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Kernel
提交 4d732138 编写于 作者: I Ingo Molnar
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x86/asm/entry/64: Clean up entry_64.S 

Make the 64-bit syscall entry code a bit more readable:

 - use consistent assembly coding style similar to the other entry_*.S files

 - remove old comments that are not true anymore

 - eliminate whitespace noise

 - use consistent vertical spacing

 - fix various comments

 - reorganize entry point generation tables to be more readable

No code changed:

  # arch/x86/entry/entry_64.o:

   text    data     bss     dec     hex filename
  12282       0       0   12282    2ffa entry_64.o.before
  12282       0       0   12282    2ffa entry_64.o.after

md5:
   cbab1f2d727a2a8a87618eeb79f391b7  entry_64.o.before.asm
   cbab1f2d727a2a8a87618eeb79f391b7  entry_64.o.after.asm

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>
上级 9dda1658
隐藏空白更改
内联 并排
Showing with 404 addition and 416 deletion
arch/x86/entry/entry_64.S
浏览文件 @ 4d732138
......@@ -4,26 +4,20 @@
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
* Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
*/
/*
*
* entry.S contains the system-call and fault low-level handling routines.
*
* Some of this is documented in Documentation/x86/entry_64.txt
*
* NOTE: This code handles signal-recognition, which happens every time
* after an interrupt and after each system call.
*
* A note on terminology:
* - iret frame: Architecture defined interrupt frame from SS to RIP
* at the top of the kernel process stack.
* - iret frame: Architecture defined interrupt frame from SS to RIP
* at the top of the kernel process stack.
*
* Some macro usage:
* - ENTRY/END Define functions in the symbol table.
* - TRACE_IRQ_* - Trace hard interrupt state for lock debugging.
* - idtentry - Define exception entry points.
* - ENTRY/END: Define functions in the symbol table.
* - TRACE_IRQ_*: Trace hardirq state for lock debugging.
* - idtentry: Define exception entry points.
*/
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/cache.h>
......@@ -46,13 +40,12 @@
/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
#include <linux/elf-em.h>
#define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
#define __AUDIT_ARCH_64BIT 0x80000000
#define __AUDIT_ARCH_LE 0x40000000
.code64
.section .entry.text, "ax"
#define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
#define __AUDIT_ARCH_64BIT 0x80000000
#define __AUDIT_ARCH_LE 0x40000000
.code64
.section .entry.text, "ax"
#ifdef CONFIG_PARAVIRT
ENTRY(native_usergs_sysret64)
......@@ -61,11 +54,10 @@ ENTRY(native_usergs_sysret64)
ENDPROC(native_usergs_sysret64)
#endif /* CONFIG_PARAVIRT */
.macro TRACE_IRQS_IRETQ
#ifdef CONFIG_TRACE_IRQFLAGS
bt $9,EFLAGS(%rsp) /* interrupts off? */
jnc 1f
bt $9, EFLAGS(%rsp) /* interrupts off? */
jnc 1f
TRACE_IRQS_ON
1:
#endif
......@@ -85,34 +77,34 @@ ENDPROC(native_usergs_sysret64)
#if defined(CONFIG_DYNAMIC_FTRACE) && defined(CONFIG_TRACE_IRQFLAGS)
.macro TRACE_IRQS_OFF_DEBUG
call debug_stack_set_zero
call debug_stack_set_zero
TRACE_IRQS_OFF
call debug_stack_reset
call debug_stack_reset
.endm
.macro TRACE_IRQS_ON_DEBUG
call debug_stack_set_zero
call debug_stack_set_zero
TRACE_IRQS_ON
call debug_stack_reset
call debug_stack_reset
.endm
.macro TRACE_IRQS_IRETQ_DEBUG
bt $9,EFLAGS(%rsp) /* interrupts off? */
jnc 1f
bt $9, EFLAGS(%rsp) /* interrupts off? */
jnc 1f
TRACE_IRQS_ON_DEBUG
1:
.endm
#else
# define TRACE_IRQS_OFF_DEBUG TRACE_IRQS_OFF
# define TRACE_IRQS_ON_DEBUG TRACE_IRQS_ON
# define TRACE_IRQS_IRETQ_DEBUG TRACE_IRQS_IRETQ
# define TRACE_IRQS_OFF_DEBUG TRACE_IRQS_OFF
# define TRACE_IRQS_ON_DEBUG TRACE_IRQS_ON
# define TRACE_IRQS_IRETQ_DEBUG TRACE_IRQS_IRETQ
#endif
/*
* 64bit SYSCALL instruction entry. Up to 6 arguments in registers.
* 64-bit SYSCALL instruction entry. Up to 6 arguments in registers.
*
* 64bit SYSCALL saves rip to rcx, clears rflags.RF, then saves rflags to r11,
* 64-bit SYSCALL saves rip to rcx, clears rflags.RF, then saves rflags to r11,
* then loads new ss, cs, and rip from previously programmed MSRs.
* rflags gets masked by a value from another MSR (so CLD and CLAC
* are not needed). SYSCALL does not save anything on the stack
......@@ -128,7 +120,7 @@ ENDPROC(native_usergs_sysret64)
* r10 arg3 (needs to be moved to rcx to conform to C ABI)
* r8 arg4
* r9 arg5
* (note: r12-r15,rbp,rbx are callee-preserved in C ABI)
* (note: r12-r15, rbp, rbx are callee-preserved in C ABI)
*
* Only called from user space.
*
......@@ -151,12 +143,12 @@ ENTRY(entry_SYSCALL_64)
*/
GLOBAL(entry_SYSCALL_64_after_swapgs)
movq %rsp,PER_CPU_VAR(rsp_scratch)
movq PER_CPU_VAR(cpu_current_top_of_stack),%rsp
movq %rsp, PER_CPU_VAR(rsp_scratch)
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
/* Construct struct pt_regs on stack */
pushq $__USER_DS /* pt_regs->ss */
pushq PER_CPU_VAR(rsp_scratch) /* pt_regs->sp */
pushq $__USER_DS /* pt_regs->ss */
pushq PER_CPU_VAR(rsp_scratch) /* pt_regs->sp */
/*
* Re-enable interrupts.
