Dear Josh,
Commit dbae0a934f09 ("x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"")
from Borislav removes the config X86_SMAP and makes smap on x86
default.
Josh, your commit 03f16cd020eb ("objtool: Add CONFIG_OBJTOOL") makes
config UBSAN_UNREACHABLE in lib/Kconfig.ubsan refer to this
non-existing config X86_SMAP.
See this hunk in lib/Kconfig.ubsan:
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index f3c57ed51838..c4fe15d38b60 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -94,7 +94,7 @@ config UBSAN_UNREACHABLE
bool "Perform checking for unreachable code"
# objtool already handles unreachable checking and gets angry about
# seeing UBSan instrumentation located in unreachable places.
- depends on !STACK_VALIDATION
+ depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || X86_SMAP))
depends on $(cc-option,-fsanitize=unreachable)
help
This option enables -fsanitize=unreachable which checks for control
I think X86_SMAP can just be dropped in this line, but I leave it up
to you to change, as I am not completely certain on the needed change
and if that just breaks the config dependencies for stack validation.
By the way, this issue was identified with the script
./scripts/checkkconfigsymbols.py
Best regards,
Lukas
