objtool: Fix stack offset tracking for indirect CFAs

When the current frame address (CFA) is stored on the stack (i.e.,
cfa->base == CFI_SP_INDIRECT), objtool neglects to adjust the stack
offset when there are subsequent pushes or pops.  This results in bad
ORC data at the end of the ENTER_IRQ_STACK macro, when it puts the
previous stack pointer on the stack and does a subsequent push.

This fixes the following unwinder warning:

  WARNING: can't dereference registers at 00000000f0a6bdba for ip interrupt_entry+0x9f/0xa0

Fixes: 627fce14809b ("objtool: Add ORC unwind table generation")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Dave Jones <dsj@fb.com>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Joe Mario <jmario@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/853d5d691b29e250333332f09b8e27410b2d9924.1587808742.git.jpoimboe@redhat.com

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 4b170fd08a28b194a6e3c006c9bcb1237dd6a246..e7184641a40c3aa385fb9e62b1c82b5d35b8318c 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1449,7 +1449,7 @@ static int update_insn_state_regs(struct instruction *insn, struct insn_state *s
        struct cfi_reg *cfa = &state->cfa;
        struct stack_op *op = &insn->stack_op;
 
-       if (cfa->base != CFI_SP)
+       if (cfa->base != CFI_SP && cfa->base != CFI_SP_INDIRECT)
                return 0;
 
        /* push */