* We use 'rsp_scratch' as a scratch space, hence irq-off block above
......@@ -165,34 +157,34 @@ GLOBAL(entry_SYSCALL_64_after_swapgs)
* with using rsp_scratch:
*/
ENABLE_INTERRUPTS(CLBR_NONE)
pushq %r11 /* pt_regs->flags */
pushq $__USER_CS /* pt_regs->cs */
pushq %rcx /* pt_regs->ip */
pushq %rax /* pt_regs->orig_ax */
pushq %rdi /* pt_regs->di */
pushq %rsi /* pt_regs->si */
pushq %rdx /* pt_regs->dx */
pushq %rcx /* pt_regs->cx */
pushq $-ENOSYS /* pt_regs->ax */
pushq %r8 /* pt_regs->r8 */
pushq %r9 /* pt_regs->r9 */
pushq %r10 /* pt_regs->r10 */
pushq %r11 /* pt_regs->r11 */
sub $(6*8),%rsp /* pt_regs->bp,bx,r12-15 not saved */
testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jnz tracesys
pushq %r11 /* pt_regs->flags */
pushq $__USER_CS /* pt_regs->cs */
pushq %rcx /* pt_regs->ip */
pushq %rax /* pt_regs->orig_ax */
pushq %rdi /* pt_regs->di */
pushq %rsi /* pt_regs->si */
pushq %rdx /* pt_regs->dx */
pushq %rcx /* pt_regs->cx */
pushq $-ENOSYS /* pt_regs->ax */
pushq %r8 /* pt_regs->r8 */
pushq %r9 /* pt_regs->r9 */
pushq %r10 /* pt_regs->r10 */
pushq %r11 /* pt_regs->r11 */
sub $(6*8), %rsp /* pt_regs->bp, bx, r12-15 not saved */
testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jnz tracesys
entry_SYSCALL_64_fastpath:
#if __SYSCALL_MASK == ~0
cmpq $__NR_syscall_max,%rax
cmpq $__NR_syscall_max, %rax
#else
andl $__SYSCALL_MASK,%eax
cmpl $__NR_syscall_max,%eax
andl $__SYSCALL_MASK, %eax
cmpl $__NR_syscall_max, %eax
#endif
ja 1f /* return -ENOSYS (already in pt_regs->ax) */
movq %r10,%rcx
call *sys_call_table(,%rax,8)
movq %rax,RAX(%rsp)
ja 1f /* return -ENOSYS (already in pt_regs->ax) */
movq %r10, %rcx
call *sys_call_table(, %rax, 8)
movq %rax, RAX(%rsp)
1:
/*
* Syscall return path ending with SYSRET (fast path).
......@@ -213,15 +205,15 @@ entry_SYSCALL_64_fastpath:
* flags (TIF_NOTIFY_RESUME, TIF_USER_RETURN_NOTIFY, etc) set is
* very bad.
*/
testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jnz int_ret_from_sys_call_irqs_off /* Go to the slow path */
testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jnz int_ret_from_sys_call_irqs_off /* Go to the slow path */
RESTORE_C_REGS_EXCEPT_RCX_R11
movq RIP(%rsp),%rcx
movq EFLAGS(%rsp),%r11
movq RSP(%rsp),%rsp
movq RIP(%rsp), %rcx
movq EFLAGS(%rsp), %r11
movq RSP(%rsp), %rsp
/*
* 64bit SYSRET restores rip from rcx,
* 64-bit SYSRET restores rip from rcx,
* rflags from r11 (but RF and VM bits are forced to 0),
* cs and ss are loaded from MSRs.
* Restoration of rflags re-enables interrupts.
......@@ -239,21 +231,21 @@ entry_SYSCALL_64_fastpath:
/* Do syscall entry tracing */
tracesys:
movq %rsp, %rdi
movl $AUDIT_ARCH_X86_64, %esi
call syscall_trace_enter_phase1
test %rax, %rax
jnz tracesys_phase2 /* if needed, run the slow path */
RESTORE_C_REGS_EXCEPT_RAX /* else restore clobbered regs */
movq ORIG_RAX(%rsp), %rax
jmp entry_SYSCALL_64_fastpath /* and return to the fast path */
movq %rsp, %rdi
movl $AUDIT_ARCH_X86_64, %esi
call syscall_trace_enter_phase1
test %rax, %rax
jnz tracesys_phase2 /* if needed, run the slow path */
RESTORE_C_REGS_EXCEPT_RAX /* else restore clobbered regs */
movq ORIG_RAX(%rsp), %rax
jmp entry_SYSCALL_64_fastpath /* and return to the fast path */
tracesys_phase2:
SAVE_EXTRA_REGS
movq %rsp, %rdi
movl $AUDIT_ARCH_X86_64, %esi
movq %rax,%rdx
call syscall_trace_enter_phase2
movq %rsp, %rdi
movl $AUDIT_ARCH_X86_64, %esi
movq %rax, %rdx
call syscall_trace_enter_phase2
/*
* Reload registers from stack in case ptrace changed them.
