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| author | Paul Burton <paul.burton@mips.com> | 2018-06-14 19:20:54 +0200 |
|---|---|---|
| committer | Paul Burton <paul.burton@mips.com> | 2018-06-20 06:13:56 +0200 |
| commit | 9bcf53598dfe1bd8caaf8e03738d3cc51d45904e (patch) | |
| tree | ee25419bb284148763c5a9cd2ae30424d006ca44 | |
| parent | MIPS: Add support for restartable sequences (diff) | |
| download | linux-9bcf53598dfe1bd8caaf8e03738d3cc51d45904e.tar.xz linux-9bcf53598dfe1bd8caaf8e03738d3cc51d45904e.zip | |
MIPS: Add syscall detection for restartable sequences
Syscalls are not allowed inside restartable sequences, so add a call to
rseq_syscall() at the very beginning of the system call exit path when
CONFIG_DEBUG_RSEQ=y. This will help us to detect whether there is a
syscall issued erroneously inside a restartable sequence.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: James Hogan <jhogan@kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/19522/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
| -rw-r--r-- | arch/mips/kernel/entry.S | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S index 38a302919e6b..d7de8adcfcc8 100644 --- a/arch/mips/kernel/entry.S +++ b/arch/mips/kernel/entry.S @@ -79,6 +79,10 @@ FEXPORT(ret_from_fork) jal schedule_tail # a0 = struct task_struct *prev FEXPORT(syscall_exit) +#ifdef CONFIG_DEBUG_RSEQ + move a0, sp + jal rseq_syscall +#endif local_irq_disable # make sure need_resched and # signals dont change between # sampling and return @@ -141,6 +145,10 @@ work_notifysig: # deal with pending signals and j resume_userspace_check FEXPORT(syscall_exit_partial) +#ifdef CONFIG_DEBUG_RSEQ + move a0, sp + jal rseq_syscall +#endif local_irq_disable # make sure need_resched doesn't # change between and return LONG_L a2, TI_FLAGS($28) # current->work |