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/Makefile b/fs/pstore/Makefile
index 278a44e..4c9095c 100644
--- a/fs/pstore/Makefile
+++ b/fs/pstore/Makefile
@@ -5,6 +5,7 @@
obj-y += pstore.o
pstore-objs += inode.o platform.o
+obj-$(CONFIG_PSTORE_FTRACE) += ftrace.o
ramoops-objs += ram.o ram_core.o
obj-$(CONFIG_PSTORE_RAM) += ramoops.o