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authorNathaniel Husted2012-01-03 20:23:09 +0100
committerAl Viro2012-01-17 22:17:01 +0100
commit29ef73b7a823b77a7cd0bdd7d7cded3fb6c2587b (patch)
tree4edfccf0b4d2b24c8e6069113eb69bb8c7a9b037 /arch/arm/kernel
parentaudit: do not call audit_getname on error (diff)
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Kernel: Audit Support For The ARM Platform
This patch provides functionality to audit system call events on the ARM platform. The implementation was based off the structure of the MIPS platform and information in this (http://lists.fedoraproject.org/pipermail/arm/2009-October/000382.html) mailing list thread. The required audit_syscall_exit and audit_syscall_entry checks were added to ptrace using the standard registers for system call values (r0 through r3). A thread information flag was added for auditing (TIF_SYSCALL_AUDIT) and a meta-flag was added (_TIF_SYSCALL_WORK) to simplify modifications to the syscall entry/exit. Now, if either the TRACE flag is set or the AUDIT flag is set, the syscall_trace function will be executed. The prober changes were made to Kconfig to allow CONFIG_AUDITSYSCALL to be enabled. Due to platform availability limitations, this patch was only tested on the Android platform running the modified "android-goldfish-2.6.29" kernel. A test compile was performed using Code Sourcery's cross-compilation toolset and the current linux-3.0 stable kernel. The changes compile without error. I'm hoping, due to the simple modifications, the patch is "obviously correct". Signed-off-by: Nathaniel Husted <nhusted@gmail.com> Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/entry-common.S4
-rw-r--r--arch/arm/kernel/ptrace.c16
2 files changed, 13 insertions, 7 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index b2a27b6b0046..520889cf1b5b 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -87,7 +87,7 @@ ENTRY(ret_from_fork)
get_thread_info tsk
ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
mov why, #1
- tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
+ tst r1, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
beq ret_slow_syscall
mov r1, sp
mov r0, #1 @ trace exit [IP = 1]
@@ -443,7 +443,7 @@ ENTRY(vector_swi)
1:
#endif
- tst r10, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
+ tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
bne __sys_trace
cmp scno, #NR_syscalls @ check upper syscall limit
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 483727ad6892..e1d5e1929fbd 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -906,11 +906,6 @@ asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
{
unsigned long ip;
- if (!test_thread_flag(TIF_SYSCALL_TRACE))
- return scno;
- if (!(current->ptrace & PT_PTRACED))
- return scno;
-
/*
* Save IP. IP is used to denote syscall entry/exit:
* IP = 0 -> entry, = 1 -> exit
@@ -918,6 +913,17 @@ asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
ip = regs->ARM_ip;
regs->ARM_ip = why;
+ if (!ip)
+ audit_syscall_exit(regs);
+ else
+ audit_syscall_entry(AUDIT_ARCH_ARMEB, 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;
/* the 0x80 provides a way for the tracing parent to distinguish