* - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack
* frame that is otherwise undefined after a SYSCALL
* - TRACE_IRQ_* - Trace hard interrupt state for lock debugging.
- * - errorentry/paranoidentry/zeroentry - Define exception entry points.
+ * - idtentry - Define exception entry points.
*/
#include <linux/linkage.h>
#include <asm/asm.h>
#include <asm/context_tracking.h>
#include <asm/smap.h>
+#include <asm/pgtable_types.h>
#include <linux/err.h>
/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
RESTORE_ARGS 1,8,1
irq_return:
+ /*
+ * Are we returning to a stack segment from the LDT? Note: in
+ * 64-bit mode SS:RSP on the exception stack is always valid.
+ */
+#ifdef CONFIG_X86_ESPFIX64
+ testb $4,(SS-RIP)(%rsp)
+ jnz irq_return_ldt
+#endif
+
+irq_return_iret:
INTERRUPT_RETURN
- _ASM_EXTABLE(irq_return, bad_iret)
+ _ASM_EXTABLE(irq_return_iret, bad_iret)
#ifdef CONFIG_PARAVIRT
ENTRY(native_iret)
_ASM_EXTABLE(native_iret, bad_iret)
#endif
+#ifdef CONFIG_X86_ESPFIX64
+irq_return_ldt:
+ pushq_cfi %rax
+ pushq_cfi %rdi
+ SWAPGS
+ movq PER_CPU_VAR(espfix_waddr),%rdi
+ movq %rax,(0*8)(%rdi) /* RAX */
+ movq (2*8)(%rsp),%rax /* RIP */
+ movq %rax,(1*8)(%rdi)
+ movq (3*8)(%rsp),%rax /* CS */
+ movq %rax,(2*8)(%rdi)
+ movq (4*8)(%rsp),%rax /* RFLAGS */
+ movq %rax,(3*8)(%rdi)
+ movq (6*8)(%rsp),%rax /* SS */
+ movq %rax,(5*8)(%rdi)
+ movq (5*8)(%rsp),%rax /* RSP */
+ movq %rax,(4*8)(%rdi)
+ andl $0xffff0000,%eax
+ popq_cfi %rdi
+ orq PER_CPU_VAR(espfix_stack),%rax
+ SWAPGS
+ movq %rax,%rsp
+ popq_cfi %rax
+ jmp irq_return_iret
+#endif
+
.section .fixup,"ax"
bad_iret:
/*
call preempt_schedule_irq
jmp exit_intr
#endif
-
CFI_ENDPROC
END(common_interrupt)
+
+ /*
+ * If IRET takes a fault on the espfix stack, then we
+ * end up promoting it to a doublefault. In that case,
+ * modify the stack to make it look like we just entered
+ * the #GP handler from user space, similar to bad_iret.
+ */
+#ifdef CONFIG_X86_ESPFIX64
+ ALIGN
+__do_double_fault:
+ XCPT_FRAME 1 RDI+8
+ movq RSP(%rdi),%rax /* Trap on the espfix stack? */
+ sarq $PGDIR_SHIFT,%rax
+ cmpl $ESPFIX_PGD_ENTRY,%eax
+ jne do_double_fault /* No, just deliver the fault */
+ cmpl $__KERNEL_CS,CS(%rdi)
+ jne do_double_fault
+ movq RIP(%rdi),%rax
+ cmpq $irq_return_iret,%rax
+#ifdef CONFIG_PARAVIRT
+ je 1f
+ cmpq $native_iret,%rax
+#endif
+ jne do_double_fault /* This shouldn't happen... */
+1:
+ movq PER_CPU_VAR(kernel_stack),%rax
+ subq $(6*8-KERNEL_STACK_OFFSET),%rax /* Reset to original stack */
+ movq %rax,RSP(%rdi)
+ movq $0,(%rax) /* Missing (lost) #GP error code */
+ movq $general_protection,RIP(%rdi)
+ retq
+ CFI_ENDPROC
+END(__do_double_fault)
+#else
+# define __do_double_fault do_double_fault
+#endif
+
/*
* End of kprobes section
*/
/*
* Exception entry points.
