From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A83193229 for ; Mon, 30 Jan 2023 14:23:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8CE1C433D2; Mon, 30 Jan 2023 14:23:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675088628; bh=Ti0svx79X+fRJvH3mDjnQrKehohEvLPWJWqJATTDRu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IUm6GEKi/40HRNUzPIdRHoHphb1C9Z8jcoK1uIrehV0S1VkrxYlesPkt3hFyQqQ/Y PfpmYJ/DR9Yg0P/AVeOpeUeMkCz+vy0QexO54Yy4vGFYLxyRI7VWrF6QXWqisnfdRT pJKQFtx3aH01zcNWirIuVIo9lV4jiSft0pvHXMeA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tiezhu Yang , Marco Elver , Andrey Ryabinin , Baoquan He , Jonathan Corbet , Xuefeng Li , Andrew Morton , Linus Torvalds , Eric Biggers , Sasha Levin Subject: [PATCH 5.10 081/143] panic: unset panic_on_warn inside panic() Date: Mon, 30 Jan 2023 14:52:18 +0100 Message-Id: <20230130134310.234331447@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230130134306.862721518@linuxfoundation.org> References: <20230130134306.862721518@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tiezhu Yang commit 1a2383e8b84c0451fd9b1eec3b9aab16f30b597c upstream. In the current code, the following three places need to unset panic_on_warn before calling panic() to avoid recursive panics: kernel/kcsan/report.c: print_report() kernel/sched/core.c: __schedule_bug() mm/kfence/report.c: kfence_report_error() In order to avoid copy-pasting "panic_on_warn = 0" all over the places, it is better to move it inside panic() and then remove it from the other places. Link: https://lkml.kernel.org/r/1644324666-15947-4-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang Reviewed-by: Marco Elver Cc: Andrey Ryabinin Cc: Baoquan He Cc: Jonathan Corbet Cc: Xuefeng Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Eric Biggers Signed-off-by: Sasha Levin --- kernel/panic.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/kernel/panic.c b/kernel/panic.c index f567195d45d9..960c2be2759c 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -207,6 +207,16 @@ void panic(const char *fmt, ...) int old_cpu, this_cpu; bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; + if (panic_on_warn) { + /* + * This thread may hit another WARN() in the panic path. + * Resetting this prevents additional WARN() from panicking the + * system on this thread. Other threads are blocked by the + * panic_mutex in panic(). + */ + panic_on_warn = 0; + } + /* * Disable local interrupts. This will prevent panic_smp_self_stop * from deadlocking the first cpu that invokes the panic, since @@ -618,16 +628,8 @@ void __warn(const char *file, int line, void *caller, unsigned taint, if (regs) show_regs(regs); - if (panic_on_warn) { - /* - * This thread may hit another WARN() in the panic path. - * Resetting this prevents additional WARN() from panicking the - * system on this thread. Other threads are blocked by the - * panic_mutex in panic(). - */ - panic_on_warn = 0; + if (panic_on_warn) panic("panic_on_warn set ...\n"); - } if (!regs) dump_stack(); -- 2.39.0