lkml.org 
[lkml]   [2012]   [Oct]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/4] arch/arm: move secure_computing into trace
Date
From: Will Drewry <wad@chromium.org>

There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_TRACE
path in entry-common.S. In order to add support for
CONFIG_HAVE_ARCH_SECCOMP_FILTER without mangling the assembly too badly,
seccomp was moved into the syscall_trace_enter() handler.

Additionally, the return value for secure_computing() is now checked
and a -1 value will result in the system call being skipped.

Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/arm/kernel/entry-common.S | 9 ++-------
arch/arm/kernel/ptrace.c | 3 +++
2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 3471175..c781012 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -418,13 +418,8 @@ local_restart:
stmdb sp!, {r4, r5} @ push fifth and sixth args

#ifdef CONFIG_SECCOMP
- tst r10, #_TIF_SECCOMP
- beq 1f
- mov r0, scno
- bl __secure_computing
- add r0, sp, #S_R0 + S_OFF @ pointer to regs
- ldmia r0, {r0 - r3} @ have to reload r0 - r3
-1:
+ tst r10, #_TIF_SECCOMP @ is seccomp enabled?
+ bne __sys_trace
#endif

tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 739db3a..aa4d93f 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -923,6 +923,9 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno,

current_thread_info()->syscall = scno;

+ if (dir == PTRACE_SYSCALL_ENTER && secure_computing(scno) == -1)
+ return -1;
+
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return scno;

--
1.7.9.5


\
 
 \ /
  Last update: 2012-10-30 03:21    [W:0.042 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site