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>
49 lines
1 KiB
C
49 lines
1 KiB
C
#ifndef __PSTORE_INTERNAL_H__
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#define __PSTORE_INTERNAL_H__
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#include <linux/pstore.h>
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#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
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#define PSTORE_CPU_IN_IP 0x1
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#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
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#define PSTORE_CPU_IN_IP 0x3
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#endif
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struct pstore_ftrace_record {
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unsigned long ip;
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unsigned long parent_ip;
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#ifndef PSTORE_CPU_IN_IP
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unsigned int cpu;
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#endif
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};
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static inline void
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pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
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{
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#ifndef PSTORE_CPU_IN_IP
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rec->cpu = cpu;
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#else
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rec->ip |= cpu;
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#endif
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}
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static inline unsigned int
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pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
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{
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#ifndef PSTORE_CPU_IN_IP
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return rec->cpu;
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#else
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return rec->ip & PSTORE_CPU_IN_IP;
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#endif
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}
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extern struct pstore_info *psinfo;
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extern void pstore_set_kmsg_bytes(int);
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extern void pstore_get_records(int);
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extern int pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
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char *data, size_t size,
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struct timespec time, struct pstore_info *psi);
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extern int pstore_is_mounted(void);
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#endif
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