......@@ -263,15 +255,15 @@ tracesys_phase2:
RESTORE_C_REGS_EXCEPT_RAX
RESTORE_EXTRA_REGS
#if __SYSCALL_MASK == ~0
cmpq $__NR_syscall_max,%rax
cmpq $__NR_syscall_max, %rax
#else
andl $__SYSCALL_MASK,%eax
cmpl $__NR_syscall_max,%eax
andl $__SYSCALL_MASK, %eax
cmpl $__NR_syscall_max, %eax
#endif
ja 1f /* return -ENOSYS (already in pt_regs->ax) */
movq %r10,%rcx /* fixup for C */
call *sys_call_table(,%rax,8)
movq %rax,RAX(%rsp)
ja 1f /* return -ENOSYS (already in pt_regs->ax) */
movq %r10, %rcx /* fixup for C */
call *sys_call_table(, %rax, 8)
movq %rax, RAX(%rsp)
1:
/* Use IRET because user could have changed pt_regs->foo */
......@@ -283,31 +275,33 @@ GLOBAL(int_ret_from_sys_call)
DISABLE_INTERRUPTS(CLBR_NONE)
int_ret_from_sys_call_irqs_off: /* jumps come here from the irqs-off SYSRET path */
TRACE_IRQS_OFF
movl $_TIF_ALLWORK_MASK,%edi
movl $_TIF_ALLWORK_MASK, %edi
/* edi: mask to check */
GLOBAL(int_with_check)
LOCKDEP_SYS_EXIT_IRQ
GET_THREAD_INFO(%rcx)
movl TI_flags(%rcx),%edx
andl %edi,%edx
jnz int_careful
andl $~TS_COMPAT,TI_status(%rcx)
movl TI_flags(%rcx), %edx
andl %edi, %edx
jnz int_careful
andl $~TS_COMPAT, TI_status(%rcx)
jmp syscall_return
/* Either reschedule or signal or syscall exit tracking needed. */
/* First do a reschedule test. */
/* edx: work, edi: workmask */
/*
* Either reschedule or signal or syscall exit tracking needed.
* First do a reschedule test.
* edx: work, edi: workmask
*/
int_careful:
bt $TIF_NEED_RESCHED,%edx
jnc int_very_careful
bt $TIF_NEED_RESCHED, %edx
jnc int_very_careful
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq %rdi
pushq %rdi
SCHEDULE_USER
popq %rdi
popq %rdi
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
jmp int_with_check
jmp int_with_check
/* handle signals and tracing -- both require a full pt_regs */
int_very_careful:
......@@ -315,27 +309,27 @@ int_very_careful:
ENABLE_INTERRUPTS(CLBR_NONE)
SAVE_EXTRA_REGS
/* Check for syscall exit trace */
testl $_TIF_WORK_SYSCALL_EXIT,%edx
jz int_signal
pushq %rdi
leaq 8(%rsp),%rdi # &ptregs -> arg1
call syscall_trace_leave
popq %rdi
andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi
jmp int_restore_rest
testl $_TIF_WORK_SYSCALL_EXIT, %edx
jz int_signal
pushq %rdi
leaq 8(%rsp), %rdi /* &ptregs -> arg1 */
call syscall_trace_leave
popq %rdi
andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU), %edi
jmp int_restore_rest
int_signal:
testl $_TIF_DO_NOTIFY_MASK,%edx
jz 1f
movq %rsp,%rdi # &ptregs -> arg1
xorl %esi,%esi # oldset -> arg2
call do_notify_resume
1: movl $_TIF_WORK_MASK,%edi
testl $_TIF_DO_NOTIFY_MASK, %edx
jz 1f
movq %rsp, %rdi /* &ptregs -> arg1 */
xorl %esi, %esi /* oldset -> arg2 */
call do_notify_resume
1: movl $_TIF_WORK_MASK, %edi
int_restore_rest:
RESTORE_EXTRA_REGS
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
jmp int_with_check
jmp int_with_check
syscall_return:
/* The IRETQ could re-enable interrupts: */
......@@ -346,10 +340,10 @@ syscall_return:
* Try to use SYSRET instead of IRET if we're returning to
* a completely clean 64-bit userspace context.
*/
movq RCX(%rsp),%rcx
movq RIP(%rsp),%r11
cmpq %rcx,%r11 /* RCX == RIP */
jne opportunistic_sysret_failed
movq RCX(%rsp), %rcx
movq RIP(%rsp), %r11
cmpq %rcx, %r11 /* RCX == RIP */
jne opportunistic_sysret_failed
/*
* On Intel CPUs, SYSRET with non-canonical RCX/RIP will #GP
......@@ -362,19 +356,21 @@ syscall_return:
.ifne __VIRTUAL_MASK_SHIFT - 47
.error "virtual address width changed -- SYSRET checks need update"
.endif
/* Change top 16 bits to be the sign-extension of 47th bit */
shl $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx
sar $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx
/* If this changed %rcx, it was not canonical */
cmpq %rcx, %r11
jne opportunistic_sysret_failed
cmpq $__USER_CS,CS(%rsp) /* CS must match SYSRET */
jne opportunistic_sysret_failed
cmpq $__USER_CS, CS(%rsp) /* CS must match SYSRET */
jne opportunistic_sysret_failed
movq R11(%rsp),%r11
cmpq %r11,EFLAGS(%rsp) /* R11 == RFLAGS */
jne opportunistic_sysret_failed
movq R11(%rsp), %r11
cmpq %r11, EFLAGS(%rsp) /* R11 == RFLAGS */
jne opportunistic_sysret_failed
/*
* SYSRET can't restore RF. SYSRET can restore TF, but unlike IRET,
......@@ -383,29 +379,29 @@ syscall_return:
* with register state that satisfies the opportunistic SYSRET
* conditions. For example, single-stepping this user code:
*
* movq $stuck_here,%rcx
* movq $stuck_here, %rcx
* pushfq
* popq %r11
* stuck_here:
*
* would never get past 'stuck_here'.
*/
testq $(X86_EFLAGS_RF|X86_EFLAGS_TF), %r11
jnz opportunistic_sysret_failed
testq $(X86_EFLAGS_RF|X86_EFLAGS_TF), %r11
jnz opportunistic_sysret_failed
/* nothing to check for RSP */
cmpq $__USER_DS,SS(%rsp) /* SS must match SYSRET */
jne opportunistic_sysret_failed
cmpq $__USER_DS, SS(%rsp) /* SS must match SYSRET */
jne opportunistic_sysret_failed
/*
* We win! This label is here just for ease of understanding
* perf profiles. Nothing jumps here.
* We win! This label is here just for ease of understanding
* perf profiles. Nothing jumps here.
