[PATCH v2 1/1] arm64: make a single hook to syscall_trace() for all syscall features
Currently syscall_trace() is called only for ptrace.
With additional TIF_xx flags defined, it is now called in all the cases
of audit, ftrace and seccomp in addition to ptrace.
Signed-off-by: AKASHI Takahiro <takahiro.akashi(a)linaro.org>
Acked-by: Richard Guy Briggs <rgb(a)redhat.com>
---
arch/arm64/include/asm/thread_info.h | 13 ++++++++++
arch/arm64/kernel/entry.S | 5 ++--
arch/arm64/kernel/ptrace.c | 45 +++++++++++++++++-----------------
3 files changed, 38 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 720e70b..0a8b2a9 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -91,6 +91,9 @@ static inline struct thread_info *current_thread_info(void)
/*
* thread information flags:
* TIF_SYSCALL_TRACE - syscall trace active
+ * TIF_SYSCALL_TRACEPOINT - syscall tracepoint for ftrace
+ * TIF_SYSCALL_AUDIT - syscall auditing
+ * TIF_SECOMP - syscall secure computing
* TIF_SIGPENDING - signal pending
* TIF_NEED_RESCHED - rescheduling necessary
* TIF_NOTIFY_RESUME - callback before returning to user
@@ -101,6 +104,9 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NEED_RESCHED 1
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_SYSCALL_TRACE 8
+#define TIF_SYSCALL_AUDIT 9
+#define TIF_SYSCALL_TRACEPOINT 10
+#define TIF_SECCOMP 11
#define TIF_POLLING_NRFLAG 16
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_FREEZE 19
@@ -112,10 +118,17 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
+#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
+#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_32BIT (1 << TIF_32BIT)
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
_TIF_NOTIFY_RESUME)
+#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
+ _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
+
#endif /* __KERNEL__ */
#endif /* __ASM_THREAD_INFO_H */
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 0d7b789..6d613cd 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -630,8 +630,9 @@ el0_svc_naked: // compat entry point
enable_irq
get_thread_info tsk
- ldr x16, [tsk, #TI_FLAGS] // check for syscall tracing
- tbnz x16, #TIF_SYSCALL_TRACE, __sys_trace // are we tracing syscalls?
+ ldr x16, [tsk, #TI_FLAGS] // check for syscall hooks
+ tst x16, #_TIF_SYSCALL_WORK
+ b.ne __sys_trace
adr lr, ret_fast_syscall // return address
cmp scno, sc_nr // check upper syscall limit
b.hs ni_sys
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 6a8928b..c70133e 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1062,31 +1062,30 @@ asmlinkage int syscall_trace(int dir, struct pt_regs *regs)
{
unsigned long saved_reg;
- if (!test_thread_flag(TIF_SYSCALL_TRACE))
- return regs->syscallno;
-
- if (is_compat_task()) {
- /* AArch32 uses ip (r12) for scratch */
- saved_reg = regs->regs[12];
- regs->regs[12] = dir;
- } else {
- /*
- * Save X7. X7 is used to denote syscall entry/exit:
- * X7 = 0 -> entry, = 1 -> exit
- */
- saved_reg = regs->regs[7];
- regs->regs[7] = dir;
- }
+ if (test_thread_flag(TIF_SYSCALL_TRACE)) {
+ if (is_compat_task()) {
+ /* AArch32 uses ip (r12) for scratch */
+ saved_reg = regs->regs[12];
+ regs->regs[12] = dir;
+ } else {
+ /*
+ * Save X7. X7 is used to denote syscall entry/exit:
+ * X7 = 0 -> entry, = 1 -> exit
+ */
+ saved_reg = regs->regs[7];
+ regs->regs[7] = dir;
+ }
- if (dir)
- tracehook_report_syscall_exit(regs, 0);
- else if (tracehook_report_syscall_entry(regs))
- regs->syscallno = ~0UL;
+ if (dir)
+ tracehook_report_syscall_exit(regs, 0);
+ else if (tracehook_report_syscall_entry(regs))
+ regs->syscallno = ~0UL;
- if (is_compat_task())
- regs->regs[12] = saved_reg;
- else
- regs->regs[7] = saved_reg;
+ if (is_compat_task())
+ regs->regs[12] = saved_reg;
+ else
+ regs->regs[7] = saved_reg;
+ }
return regs->syscallno;
}
--
1.7.9.5