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| author | Timothy E Baldwin <T.E.Baldwin99@members.leeds.ac.uk> | 2018-10-08 19:26:48 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2018-10-10 13:53:12 +0100 |
| commit | f18aef742c8fbd68e280dff0a63ba0ca6ee8ad85 (patch) | |
| tree | 9946ae6b6af6895339aaa19ddcf0347bdff7d962 /arch/arm | |
| parent | 8403bcb779a0be4080510c59b1a582e6ab7a748c (diff) | |
| download | linux-f18aef742c8fbd68e280dff0a63ba0ca6ee8ad85.tar.bz2 | |
ARM: 8802/1: Call syscall_trace_exit even when system call skipped
On at least x86 and ARM64, and as documented in the ptrace man page
a skipped system call will still cause a syscall exit ptrace stop.
Previous to this commit 32-bit ARM did not, resulting in strace
being confused when seccomp skips system calls.
This change also impacts programs that use ptrace to skip system calls.
Fixes: ad75b51459ae ("ARM: 7579/1: arch/allow a scno of -1 to not cause a SIGILL")
Signed-off-by: Timothy E Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Signed-off-by: Eugene Syromyatnikov <evgsyr@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Eugene Syromyatnikov <evgsyr@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 746565a876dc..0465d65d23de 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -296,16 +296,15 @@ __sys_trace: cmp scno, #-1 @ skip the syscall? bne 2b add sp, sp, #S_OFF @ restore stack - b ret_slow_syscall -__sys_trace_return: - str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 +__sys_trace_return_nosave: + enable_irq_notrace mov r0, sp bl syscall_trace_exit b ret_slow_syscall -__sys_trace_return_nosave: - enable_irq_notrace +__sys_trace_return: + str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 mov r0, sp bl syscall_trace_exit b ret_slow_syscall |