*/
syscall_return_via_sysret:
/* rcx and r11 are already restored (see code above) */
RESTORE_C_REGS_EXCEPT_RCX_R11
movq RSP(%rsp),%rsp
movq RSP(%rsp), %rsp
USERGS_SYSRET64
opportunistic_sysret_failed:
......@@ -417,7 +413,7 @@ END(entry_SYSCALL_64)
.macro FORK_LIKE func
ENTRY(stub_\func)
SAVE_EXTRA_REGS 8
jmp sys_\func
jmp sys_\func
END(stub_\func)
.endm
......@@ -436,7 +432,7 @@ return_from_execve:
/* must use IRET code path (pt_regs->cs may have changed) */
addq $8, %rsp
ZERO_EXTRA_REGS
movq %rax,RAX(%rsp)
movq %rax, RAX(%rsp)
jmp int_ret_from_sys_call
END(stub_execve)
/*
......@@ -479,19 +475,19 @@ ENTRY(stub_rt_sigreturn)
* we SAVE_EXTRA_REGS here.
*/
SAVE_EXTRA_REGS 8
call sys_rt_sigreturn
call sys_rt_sigreturn
return_from_stub:
addq $8, %rsp
RESTORE_EXTRA_REGS
movq %rax,RAX(%rsp)
jmp int_ret_from_sys_call
movq %rax, RAX(%rsp)
jmp int_ret_from_sys_call
END(stub_rt_sigreturn)
#ifdef CONFIG_X86_X32_ABI
ENTRY(stub_x32_rt_sigreturn)
SAVE_EXTRA_REGS 8
call sys32_x32_rt_sigreturn
jmp return_from_stub
call sys32_x32_rt_sigreturn
jmp return_from_stub
END(stub_x32_rt_sigreturn)
#endif
......@@ -502,16 +498,16 @@ END(stub_x32_rt_sigreturn)
*/
ENTRY(ret_from_fork)
LOCK ; btr $TIF_FORK,TI_flags(%r8)
LOCK ; btr $TIF_FORK, TI_flags(%r8)
pushq $0x0002
popfq # reset kernel eflags
pushq $0x0002
popfq /* reset kernel eflags */
call schedule_tail # rdi: 'prev' task parameter
call schedule_tail /* rdi: 'prev' task parameter */
RESTORE_EXTRA_REGS
testb $3, CS(%rsp) # from kernel_thread?
testb $3, CS(%rsp) /* from kernel_thread? */
/*
* By the time we get here, we have no idea whether our pt_regs,
......@@ -522,13 +518,15 @@ ENTRY(ret_from_fork)
*/
jnz int_ret_from_sys_call
/* We came from kernel_thread */
/* nb: we depend on RESTORE_EXTRA_REGS above */
movq %rbp, %rdi
call *%rbx
movl $0, RAX(%rsp)
/*
* We came from kernel_thread
* nb: we depend on RESTORE_EXTRA_REGS above
*/
movq %rbp, %rdi
call *%rbx
movl $0, RAX(%rsp)
RESTORE_EXTRA_REGS
jmp int_ret_from_sys_call
jmp int_ret_from_sys_call
END(ret_from_fork)
/*
......@@ -539,7 +537,7 @@ END(ret_from_fork)
ENTRY(irq_entries_start)
vector=FIRST_EXTERNAL_VECTOR
.rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
pushq $(~vector+0x80) /* Note: always in signed byte range */
pushq $(~vector+0x80) /* Note: always in signed byte range */
vector=vector+1
jmp common_interrupt
.align 8
......@@ -569,7 +567,7 @@ END(irq_entries_start)
/* this goes to 0(%rsp) for unwinder, not for saving the value: */
SAVE_EXTRA_REGS_RBP -RBP
leaq -RBP(%rsp),%rdi /* arg1 for \func (pointer to pt_regs) */
leaq -RBP(%rsp), %rdi /* arg1 for \func (pointer to pt_regs) */
testb $3, CS-RBP(%rsp)
jz 1f
......@@ -582,14 +580,14 @@ END(irq_entries_start)
* a little cheaper to use a separate counter in the PDA (short of
* moving irq_enter into assembly, which would be too much work)
*/
movq %rsp, %rsi
incl PER_CPU_VAR(irq_count)
cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp
pushq %rsi
movq %rsp, %rsi
incl PER_CPU_VAR(irq_count)
cmovzq PER_CPU_VAR(irq_stack_ptr), %rsp
pushq %rsi
/* We entered an interrupt context - irqs are off: */
TRACE_IRQS_OFF
call \func
call \func
.endm
/*
......@@ -599,36 +597,35 @@ END(irq_entries_start)
.p2align CONFIG_X86_L1_CACHE_SHIFT
common_interrupt:
ASM_CLAC
addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */
addq $-0x80, (%rsp) /* Adjust vector to [-256, -1] range */
interrupt do_IRQ
/* 0(%rsp): old RSP */
ret_from_intr:
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
decl PER_CPU_VAR(irq_count)
decl PER_CPU_VAR(irq_count)
/* Restore saved previous stack */
popq %rsi
popq %rsi
/* return code expects complete pt_regs - adjust rsp accordingly: */
leaq -RBP(%rsi),%rsp
leaq -RBP(%rsi), %rsp
testb $3, CS(%rsp)
jz retint_kernel
/* Interrupt came from user space */
retint_user:
GET_THREAD_INFO(%rcx)
/*
* %rcx: thread info. Interrupts off.
*/
/* %rcx: thread info. Interrupts are off. */
retint_with_reschedule:
movl $_TIF_WORK_MASK,%edi
movl $_TIF_WORK_MASK, %edi
retint_check:
LOCKDEP_SYS_EXIT_IRQ
movl TI_flags(%rcx),%edx
andl %edi,%edx
jnz retint_careful
movl TI_flags(%rcx), %edx
andl %edi, %edx
jnz retint_careful
retint_swapgs: /* return to user-space */
retint_swapgs: /* return to user-space */
/*
* The iretq could re-enable interrupts:
*/
......@@ -643,9 +640,9 @@ retint_kernel:
#ifdef CONFIG_PREEMPT
/* Interrupts are off */
/* Check if we need preemption */
bt $9,EFLAGS(%rsp) /* interrupts were off? */
bt $9, EFLAGS(%rsp) /* were interrupts off? */
jnc 1f
0: cmpl $0,PER_CPU_VAR(__preempt_count)
0: cmpl $0, PER_CPU_VAR(__preempt_count)
jnz 1f
call preempt_schedule_irq
jmp 0b
......@@ -671,8 +668,8 @@ ENTRY(native_iret)
* 64-bit mode SS:RSP on the exception stack is always valid.
