From: Michael Ellerman <mpe@ellerman.id.au>
To: Christophe Leroy <christophe.leroy@csgroup.eu>,
Benjamin Gray <bgray@linux.ibm.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH 0/7] Rework perf and ptrace watchpoint tracking
Date: Wed, 02 Aug 2023 22:00:47 +1000 [thread overview]
Message-ID: <874jlh1wnk.fsf@mail.lhotse> (raw)
In-Reply-To: <4a0d1740-bf19-0a96-1668-23d6188657cb@csgroup.eu>
Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 01/08/2023 à 03:17, Benjamin Gray a écrit :
>> Syzkaller triggered a null pointer dereference in the
>> arch_unregister_hw_breakpoint() hook. This is due to accessing
>> the bp->ctx->task field changing to -1 while we iterate the breakpoints.
>>
>> This series refactors the breakpoint tracking logic to remove the
>> dependency on bp->ctx entirely. It also simplifies handling of ptrace and
>> perf breakpoints, making insertion less restrictive.
>
> Is there any link between this series and the following issue:
> https://github.com/linuxppc/issues/issues/38
AFAIK no, Ben started looking at the breakpoint code due to a syzkaller
report of an oops.
But this series would resolve that issue AFAICS, so I guess they are
linked in that sense.
cheers
next prev parent reply other threads:[~2023-08-02 12:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-01 1:17 [PATCH 0/7] Rework perf and ptrace watchpoint tracking Benjamin Gray
2023-08-01 1:17 ` [PATCH 1/7] powerpc/watchpoints: Explain thread_change_pc() more Benjamin Gray
2023-08-01 1:17 ` [PATCH 2/7] powerpc/watchpoints: Don't track info persistently Benjamin Gray
2023-08-01 1:17 ` [PATCH 3/7] powerpc/watchpoints: Track perf single step directly on the breakpoint Benjamin Gray
2023-08-01 1:17 ` [PATCH 4/7] powerpc/watchpoints: Simplify watchpoint reinsertion Benjamin Gray
2023-08-01 1:17 ` [PATCH 5/7] powerpc/watchpoints: Remove ptrace/perf exclusion tracking Benjamin Gray
2023-08-01 1:17 ` [PATCH 6/7] selftests/powerpc/ptrace: Update ptrace-perf watchpoint selftest Benjamin Gray
2023-08-01 1:17 ` [PATCH 7/7] perf/hw_breakpoint: Remove arch breakpoint hooks Benjamin Gray
2023-08-01 9:50 ` [PATCH 0/7] Rework perf and ptrace watchpoint tracking Christophe Leroy
2023-08-02 12:00 ` Michael Ellerman [this message]
2023-08-23 11:55 ` Michael Ellerman
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