| Message ID | 20220810154028.662395-1-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] elf: Remove -fno-tree-loop-distribute-patterns usage on dl-support | expand |
On Wed, Aug 10, 2022 at 8:40 AM Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote: > > Besides the option being gcc specific, this approach is still fragile > and not future proof since we do not if this will be the only > optimization option gcc will add that transform loops to memset > (or any libcall). > > This patch add a new header dl-symbol-hacks.h that can be used to > redirect the compiler generated libcalls to port specific string > implementatation if required (defined by dl-ifunc-generic.h). > > Checked on x86_64-linux-gnu and aarch64-linux-gnu. > --- > elf/Makefile | 5 --- > elf/dl-support.c | 1 + > elf/dl-symbol-hacks.h | 31 ++++++++++++++++ > elf/dl-tunables.c | 1 + > sysdeps/generic/dl-ifunc-generic.h | 37 +++++++++++++++++++ > .../sysv/linux/aarch64/dl-ifunc-generic.h | 24 ++++++++++++ > .../unix/sysv/linux/i386/dl-ifunc-generic.h | 26 +++++++++++++ > .../sysv/linux/powerpc/dl-ifunc-generic.h | 28 ++++++++++++++ > .../unix/sysv/linux/s390/dl-ifunc-generic.h | 31 ++++++++++++++++ > .../unix/sysv/linux/sparc/dl-ifunc-generic.h | 26 +++++++++++++ > .../unix/sysv/linux/x86_64/dl-ifunc-generic.h | 32 ++++++++++++++++ > 11 files changed, 237 insertions(+), 5 deletions(-) > create mode 100644 elf/dl-symbol-hacks.h > create mode 100644 sysdeps/generic/dl-ifunc-generic.h > create mode 100644 sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h > create mode 100644 sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h > create mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h > create mode 100644 sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h > create mode 100644 sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h > create mode 100644 sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h > > diff --git a/elf/Makefile b/elf/Makefile > index 3386f0ce77..4b992bd348 100644 > --- a/elf/Makefile > +++ b/elf/Makefile > @@ -162,11 +162,6 @@ ifeq (yes,$(have-loop-to-function)) > CFLAGS-rtld.c += -fno-tree-loop-distribute-patterns > endif > > -ifeq (yes,$(have-loop-to-function)) > -# Likewise, during static library startup, memset is not yet available. > -CFLAGS-dl-support.c = -fno-tree-loop-distribute-patterns > -endif > - > # Compile rtld itself without stack protection. > # Also compile all routines in the static library that are elided from > # the shared libc because they are in libc.a in the same way. > diff --git a/elf/dl-support.c b/elf/dl-support.c > index 4af0b5b2ce..6d1996ae6e 100644 > --- a/elf/dl-support.c > +++ b/elf/dl-support.c > @@ -44,6 +44,7 @@ > #include <dl-auxv.h> > #include <dl-find_object.h> > #include <array_length.h> > +#include <dl-symbol-hacks.h> > > extern char *__progname; > char **_dl_argv = &__progname; /* This is checked for some error messages. */ > diff --git a/elf/dl-symbol-hacks.h b/elf/dl-symbol-hacks.h > new file mode 100644 > index 0000000000..6b9d24ed03 > --- /dev/null > +++ b/elf/dl-symbol-hacks.h > @@ -0,0 +1,31 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_SYMBOL_HACKS_H > +#define _DL_SYMBOL_HACKS_H > + > +#include <dl-ifunc-generic.h> > + > +/* Some compiler optimizations may transform loops into memset/memmove > + calls and without proper redirection it might call PLT throught > + ifunc without relocations being processed. */ > +#if !IS_IN(rtld) && defined HAVE_MEMSET_IFUNC_GENERIC > +asm ("memset = " HAVE_MEMSET_IFUNC_GENERIC); > +#endif > + > +#endif > diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c > index 8e7ee9df10..c797484522 100644 > --- a/elf/dl-tunables.c > +++ b/elf/dl-tunables.c > @@ -32,6 +32,7 @@ > #include <ldsodefs.h> > #include <array_length.h> > #include <dl-minimal-malloc.h> > +#include <dl-symbol-hacks.h> > > #define TUNABLES_INTERNAL 1 > #include "dl-tunables.h" > diff --git a/sysdeps/generic/dl-ifunc-generic.h b/sysdeps/generic/dl-ifunc-generic.h > new file mode 100644 > index 0000000000..5e1d5c1fd8 > --- /dev/null > +++ b/sysdeps/generic/dl-ifunc-generic.h > @@ -0,0 +1,37 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_IFUNC_GENERIC_H > +#define _DL_IFUNC_GENERIC_H > + > +/* The compiler might optimize loops or other constructs to library calls even > + in freestanding mode. Although it is safe in most scenarios, on program > + loading and static startup, iFUNC resolution might require other dynamic > + relocation that are not yet done. > + > + Instead of adding per-file compiler flags to avoid the libcall generation, > + this header defines generic symbols that will be routed instead of the > + default symbols name. > + > + Each port can then define the following macro to the expected generic > + implementation if the symbol is provided as iFUNC: > + > + HAVE_MEMSET_IFUNC_GENERIC - the generic memset call. > + */ > + > +#endif > diff --git a/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h > new file mode 100644 > index 0000000000..1278a06ff0 > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h > @@ -0,0 +1,24 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_IFUNC_GENERIC_H > +#define _DL_IFUNC_GENERIC_H > + > +#define HAVE_MEMSET_IFUNC_GENERIC "__memset_generic" > + > +#endif > diff --git a/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h > new file mode 100644 > index 0000000000..c8e294b3c9 > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h > @@ -0,0 +1,26 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_IFUNC_GENERIC_H > +#define _DL_IFUNC_GENERIC_H > + > +#ifdef USE_MULTIARCH > +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ia32" > +#endif > + > +#endif This file should be in sysdeps/i386/i686/multiarch. > diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h > new file mode 100644 > index 0000000000..b0f9401670 > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h > @@ -0,0 +1,28 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_IFUNC_GENERIC_H > +#define _DL_IFUNC_GENERIC_H > + > +/* powerpc and powerpc64 provides the default memset as 'memset', so > + no need to redirect it. */ > +#if defined USE_MULTIARCH && defined __powerpc64__ && _CALL_ELF != 2 > +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_power8" > +#endif > + > +#endif > diff --git a/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h > new file mode 100644 > index 0000000000..f664ac07a7 > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h > @@ -0,0 +1,31 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_IFUNC_GENERIC_H > +#define _DL_IFUNC_GENERIC_H > + > +#ifdef USE_MULTIARCH > +# include <ifunc-memset.h> > + > +# define IFUNC_SYMBOL_STR1(s) #s > +# define IFUNC_SYMBOL_STR(s) IFUNC_SYMBOL_STR1(s) > + > +# define HAVE_MEMSET_IFUNC_GENERIC IFUNC_SYMBOL_STR(MEMSET_DEFAULT) > +#endif > + > +#endif > diff --git a/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h > new file mode 100644 > index 0000000000..86815317a9 > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h > @@ -0,0 +1,26 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_IFUNC_GENERIC_H > +#define _DL_IFUNC_GENERIC_H > + > +#ifdef USE_MULTIARCH > +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ultra1" > +#endif > + > +#endif > diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h > new file mode 100644 > index 0000000000..7b7cf1c3d6 > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h > @@ -0,0 +1,32 @@ > +/* Symbol rediretion for loader/static initialization code. > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _DL_IFUNC_GENERIC_H > +#define _DL_IFUNC_GENERIC_H > + > +#include <isa-level.h> > + > +#if MINIMUM_X86_ISA_LEVEL >= 4 > +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_evex_unaligned" > +#elif MINIMUM_X86_ISA_LEVEL == 3 > +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_avx2_unaligned" > +#else > +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_sse2_unaligned" > +#endif > + > +#endif > -- > 2.34.1 > This file should be in sysdeps/x86_64/multiarch and the generic memset should follow sysdeps/x86_64/memset.S: #define DEFAULT_IMPL_V1 "multiarch/memset-sse2-unaligned-erms.S" #define DEFAULT_IMPL_V3 "multiarch/memset-avx2-unaligned-erms.S" #define DEFAULT_IMPL_V4 "multiarch/memset-evex-unaligned-erms.S"
On 10/08/22 14:24, H.J. Lu wrote: > On Wed, Aug 10, 2022 at 8:40 AM Adhemerval Zanella > <adhemerval.zanella@linaro.org> wrote: >> >> Besides the option being gcc specific, this approach is still fragile >> and not future proof since we do not if this will be the only >> optimization option gcc will add that transform loops to memset >> (or any libcall). >> >> This patch add a new header dl-symbol-hacks.h that can be used to >> redirect the compiler generated libcalls to port specific string >> implementatation if required (defined by dl-ifunc-generic.h). >> >> Checked on x86_64-linux-gnu and aarch64-linux-gnu. >> --- >> elf/Makefile | 5 --- >> elf/dl-support.c | 1 + >> elf/dl-symbol-hacks.h | 31 ++++++++++++++++ >> elf/dl-tunables.c | 1 + >> sysdeps/generic/dl-ifunc-generic.h | 37 +++++++++++++++++++ >> .../sysv/linux/aarch64/dl-ifunc-generic.h | 24 ++++++++++++ >> .../unix/sysv/linux/i386/dl-ifunc-generic.h | 26 +++++++++++++ >> .../sysv/linux/powerpc/dl-ifunc-generic.h | 28 ++++++++++++++ >> .../unix/sysv/linux/s390/dl-ifunc-generic.h | 31 ++++++++++++++++ >> .../unix/sysv/linux/sparc/dl-ifunc-generic.h | 26 +++++++++++++ >> .../unix/sysv/linux/x86_64/dl-ifunc-generic.h | 32 ++++++++++++++++ >> 11 files changed, 237 insertions(+), 5 deletions(-) >> create mode 100644 elf/dl-symbol-hacks.h >> create mode 100644 sysdeps/generic/dl-ifunc-generic.h >> create mode 100644 sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h >> create mode 100644 sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h >> create mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h >> create mode 100644 sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h >> create mode 100644 sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h >> create mode 100644 sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h >> >> diff --git a/elf/Makefile b/elf/Makefile >> index 3386f0ce77..4b992bd348 100644 >> --- a/elf/Makefile >> +++ b/elf/Makefile >> @@ -162,11 +162,6 @@ ifeq (yes,$(have-loop-to-function)) >> CFLAGS-rtld.c += -fno-tree-loop-distribute-patterns >> endif >> >> -ifeq (yes,$(have-loop-to-function)) >> -# Likewise, during static library startup, memset is not yet available. >> -CFLAGS-dl-support.c = -fno-tree-loop-distribute-patterns >> -endif >> - >> # Compile rtld itself without stack protection. >> # Also compile all routines in the static library that are elided from >> # the shared libc because they are in libc.a in the same way. >> diff --git a/elf/dl-support.c b/elf/dl-support.c >> index 4af0b5b2ce..6d1996ae6e 100644 >> --- a/elf/dl-support.c >> +++ b/elf/dl-support.c >> @@ -44,6 +44,7 @@ >> #include <dl-auxv.h> >> #include <dl-find_object.h> >> #include <array_length.h> >> +#include <dl-symbol-hacks.h> >> >> extern char *__progname; >> char **_dl_argv = &__progname; /* This is checked for some error messages. */ >> diff --git a/elf/dl-symbol-hacks.h b/elf/dl-symbol-hacks.h >> new file mode 100644 >> index 