*/
#ifdef CONFIG_X86_ESPFIX64
testb $4,(SS-RIP)(%rsp)
jnz native_irq_return_ldt
testb $4, (SS-RIP)(%rsp)
jnz native_irq_return_ldt
#endif
.global native_irq_return_iret
......@@ -687,59 +684,59 @@ native_irq_return_iret:
#ifdef CONFIG_X86_ESPFIX64
native_irq_return_ldt:
pushq %rax
pushq %rdi
pushq %rax
pushq %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 %rdi
orq PER_CPU_VAR(espfix_stack),%rax
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 %rdi
orq PER_CPU_VAR(espfix_stack), %rax
SWAPGS
movq %rax,%rsp
popq %rax
jmp native_irq_return_iret
movq %rax, %rsp
popq %rax
jmp native_irq_return_iret
#endif
/* edi: workmask, edx: work */
retint_careful:
bt $TIF_NEED_RESCHED,%edx
jnc retint_signal
bt $TIF_NEED_RESCHED, %edx
jnc retint_signal
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq %rdi
pushq %rdi
SCHEDULE_USER
popq %rdi
popq %rdi
GET_THREAD_INFO(%rcx)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
jmp retint_check
jmp retint_check
retint_signal:
testl $_TIF_DO_NOTIFY_MASK,%edx
jz retint_swapgs
testl $_TIF_DO_NOTIFY_MASK, %edx
jz retint_swapgs
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
SAVE_EXTRA_REGS
movq $-1,ORIG_RAX(%rsp)
xorl %esi,%esi # oldset
movq %rsp,%rdi # &pt_regs
call do_notify_resume
movq $-1, ORIG_RAX(%rsp)
xorl %esi, %esi /* oldset */
movq %rsp, %rdi /* &pt_regs */
call do_notify_resume
RESTORE_EXTRA_REGS
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
GET_THREAD_INFO(%rcx)
jmp retint_with_reschedule
jmp retint_with_reschedule
END(common_interrupt)
......@@ -749,10 +746,10 @@ END(common_interrupt)
.macro apicinterrupt3 num sym do_sym
ENTRY(\sym)
ASM_CLAC
pushq $~(\num)
pushq $~(\num)
.Lcommon_\sym:
interrupt \do_sym
jmp ret_from_intr
jmp ret_from_intr
END(\sym)
.endm
......@@ -774,60 +771,45 @@ trace_apicinterrupt \num \sym
.endm
#ifdef CONFIG_SMP
apicinterrupt3 IRQ_MOVE_CLEANUP_VECTOR \
irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt
apicinterrupt3 REBOOT_VECTOR \
reboot_interrupt smp_reboot_interrupt
apicinterrupt3 IRQ_MOVE_CLEANUP_VECTOR irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt
apicinterrupt3 REBOOT_VECTOR reboot_interrupt smp_reboot_interrupt
#endif
#ifdef CONFIG_X86_UV
apicinterrupt3 UV_BAU_MESSAGE \
uv_bau_message_intr1 uv_bau_message_interrupt
apicinterrupt3 UV_BAU_MESSAGE uv_bau_message_intr1 uv_bau_message_interrupt
#endif
apicinterrupt LOCAL_TIMER_VECTOR \
apic_timer_interrupt smp_apic_timer_interrupt
apicinterrupt X86_PLATFORM_IPI_VECTOR \
x86_platform_ipi smp_x86_platform_ipi
apicinterrupt LOCAL_TIMER_VECTOR apic_timer_interrupt smp_apic_timer_interrupt
apicinterrupt X86_PLATFORM_IPI_VECTOR x86_platform_ipi smp_x86_platform_ipi
#ifdef CONFIG_HAVE_KVM
apicinterrupt3 POSTED_INTR_VECTOR \
kvm_posted_intr_ipi smp_kvm_posted_intr_ipi
apicinterrupt3 POSTED_INTR_WAKEUP_VECTOR \
kvm_posted_intr_wakeup_ipi smp_kvm_posted_intr_wakeup_ipi
apicinterrupt3 POSTED_INTR_VECTOR kvm_posted_intr_ipi smp_kvm_posted_intr_ipi
apicinterrupt3 POSTED_INTR_WAKEUP_VECTOR kvm_posted_intr_wakeup_ipi smp_kvm_posted_intr_wakeup_ipi
#endif
#ifdef CONFIG_X86_MCE_THRESHOLD
apicinterrupt THRESHOLD_APIC_VECTOR \
threshold_interrupt smp_threshold_interrupt
apicinterrupt THRESHOLD_APIC_VECTOR threshold_interrupt smp_threshold_interrupt
#endif
#ifdef CONFIG_X86_MCE_AMD
apicinterrupt DEFERRED_ERROR_VECTOR \
deferred_error_interrupt smp_deferred_error_interrupt
apicinterrupt DEFERRED_ERROR_VECTOR deferred_error_interrupt smp_deferred_error_interrupt
#endif
#ifdef CONFIG_X86_THERMAL_VECTOR
apicinterrupt THERMAL_APIC_VECTOR \
thermal_interrupt smp_thermal_interrupt
apicinterrupt THERMAL_APIC_VECTOR thermal_interrupt smp_thermal_interrupt
#endif
#ifdef CONFIG_SMP
apicinterrupt CALL_FUNCTION_SINGLE_VECTOR \
call_function_single_interrupt smp_call_function_single_interrupt
apicinterrupt CALL_FUNCTION_VECTOR \
call_function_interrupt smp_call_function_interrupt
apicinterrupt RESCHEDULE_VECTOR \
reschedule_interrupt smp_reschedule_interrupt
apicinterrupt CALL_FUNCTION_SINGLE_VECTOR call_function_single_interrupt smp_call_function_single_interrupt
apicinterrupt CALL_FUNCTION_VECTOR call_function_interrupt smp_call_function_interrupt
apicinterrupt RESCHEDULE_VECTOR reschedule_interrupt smp_reschedule_interrupt
#endif
apicinterrupt ERROR_APIC_VECTOR \
error_interrupt smp_error_interrupt
apicinterrupt SPURIOUS_APIC_VECTOR \
spurious_interrupt smp_spurious_interrupt
apicinterrupt ERROR_APIC_VECTOR error_interrupt smp_error_interrupt
apicinterrupt SPURIOUS_APIC_VECTOR spurious_interrupt smp_spurious_interrupt
#ifdef CONFIG_IRQ_WORK
apicinterrupt IRQ_WORK_VECTOR \
irq_work_interrupt smp_irq_work_interrupt
apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt
#endif
/*
......@@ -846,54 +828,54 @@ ENTRY(\sym)
PARAVIRT_ADJUST_EXCEPTION_FRAME
