aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/x86_64/dl-trampoline.h
AgeCommit message (Collapse)Author
2017-03-21x86-64: Improve branch predication in _dl_runtime_resolve_avx512_opt [BZ #21258]H.J. Lu
On Skylake server, _dl_runtime_resolve_avx512_opt is used to preserve the first 8 vector registers. The code layout is if only %xmm0 - %xmm7 registers are used preserve %xmm0 - %xmm7 registers if only %ymm0 - %ymm7 registers are used preserve %ymm0 - %ymm7 registers preserve %zmm0 - %zmm7 registers Branch predication always executes the fallthrough code path to preserve %zmm0 - %zmm7 registers speculatively, even though only %xmm0 - %xmm7 registers are used. This leads to lower CPU frequency on Skylake server. This patch changes the fallthrough code path to preserve %xmm0 - %xmm7 registers instead: if whole %zmm0 - %zmm7 registers are used preserve %zmm0 - %zmm7 registers if only %ymm0 - %ymm7 registers are used preserve %ymm0 - %ymm7 registers preserve %xmm0 - %xmm7 registers Tested on Skylake server. [BZ #21258] * sysdeps/x86_64/dl-trampoline.S (_dl_runtime_resolve_opt): Define only if _dl_runtime_resolve is defined to _dl_runtime_resolve_sse_vex. * sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve_opt): Fallthrough to _dl_runtime_resolve_sse_vex.
2017-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
2016-09-06X86-64: Add _dl_runtime_resolve_avx[512]_{opt|slow} [BZ #20508]H.J. Lu
There is transition penalty when SSE instructions are mixed with 256-bit AVX or 512-bit AVX512 load instructions. Since _dl_runtime_resolve_avx and _dl_runtime_profile_avx512 save/restore 256-bit YMM/512-bit ZMM registers, there is transition penalty when SSE instructions are used with lazy binding on AVX and AVX512 processors. To avoid SSE transition penalty, if only the lower 128 bits of the first 8 vector registers are non-zero, we can preserve %xmm0 - %xmm7 registers with the zero upper bits. For AVX and AVX512 processors which support XGETBV with ECX == 1, we can use XGETBV with ECX == 1 to check if the upper 128 bits of YMM registers or the upper 256 bits of ZMM registers are zero. We can restore only the non-zero portion of vector registers with AVX/AVX512 load instructions which will zero-extend upper bits of vector registers. This patch adds _dl_runtime_resolve_sse_vex which saves and restores XMM registers with 128-bit AVX store/load instructions. It is used to preserve YMM/ZMM registers when only the lower 128 bits are non-zero. _dl_runtime_resolve_avx_opt and _dl_runtime_resolve_avx512_opt are added and used on AVX/AVX512 processors supporting XGETBV with ECX == 1 so that we store and load only the non-zero portion of vector registers. This avoids SSE transition penalty caused by _dl_runtime_resolve_avx and _dl_runtime_profile_avx512 when only the lower 128 bits of vector registers are used. _dl_runtime_resolve_avx_slow is added and used for AVX processors which don't support XGETBV with ECX == 1. Since there is no SSE transition penalty on AVX512 processors which don't support XGETBV with ECX == 1, _dl_runtime_resolve_avx512_slow isn't provided. [BZ #20495] [BZ #20508] * sysdeps/x86/cpu-features.c (init_cpu_features): For Intel processors, set Use_dl_runtime_resolve_slow and set Use_dl_runtime_resolve_opt if XGETBV suports ECX == 1. * sysdeps/x86/cpu-features.h (bit_arch_Use_dl_runtime_resolve_opt): New. (bit_arch_Use_dl_runtime_resolve_slow): Likewise. (index_arch_Use_dl_runtime_resolve_opt): Likewise. (index_arch_Use_dl_runtime_resolve_slow): Likewise. * sysdeps/x86_64/dl-machine.h (elf_machine_runtime_setup): Use _dl_runtime_resolve_avx512_opt and _dl_runtime_resolve_avx_opt if Use_dl_runtime_resolve_opt is set. Use _dl_runtime_resolve_slow if Use_dl_runtime_resolve_slow is set. * sysdeps/x86_64/dl-trampoline.S: Include <cpu-features.h>. (_dl_runtime_resolve_opt): New. Defined for AVX and AVX512. (_dl_runtime_resolve): Add one for _dl_runtime_resolve_sse_vex. * sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve_avx_slow): New. (_dl_runtime_resolve_opt): Likewise. (_dl_runtime_profile): Define only if _dl_runtime_profile is defined.