*/
-.macro zeroentry sym do_sym
-ENTRY(\sym)
- INTR_FRAME
- ASM_CLAC
- PARAVIRT_ADJUST_EXCEPTION_FRAME
- pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
- subq $ORIG_RAX-R15, %rsp
- CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
- call error_entry
- DEFAULT_FRAME 0
- movq %rsp,%rdi /* pt_regs pointer */
- xorl %esi,%esi /* no error code */
- call \do_sym
- jmp error_exit /* %ebx: no swapgs flag */
- CFI_ENDPROC
-END(\sym)
-.endm
+#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
-.macro paranoidzeroentry sym do_sym
+.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
ENTRY(\sym)
- INTR_FRAME
- ASM_CLAC
- PARAVIRT_ADJUST_EXCEPTION_FRAME
- pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
- subq $ORIG_RAX-R15, %rsp
- CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
- call save_paranoid
- TRACE_IRQS_OFF
- movq %rsp,%rdi /* pt_regs pointer */
- xorl %esi,%esi /* no error code */
- call \do_sym
- jmp paranoid_exit /* %ebx: no swapgs flag */
- CFI_ENDPROC
-END(\sym)
-.endm
+ /* Sanity check */
+ .if \shift_ist != -1 && \paranoid == 0
+ .error "using shift_ist requires paranoid=1"
+ .endif
-#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
-.macro paranoidzeroentry_ist sym do_sym ist
-ENTRY(\sym)
+ .if \has_error_code
+ XCPT_FRAME
+ .else
INTR_FRAME
- ASM_CLAC
- PARAVIRT_ADJUST_EXCEPTION_FRAME
- pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
- subq $ORIG_RAX-R15, %rsp
- CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
- call save_paranoid
- TRACE_IRQS_OFF_DEBUG
- movq %rsp,%rdi /* pt_regs pointer */
- xorl %esi,%esi /* no error code */
- subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
- call \do_sym
- addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
- jmp paranoid_exit /* %ebx: no swapgs flag */
- CFI_ENDPROC
-END(\sym)
-.endm
+ .endif
-.macro errorentry sym do_sym
-ENTRY(\sym)
- XCPT_FRAME
ASM_CLAC
PARAVIRT_ADJUST_EXCEPTION_FRAME
+
+ .ifeq \has_error_code
+ pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
+ .endif
+
subq $ORIG_RAX-R15, %rsp
CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
+
+ .if \paranoid
+ call save_paranoid
+ .else
call error_entry
+ .endif
+
DEFAULT_FRAME 0
+
+ .if \paranoid
+ .if \shift_ist != -1
+ TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */
+ .else
+ TRACE_IRQS_OFF
+ .endif
+ .endif
+
movq %rsp,%rdi /* pt_regs pointer */
+
+ .if \has_error_code
movq ORIG_RAX(%rsp),%rsi /* get error code */
movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */
+ .else
+ xorl %esi,%esi /* no error code */
+ .endif
+
+ .if \shift_ist != -1
+ subq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+ .endif
+
call \do_sym
+
+ .if \shift_ist != -1
+ addq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+ .endif
+
+ .if \paranoid
+ jmp paranoid_exit /* %ebx: no swapgs flag */
+ .else
jmp error_exit /* %ebx: no swapgs flag */
+ .endif
+
CFI_ENDPROC
END(\sym)
.endm
#ifdef CONFIG_TRACING
-.macro trace_errorentry sym do_sym
-errorentry trace(\sym) trace(\do_sym)
-errorentry \sym \do_sym
+.macro trace_idtentry sym do_sym has_error_code:req
+idtentry trace(\sym) trace(\do_sym) has_error_code=\has_error_code
+idtentry \sym \do_sym has_error_code=\has_error_code
.endm
#else
-.macro trace_errorentry sym do_sym
-errorentry \sym \do_sym
+.macro trace_idtentry sym do_sym has_error_code:req
+idtentry \sym \do_sym has_error_code=\has_error_code
.endm
#endif
- /* error code is on the stack already */
-.macro paranoiderrorentry sym do_sym