.ifeq \has_error_code
pushq $-1 /* ORIG_RAX: no syscall to restart */
pushq $-1 /* ORIG_RAX: no syscall to restart */
.endif
ALLOC_PT_GPREGS_ON_STACK
.if \paranoid
.if \paranoid == 1
testb $3, CS(%rsp) /* If coming from userspace, switch */
jnz 1f /* stacks. */
testb $3, CS(%rsp) /* If coming from userspace, switch stacks */
jnz 1f
.endif
call paranoid_entry
call paranoid_entry
.else
call error_entry
call error_entry
.endif
/* returned flag: ebx=0: need swapgs on exit, ebx=1: don't need it */
.if \paranoid
.if \shift_ist != -1
TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */
TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */
.else
TRACE_IRQS_OFF
.endif
.endif
movq %rsp,%rdi /* pt_regs pointer */
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 */
movq ORIG_RAX(%rsp), %rsi /* get error code */
movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
.else
xorl %esi,%esi /* no error code */
xorl %esi, %esi /* no error code */
.endif
.if \shift_ist != -1
subq $EXCEPTION_STKSZ, CPU_TSS_IST(\shift_ist)
subq $EXCEPTION_STKSZ, CPU_TSS_IST(\shift_ist)
.endif
call \do_sym
call \do_sym
.if \shift_ist != -1
addq $EXCEPTION_STKSZ, CPU_TSS_IST(\shift_ist)
addq $EXCEPTION_STKSZ, CPU_TSS_IST(\shift_ist)
.endif
/* these procedures expect "no swapgs" flag in ebx */
.if \paranoid
jmp paranoid_exit
jmp paranoid_exit
.else
jmp error_exit
jmp error_exit
.endif
.if \paranoid == 1
......@@ -903,25 +885,25 @@ ENTRY(\sym)
* run in real process context if user_mode(regs).
*/
1:
call error_entry
call error_entry
movq %rsp,%rdi /* pt_regs pointer */
call sync_regs
movq %rax,%rsp /* switch stack */
movq %rsp, %rdi /* pt_regs pointer */
call sync_regs
movq %rax, %rsp /* switch stack */
movq %rsp,%rdi /* pt_regs pointer */
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 */
movq ORIG_RAX(%rsp), %rsi /* get error code */
movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
.else
xorl %esi,%esi /* no error code */
xorl %esi, %esi /* no error code */
.endif
call \do_sym
call \do_sym
jmp error_exit /* %ebx: no swapgs flag */
jmp error_exit /* %ebx: no swapgs flag */
.endif
END(\sym)
.endm
......@@ -937,55 +919,57 @@ idtentry \sym \do_sym has_error_code=\has_error_code
.endm
#endif
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=2
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 */
/* edi: new selector */
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=2
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
* edi: new selector
*/
ENTRY(native_load_gs_index)
pushfq
DISABLE_INTERRUPTS(CLBR_ANY & ~CLBR_RDI)
SWAPGS
gs_change:
movl %edi,%gs
2: mfence /* workaround */
movl %edi, %gs
2: mfence /* workaround */
SWAPGS
popfq
ret
END(native_load_gs_index)
_ASM_EXTABLE(gs_change,bad_gs)
.section .fixup,"ax"
_ASM_EXTABLE(gs_change, bad_gs)
.section .fixup, "ax"
/* running with kernelgs */
bad_gs:
SWAPGS /* switch back to user gs */
xorl %eax,%eax
movl %eax,%gs
jmp 2b
SWAPGS /* switch back to user gs */
xorl %eax, %eax
movl %eax, %gs
jmp 2b
.previous
/* Call softirq on interrupt stack. Interrupts are off. */
ENTRY(do_softirq_own_stack)
pushq %rbp
mov %rsp,%rbp
incl PER_CPU_VAR(irq_count)
cmove PER_CPU_VAR(irq_stack_ptr),%rsp
push %rbp # backlink for old unwinder
call __do_softirq
pushq %rbp
mov %rsp, %rbp
incl PER_CPU_VAR(irq_count)
cmove PER_CPU_VAR(irq_stack_ptr), %rsp
push %rbp /* frame pointer backlink */
call __do_softirq
leaveq
decl PER_CPU_VAR(irq_count)
decl PER_CPU_VAR(irq_count)
ret
END(do_softirq_own_stack)
......@@ -1005,23 +989,24 @@ idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
* existing activation in its critical region -- if so, we pop the current
* activation and restart the handler using the previous one.
*/
ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
ENTRY(xen_do_hypervisor_callback) /* do_hypervisor_callback(struct *pt_regs) */
/*
* Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will
* see the correct pointer to the pt_regs
*/
movq %rdi, %rsp # we don't return, adjust the stack frame
11: incl PER_CPU_VAR(irq_count)
movq %rsp,%rbp
cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp
pushq %rbp # backlink for old unwinder
call xen_evtchn_do_upcall
popq %rsp
decl PER_CPU_VAR(irq_count)
movq %rdi, %rsp /* we don't return, adjust the stack frame */
11: incl PER_CPU_VAR(irq_count)
movq %rsp, %rbp
cmovzq PER_CPU_VAR(irq_stack_ptr), %rsp
pushq %rbp /* frame pointer backlink */
call xen_evtchn_do_upcall
popq %rsp
decl PER_CPU_VAR(irq_count)
#ifndef CONFIG_PREEMPT
call xen_maybe_preempt_hcall
call xen_maybe_preempt_hcall
#endif
jmp error_exit
jmp error_exit
END(xen_do_hypervisor_callback)
/*
......@@ -1038,35 +1023,35 @@ END(xen_do_hypervisor_callback)
* with its current contents: any discrepancy means we in category 1.
