This is a note to let you know that I've just added the patch titled MIPS: Negate error syscall return in trace to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mips-negate-error-syscall-return-in-trace.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4f32a39d49b25eaa66d2420f1f03d371ea4cd906 Mon Sep 17 00:00:00 2001 From: James Hogan <james.hogan@xxxxxxxxxx> Date: Thu, 29 Jun 2017 10:12:34 +0100 Subject: MIPS: Negate error syscall return in trace From: James Hogan <james.hogan@xxxxxxxxxx> commit 4f32a39d49b25eaa66d2420f1f03d371ea4cd906 upstream. 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@xxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/16651/ Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -927,7 +927,7 @@ asmlinkage void syscall_trace_leave(stru 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); Patches currently in stable-queue which might be from james.hogan@xxxxxxxxxx are queue-4.4/mips-send-sigill-for-bposge32-in-__compute_return_epc_for_insn.patch queue-4.4/mips-actually-decode-jalx-in-__compute_return_epc_for_insn.patch queue-4.4/mips-fix-mips_atomic_set-retry-condition.patch queue-4.4/mips-fix-a-typo-s-preset-present-in-r2-to-r6-emulation-error-message.patch queue-4.4/mips-fix-mips_atomic_set-with-eva.patch queue-4.4/mips-save-static-registers-before-sysmips.patch queue-4.4/mips-fix-unaligned-pc-interpretation-in-compute_return_epc.patch queue-4.4/mips-fix-mips-i-isa-proc-cpuinfo-reporting.patch queue-4.4/mips-rename-sigill_r6-to-sigill_r2r6-in-__compute_return_epc_for_insn.patch queue-4.4/mips-negate-error-syscall-return-in-trace.patch queue-4.4/mips-send-sigill-for-linked-branches-in-__compute_return_epc_for_insn.patch queue-4.4/mips-math-emu-prevent-wrong-isa-mode-instruction-emulation.patch