Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [RFC PATCH for 4.18 09/16] powerpc: Add syscall detection for restartable sequences | Date | Tue, 05 Jun 2018 15:21:28 +1000 |
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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>
cheers
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