From: Petr Mladek <pmladek@suse.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Russell King <rmk+kernel@arm.linux.org.uk>,
Daniel Thompson <daniel.thompson@linaro.org>,
Jiri Kosina <jkosina@suse.com>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, x86@kernel.org,
linux-arm-kernel@lists.infradead.org,
adi-buildroot-devel@lists.sourceforge.net,
linux-cris-kernel@axis.com, linux-mips@linux-mips.org,
linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
linux-sh@vger.kernel.org, sparclinux@vger.kernel.org,
Petr Mladek <pmladek@suse.com>
Subject: [PATCH v2 5/5] printk/nmi: Increase the size of the temporary buffer
Date: Fri, 27 Nov 2015 12:09:32 +0100 [thread overview]
Message-ID: <1448622572-16900-6-git-send-email-pmladek@suse.com> (raw)
In-Reply-To: <1448622572-16900-1-git-send-email-pmladek@suse.com>
Testing has shown that the backtrace sometimes does not fit
into the 4kB temporary buffer that is used in NMI context.
The warnings are gone when I double the temporary buffer size.
Note that this problem existed even in the x86-specific
implementation that was added by the commit a9edc8809328
("x86/nmi: Perform a safe NMI stack trace on all CPUs").
Nobody noticed it because it did not print any warnings.
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
kernel/printk/nmi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/printk/nmi.c b/kernel/printk/nmi.c
index 8af1e4016719..6111644d5f01 100644
--- a/kernel/printk/nmi.c
+++ b/kernel/printk/nmi.c
@@ -42,7 +42,7 @@ atomic_t nmi_message_lost;
struct nmi_seq_buf {
atomic_t len; /* length of written data */
struct irq_work work; /* IRQ work that flushes the buffer */
- unsigned char buffer[PAGE_SIZE - sizeof(atomic_t) -
+ unsigned char buffer[2 * PAGE_SIZE - sizeof(atomic_t) -
sizeof(struct irq_work)];
};
static DEFINE_PER_CPU(struct nmi_seq_buf, nmi_print_seq);
--
1.8.5.6
next prev parent reply other threads:[~2015-11-27 11:10 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-27 11:09 [PATCH v2 0/5] Cleaning printk stuff in NMI context Petr Mladek
2015-11-27 11:09 ` [PATCH v2 1/5] printk/nmi: Generic solution for safe printk in NMI Petr Mladek
2015-11-27 11:49 ` kbuild test robot
2015-11-27 15:38 ` Petr Mladek
2015-12-01 23:24 ` Jiri Kosina
2015-12-04 16:57 ` Petr Mladek
2016-03-17 19:35 ` Andrew Morton
2016-03-18 10:03 ` Petr Mladek
2015-11-27 12:02 ` kbuild test robot
2015-11-27 14:26 ` Max Filippov
2015-11-30 14:25 ` Petr Mladek
2015-12-02 2:45 ` Michael Ellerman
2015-12-04 15:29 ` Petr Mladek
2015-11-27 11:09 ` [PATCH v2 2/5] printk/nmi: Use IRQ work only when ready Petr Mladek
2015-11-27 11:09 ` [PATCH v2 3/5] printk/nmi: Try hard to print Oops message in NMI context Petr Mladek
2015-12-01 23:44 ` Russell King - ARM Linux
2015-12-04 15:27 ` Petr Mladek
2015-12-04 17:12 ` Russell King - ARM Linux
2015-12-07 15:48 ` David Laight
2015-12-08 14:49 ` Petr Mladek
2015-12-08 11:21 ` Petr Mladek
2015-11-27 11:09 ` [PATCH v2 4/5] printk/nmi: Warn when some message has been lost " Petr Mladek
2015-11-27 11:09 ` Petr Mladek [this message]
2015-11-30 16:42 ` [PATCH v2 5/5] printk/nmi: Increase the size of the temporary buffer yalin wang
2015-12-02 16:20 ` David Laight
2015-12-04 15:47 ` Petr Mladek
2015-12-07 14:16 ` Petr Mladek
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