glibc/sysdeps/x86_64/x32/Makefile
H.J. Lu b304fc201d x86-64 memcmp/wmemcmp: Properly handle the length parameter [BZ# 24097]
On x32, the size_t parameter may be passed in the lower 32 bits of a
64-bit register with the non-zero upper 32 bits.  The string/memory
functions written in assembly can only use the lower 32 bits of a
64-bit register as length or must clear the upper 32 bits before using
the full 64-bit register for length.

This pach fixes memcmp/wmemcmp for x32.  Tested on x86-64 and x32.  On
x86-64, libc.so is the same with and withou the fix.

	[BZ# 24097]
	CVE-2019-6488
	* sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S: Use RDX_LP for
	length.  Clear the upper 32 bits of RDX register.
	* sysdeps/x86_64/multiarch/memcmp-sse4.S: Likewise.
	* sysdeps/x86_64/multiarch/memcmp-ssse3.S: Likewise.
	* sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memcmp and
	tst-size_t-wmemcmp.
	* sysdeps/x86_64/x32/tst-size_t-memcmp.c: New file.
	* sysdeps/x86_64/x32/tst-size_t-wmemcmp.c: Likewise.
2019-01-21 11:26:07 -08:00

15 lines
427 B
Makefile

ifeq ($(subdir),math)
# Since x32 returns 32-bit long int and 64-bit long long int in the
# same 64-bit register, we make the 32b-bit lround an alias of the
# 64-bit llround. Add -fno-builtin-lround to silence the compiler.
CFLAGS-s_llround.c += -fno-builtin-lround
endif
ifeq ($(subdir),string)
tests += tst-size_t-memchr tst-size_t-memcmp
endif
ifeq ($(subdir),wcsmbs)
tests += tst-size_t-wmemchr tst-size_t-wmemcmp
endif