[tip:x86/asm] x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too

From: tip-bot for Denys Vlasenko
Date: Thu Apr 09 2015 - 05:03:19 EST


Commit-ID: 0f90fb979d7b53d80a6d5cb6e127b4b4b249907e
Gitweb: http://git.kernel.org/tip/0f90fb979d7b53d80a6d5cb6e127b4b4b249907e
Author: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
AuthorDate: Tue, 7 Apr 2015 22:43:39 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 9 Apr 2015 10:31:24 +0200

x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too

The change which affected how execve clears EXTRA_REGS missed
32-bit execve syscalls.

Fix this by using 64-bit execve stub epilogue for them too.

Run-tested.

Signed-off-by: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Drewry <wad@xxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1428439424-7258-3-git-send-email-dvlasenk@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/ia32/ia32entry.S | 2 --
arch/x86/kernel/entry_64.S | 15 +++++++++++++++
2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 5d8f987..a821b1c 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -571,8 +571,6 @@ GLOBAL(\label)

PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
PTREGSCALL stub32_sigreturn, sys32_sigreturn
- PTREGSCALL stub32_execve, compat_sys_execve
- PTREGSCALL stub32_execveat, compat_sys_execveat
PTREGSCALL stub32_fork, sys_fork
PTREGSCALL stub32_vfork, sys_vfork

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index f7d9ba6..5380b3a 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -538,6 +538,21 @@ ENTRY(stub_x32_execveat)
END(stub_x32_execveat)
#endif

+#ifdef CONFIG_IA32_EMULATION
+ENTRY(stub32_execve)
+ CFI_STARTPROC
+ call compat_sys_execve
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub32_execve)
+ENTRY(stub32_execveat)
+ CFI_STARTPROC
+ call compat_sys_execveat
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub32_execveat)
+#endif
+
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
--
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