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authorH.J. Lu <hjl.tools@gmail.com>2015-08-25 04:33:54 -0700
committerH.J. Lu <hjl.tools@gmail.com>2015-08-25 04:34:13 -0700
commitf3dcae82d54e5097e18e1d6ef4ff55c2ea4e621e (patch)
treee43395ded84bf0aa25ecbe2d395082a182aae8b7 /debug
parent2d02fd07371bcd492c320cec649c6265787d794a (diff)
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Save and restore vector registers in x86-64 ld.so
This patch adds SSE, AVX and AVX512 versions of _dl_runtime_resolve
and _dl_runtime_profile, which save and restore the first 8 vector
registers used for parameter passing.  elf_machine_runtime_setup
selects the proper _dl_runtime_resolve or _dl_runtime_profile based
on _dl_x86_cpu_features.  It avoids race condition caused by
FOREIGN_CALL macros, which are only used for x86-64.

Performance impact of saving and restoring 8 vector registers are
negligible on Nehalem, Sandy Bridge, Ivy Bridge and Haswell when
ld.so is optimized with SSE2.

	[BZ #15128]
	* sysdeps/x86_64/Makefile [$(subdir) == elf] (tests): Add
	ifuncmain8.
	(modules-names): Add ifuncmod8.
	($(objpfx)ifuncmain8): New rule.
	* sysdeps/x86_64/dl-machine.h: Include <dl-procinfo.h> and
	<cpuid.h>.
	(elf_machine_runtime_setup): Use _dl_runtime_resolve_sse,
	_dl_runtime_resolve_avx, or _dl_runtime_resolve_avx512,
	_dl_runtime_profile_sse, _dl_runtime_profile_avx, or
	_dl_runtime_profile_avx512, based on HAS_ARCH_FEATURE.
	* sysdeps/x86_64/dl-trampoline.S: Rewrite.
	* sysdeps/x86_64/dl-trampoline.h: Likewise.
	* sysdeps/x86_64/ifuncmain8.c: New file.
	* sysdeps/x86_64/ifuncmod8.c: Likewise.
	* sysdeps/x86_64/nptl/tcb-offsets.sym (RTLD_SAVESPACE_SSE):
	Removed.
	* sysdeps/x86_64/nptl/tls.h (__128bits): Removed.
	(tcbhead_t): Change rtld_must_xmm_save to __glibc_unused1.
	Change rtld_savespace_sse to __glibc_unused2.
	(RTLD_CHECK_FOREIGN_CALL): Removed.
	(RTLD_ENABLE_FOREIGN_CALL): Likewise.
	(RTLD_PREPARE_FOREIGN_CALL): Likewise.
	(RTLD_FINALIZE_FOREIGN_CALL): Likewise.
Diffstat (limited to 'debug')
0 files changed, 0 insertions, 0 deletions