From: Robin Murphy robin.murphy@arm.com
commit 59a68d4138086c015ab8241c3267eec5550fbd44 upstream.
As with strlen(), the patches importing the updated str{n}cmp() implementations were originally developed and tested before the advent of CONFIG_KASAN_HW_TAGS, and have subsequently revealed not to be MTE-safe. Since in-kernel MTE is still a rather niche case, let it temporarily fall back to the generic C versions for correctness until we can figure out the best fix.
Fixes: 758602c04409 ("arm64: Import latest version of Cortex Strings' strcmp") Fixes: 020b199bc70d ("arm64: Import latest version of Cortex Strings' strncmp") Cc: stable@vger.kernel.org # 5.14.x Reported-by: Branislav Rankov branislav.rankov@arm.com Signed-off-by: Robin Murphy robin.murphy@arm.com Acked-by: Mark Rutland mark.rutland@arm.com Link: https://lore.kernel.org/r/34dc4d12eec0adae49b0ac927df642ed10089d40.163189077... Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/include/asm/assembler.h | 5 +++++ arch/arm64/include/asm/string.h | 2 ++ arch/arm64/lib/strcmp.S | 2 +- arch/arm64/lib/strncmp.S | 2 +- 4 files changed, 9 insertions(+), 2 deletions(-)
--- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -525,6 +525,11 @@ alternative_endif #define EXPORT_SYMBOL_NOKASAN(name) EXPORT_SYMBOL(name) #endif
+#ifdef CONFIG_KASAN_HW_TAGS +#define EXPORT_SYMBOL_NOHWKASAN(name) +#else +#define EXPORT_SYMBOL_NOHWKASAN(name) EXPORT_SYMBOL_NOKASAN(name) +#endif /* * Emit a 64-bit absolute little endian symbol reference in a way that * ensures that it will be resolved at build time, even when building a --- a/arch/arm64/include/asm/string.h +++ b/arch/arm64/include/asm/string.h @@ -12,11 +12,13 @@ extern char *strrchr(const char *, int c #define __HAVE_ARCH_STRCHR extern char *strchr(const char *, int c);
+#ifndef CONFIG_KASAN_HW_TAGS #define __HAVE_ARCH_STRCMP extern int strcmp(const char *, const char *);
#define __HAVE_ARCH_STRNCMP extern int strncmp(const char *, const char *, __kernel_size_t); +#endif
#define __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); --- a/arch/arm64/lib/strcmp.S +++ b/arch/arm64/lib/strcmp.S @@ -173,4 +173,4 @@ L(done): ret
SYM_FUNC_END_PI(strcmp) -EXPORT_SYMBOL_NOKASAN(strcmp) +EXPORT_SYMBOL_NOHWKASAN(strcmp) --- a/arch/arm64/lib/strncmp.S +++ b/arch/arm64/lib/strncmp.S @@ -258,4 +258,4 @@ L(ret0): ret
SYM_FUNC_END_PI(strncmp) -EXPORT_SYMBOL_NOKASAN(strncmp) +EXPORT_SYMBOL_NOHWKASAN(strncmp)