060287b8c4
With this support kernel can save function call chain log into a persistent ram buffer that can be decoded and dumped after reboot through pstore filesystem. It can be used to determine what function was last called before a reset or panic. We store the log in a binary format and then decode it at read time. p.s. Mostly the code comes from trace_persistent.c driver found in the Android git tree, written by Colin Cross <ccross@android.com> (according to sign-off history). I reworked the driver a little bit, and ported it to pstore. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
36 lines
1 KiB
C
36 lines
1 KiB
C
/*
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* Copyright 2012 Google, Inc.
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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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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#include <linux/kernel.h>
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#include <linux/compiler.h>
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#include <linux/irqflags.h>
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#include <linux/percpu.h>
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#include <linux/smp.h>
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#include <linux/atomic.h>
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#include <asm/barrier.h>
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#include "internal.h"
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void notrace pstore_ftrace_call(unsigned long ip, unsigned long parent_ip)
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{
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struct pstore_ftrace_record rec = {};
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if (unlikely(oops_in_progress))
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return;
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rec.ip = ip;
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rec.parent_ip = parent_ip;
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pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id());
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psinfo->write_buf(PSTORE_TYPE_FTRACE, 0, NULL, 0, (void *)&rec,
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sizeof(rec), psinfo);
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}
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