b522deabc6
We could not resize the temporary buffer in NMI context. Let's warn if a message is lost. This is rather theoretical. printk() should not be used in NMI. The only sensible use is when we want to print backtrace from all CPUs. The current buffer should be enough for this purpose. [akpm@linux-foundation.org: whitespace fixlet] Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*
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* internal.h - printk internal definitions
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/percpu.h>
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typedef __printf(1, 0) int (*printk_func_t)(const char *fmt, va_list args);
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int __printf(1, 0) vprintk_default(const char *fmt, va_list args);
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#ifdef CONFIG_PRINTK_NMI
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/*
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* printk() could not take logbuf_lock in NMI context. Instead,
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* it temporary stores the strings into a per-CPU buffer.
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* The alternative implementation is chosen transparently
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* via per-CPU variable.
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*/
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DECLARE_PER_CPU(printk_func_t, printk_func);
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static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
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{
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return this_cpu_read(printk_func)(fmt, args);
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}
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extern atomic_t nmi_message_lost;
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static inline int get_nmi_message_lost(void)
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{
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return atomic_xchg(&nmi_message_lost, 0);
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}
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#else /* CONFIG_PRINTK_NMI */
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static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
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{
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return vprintk_default(fmt, args);
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}
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static inline int get_nmi_message_lost(void)
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{
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return 0;
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}
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#endif /* CONFIG_PRINTK_NMI */
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