Various flavors of stub_{sigreturn,execve}, six functions in total,
repeat
movq %rax,RAX(%rsp)
RESTORE_EXTRA_REGS
jmp int_ret_from_sys_call
sequence. RESTORE_EXTRA_REGS is six 5-byte insns.
Reuse this code.
Signed-off-by: Denys Vlasenko <dvlas...@redhat.com>
CC: Linus Torvalds <torva...@linux-foundation.org>
CC: Steven Rostedt <rost...@goodmis.org>
CC: Ingo Molnar <mi...@kernel.org>
CC: Borislav Petkov <b...@alien8.de>
CC: "H. Peter Anvin" <h...@zytor.com>
CC: Andy Lutomirski <l...@amacapital.net>
CC: Oleg Nesterov <o...@redhat.com>
CC: Frederic Weisbecker <fweis...@gmail.com>
CC: Alexei Starovoitov <a...@plumgrid.com>
CC: Will Drewry <w...@chromium.org>
CC: Kees Cook <keesc...@chromium.org>
CC: x...@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 21 ++++++---------------
1 file changed, 6 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 13185c5..765436c 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -423,6 +423,7 @@ ENTRY(stub_execve)
DEFAULT_FRAME 0
SAVE_EXTRA_REGS
call sys_execve
+return_from_stub:
movq %rax,RAX(%rsp)
RESTORE_EXTRA_REGS
jmp int_ret_from_sys_call
@@ -435,9 +436,7 @@ ENTRY(stub_execveat)
DEFAULT_FRAME 0
SAVE_EXTRA_REGS
call sys_execveat
- movq %rax,RAX(%rsp)
- RESTORE_EXTRA_REGS
- jmp int_ret_from_sys_call
+ jmp return_from_stub
CFI_ENDPROC
END(stub_execveat)
@@ -451,9 +450,7 @@ ENTRY(stub_rt_sigreturn)
DEFAULT_FRAME 0
SAVE_EXTRA_REGS
call sys_rt_sigreturn
- movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
- RESTORE_EXTRA_REGS
- jmp int_ret_from_sys_call
+ jmp return_from_stub
CFI_ENDPROC
END(stub_rt_sigreturn)
@@ -464,9 +461,7 @@ ENTRY(stub_x32_rt_sigreturn)
DEFAULT_FRAME 0
SAVE_EXTRA_REGS
call sys32_x32_rt_sigreturn
- movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
- RESTORE_EXTRA_REGS
- jmp int_ret_from_sys_call
+ jmp return_from_stub
CFI_ENDPROC
END(stub_x32_rt_sigreturn)
@@ -476,9 +471,7 @@ ENTRY(stub_x32_execve)
DEFAULT_FRAME 0
SAVE_EXTRA_REGS
call compat_sys_execve
- movq %rax,RAX(%rsp)
- RESTORE_EXTRA_REGS
- jmp int_ret_from_sys_call
+ jmp return_from_stub
CFI_ENDPROC
END(stub_x32_execve)
@@ -488,9 +481,7 @@ ENTRY(stub_x32_execveat)
DEFAULT_FRAME 0
SAVE_EXTRA_REGS
call compat_sys_execveat
- movq %rax,RAX(%rsp)
- RESTORE_EXTRA_REGS
- jmp int_ret_from_sys_call
+ jmp return_from_stub
CFI_ENDPROC
END(stub_x32_execveat)
--
1.8.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