*/
ENTRY(xen_failsafe_callback)
movl %ds,%ecx
cmpw %cx,0x10(%rsp)
jne 1f
movl %es,%ecx
cmpw %cx,0x18(%rsp)
jne 1f
movl %fs,%ecx
cmpw %cx,0x20(%rsp)
jne 1f
movl %gs,%ecx
cmpw %cx,0x28(%rsp)
jne 1f
movl %ds, %ecx
cmpw %cx, 0x10(%rsp)
jne 1f
movl %es, %ecx
cmpw %cx, 0x18(%rsp)
jne 1f
movl %fs, %ecx
cmpw %cx, 0x20(%rsp)
jne 1f
movl %gs, %ecx
cmpw %cx, 0x28(%rsp)
jne 1f
/* All segments match their saved values => Category 2 (Bad IRET). */
movq (%rsp),%rcx
movq 8(%rsp),%r11
addq $0x30,%rsp
pushq $0 /* RIP */
pushq %r11
pushq %rcx
jmp general_protection
movq (%rsp), %rcx
movq 8(%rsp), %r11
addq $0x30, %rsp
pushq $0 /* RIP */
pushq %r11
pushq %rcx
jmp general_protection
1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
movq (%rsp),%rcx
movq 8(%rsp),%r11
addq $0x30,%rsp
pushq $-1 /* orig_ax = -1 => not a system call */
movq (%rsp), %rcx
movq 8(%rsp), %r11
addq $0x30, %rsp
pushq $-1 /* orig_ax = -1 => not a system call */
ALLOC_PT_GPREGS_ON_STACK
SAVE_C_REGS
SAVE_EXTRA_REGS
jmp error_exit
jmp error_exit
END(xen_failsafe_callback)
apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
......@@ -1079,21 +1064,25 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
hyperv_callback_vector hyperv_vector_handler
#endif /* CONFIG_HYPERV */
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
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
#ifdef CONFIG_XEN
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
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
idtentry general_protection do_general_protection has_error_code=1
trace_idtentry page_fault do_page_fault has_error_code=1
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
idtentry async_page_fault do_async_page_fault has_error_code=1
idtentry async_page_fault do_async_page_fault has_error_code=1
#endif
#ifdef CONFIG_X86_MCE
idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
#endif
/*
......@@ -1105,13 +1094,13 @@ ENTRY(paranoid_entry)
cld
SAVE_C_REGS 8
SAVE_EXTRA_REGS 8
movl $1,%ebx
movl $MSR_GS_BASE,%ecx
movl $1, %ebx
movl $MSR_GS_BASE, %ecx
rdmsr
testl %edx,%edx
js 1f /* negative -> in kernel */
testl %edx, %edx
js 1f /* negative -> in kernel */
SWAPGS
xorl %ebx,%ebx
xorl %ebx, %ebx
1: ret
END(paranoid_entry)
......@@ -1124,16 +1113,17 @@ END(paranoid_entry)
* in syscall entry), so checking for preemption here would
* be complicated. Fortunately, we there's no good reason
* to try to handle preemption here.
*
* On entry, ebx is "no swapgs" flag (1: don't need swapgs, 0: need it)
*/
/* On entry, ebx is "no swapgs" flag (1: don't need swapgs, 0: need it) */
ENTRY(paranoid_exit)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF_DEBUG
testl %ebx,%ebx /* swapgs needed? */
jnz paranoid_exit_no_swapgs
testl %ebx, %ebx /* swapgs needed? */
jnz paranoid_exit_no_swapgs
TRACE_IRQS_IRETQ
SWAPGS_UNSAFE_STACK
jmp paranoid_exit_restore
jmp paranoid_exit_restore
paranoid_exit_no_swapgs:
TRACE_IRQS_IRETQ_DEBUG
paranoid_exit_restore:
......@@ -1151,7 +1141,7 @@ ENTRY(error_entry)
cld
SAVE_C_REGS 8
SAVE_EXTRA_REGS 8
xorl %ebx,%ebx
xorl %ebx, %ebx
testb $3, CS+8(%rsp)
jz error_kernelspace
error_swapgs:
......@@ -1167,41 +1157,41 @@ error_sti:
* for these here too.
*/
error_kernelspace:
incl %ebx
leaq native_irq_return_iret(%rip),%rcx
cmpq %rcx,RIP+8(%rsp)
je error_bad_iret
movl %ecx,%eax /* zero extend */
cmpq %rax,RIP+8(%rsp)
je bstep_iret
cmpq $gs_change,RIP+8(%rsp)
je error_swapgs
jmp error_sti
incl %ebx
leaq native_irq_return_iret(%rip), %rcx
cmpq %rcx, RIP+8(%rsp)
je error_bad_iret
movl %ecx, %eax /* zero extend */
cmpq %rax, RIP+8(%rsp)
je bstep_iret
cmpq $gs_change, RIP+8(%rsp)
je error_swapgs
jmp error_sti
bstep_iret:
/* Fix truncated RIP */
movq %rcx,RIP+8(%rsp)
movq %rcx, RIP+8(%rsp)
/* fall through */
error_bad_iret:
SWAPGS
mov %rsp,%rdi
call fixup_bad_iret
mov %rax,%rsp
decl %ebx /* Return to usergs */
jmp error_sti
mov %rsp, %rdi
call fixup_bad_iret
mov %rax, %rsp
decl %ebx /* Return to usergs */
jmp error_sti
END(error_entry)
/* On entry, ebx is "no swapgs" flag (1: don't need swapgs, 0: need it) */
ENTRY(error_exit)
movl %ebx,%eax
movl %ebx, %eax
RESTORE_EXTRA_REGS
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
testl %eax,%eax
jnz retint_kernel
jmp retint_user
testl %eax, %eax
jnz retint_kernel
jmp retint_user
END(error_exit)
/* Runs on exception stack */
......@@ -1240,21 +1230,21 @@ ENTRY(nmi)
*/
/* Use %rdx as our temp variable throughout */
pushq %rdx
pushq %rdx
/*
* If %cs was not the kernel segment, then the NMI triggered in user
* space, which means it is definitely not nested.
