diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-09-10 16:44:54 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-09-30 22:53:31 -0400 |
| commit | 7076aada1040de4ed79a5977dbabdb5e5ea5e249 (patch) | |
| tree | dfcf480d21cd714a1cc42f38417c427d06526f5a /arch/x86/kernel/entry_64.S | |
| parent | 44f4b56b54d2ab5d06c1726f2cde8ca15c8fac47 (diff) | |
x86: split ret_from_fork
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 27 |
1 files changed, 11 insertions, 16 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 69babd8c834f..5526d17db676 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -450,7 +450,7 @@ ENTRY(ret_from_fork) RESTORE_REST testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? - jz retint_restore_args + jz 1f testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET jnz int_ret_from_sys_call @@ -458,6 +458,16 @@ ENTRY(ret_from_fork) RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET jmp ret_from_sys_call # go to the SYSRET fastpath +1: + subq $REST_SKIP, %rsp # move the stack pointer back + CFI_ADJUST_CFA_OFFSET REST_SKIP + movq %rbp, %rdi + call *%rbx + # exit + mov %eax, %edi + call do_exit + ud2 # padding for call trace + CFI_ENDPROC END(ret_from_fork) @@ -1206,21 +1216,6 @@ bad_gs: jmp 2b .previous -ENTRY(kernel_thread_helper) - pushq $0 # fake return address - CFI_STARTPROC - /* - * Here we are in the child and the registers are set as they were - * at kernel_thread() invocation in the parent. - */ - call *%rsi - # exit - mov %eax, %edi - call do_exit - ud2 # padding for call trace - CFI_ENDPROC -END(kernel_thread_helper) - /* * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. * |