diff options
Diffstat (limited to 'arch/x86/entry/entry_32.S')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 37 |
1 files changed, 37 insertions, 0 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 |