2016-08-26X86-64: Correct CFA in _dl_runtime_resolveH.J. Lu
When stack is re-aligned in _dl_runtime_resolve, there is no need to adjust CFA when allocating register save area on stack. * sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve): Don't adjust CFA when allocating register save area on re-aligned stack.
2016-02-19[x86_64] Set DL_RUNTIME_UNALIGNED_VEC_SIZE to 8H.J. Lu
Due to GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 __tls_get_addr may be called with 8-byte stack alignment. Although this bug has been fixed in GCC 4.9.4, 5.3 and 6, we can't assume that stack will be always aligned at 16 bytes. Since SSE optimized memory/string functions with aligned SSE register load and store are used in the dynamic linker, we must set DL_RUNTIME_UNALIGNED_VEC_SIZE to 8 so that _dl_runtime_resolve_sse will align the stack before calling _dl_fixup: Dump of assembler code for function _dl_runtime_resolve_sse: 0x00007ffff7deea90 <+0>: push %rbx 0x00007ffff7deea91 <+1>: mov %rsp,%rbx 0x00007ffff7deea94 <+4>: and $0xfffffffffffffff0,%rsp ^^^^^^^^^^^ Align stack to 16 bytes 0x00007ffff7deea98 <+8>: sub $0x100,%rsp 0x00007ffff7deea9f <+15>: mov %rax,0xc0(%rsp) 0x00007ffff7deeaa7 <+23>: mov %rcx,0xc8(%rsp) 0x00007ffff7deeaaf <+31>: mov %rdx,0xd0(%rsp) 0x00007ffff7deeab7 <+39>: mov %rsi,0xd8(%rsp) 0x00007ffff7deeabf <+47>: mov %rdi,0xe0(%rsp) 0x00007ffff7deeac7 <+55>: mov %r8,0xe8(%rsp) 0x00007ffff7deeacf <+63>: mov %r9,0xf0(%rsp) 0x00007ffff7deead7 <+71>: movaps %xmm0,(%rsp) 0x00007ffff7deeadb <+75>: movaps %xmm1,0x10(%rsp) 0x00007ffff7deeae0 <+80>: movaps %xmm2,0x20(%rsp) 0x00007ffff7deeae5 <+85>: movaps %xmm3,0x30(%rsp) 0x00007ffff7deeaea <+90>: movaps %xmm4,0x40(%rsp) 0x00007ffff7deeaef <+95>: movaps %xmm5,0x50(%rsp) 0x00007ffff7deeaf4 <+100>: movaps %xmm6,0x60(%rsp) 0x00007ffff7deeaf9 <+105>: movaps %xmm7,0x70(%rsp) [BZ #19679] * sysdeps/x86_64/dl-trampoline.S (DL_RUNIME_UNALIGNED_VEC_SIZE): Renamed to ... (DL_RUNTIME_UNALIGNED_VEC_SIZE): This. Set to 8. (DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ... (DL_RUNTIME_RESOLVE_REALIGN_STACK): This. Updated. (DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ... (DL_RUNTIME_RESOLVE_REALIGN_STACK): This. * sysdeps/x86_64/dl-trampoline.h (DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ... (DL_RUNTIME_RESOLVE_REALIGN_STACK): This.
