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From: Sven Schnelle <svens@stackframe.org>
To: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Subject: Re: [PATCH] parisc/entry: fix trace test in syscall exit path
Date: Fri, 12 Nov 2021 08:18:35 +0100	[thread overview]
Message-ID: <87tughalkk.fsf@x1.stackframe.org> (raw)
In-Reply-To: <20211111220429.797-1-svens@stackframe.org> (Sven Schnelle's message of "Thu, 11 Nov 2021 23:04:29 +0100")

Sven Schnelle <svens@stackframe.org> writes:

> commit 8779e05ba8aa ("parisc: Fix ptrace check on syscall return")
> fixed testing of TI_FLAGS. This uncovered a bug in the test mask.
> syscall_restore_rfi is only used when the kernel needs to exit to
> usespace with single stepping via recovery counter enabled. The test
> however used _TIF_SYSCALL_TRACE_MASK, which includes a lot of bits
> that shouldn't be tested here.
>
> Fix this by using TIF_SINGLESTEP and TIF_BLOCKSTEP directly and
> remove those bits from TIF_SYSCALL_TRACE_MASK.

I think we need to have TIF_SINGLESTEP and TIF_BLOCKSTEP in
TIF_SYSCALL_TRACE_MASK otherwise do_syscall_trace_exit() isn't
called when leaving to userspace. I'll read the code a bit more
during the weekend and prepare a v2.

  parent reply	other threads:[~2021-11-12  8:04 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-11 22:04 [PATCH] parisc/entry: fix trace test in syscall exit path Sven Schnelle
2021-11-11 23:24 ` John David Anglin
2021-11-11 23:39   ` John David Anglin
2021-11-12  7:18 ` Sven Schnelle [this message]
2021-11-13 14:31   ` John David Anglin

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