summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r--arch/x86/include/asm/processor.h3
-rw-r--r--arch/x86/include/asm/switch_to.h139
-rw-r--r--arch/x86/include/asm/thread_info.h2
3 files changed, 21 insertions, 123 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 63def9537a2d..6fee8635340b 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -389,9 +389,6 @@ struct thread_struct {
unsigned short fsindex;
unsigned short gsindex;
#endif
-#ifdef CONFIG_X86_32
- unsigned long ip;
-#endif
#ifdef CONFIG_X86_64
unsigned long fsbase;
unsigned long gsbase;
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index ec689c62c01f..886d5ea09dba 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -2,8 +2,12 @@
#define _ASM_X86_SWITCH_TO_H
struct task_struct; /* one of the stranger aspects of C forward declarations */
+
+struct task_struct *__switch_to_asm(struct task_struct *prev,
+ struct task_struct *next);
+
__visible struct task_struct *__switch_to(struct task_struct *prev,
- struct task_struct *next);
+ struct task_struct *next);
struct tss_struct;
void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
struct tss_struct *tss);
@@ -32,131 +36,30 @@ static inline void prepare_switch_to(struct task_struct *prev,
/* data that is pointed to by thread.sp */
struct inactive_task_frame {
+#ifdef CONFIG_X86_64
+ unsigned long r15;
+ unsigned long r14;
+ unsigned long r13;
+ unsigned long r12;
+#else
+ unsigned long si;
+ unsigned long di;
+#endif
+ unsigned long bx;
unsigned long bp;
+ unsigned long ret_addr;
};
-#ifdef CONFIG_X86_32
-
-#ifdef CONFIG_CC_STACKPROTECTOR
-#define __switch_canary \
- "movl %P[task_canary](%[next]), %%ebx\n\t" \
- "movl %%ebx, "__percpu_arg([stack_canary])"\n\t"
-#define __switch_canary_oparam \
- , [stack_canary] "=m" (stack_canary.canary)
-#define __switch_canary_iparam \
- , [task_canary] "i" (offsetof(struct task_struct, stack_canary))
-#else /* CC_STACKPROTECTOR */
-#define __switch_canary
-#define __switch_canary_oparam
-#define __switch_canary_iparam
-#endif /* CC_STACKPROTECTOR */
+struct fork_frame {
+ struct inactive_task_frame frame;
+ struct pt_regs regs;
+};
-/*
- * Saving eflags is important. It switches not only IOPL between tasks,
- * it also protects other tasks from NT leaking through sysenter etc.
- */
#define switch_to(prev, next, last) \
do { \
- /* \
- * Context-switching clobbers all registers, so we clobber \
- * them explicitly, via unused output variables. \
- * (EAX and EBP is not listed because EBP is saved/restored \
- * explicitly for wchan access and EAX is the return value of \
- * __switch_to()) \
- */ \
- unsigned long ebx, ecx, edx, esi, edi; \
- \
prepare_switch_to(prev, next); \
\
- asm volatile("pushl %%ebp\n\t" /* save EBP */ \
- "movl %%esp,%[prev_sp]\n\t" /* save ESP */ \
- "movl %[next_sp],%%esp\n\t" /* restore ESP */ \
- "movl $1f,%[prev_ip]\n\t" /* save EIP */ \
- "pushl %[next_ip]\n\t" /* restore EIP */ \
- __switch_canary \
- "jmp __switch_to\n" /* regparm call */ \
- "1:\t" \
- "popl %%ebp\n\t" /* restore EBP */ \
- \
- /* output parameters */ \
- : [prev_sp] "=m" (prev->thread.sp), \
- [prev_ip] "=m" (prev->thread.ip), \
- "=a" (last), \
- \
- /* clobbered output registers: */ \
- "=b" (ebx), "=c" (ecx), "=d" (edx), \
- "=S" (esi), "=D" (edi) \
- \
- __switch_canary_oparam \
- \
- /* input parameters: */ \
- : [next_sp] "m" (next->thread.sp), \
- [next_ip] "m" (next->thread.ip), \
- \
- /* regparm parameters for __switch_to(): */ \
- [prev] "a" (prev), \
- [next] "d" (next) \
- \
- __switch_canary_iparam \
- \
- : /* reloaded segment registers */ \
- "memory"); \
+ ((last) = __switch_to_asm((prev), (next))); \
} while (0)
-#else /* CONFIG_X86_32 */
-
-/* frame pointer must be last for get_wchan */
-#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
-#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\t"
-
-#define __EXTRA_CLOBBER \
- , "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
- "r12", "r13", "r14", "r15", "flags"
-
-#ifdef CONFIG_CC_STACKPROTECTOR
-#define __switch_canary \
- "movq %P[task_canary](%%rsi),%%r8\n\t" \
- "movq %%r8,"__percpu_arg([gs_canary])"\n\t"
-#define __switch_canary_oparam \
- , [gs_canary] "=m" (irq_stack_union.stack_canary)
-#define __switch_canary_iparam \
- , [task_canary] "i" (offsetof(struct task_struct, stack_canary))
-#else /* CC_STACKPROTECTOR */
-#define __switch_canary
-#define __switch_canary_oparam
-#define __switch_canary_iparam
-#endif /* CC_STACKPROTECTOR */
-
-/*
- * There is no need to save or restore flags, because flags are always
- * clean in kernel mode, with the possible exception of IOPL. Kernel IOPL
- * has no effect.
- */
-#define switch_to(prev, next, last) \
- prepare_switch_to(prev, next); \
- \
- asm volatile(SAVE_CONTEXT \
- "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
- "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
- "call __switch_to\n\t" \
- "movq "__percpu_arg([current_task])",%%rsi\n\t" \
- __switch_canary \
- "movq %P[thread_info](%%rsi),%%r8\n\t" \
- "movq %%rax,%%rdi\n\t" \
- "testl %[_tif_fork],%P[ti_flags](%%r8)\n\t" \
- "jnz ret_from_fork\n\t" \
- RESTORE_CONTEXT \
- : "=a" (last) \
- __switch_canary_oparam \
- : [next] "S" (next), [prev] "D" (prev), \
- [threadrsp] "i" (offsetof(struct task_struct, thread.sp)), \
- [ti_flags] "i" (offsetof(struct thread_info, flags)), \
- [_tif_fork] "i" (_TIF_FORK), \
- [thread_info] "i" (offsetof(struct task_struct, stack)), \
- [current_task] "m" (current_task) \
- __switch_canary_iparam \
- : "memory", "cc" __EXTRA_CLOBBER)
-
-#endif /* CONFIG_X86_32 */
-
#endif /* _ASM_X86_SWITCH_TO_H */
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 8b7c8d8e0852..494c4b5ada34 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -95,7 +95,6 @@ struct thread_info {
#define TIF_UPROBE 12 /* breakpointed or singlestepping */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* IA32 compatibility process */
-#define TIF_FORK 18 /* ret_from_fork */
#define TIF_NOHZ 19 /* in adaptive nohz mode */
#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
#define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */
@@ -119,7 +118,6 @@ struct thread_info {
#define _TIF_UPROBE (1 << TIF_UPROBE)
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
-#define _TIF_FORK (1 << TIF_FORK)
#define _TIF_NOHZ (1 << TIF_NOHZ)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 21:26:29 +0000