-#endif
-
                if ((domain & domain_mask(DOMAIN_USER)) ==
                    domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
                        segment = "none";
@@ -163,11 +166,11 @@ void __show_regs(struct pt_regs *regs)
                buf[0] = '\0';
 #ifdef CONFIG_CPU_CP15_MMU
                {
-                       unsigned int transbase, dac = get_domain();
+                       unsigned int transbase;
                        asm("mrc p15, 0, %0, c2, c0\n\t"
                            : "=r" (transbase));
                        snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
-                               transbase, dac);
+                               transbase, domain);
                }
 #endif
                asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
index 5b26e7efa9ea415967b63ede27ab1edf2bc8e888..c3fe769d75584c7248015b855bca904589f3e29f 100644 (file)
  */
 #define __user_swpX_asm(data, addr, res, temp, B)              \
        __asm__ __volatile__(                                   \
-       "       mov             %2, %1\n"                       \
-       "0:     ldrex"B"        %1, [%3]\n"                     \
-       "1:     strex"B"        %0, %2, [%3]\n"                 \
+       "0:     ldrex"B"        %2, [%3]\n"                     \
+       "1:     strex"B"        %0, %1, [%3]\n"                 \
        "       cmp             %0, #0\n"                       \
+       "       moveq           %1, %2\n"                       \
        "       movne           %0, %4\n"                       \
        "2:\n"                                                  \
        "       .section         .text.fixup,\"ax\"\n"          \
index d72b90905132487257220939a255ac7ed1d3754d..588bbc288396ae52fe0d801bc537906b3e5dbfce 100644 (file)
@@ -88,6 +88,7 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
 static unsigned long noinline
 __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
 {
+       unsigned long ua_flags;
        int atomic;
 
        if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
@@ -118,7 +119,9 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
                if (tocopy > n)
                        tocopy = n;
 
+               ua_flags = uaccess_save_and_enable();
                memcpy((void *)to, from, tocopy);
+               uaccess_restore(ua_flags);
                to += tocopy;
                from += tocopy;
                n -= tocopy;
@@ -145,14 +148,21 @@ arm_copy_to_user(void __user *to, const void *from, unsigned long n)
         * With frame pointer disabled, tail call optimization kicks in
         * as well making this test almost invisible.
         */
-       if (n < 64)
-               return __copy_to_user_std(to, from, n);
-       return __copy_to_user_memcpy(to, from, n);
+       if (n < 64) {
+               unsigned long ua_flags = uaccess_save_and_enable();
+               n = __copy_to_user_std(to, from, n);
+               uaccess_restore(ua_flags);
+       } else {
+               n = __copy_to_user_memcpy(to, from, n);
+       }
+       return n;
 }
        
 static unsigned long noinline
 __clear_user_memset(void __user *addr, unsigned long n)
 {
+       unsigned long ua_flags;
+
        if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
                memset((void *)addr, 0, n);
                return 0;
@@ -175,7 +185,9 @@ __clear_user_memset(void __user *addr, unsigned long n)
                if (tocopy > n)
                        tocopy = n;
 
+               ua_flags = uaccess_save_and_enable();
                memset((void *)addr, 0, tocopy);
+               uaccess_restore(ua_flags);
                addr += tocopy;
                n -= tocopy;
 
@@ -193,9 +205,14 @@ out:
 unsigned long arm_clear_user(void __user *addr, unsigned long n)
 {
        /* See rational for this in __copy_to_user() above. */
-       if (n < 64)
-               return __clear_user_std(addr, n);
-       return __clear_user_memset(addr, n);
+       if (n < 64) {
+               unsigned long ua_flags = uaccess_save_and_enable();
+               n = __clear_user_std(addr, n);
+               uaccess_restore(ua_flags);
+       } else {
+               n = __clear_user_memset(addr, n);
+       }
+       return n;
 }
 