2016-01-04Update copyright dates with scripts/update-copyrights.Joseph Myers
2015-10-08Remove configure tests for AVX support.Joseph Myers
GCC added support for -mavx and -msse2avx in version 4.4. Thus the configure tests for this support are obsolete, and this patch removes them. Tested for x86_64 and x86 (testsuite, and that installed stripped shared libraries are unchanged by this patch). * sysdeps/i386/configure.ac (libc_cv_cc_avx): Remove configure test. (libc_cv_cc_sse2avx): Likewise. * sysdeps/i386/configure: Regenerated. * sysdeps/i386/i686/multiarch/Makefile [$(subdir)$(config-cflags-avx) = mathyes]: Change conditional to [$(subdir) = math]. * sysdeps/i386/i686/multiarch/s_fma-fma.c [HAVE_AVX_SUPPORT]: Make code unconditional. * sysdeps/i386/i686/multiarch/s_fma.c [HAVE_AVX_SUPPORT]: Likewise. * sysdeps/i386/i686/multiarch/s_fmaf-fma.c [HAVE_AVX_SUPPORT]: Likewise. * sysdeps/i386/i686/multiarch/s_fmaf.c [HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/configure.ac (libc_cv_cc_avx): Remove configure test. (libc_cv_cc_sse2avx): Likewise. * sysdeps/x86_64/configure: Regenerated. * sysdeps/x86_64/Makefile [$(config-cflags-avx) = yes]: Make code unconditional. * sysdeps/x86_64/dl-trampoline.h (_dl_runtime_profile) [HAVE_AVX_SUPPORT || HAVE_AVX512_ASM_SUPPORT]: Make code unconditional. (_dl_runtime_profile) [!(HAVE_AVX_SUPPORT || HAVE_AVX512_ASM_SUPPORT)]: Remove conditional code. * sysdeps/x86_64/fpu/multiarch/Makefile [$(config-cflags-sse2avx) = yes]: Make code unconditional. * sysdeps/x86_64/fpu/multiarch/e_atan2.c [HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/fpu/multiarch/e_exp.c [HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/fpu/multiarch/e_log.c [HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/fpu/multiarch/s_atan.c [HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/fpu/multiarch/s_fma.c [HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/fpu/multiarch/s_fmaf.c [HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/fpu/multiarch/s_sin.c [HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/fpu/multiarch/s_tan.c [HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise. * sysdeps/x86_64/multiarch/strcmp.S [HAVE_AVX_SUPPORT]: Likewise. * config.h.in (HAVE_AVX_SUPPORT): Remove #undef. (HAVE_SSE2AVX_SUPPORT): Likewise.
2015-08-25Save and restore vector registers in x86-64 ld.soH.J. Lu
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.
2015-07-09Preserve bound registers for pointer pass/returnIgor Zamyatin
We need to save/restore bound registers and add a BND prefix before branches in _dl_runtime_profile so that bound registers for pointer pass and return are preserved when LD_AUDIT is used. [BZ #18134] * sysdeps/i386/configure.ac: Set HAVE_MPX_SUPPORT. * sysdeps/i386/configure: Regenerated. * sysdeps/i386/dl-trampoline.S (PRESERVE_BND_REGS_PREFIX): New. (_dl_runtime_profile): Save and restore Intel MPX return bound registers when calling _dl_call_pltexit. Add PRESERVE_BND_REGS_PREFIX before return. * sysdeps/i386/link-defines.sym (LRV_BND0_OFFSET): New. (LRV_BND1_OFFSET): Likewise. * sysdeps/x86/bits/link.h (La_i86_retval): Add lrv_bnd0 and lrv_bnd1. * sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Fix typo in bndmov encoding. * sysdeps/x86_64/dl-trampoline.h: Properly save and restore Intel MPX bound registers. Add PRESERVE_BND_REGS_PREFIX before branch instructions to preserve bounds.
