From: Ingo Molnar <mingo@kernel.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
Nathan Chancellor <nathan@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
David Laight <david.laight.linux@gmail.com>
Subject: Re: [PATCH] objtool: Fix stack overflow in validate_branch()
Date: Tue, 2 Dec 2025 17:20:22 +0100 [thread overview]
Message-ID: <aS8Rxqvdg28C7wNS@gmail.com> (raw)
In-Reply-To: <21bb161c23ca0d8c942a960505c0d327ca2dc7dc.1764691895.git.jpoimboe@kernel.org>
* Josh Poimboeuf <jpoimboe@kernel.org> wrote:
> On an allmodconfig kernel compiled with Clang, objtool is segfaulting in
> drivers/scsi/qla2xxx/qla2xxx.o due to a stack overflow in
> validate_branch().
>
> Due in part to KASAN being enabled, the qla2xxx code has a large number
> of conditional jumps, causing objtool to go quite deep in its recursion.
>
> By far the biggest offender of stack usage is the recently added
> 'prev_state' stack variable in validate_insn(), coming in at 328 bytes.
That's weird - how can a user-space tool run into stack
limits, are they set particularly conservatively?
In any case, applied to tip:objtool/urgent, thanks!
Ingo
next prev parent reply other threads:[~2025-12-02 16:20 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-02 16:16 [PATCH] objtool: Fix stack overflow in validate_branch() Josh Poimboeuf
2025-12-02 16:20 ` Ingo Molnar [this message]
2025-12-02 16:49 ` Josh Poimboeuf
2025-12-02 17:03 ` Ingo Molnar
2025-12-02 17:11 ` Josh Poimboeuf
2025-12-02 19:56 ` Josh Poimboeuf
2025-12-02 20:20 ` Ingo Molnar
2025-12-02 22:05 ` David Laight
2025-12-02 23:01 ` Josh Poimboeuf
2025-12-03 11:02 ` David Laight
2025-12-03 16:11 ` Ingo Molnar
2025-12-03 16:40 ` [tip: objtool/urgent] objtool: Add more robust signal error handling, detect and warn about stack overflows tip-bot2 for Josh Poimboeuf
2025-12-03 18:48 ` tip-bot2 for Josh Poimboeuf
2025-12-03 9:25 ` [PATCH] objtool: Fix stack overflow in validate_branch() Ingo Molnar
2025-12-03 18:54 ` Josh Poimboeuf
2025-12-03 18:58 ` Josh Poimboeuf
2025-12-03 19:15 ` Ingo Molnar
2025-12-03 19:37 ` David Laight
2025-12-03 20:30 ` Linus Torvalds
2025-12-03 23:53 ` Josh Poimboeuf
2025-12-03 19:11 ` Ingo Molnar
2025-12-04 2:47 ` Josh Poimboeuf
2025-12-02 16:27 ` [tip: objtool/urgent] " tip-bot2 for Josh Poimboeuf
2025-12-02 16:28 ` [PATCH] " Josh Poimboeuf
2025-12-02 16:41 ` Ingo Molnar
2025-12-02 16:44 ` [tip: objtool/urgent] " tip-bot2 for Josh Poimboeuf
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