This is a note to let you know that I've just added the patch titled
kselftest/arm64: bti: force static linking
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kselftest-arm64-bti-force-static-linking.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 029bfe42782fe361c14299a40a53eb00f6bd4469
Author: Andre Przywara <andre.przywara@xxxxxxx>
Date: Wed May 11 18:21:29 2022 +0100
kselftest/arm64: bti: force static linking
[ Upstream commit d7a49291d786b4400996afe3afcc3ef5eeb6f0ef ]
The "bti" selftests are built with -nostdlib, which apparently
automatically creates a statically linked binary, which is what we want
and need for BTI (to avoid interactions with the dynamic linker).
However this is not true when building a PIE binary, which some
toolchains (Ubuntu) configure as the default.
When compiling btitest with such a toolchain, it will create a
dynamically linked binary, which will probably fail some tests, as the
dynamic linker might not support BTI:
===================
TAP version 13
1..18
not ok 1 nohint_func/call_using_br_x0
not ok 2 nohint_func/call_using_br_x16
not ok 3 nohint_func/call_using_blr
....
===================
To make sure we create static binaries, add an explicit -static on the
linker command line. This forces static linking even if the toolchain
defaults to PIE builds, and fixes btitest runs on BTI enabled machines.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
Reviewed-by: Mark Brown <broonie@xxxxxxxxxx>
Fixes: 314bcbf09f14 ("kselftest: arm64: Add BTI tests")
Link: https://lore.kernel.org/r/20220511172129.2078337-1-andre.przywara@xxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/arm64/bti/Makefile b/tools/testing/selftests/arm64/bti/Makefile
index 73e013c082a6..dafa1c2aa5c4 100644
--- a/tools/testing/selftests/arm64/bti/Makefile
+++ b/tools/testing/selftests/arm64/bti/Makefile
@@ -39,7 +39,7 @@ BTI_OBJS = \
teststubs-bti.o \
trampoline-bti.o
gen/btitest: $(BTI_OBJS)
- $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -o $@ $^
+ $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -static -o $@ $^
NOBTI_OBJS = \
test-nobti.o \
@@ -50,7 +50,7 @@ NOBTI_OBJS = \
teststubs-nobti.o \
trampoline-nobti.o
gen/nobtitest: $(NOBTI_OBJS)
- $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -o $@ $^
+ $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -static -o $@ $^
# Including KSFT lib.mk here will also mangle the TEST_GEN_PROGS list
# to account for any OUTPUT target-dirs optionally provided by