2015-01-02Update copyright dates with scripts/update-copyrights.Joseph Myers
2014-04-16Save/restore bound registers for _dl_runtime_profileIgor Zamyatin
This patch saves and restores bound registers in x86-64 PLT for ld.so profile and LD_AUDIT: * sysdeps/x86_64/bits/link.h (La_x86_64_regs): Add lr_bnd. (La_x86_64_retval): Add lrv_bnd0 and lrv_bnd1. * sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Save Intel MPX bound registers before _dl_profile_fixup. * sysdeps/x86_64/dl-trampoline.h: Restore Intel MPX bound registers after _dl_profile_fixup. Save and restore bound registers bnd0/bnd1 when calling _dl_call_pltexit. * sysdeps/x86_64/link-defines.sym (BND_SIZE): New. (LR_BND_OFFSET): Likewise. (LRV_BND0_OFFSET): Likewise. (LRV_BND1_OFFSET): Likewise.
2014-03-13Save and restore AVX-512 zmm registers to x86-64 ld.soIgor Zamyatin
AVX-512 ISA adds 512-bit zmm registers. This patch updates _dl_runtime_profile to pass zmm registers to run-time audit. It also changes _dl_x86_64_save_sse and _dl_x86_64_restore_sse to upport zmm registers, which are called when only when RTLD_PREPARE_FOREIGN_CALL is used. Its performance impact is minimum. * config.h.in (HAVE_AVX512_SUPPORT): New #undef. (HAVE_AVX512_ASM_SUPPORT): Likewise. * sysdeps/x86_64/bits/link.h (La_x86_64_zmm): New. (La_x86_64_vector): Add zmm. * sysdeps/x86_64/Makefile (tests): Add tst-audit10. (modules-names): Add tst-auditmod10a and tst-auditmod10b. ($(objpfx)tst-audit10): New target. ($(objpfx)tst-audit10.out): Likewise. (tst-audit10-ENV): New. (AVX512-CFLAGS): Likewise. (CFLAGS-tst-audit10.c): Likewise. (CFLAGS-tst-auditmod10a.c): Likewise. (CFLAGS-tst-auditmod10b.c): Likewise. * sysdeps/x86_64/configure.ac: Set config-cflags-avx512, HAVE_AVX512_SUPPORT and HAVE_AVX512_ASM_SUPPORT. * sysdeps/x86_64/configure: Regenerated. * sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Add AVX-512 zmm register support. (_dl_x86_64_save_sse): Likewise. (_dl_x86_64_restore_sse): Likewise. * sysdeps/x86_64/dl-trampoline.h: Updated to support different size vector registers. * sysdeps/x86_64/link-defines.sym (YMM_SIZE): New. (ZMM_SIZE): Likewise. * sysdeps/x86_64/tst-audit10.c: New file. * sysdeps/x86_64/tst-auditmod10a.c: Likewise. * sysdeps/x86_64/tst-auditmod10b.c: Likewise.
2014-01-01Update copyright notices with scripts/update-copyrightsAllan McRae
2013-01-02Update copyright notices with scripts/update-copyrights.Joseph Myers
2012-05-15Use R*_LP to call _dl_profile_fixup and frame sizeH.J. Lu
2012-02-09Replace FSF snail mail address with URLs.Paul Eggert
2011-08-20Fix CFI info in x86-64 trampolines for non-AVX codeUlrich Drepper
2009-08-08Support mixed SSE/AVX audit and check AVX only once.H.J. Lu
This patch fixes mixed SSE/AVX audit and checks AVX only once in _dl_runtime_profile. When an AVX or SSE register value in pltenter is modified, we have to make sure that the SSE part value is the same in both lr_xmm and lr_vector fields so that pltexit will get the correct value from either lr_xmm or lr_vector fields. AVX-enabled pltenter should update both lr_xmm and lr_vector fields to support stacked AVX/SSE pltenter functions.
2009-07-15Secure AVX changes for auditing code.Ulrich Drepper
The original AVX patch used a function pointer to handle the difference between machines with and without AVX support. This is insecure. A well-placed memory exploit could lead to redirection of the execution. Using a variable and several tests is a bit slower but cannot be exploited in this way.
2009-07-10Add AVX support to ld.so auditing for x86-64.H.J. Lu
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 13:11:39 +0000