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| author | Zhiquan Li <zhiquan_li@163.com> | 2026-01-22 08:35:50 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-01-23 19:38:31 +0300 |
| commit | e396a74222654486d6ab45dca5d0c54c408b8b91 (patch) | |
| tree | bd341090044dbb9655424369c6e579a373794c98 /tools | |
| parent | ef3719e33e6649164382c629d58704b828f56079 (diff) | |
| download | linux-e396a74222654486d6ab45dca5d0c54c408b8b91.tar.xz | |
KVM: selftests: Add -U_FORTIFY_SOURCE to avoid some unpredictable test failures
Some distributions (such as Ubuntu) configure GCC so that
_FORTIFY_SOURCE is automatically enabled at -O1 or above. This results
in some fortified version of definitions of standard library functions
are included. While linker resolves the symbols, the fortified versions
might override the definitions in lib/string_override.c and reference to
those PLT entries in GLIBC. This is not a problem for the code in host,
but it is a disaster for the guest code. E.g., if build and run
x86/nested_emulation_test on Ubuntu 24.04 will encounter a L1 #PF due to
memset() reference to __memset_chk@plt.
The option -fno-builtin-memset is not helpful here, because those
fortified versions are not built-in but some definitions which are
included by header, they are for different intentions.
In order to eliminate the unpredictable behaviors may vary depending on
the linker and platform, add the "-U_FORTIFY_SOURCE" into CFLAGS to
prevent from introducing the fortified definitions.
Signed-off-by: Zhiquan Li <zhiquan_li@163.com>
Link: https://patch.msgid.link/20260122053551.548229-1-zhiquan_li@163.com
Fixes: 6b6f71484bf4 ("KVM: selftests: Implement memcmp(), memcpy(), and memset() for guest use")
Cc: stable@vger.kernel.org
[sean: tag for stable]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/kvm/Makefile.kvm | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index ba5c2b643efa..d45bf4ccb3bf 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -251,6 +251,7 @@ LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include LINUX_TOOL_ARCH_INCLUDE = $(top_srcdir)/tools/arch/$(ARCH)/include CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \ -Wno-gnu-variable-sized-type-not-at-end -MD -MP -DCONFIG_64BIT \ + -U_FORTIFY_SOURCE \ -fno-builtin-memcmp -fno-builtin-memcpy \ -fno-builtin-memset -fno-builtin-strnlen \ -fno-stack-protector -fno-PIE -fno-strict-aliasing \ |