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| author | James Hogan <james.hogan@imgtec.com> | 2017-06-29 10:12:34 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2017-07-11 14:13:06 +0200 |
| commit | 4f32a39d49b25eaa66d2420f1f03d371ea4cd906 (patch) | |
| tree | b820010fc55710af5db78a1dcc486806a1fa1ef0 /arch | |
| parent | 54eca7eccc5e149825f831859123b692a565bca9 (diff) | |
| download | linux-0-day-4f32a39d49b25eaa66d2420f1f03d371ea4cd906.tar.gz linux-0-day-4f32a39d49b25eaa66d2420f1f03d371ea4cd906.tar.xz | |
MIPS: Negate error syscall return in trace
The sys_exit trace event takes a single return value for the system
call, which MIPS passes the value of the $v0 (result) register, however
MIPS returns positive error codes in $v0 with $a3 specifying that $v0
contains an error code. As a result erroring system calls are traced
returning positive error numbers that can't always be distinguished from
success.
Use regs_return_value() to negate the error code if $a3 is set.
Fixes: 1d7bf993e073 ("MIPS: ftrace: Add support for syscall tracepoints.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.13+
Patchwork: https://patchwork.linux-mips.org/patch/16651/
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/kernel/ptrace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index ba3b1f771256f..8e2ea86dc23e8 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -913,7 +913,7 @@ asmlinkage void syscall_trace_leave(struct pt_regs *regs) audit_syscall_exit(regs); if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) - trace_sys_exit(regs, regs->regs[2]); + trace_sys_exit(regs, regs_return_value(regs)); if (test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall_exit(regs, 0); |