 #if 0
index 845769e413323120b6d7b4afed7640746413bc98..c8c8b9ed02e09b57a79bee1ab5db9c337be0d338 100644 (file)
@@ -165,13 +165,28 @@ static void flush_context(unsigned int cpu)
                __flush_icache_all();
 }
 
-static int is_reserved_asid(u64 asid)
+static bool check_update_reserved_asid(u64 asid, u64 newasid)
 {
        int cpu;
-       for_each_possible_cpu(cpu)
-               if (per_cpu(reserved_asids, cpu) == asid)
-                       return 1;
-       return 0;
+       bool hit = false;
+
+       /*
+        * Iterate over the set of reserved ASIDs looking for a match.
+        * If we find one, then we can update our mm to use newasid
+        * (i.e. the same ASID in the current generation) but we can't
+        * exit the loop early, since we need to ensure that all copies
+        * of the old ASID are updated to reflect the mm. Failure to do
+        * so could result in us missing the reserved ASID in a future
+        * generation.
+        */
+       for_each_possible_cpu(cpu) {
+               if (per_cpu(reserved_asids, cpu) == asid) {
+                       hit = true;
+                       per_cpu(reserved_asids, cpu) = newasid;
+               }
+       }
+
+       return hit;
 }
 
 static u64 new_context(struct mm_struct *mm, unsigned int cpu)
@@ -181,12 +196,14 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu)
        u64 generation = atomic64_read(&asid_generation);
 
        if (asid != 0) {
+               u64 newasid = generation | (asid & ~ASID_MASK);
+
                /*
                 * If our current ASID was active during a rollover, we
                 * can continue to use it and this was just a false alarm.
                 */
-               if (is_reserved_asid(asid))
-                       return generation | (asid & ~ASID_MASK);
+               if (check_update_reserved_asid(asid, newasid))
+                       return newasid;
 
                /*
                 * We had a valid ASID in a previous life, so try to re-use
@@ -194,7 +211,7 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu)
                 */
                asid &= ~ASID_MASK;
                if (!__test_and_set_bit(asid, asid_map))
-                       goto bump_gen;
+                       return newasid;
        }
 
        /*
@@ -216,11 +233,8 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu)
 
        __set_bit(asid, asid_map);
        cur_idx = asid;
-
-bump_gen:
-       asid |= generation;
        cpumask_clear(mm_cpumask(mm));
-       return asid;
+       return asid | generation;
 }
 
 void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk)
index 8a63b4cdc0f27d0fa7cf69f0bb1ffa51b6289e39..7f8cd1b3557f071a64dafc05eba4c481ef82c79d 100644 (file)
@@ -22,6 +22,7 @@
 #include <linux/memblock.h>
 #include <linux/dma-contiguous.h>
 #include <linux/sizes.h>
+#include <linux/stop_machine.h>
 
 #include <asm/cp15.h>
 #include <asm/mach-types.h>
@@ -627,12 +628,10 @@ static struct section_perm ro_perms[] = {
  * safe to be called with preemption disabled, as under stop_machine().
  */
 static inline void section_update(unsigned long addr, pmdval_t mask,
-                                 pmdval_t prot)
+                                 pmdval_t prot, struct mm_struct *mm)
 {
-       struct mm_struct *mm;
        pmd_t *pmd;
 
-       mm = current->active_mm;
        pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
 
 #ifdef CONFIG_ARM_LPAE
@@ -656,49 +655,82 @@ static inline bool arch_has_strict_perms(void)
        return !!(get_cr() & CR_XP);
 }
 
