From 339b8675128d1623ce0c844a176194edce7e7d24 Mon Sep 17 00:00:00 2001
From: Will Drewry <wad@chromium.org>
Date: Mon, 16 Apr 2012 16:37:17 -0500
Subject: [PATCH] CHROMIUM: arch/arm: move secure_computing into trace; respect
return code
There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_TRACE
patsh 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() handler.
Additionally, the return value for secure_computing() is now checked
and a -1 value will result in the system call being skipped.
(Reworked for 3.4 merge to just piggyback on the audit enter path.)
Signed-off-by: Will Drewry <wad@chromium.org>
BUG=chromium-os:27878
TEST=compiles for arm. Need to test on a live machine.
Change-Id: I9493f28c30356a10eccb320e0a2d1a141388af9a
Reviewed-on: https://gerrit.chromium.org/gerrit/21376
Reviewed-by: Will Drewry <wad@chromium.org>
Tested-by: Will Drewry <wad@chromium.org>
Signed-off-by: Sasha Levitskiy <sanek@google.com>
---
arch/arm/kernel/entry-common.S | 7 +------
arch/arm/kernel/ptrace.c | 13 +++++++++++--
2 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 54ee265dd819..e46333113252 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -444,12 +444,7 @@ ENTRY(vector_swi)
#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:
+ 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 9650c143afc1..75902f8fa1a7 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -909,19 +909,28 @@ long arch_ptrace(struct task_struct *child, long request,
asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
{
unsigned long ip;
+ current_thread_info()->syscall = scno;
if (why)
audit_syscall_exit(regs);
- else
+ else {
+ if (secure_computing(scno) == -1)
+ return -1;
audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0,
regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
+ }
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return scno;
if (!(current->ptrace & PT_PTRACED))
return scno;
- current_thread_info()->syscall = scno;
+ /*
+ * IP is used to denote syscall entry/exit:
+ * IP = 0 -> entry, =1 -> exit
+ */
+ ip = regs->ARM_ip;
+ regs->ARM_ip = why;
/*
* IP is used to denote syscall entry/exit:
--
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