diff options
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 37 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64.S | 41 |
2 files changed, 75 insertions, 3 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 0b56666e6039..bf8f221f9c94 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -204,6 +204,43 @@ POP_GS_EX .endm +/* + * %eax: prev task + * %edx: next task + */ +ENTRY(__switch_to_asm) + /* + * Save callee-saved registers + * This must match the order in struct inactive_task_frame + */ + pushl %ebp + pushl %ebx + pushl %edi + pushl %esi + + /* switch stack */ + movl %esp, TASK_threadsp(%eax) + movl TASK_threadsp(%edx), %esp + +#ifdef CONFIG_CC_STACKPROTECTOR + movl TASK_stack_canary(%edx), %ebx + movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset +#endif + + /* restore callee-saved registers */ + popl %esi + popl %edi + popl %ebx + popl %ebp + + jmp __switch_to +END(__switch_to_asm) + +/* + * A newly forked process directly context switches into this address. + * + * eax: prev task we switched from + */ ENTRY(ret_from_fork) pushl %eax call schedule_tail diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index f6b40e5c88f1..c1af8acd366b 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -368,13 +368,48 @@ END(ptregs_\func) #include <asm/syscalls_64.h> /* + * %rdi: prev task + * %rsi: next task + */ +ENTRY(__switch_to_asm) + /* + * Save callee-saved registers + * This must match the order in inactive_task_frame + */ + pushq %rbp + pushq %rbx + pushq %r12 + pushq %r13 + pushq %r14 + pushq %r15 + + /* switch stack */ + movq %rsp, TASK_threadsp(%rdi) + movq TASK_threadsp(%rsi), %rsp + +#ifdef CONFIG_CC_STACKPROTECTOR + movq TASK_stack_canary(%rsi), %rbx + movq %rbx, PER_CPU_VAR(irq_stack_union)+stack_canary_offset +#endif + + /* restore callee-saved registers */ + popq %r15 + popq %r14 + popq %r13 + popq %r12 + popq %rbx + popq %rbp + + jmp __switch_to +END(__switch_to_asm) + +/* * A newly forked process directly context switches into this address. * - * rdi: prev task we switched from + * rax: prev task we switched from */ ENTRY(ret_from_fork) - LOCK ; btr $TIF_FORK, TI_flags(%r8) - + movq %rax, %rdi call schedule_tail /* rdi: 'prev' task parameter */ testb $3, CS(%rsp) /* from kernel_thread? */ |