lkml.org 
[lkml]   [2018]   [Jun]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH for 4.18 09/16] powerpc: Add syscall detection for restartable sequences
----- On Jun 5, 2018, at 1:21 AM, Michael Ellerman mpe@ellerman.id.au wrote:

> Mathieu Desnoyers <mathieu.desnoyers@efficios.com> writes:
>> From: Boqun Feng <boqun.feng@gmail.com>
>>
>> Syscalls are not allowed inside restartable sequences, so add a call to
>> rseq_syscall() at the very beginning of system call exiting path for
>> CONFIG_DEBUG_RSEQ=y kernel. This could help us to detect whether there
>> is a syscall issued inside restartable sequences.
>>
>> [ Tested on 64-bit powerpc kernel by Mathieu Desnoyers. Still needs to
>> be tested on 32-bit powerpc kernel. ]
>>
>> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
>> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
>> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> CC: Paul Mackerras <paulus@samba.org>
>> CC: Michael Ellerman <mpe@ellerman.id.au>
>> CC: Peter Zijlstra <peterz@infradead.org>
>> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
>> CC: linuxppc-dev@lists.ozlabs.org
>> ---
>> arch/powerpc/kernel/entry_32.S | 7 +++++++
>> arch/powerpc/kernel/entry_64.S | 8 ++++++++
>> 2 files changed, 15 insertions(+)
>
> I don't _love_ the #ifdefs in here, but they look correct and there's
> not really a better option until we rewrite the syscall handler in C.
>
> The rseq selftests passed for me with this applied and enabled. So if
> you like here's some tags:
>
> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
>

Adding you ack to the series.

Thanks!

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

\
 
 \ /
  Last update: 2018-06-05 14:51    [W:0.149 / U:0.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site