*/
cmpl $__KERNEL_CS, 16(%rsp)
jne first_nmi
cmpl $__KERNEL_CS, 16(%rsp)
jne first_nmi
/*
* Check the special variable on the stack to see if NMIs are
* executing.
*/
cmpl $1, -8(%rsp)
je nested_nmi
cmpl $1, -8(%rsp)
je nested_nmi
/*
* Now test if the previous stack was an NMI stack.
......@@ -1268,6 +1258,7 @@ ENTRY(nmi)
cmpq %rdx, 4*8(%rsp)
/* If the stack pointer is above the NMI stack, this is a normal NMI */
ja first_nmi
subq $EXCEPTION_STKSZ, %rdx
cmpq %rdx, 4*8(%rsp)
/* If it is below the NMI stack, it is a normal NMI */
......@@ -1280,29 +1271,29 @@ nested_nmi:
* It's about to repeat the NMI handler, so we are fine
* with ignoring this one.
*/
movq $repeat_nmi, %rdx
cmpq 8(%rsp), %rdx
ja 1f
movq $end_repeat_nmi, %rdx
cmpq 8(%rsp), %rdx
ja nested_nmi_out
movq $repeat_nmi, %rdx
cmpq 8(%rsp), %rdx
ja 1f
movq $end_repeat_nmi, %rdx
cmpq 8(%rsp), %rdx
ja nested_nmi_out
1:
/* Set up the interrupted NMIs stack to jump to repeat_nmi */
leaq -1*8(%rsp), %rdx
movq %rdx, %rsp
leaq -10*8(%rsp), %rdx
pushq $__KERNEL_DS
pushq %rdx
leaq -1*8(%rsp), %rdx
movq %rdx, %rsp
leaq -10*8(%rsp), %rdx
pushq $__KERNEL_DS
pushq %rdx
pushfq
pushq $__KERNEL_CS
pushq $repeat_nmi
pushq $__KERNEL_CS
pushq $repeat_nmi
/* Put stack back */
addq $(6*8), %rsp
addq $(6*8), %rsp
nested_nmi_out:
popq %rdx
popq %rdx
/* No need to check faults here */
INTERRUPT_RETURN
......@@ -1344,19 +1335,17 @@ first_nmi:
* is also used by nested NMIs and can not be trusted on exit.
*/
/* Do not pop rdx, nested NMIs will corrupt that part of the stack */
movq (%rsp), %rdx
movq (%rsp), %rdx
/* Set the NMI executing variable on the stack. */
pushq $1
pushq $1
/*
* Leave room for the "copied" frame
*/
subq $(5*8), %rsp
/* Leave room for the "copied" frame */
subq $(5*8), %rsp
/* Copy the stack frame to the Saved frame */
.rept 5
pushq 11*8(%rsp)
pushq 11*8(%rsp)
.endr
/* Everything up to here is safe from nested NMIs */
......@@ -1376,14 +1365,14 @@ repeat_nmi:
* is benign for the non-repeat case, where 1 was pushed just above
* to this very stack slot).
*/
movq $1, 10*8(%rsp)
movq $1, 10*8(%rsp)
/* Make another copy, this one may be modified by nested NMIs */
addq $(10*8), %rsp
addq $(10*8), %rsp
.rept 5
pushq -6*8(%rsp)
pushq -6*8(%rsp)
.endr
subq $(5*8), %rsp
subq $(5*8), %rsp
end_repeat_nmi:
/*
......@@ -1391,7 +1380,7 @@ end_repeat_nmi:
* NMI if the first NMI took an exception and reset our iret stack
* so that we repeat another NMI.
*/
pushq $-1 /* ORIG_RAX: no syscall to restart */
pushq $-1 /* ORIG_RAX: no syscall to restart */
ALLOC_PT_GPREGS_ON_STACK
/*
......@@ -1401,7 +1390,7 @@ end_repeat_nmi:
* setting NEED_RESCHED or anything that normal interrupts and
* exceptions might do.
*/
call paranoid_entry
call paranoid_entry
/*
* Save off the CR2 register. If we take a page fault in the NMI then
......@@ -1412,21 +1401,21 @@ end_repeat_nmi:
* origin fault. Save it off and restore it if it changes.
* Use the r12 callee-saved register.
*/
movq %cr2, %r12
movq %cr2, %r12
/* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
movq %rsp,%rdi
movq $-1,%rsi
call do_nmi
movq %rsp, %rdi
movq $-1, %rsi
call do_nmi
/* Did the NMI take a page fault? Restore cr2 if it did */
movq %cr2, %rcx
cmpq %rcx, %r12
je 1f
movq %r12, %cr2
movq %cr2, %rcx
cmpq %rcx, %r12
je 1f
movq %r12, %cr2
1:
testl %ebx,%ebx /* swapgs needed? */
jnz nmi_restore
testl %ebx, %ebx /* swapgs needed? */
jnz nmi_restore
nmi_swapgs:
SWAPGS_UNSAFE_STACK
nmi_restore:
......@@ -1436,12 +1425,11 @@ nmi_restore:
REMOVE_PT_GPREGS_FROM_STACK 6*8
/* Clear the NMI executing stack variable */
movq $0, 5*8(%rsp)
movq $0, 5*8(%rsp)
INTERRUPT_RETURN
END(nmi)
ENTRY(ignore_sysret)
mov $-ENOSYS,%eax
mov $-ENOSYS, %eax
sysret
END(ignore_sysret)
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