![Anton Vorontsov](/assets/img/avatar_default.png)
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>
50 lines
1.5 KiB
Plaintext
50 lines
1.5 KiB
Plaintext
config PSTORE
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bool "Persistent store support"
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default n
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help
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This option enables generic access to platform level
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persistent storage via "pstore" filesystem that can
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be mounted as /dev/pstore. Only useful if you have
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a platform level driver that registers with pstore to
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provide the data, so you probably should just go say "Y"
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(or "M") to a platform specific persistent store driver
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(e.g. ACPI_APEI on X86) which will select this for you.
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If you don't have a platform persistent store driver,
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say N.
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config PSTORE_CONSOLE
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bool "Log kernel console messages"
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depends on PSTORE
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help
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When the option is enabled, pstore will log all kernel
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messages, even if no oops or panic happened.
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config PSTORE_FTRACE
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bool "Persistent function tracer"
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depends on PSTORE
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depends on FUNCTION_TRACER
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help
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With this option kernel traces function calls into a persistent
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ram buffer that can be decoded and dumped after reboot through
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pstore filesystem. It can be used to determine what function
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was last called before a reset or panic.
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If unsure, say N.
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config PSTORE_RAM
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tristate "Log panic/oops to a RAM buffer"
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depends on PSTORE
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depends on HAS_IOMEM
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depends on HAVE_MEMBLOCK
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select REED_SOLOMON
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select REED_SOLOMON_ENC8
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select REED_SOLOMON_DEC8
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help
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This enables panic and oops messages to be logged to a circular
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buffer in RAM where it can be read back at some later point.
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Note that for historical reasons, the module will be named
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"ramoops.ko".
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For more information, see Documentation/ramoops.txt.
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