]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
x86/dumpstack: Fix partial register dumps
authorJosh Poimboeuf <jpoimboe@redhat.com>
Sun, 31 Dec 2017 16:18:06 +0000 (10:18 -0600)
committerIngo Molnar <mingo@kernel.org>
Wed, 3 Jan 2018 15:14:46 +0000 (16:14 +0100)
commita9cdbe72c4e8bf3b38781c317a79326e2e1a230d
tree68cdaf511eb0f093cebb50d201d5ee8f399549cd
parent52994c256df36fda9a715697431cba9daecb6b11
x86/dumpstack: Fix partial register dumps

The show_regs_safe() logic is wrong.  When there's an iret stack frame,
it prints the entire pt_regs -- most of which is random stack data --
instead of just the five registers at the end.

show_regs_safe() is also poorly named: the on_stack() checks aren't for
safety.  Rename the function to show_regs_if_on_stack() and add a
comment to explain why the checks are needed.

These issues were introduced with the "partial register dump" feature of
the following commit:

  b02fcf9ba121 ("x86/unwinder: Handle stack overflows more gracefully")

That patch had gone through a few iterations of development, and the
above issues were artifacts from a previous iteration of the patch where
'regs' pointed directly to the iret frame rather than to the (partially
empty) pt_regs.

Tested-by: Alexander Tsoy <alexander@tsoy.me>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toralf Förster <toralf.foerster@gmx.de>
Cc: stable@vger.kernel.org
Fixes: b02fcf9ba121 ("x86/unwinder: Handle stack overflows more gracefully")
Link: http://lkml.kernel.org/r/5b05b8b344f59db2d3d50dbdeba92d60f2304c54.1514736742.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/include/asm/unwind.h
arch/x86/kernel/dumpstack.c
arch/x86/kernel/stacktrace.c