tree 10a1653fa1da45343b11311c0c4336f77c4f4180
parent 5fe599e02e41550c59831613a11c8ae057897c29
author Josh Poimboeuf <jpoimboe@redhat.com> 1473905264 -0500
committer Ingo Molnar <mingo@kernel.org> 1473919995 +0200

x86/dumpstack: Add recursion checking for all stacks

in_exception_stack() has some recursion checking which makes sure the
stack trace code never traverses a given exception stack more than once.
This prevents an infinite loop if corruption somehow causes a stack's
"next stack" pointer to point to itself (directly or indirectly).

The recursion checking can be useful for other stacks in addition to the
exception stack, so extend it to work for all stacks.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/95de5db4cfe111754845a5cef04e20630d01423f.1473905218.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>