diff options
| author | Ingo Molnar <mingo@kernel.org> | 2017-01-28 09:30:11 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-01-28 09:30:11 +0100 |
| commit | 9a1f4150fe932fb892c05084029b3718b8ed1baf (patch) | |
| tree | b8f18ea5f0bdc842e3cf8da4700c1d577a3b1c66 /arch/x86/entry/entry_32.S | |
| parent | f28442497b5caf7bf573ade22a7f8d3559e3ef56 (diff) | |
| parent | 1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff) | |
| download | linux-9a1f4150fe932fb892c05084029b3718b8ed1baf.tar.bz2 | |
Merge branch 'linus' into x86/boot, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry/entry_32.S')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 30 |
1 files changed, 11 insertions, 19 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 701d29f8e4d3..57f7ec35216e 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -255,23 +255,6 @@ ENTRY(__switch_to_asm) END(__switch_to_asm) /* - * The unwinder expects the last frame on the stack to always be at the same - * offset from the end of the page, which allows it to validate the stack. - * Calling schedule_tail() directly would break that convention because its an - * asmlinkage function so its argument has to be pushed on the stack. This - * wrapper creates a proper "end of stack" frame header before the call. - */ -ENTRY(schedule_tail_wrapper) - FRAME_BEGIN - - pushl %eax - call schedule_tail - popl %eax - - FRAME_END - ret -ENDPROC(schedule_tail_wrapper) -/* * A newly forked process directly context switches into this address. * * eax: prev task we switched from @@ -279,15 +262,24 @@ ENDPROC(schedule_tail_wrapper) * edi: kernel thread arg */ ENTRY(ret_from_fork) - call schedule_tail_wrapper + FRAME_BEGIN /* help unwinder find end of stack */ + + /* + * schedule_tail() is asmlinkage so we have to put its 'prev' argument + * on the stack. + */ + pushl %eax + call schedule_tail + popl %eax testl %ebx, %ebx jnz 1f /* kernel threads are uncommon */ 2: /* When we fork, we trace the syscall return in the child, too. */ - movl %esp, %eax + leal FRAME_OFFSET(%esp), %eax call syscall_return_slowpath + FRAME_END jmp restore_all /* kernel thread */ |