• Josh Poimboeuf's avatar
    x86/dumpstack: Add support for unwinding empty IRQ stacks · 5fe599e0
    Josh Poimboeuf authored
    When an interrupt happens in entry code while running on a software IRQ
    stack, and the IRQ stack was empty, regs->sp will contain the stack end
    address (e.g., irq_stack_ptr).  If the regs are passed to dump_trace(),
    get_stack_info() will report STACK_TYPE_UNKNOWN, causing dump_trace() to
    return prematurely without trying to go to the next stack.
    
    Update the bounds checking for software interrupt stacks so that the
    ending address is now considered part of the stack.
    
    This means that it's now possible for the 'walk_stack' callbacks --
    print_context_stack() and print_context_stack_bp() -- to be called with
    an empty stack.  But that's fine; they're already prepared to deal with
    that due to their on_stack() checks.
    Signed-off-by: default avatarJosh 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/5a5e5de92dcf11e8dc6b6e8e50ad7639d067830b.1473905218.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    5fe599e0
dumpstack_32.c 4.7 KB