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| author | Timothy E Baldwin <T.E.Baldwin99@members.leeds.ac.uk> | 2018-10-08 19:26:48 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-25 09:53:49 +0100 |
| commit | 522442b30b124df2056004766872a99636d7745b (patch) | |
| tree | 114199dd0c782e2f32c4f992bf8ea5de6bde14eb | |
| parent | 2aa7816390d83f72d0e8e7c79b55bb653254bee6 (diff) | |
| download | linux-stable-522442b30b124df2056004766872a99636d7745b.tar.gz linux-stable-522442b30b124df2056004766872a99636d7745b.tar.bz2 linux-stable-522442b30b124df2056004766872a99636d7745b.zip | |
ARM: 8802/1: Call syscall_trace_exit even when system call skipped
[ Upstream commit f18aef742c8fbd68e280dff0a63ba0ca6ee8ad85 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 d69adfb3d79e..178a2a960659 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -263,16 +263,15 @@ __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 |