Author: dim
Date: Tue Jan 4 20:51:28 2011
New Revision: 216977
URL: http://svn.freebsd.org/changeset/base/216977
Log:
On amd64 and i386, tell the compiler to refrain from generating SSE,
3DNow, MMX and floating point instructions in rtld-elf.
Otherwise, _rtld_bind() (and whatever it calls) could possibly clobber
function arguments that are passed in SSE/3DNow/MMX/FP registers,
usually floating point values. This can happen, for example, when clang
generates SSE code for memset() or memcpy() calls.
One symptom of this is sshd dying early on amd64 with "PRNG not seeded",
which is ultimately caused by libcrypto.so.6 calling RAND_add() with a
double parameter. That parameter is passed via %xmm0, which gets wiped
out by an SSE memset() in _rtld_bind().
Reviewed by: kib, kan
Modified:
head/libexec/rtld-elf/amd64/Makefile.inc
head/libexec/rtld-elf/i386/Makefile.inc
Modified: head/libexec/rtld-elf/amd64/Makefile.inc
==============================================================================
--- head/libexec/rtld-elf/amd64/Makefile.inc Tue Jan 4 20:38:52 2011
(r216976)
+++ head/libexec/rtld-elf/amd64/Makefile.inc Tue Jan 4 20:51:28 2011
(r216977)
@@ -1,5 +1,6 @@
# $FreeBSD$
+CFLAGS+= -mno-sse -mno-sse2 -mno-sse3 -mno-mmx -mno-3dnow -msoft-float
# Uncomment this to build the dynamic linker as an executable instead
# of a shared library:
#LDSCRIPT= ${.CURDIR}/${MACHINE_CPUARCH}/elf_rtld.x
Modified: head/libexec/rtld-elf/i386/Makefile.inc
==============================================================================
--- head/libexec/rtld-elf/i386/Makefile.inc Tue Jan 4 20:38:52 2011
(r216976)
+++ head/libexec/rtld-elf/i386/Makefile.inc Tue Jan 4 20:51:28 2011
(r216977)
@@ -1,5 +1,6 @@
# $FreeBSD$
+CFLAGS+= -mno-sse -mno-sse2 -mno-sse3 -mno-mmx -mno-3dnow -msoft-float
# Uncomment this to build the dynamic linker as an executable instead
# of a shared library:
#LDSCRIPT= ${.CURDIR}/${MACHINE_CPUARCH}/elf_rtld.x
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