From mboxrd@z Thu Jan 1 00:00:00 1970 From: jpoimboe@redhat.com (Josh Poimboeuf) Date: Fri, 10 Aug 2018 15:44:49 -0500 Subject: [PATCH 3/3] arm64: reliable stacktraces In-Reply-To: <20180810160311.C988D68CF4@newverein.lst.de> References: <20180810160043.9E45568C76@newverein.lst.de> <20180810160311.C988D68CF4@newverein.lst.de> Message-ID: <20180810204449.4asgonydn6yfb6kq@treble> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Aug 10, 2018 at 06:03:11PM +0200, Torsten Duwe wrote: > This is more an RFC in the original sense: is this basically > the correct approach? (as I had to tweak the API a bit). > > In particular the code does not detect interrupts and exception > frames, and does not yet check whether the code address is valid. > The latter check would also have to be omitted for the latest frame > on other tasks' stacks. This would require some more tweaking. > > unwind_frame() now reports whether we had to stop normally or due to > an error condition; walk_stackframe() will pass that info. > __save_stack_trace() is used for a start to check the validity of a > frame; maybe save_stack_trace_tsk_reliable() will need its own callback. > > Any comments welcome. > > Signed-off-by: Torsten Duwe Before we do this we'll need the same analysis we did for ppc64le to figure out if objtool is needed. -- Josh