-#define set_section_perms(perms, field)        {                               \
-       size_t i;                                                       \
-       unsigned long addr;                                             \
-                                                                       \
-       if (!arch_has_strict_perms())                                   \
-               return;                                                 \
-                                                                       \
-       for (i = 0; i < ARRAY_SIZE(perms); i++) {                       \
-               if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||        \
-                   !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {          \
-                       pr_err("BUG: section %lx-%lx not aligned to %lx\n", \
-                               perms[i].start, perms[i].end,           \
-                               SECTION_SIZE);                          \
-                       continue;                                       \
-               }                                                       \
-                                                                       \
-               for (addr = perms[i].start;                             \
-                    addr < perms[i].end;                               \
-                    addr += SECTION_SIZE)                              \
-                       section_update(addr, perms[i].mask,             \
-                                      perms[i].field);                 \
-       }                                                               \
+void set_section_perms(struct section_perm *perms, int n, bool set,
+                       struct mm_struct *mm)
+{
+       size_t i;
+       unsigned long addr;
+
+       if (!arch_has_strict_perms())
+               return;
+
+       for (i = 0; i < n; i++) {
+               if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
+                   !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
+                       pr_err("BUG: section %lx-%lx not aligned to %lx\n",
+                               perms[i].start, perms[i].end,
+                               SECTION_SIZE);
+                       continue;
+               }
+
+               for (addr = perms[i].start;
+                    addr < perms[i].end;
+                    addr += SECTION_SIZE)
+                       section_update(addr, perms[i].mask,
+                               set ? perms[i].prot : perms[i].clear, mm);
+       }
+
 }
 
-static inline void fix_kernmem_perms(void)
+static void update_sections_early(struct section_perm perms[], int n)
 {
-       set_section_perms(nx_perms, prot);
+       struct task_struct *t, *s;
+
+       read_lock(&tasklist_lock);
+       for_each_process(t) {
+               if (t->flags & PF_KTHREAD)
+                       continue;
+               for_each_thread(t, s)
+                       set_section_perms(perms, n, true, s->mm);
+       }
+       read_unlock(&tasklist_lock);
+       set_section_perms(perms, n, true, current->active_mm);
+       set_section_perms(perms, n, true, &init_mm);
+}
+
+int __fix_kernmem_perms(void *unused)
+{
+       update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
+       return 0;
+}
+
+void fix_kernmem_perms(void)
+{
+       stop_machine(__fix_kernmem_perms, NULL, NULL);
 }
 
 #ifdef CONFIG_DEBUG_RODATA
+int __mark_rodata_ro(void *unused)
+{
+       update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
+       return 0;
+}
+
 void mark_rodata_ro(void)
 {
-       set_section_perms(ro_perms, prot);
+       stop_machine(__mark_rodata_ro, NULL, NULL);
 }
 
 void set_kernel_text_rw(void)
 {
-       set_section_perms(ro_perms, clear);
+       set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
+                               current->active_mm);
 }
 
 void set_kernel_text_ro(void)
 {
-       set_section_perms(ro_perms, prot);
+       set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
+                               current->active_mm);
 }
 #endif /* CONFIG_DEBUG_RODATA */
 
index de2b246fed3808fce444b560a725ed4007464174..8e1ea433c3f1e321d7ed4e91fe582a5be4eb85be 100644 (file)
@@ -95,7 +95,7 @@ ENDPROC(cpu_v7_dcache_clean_area)
 .equ   cpu_v7_suspend_size, 4 * 9
 #ifdef CONFIG_ARM_CPU_SUSPEND
 ENTRY(cpu_v7_do_suspend)
-       stmfd   sp!, {r4 - r10, lr}
+       stmfd   sp!, {r4 - r11, lr}
        mrc     p15, 0, r4, c13, c0, 0  @ FCSE/PID
        mrc     p15, 0, r5, c13, c0, 3  @ User r/o thread ID
        stmia   r0!, {r4 - r5}
@@ -112,7 +112,7 @@ ENTRY(cpu_v7_do_suspend)
        mrc     p15, 0, r9, c1, c0, 1   @ Auxiliary control register
        mrc     p15, 0, r10, c1, c0, 2  @ Co-processor access control
        stmia   r0, {r5 - r11}
-       ldmfd   sp!, {r4 - r10, pc}
+       ldmfd   sp!, {r4 - r11, pc}
 ENDPROC(cpu_v7_do_suspend)
 
 ENTRY(cpu_v7_do_resume)