-ENTRY(\sym)
- XCPT_FRAME
- ASM_CLAC
- PARAVIRT_ADJUST_EXCEPTION_FRAME
- subq $ORIG_RAX-R15, %rsp
- CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
- call save_paranoid
- DEFAULT_FRAME 0
- TRACE_IRQS_OFF
- movq %rsp,%rdi /* pt_regs pointer */
- movq ORIG_RAX(%rsp),%rsi /* get error code */
- movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */
- call \do_sym
- jmp paranoid_exit /* %ebx: no swapgs flag */
- CFI_ENDPROC
-END(\sym)
-.endm
-
-zeroentry divide_error do_divide_error
-zeroentry overflow do_overflow
-zeroentry bounds do_bounds
-zeroentry invalid_op do_invalid_op
-zeroentry device_not_available do_device_not_available
-paranoiderrorentry double_fault do_double_fault
-zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun
-errorentry invalid_TSS do_invalid_TSS
-errorentry segment_not_present do_segment_not_present
-zeroentry spurious_interrupt_bug do_spurious_interrupt_bug
-zeroentry coprocessor_error do_coprocessor_error
-errorentry alignment_check do_alignment_check
-zeroentry simd_coprocessor_error do_simd_coprocessor_error
+idtentry divide_error do_divide_error has_error_code=0
+idtentry overflow do_overflow has_error_code=0
+idtentry bounds do_bounds has_error_code=0
+idtentry invalid_op do_invalid_op has_error_code=0
+idtentry device_not_available do_device_not_available has_error_code=0
+idtentry double_fault __do_double_fault has_error_code=1 paranoid=1
+idtentry coprocessor_segment_overrun do_coprocessor_segment_overrun has_error_code=0
+idtentry invalid_TSS do_invalid_TSS has_error_code=1
+idtentry segment_not_present do_segment_not_present has_error_code=1
+idtentry spurious_interrupt_bug do_spurious_interrupt_bug has_error_code=0
+idtentry coprocessor_error do_coprocessor_error has_error_code=0
+idtentry alignment_check do_alignment_check has_error_code=1
+idtentry simd_coprocessor_error do_simd_coprocessor_error has_error_code=0
/* Reload gs selector with exception handling */
END(do_softirq_own_stack)
#ifdef CONFIG_XEN
-zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
+idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
/*
* A note on the "critical region" in our callback handler.
*/
.pushsection .kprobes.text, "ax"
-paranoidzeroentry_ist debug do_debug DEBUG_STACK
-paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
-paranoiderrorentry stack_segment do_stack_segment
+idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry stack_segment do_stack_segment has_error_code=1 paranoid=1
#ifdef CONFIG_XEN
-zeroentry xen_debug do_debug
-zeroentry xen_int3 do_int3
-errorentry xen_stack_segment do_stack_segment
+idtentry xen_debug do_debug has_error_code=0
+idtentry xen_int3 do_int3 has_error_code=0
+idtentry xen_stack_segment do_stack_segment has_error_code=1
#endif
-errorentry general_protection do_general_protection
-trace_errorentry page_fault do_page_fault
+idtentry general_protection do_general_protection has_error_code=1
+trace_idtentry page_fault do_page_fault has_error_code=1
#ifdef CONFIG_KVM_GUEST
-errorentry async_page_fault do_async_page_fault
+idtentry async_page_fault do_async_page_fault has_error_code=1
#endif
#ifdef CONFIG_X86_MCE
-paranoidzeroentry machine_check *machine_check_vector(%rip)
+idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
#endif
/*
*/
error_kernelspace:
incl %ebx
- leaq irq_return(%rip),%rcx
+ leaq irq_return_iret(%rip),%rcx
cmpq %rcx,RIP+8(%rsp)
je error_swapgs
movl %ecx,%eax /* zero extend */
projects / firefly-linux-kernel-4.4.55.git / blobdiff