[tip: x86/urgent] x86/unwind/orc: Silence warnings caused by missing ORC data

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     d072f941c1e234f8495cc4828370b180318bf49b
Gitweb:        https://git.kernel.org/tip/d072f941c1e234f8495cc4828370b180318bf49b
Author:        Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate:    Fri, 05 Feb 2021 08:24:03 -06:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Sat, 06 Mar 2021 11:37:00 +01:00

x86/unwind/orc: Silence warnings caused by missing ORC data

The ORC unwinder attempts to fall back to frame pointers when ORC data
is missing for a given instruction.  It sets state->error, but then
tries to keep going as a best-effort type of thing.  That may result in
further warnings if the unwinder gets lost.

Until we have some way to register generated code with the unwinder,
missing ORC will be expected, and occasionally going off the rails will
also be expected.  So don't warn about it.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Tested-by: Ivan Babrou <ivan@xxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/06d02c4bbb220bd31668db579278b0352538efbb.1612534649.git.jpoimboe@xxxxxxxxxx
---
 arch/x86/kernel/unwind_orc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index 1bcc14c..a120253 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -13,7 +13,7 @@
 
 #define orc_warn_current(args...)					\
 ({									\
-	if (state->task == current)					\
+	if (state->task == current && !state->error)			\
 		orc_warn(args);						\
 })