tree 2d5732aac18bb7f49215054cf50200246b24afcf
parent c5fdfb21b5bb114259b62e0110a29e3b33975ac5
author Russell King <rmk+kernel@arm.linux.org.uk> 1399111408 +0100
committer chrmhoffmann <chrmhoffmann@gmail.com> 1586074824 +0200

ARM: stacktrace: avoid listing stacktrace functions in stacktrace

commit 3683f44c42e991d313dc301504ee0fca1aeb8580 upstream.

While debugging the FEC ethernet driver using stacktrace, it was noticed
that the stacktraces always begin as follows:

 [<c00117b4>] save_stack_trace_tsk+0x0/0x98
 [<c0011870>] save_stack_trace+0x24/0x28
 ...

This is because the stack trace code includes the stack frames for itself.
This is incorrect behaviour, and also leads to "skip" doing the wrong
thing (which is the number of stack frames to avoid recording.)

Perversely, it does the right thing when passed a non-current thread.  Fix
this by ensuring that we have a known constant number of frames above the
main stack trace function, and always skip these.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>