mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 15:26:54 +07:00
35ea7903b8
This function is called from inline assembler, so has to be visible. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1375740170-7446-6-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
130 lines
4.6 KiB
C
130 lines
4.6 KiB
C
#ifndef _ASM_X86_SWITCH_TO_H
|
|
#define _ASM_X86_SWITCH_TO_H
|
|
|
|
struct task_struct; /* one of the stranger aspects of C forward declarations */
|
|
__visible struct task_struct *__switch_to(struct task_struct *prev,
|
|
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);
|
|
|
|
#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 */
|
|
|
|
/*
|
|
* 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; \
|
|
\
|
|
asm volatile("pushfl\n\t" /* save flags */ \
|
|
"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 */ \
|
|
"popfl\n" /* restore flags */ \
|
|
\
|
|
/* 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"); \
|
|
} while (0)
|
|
|
|
#else /* CONFIG_X86_32 */
|
|
|
|
/* frame pointer must be last for get_wchan */
|
|
#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
|
|
#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
|
|
|
|
#define __EXTRA_CLOBBER \
|
|
, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
|
|
"r12", "r13", "r14", "r15"
|
|
|
|
#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 */
|
|
|
|
/* Save restore flags to clear handle leaking NT */
|
|
#define switch_to(prev, next, last) \
|
|
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 */
|