pstore: Add persistent function tracing
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>
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index d044de6..d39bb5c 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -19,6 +19,18 @@
When the option is enabled, pstore will log all kernel
messages, even if no oops or panic happened.
+config PSTORE_FTRACE
+ bool "Persistent function tracer"
+ depends on PSTORE
+ depends on FUNCTION_TRACER
+ help
+ With this option kernel traces function calls 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.
+
+ If unsure, say N.
+
config PSTORE_RAM
tristate "Log panic/oops to a RAM buffer"
depends on PSTORE