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| author | Alex Richardson <arichardson@FreeBSD.org> | 2021-08-02 08:51:34 +0000 |
|---|---|---|
| committer | Alex Richardson <arichardson@FreeBSD.org> | 2021-08-02 13:33:24 +0000 |
| commit | 8185be3307232d88ddd1b6468f4ddec54a993f54 (patch) | |
| tree | d88045a7359036481a9f2db004691a01451287d0 /lib | |
| parent | f0712132b68b4271e0602b06ee5f282718bfb8c5 (diff) | |
| download | src-8185be3307232d88ddd1b6468f4ddec54a993f54.tar.gz src-8185be3307232d88ddd1b6468f4ddec54a993f54.zip | |
libc: Disable ASAN for certain string functions
They deliberately read out-of-bounds values to avoid byte-by-byte
loads and check multiple bytes at once. While this will work on x86,
it is flagged as an out-of-bounds read with ASAN, so we have to
disable instrumentation here. This also causes bounds errors for CHERI,
so in CheriBSD we use implementations that avoid OOB reads.
Differential Revision: https://reviews.freebsd.org/D31045
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libc/string/Makefile.inc | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/libc/string/Makefile.inc b/lib/libc/string/Makefile.inc index 6945155812af..1df3d40e329f 100644 --- a/lib/libc/string/Makefile.inc +++ b/lib/libc/string/Makefile.inc @@ -29,6 +29,15 @@ MISRCS+=bcmp.c bcopy.c bzero.c explicit_bzero.c \ SYM_MAPS+= ${LIBC_SRCTOP}/string/Symbol.map +.if ${MK_ASAN} != "no" +# These source files deliberately read out of bounds since they assume that +# out-of-bounds memory accesses that don't cross pages are always legal. +# Note: While this is fine on x86, it does break when running with CHERI. +CFLAGS.strlen.c+= -fno-sanitize=address +CFLAGS.strchrnul.c+= -fno-sanitize=address +CFLAGS.memchr.c+= -fno-sanitize=address +.endif + # machine-dependent string sources .sinclude "${LIBC_SRCTOP}/${LIBC_ARCH}/string/Makefile.inc" |