• Josh Poimboeuf's avatar
    objtool, x86: Add facility for asm code to provide unwind hints · 39358a03
    Josh Poimboeuf authored
    Some asm (and inline asm) code does special things to the stack which
    objtool can't understand.  (Nor can GCC or GNU assembler, for that
    matter.)  In such cases we need a facility for the code to provide
    annotations, so the unwinder can unwind through it.
    This provides such a facility, in the form of unwind hints.  They're
    similar to the GNU assembler .cfi* directives, but they give more
    information, and are needed in far fewer places, because objtool can
    fill in the blanks by following branches and adjusting the stack pointer
    for pushes and pops.
    Signed-off-by: default avatarJosh 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: Jiri Slaby <jslaby@suse.cz>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: live-patching@vger.kernel.org
    Link: http://lkml.kernel.org/r/0f5f3c9104fca559ff4088bece1d14ae3bca52d5.1499786555.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
Makefile 2.58 KB