x86/unwind: Create stack frames for saved syscall registers
authorJosh Poimboeuf <jpoimboe@redhat.com>
Thu, 20 Oct 2016 16:34:41 +0000 (11:34 -0500)
committerIngo Molnar <mingo@kernel.org>
Fri, 21 Oct 2016 07:26:04 +0000 (09:26 +0200)
commitacb4608ad1865a42af8e0a2db332a7c3a381e1f5
tree43d06faf6a55c624e21e65076e25d3226fc0d765
parent946c191161cef10c667b5ee3179db1714fa5b7c0
x86/unwind: Create stack frames for saved syscall registers

The entry code doesn't encode the pt_regs pointer for syscalls.  But the
pt_regs are always at the same location, so we can add a manual check
for them.

A later patch prints them as part of the oops stack dump.  They could be
useful, for example, to determine the arguments to a system call.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e176aa9272930cd3f51fda0b94e2eae356677da4.1476973742.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/unwind_frame.c