0000000000..6b9d24ed03 >> --- /dev/null >> +++ b/elf/dl-symbol-hacks.h >> @@ -0,0 +1,31 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_SYMBOL_HACKS_H >> +#define _DL_SYMBOL_HACKS_H >> + >> +#include <dl-ifunc-generic.h> >> + >> +/* Some compiler optimizations may transform loops into memset/memmove >> + calls and without proper redirection it might call PLT throught >> + ifunc without relocations being processed. */ >> +#if !IS_IN(rtld) && defined HAVE_MEMSET_IFUNC_GENERIC >> +asm ("memset = " HAVE_MEMSET_IFUNC_GENERIC); >> +#endif >> + >> +#endif >> diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c >> index 8e7ee9df10..c797484522 100644 >> --- a/elf/dl-tunables.c >> +++ b/elf/dl-tunables.c >> @@ -32,6 +32,7 @@ >> #include <ldsodefs.h> >> #include <array_length.h> >> #include <dl-minimal-malloc.h> >> +#include <dl-symbol-hacks.h> >> >> #define TUNABLES_INTERNAL 1 >> #include "dl-tunables.h" >> diff --git a/sysdeps/generic/dl-ifunc-generic.h b/sysdeps/generic/dl-ifunc-generic.h >> new file mode 100644 >> index 0000000000..5e1d5c1fd8 >> --- /dev/null >> +++ b/sysdeps/generic/dl-ifunc-generic.h >> @@ -0,0 +1,37 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_IFUNC_GENERIC_H >> +#define _DL_IFUNC_GENERIC_H >> + >> +/* The compiler might optimize loops or other constructs to library calls even >> + in freestanding mode. Although it is safe in most scenarios, on program >> + loading and static startup, iFUNC resolution might require other dynamic >> + relocation that are not yet done. >> + >> + Instead of adding per-file compiler flags to avoid the libcall generation, >> + this header defines generic symbols that will be routed instead of the >> + default symbols name. >> + >> + Each port can then define the following macro to the expected generic >> + implementation if the symbol is provided as iFUNC: >> + >> + HAVE_MEMSET_IFUNC_GENERIC - the generic memset call. >> + */ >> + >> +#endif >> diff --git a/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h >> new file mode 100644 >> index 0000000000..1278a06ff0 >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h >> @@ -0,0 +1,24 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_IFUNC_GENERIC_H >> +#define _DL_IFUNC_GENERIC_H >> + >> +#define HAVE_MEMSET_IFUNC_GENERIC "__memset_generic" >> + >> +#endif >> diff --git a/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h >> new file mode 100644 >> index 0000000000..c8e294b3c9 >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h >> @@ -0,0 +1,26 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_IFUNC_GENERIC_H >> +#define _DL_IFUNC_GENERIC_H >> + >> +#ifdef USE_MULTIARCH >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ia32" >> +#endif >> + >> +#endif > > This file should be in sysdeps/i386/i686/multiarch. > My understanding is we only support iFUNC for Linux, but it seems that multiarch directory is not Linux specific. I will change it. >> diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h >> new file mode 100644 >> index 0000000000..b0f9401670 >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h >> @@ -0,0 +1,28 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_IFUNC_GENERIC_H >> +#define _DL_IFUNC_GENERIC_H >> + >> +/* powerpc and powerpc64 provides the default memset as 'memset', so >> + no need to redirect it. */ >> +#if defined USE_MULTIARCH && defined __powerpc64__ && _CALL_ELF != 2 >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_power8" >> +#endif >> + >> +#endif >> diff --git a/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h >> new file mode 100644 >> index 0000000000..f664ac07a7 >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h >> @@ -0,0 +1,31 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_IFUNC_GENERIC_H >> +#define _DL_IFUNC_GENERIC_H >> + >> +#ifdef USE_MULTIARCH >> +# include <ifunc-memset.h> >> + >> +# define IFUNC_SYMBOL_STR1(s) #s >> +# define IFUNC_SYMBOL_STR(s) IFUNC_SYMBOL_STR1(s) >> + >> +# define HAVE_MEMSET_IFUNC_GENERIC IFUNC_SYMBOL_STR(MEMSET_DEFAULT) >> +#endif >> + >> +#endif >> diff --git a/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h >> new file mode 100644 >> index 0000000000..86815317a9 >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h >> @@ -0,0 +1,26 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_IFUNC_GENERIC_H >> +#define _DL_IFUNC_GENERIC_H >> + >> +#ifdef USE_MULTIARCH >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ultra1" >> +#endif >> + >> +#endif >> diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h >> new file mode 100644 >> index 0000000000..7b7cf1c3d6 >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h >> @@ -0,0 +1,32 @@ >> +/* Symbol rediretion for loader/static initialization code. >> + Copyright (C) 2022 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + The GNU C Library is free software; you can redistribute it and/or >> + modify it under the terms of the GNU Lesser General Public >> + License as published by the Free Software Foundation; either >> + version 2.1 of the License, or (at your option) any later version. >> + >> + The GNU C Library is distributed in the hope that it will be useful, >> + but WITHOUT ANY WARRANTY; without even the implied warranty of >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + Lesser General Public License for more details. >> + >> + You should have received a copy of the GNU Lesser General Public >> + License along with the GNU C Library; if not, see >> + <https://www.gnu.org/licenses/>. */ >> + >> +#ifndef _DL_IFUNC_GENERIC_H >> +#define _DL_IFUNC_GENERIC_H >> + >> +#include <isa-level.h> >> + >> +#if MINIMUM_X86_ISA_LEVEL >= 4 >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_evex_unaligned" >> +#elif MINIMUM_X86_ISA_LEVEL == 3 >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_avx2_unaligned" >> +#else >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_sse2_unaligned" >> +#endif >> + >> +#endif >> -- >> 2.34.1 >> > > This file should be in sysdeps/x86_64/multiarch and the generic > memset should follow sysdeps/x86_64/memset.S: > > #define DEFAULT_IMPL_V1 "multiarch/memset-sse2-unaligned-erms.S" > #define DEFAULT_IMPL_V3 "multiarch/memset-avx2-unaligned-erms.S" > #define DEFAULT_IMPL_V4 "multiarch/memset-evex-unaligned-erms.S" Right, my understading it does follow the provided implementation based on the MINIMUM_X86_ISA_LEVEL. What I am missing here?
On Wed, Aug 10, 2022 at 11:58 AM Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> wrote: > > > > On 10/08/22 14:24, H.J. Lu wrote: > > On Wed, Aug 10, 2022 at 8:40 AM Adhemerval Zanella > > <adhemerval.zanella@linaro.org> wrote: > >> > >> Besides the option being gcc specific, this approach is still fragile > >> and not future proof since we do not if this will be the only > >> optimization option gcc will add that transform loops to memset > >> (or any libcall). > >> > >> This patch add a new header dl-symbol-hacks.h that can be used to > >> redirect the compiler generated libcalls to port specific string > >> implementatation if required (defined by dl-ifunc-generic.h). > >> > >> Checked on x86_64-linux-gnu and aarch64-linux-gnu. > >> --- > >> elf/Makefile | 5 --- > >> elf/dl-support.c | 1 + > >> elf/dl-symbol-hacks.h | 31 ++++++++++++++++ > >> elf/dl-tunables.c | 1 + > >> sysdeps/generic/dl-ifunc-generic.h | 37 +++++++++++++++++++ > >> .../sysv/linux/aarch64/dl-ifunc-generic.h | 24 ++++++++++++ > >> .../unix/sysv/linux/i386/dl-ifunc-generic.h | 26 +++++++++++++ > >> .../sysv/linux/powerpc/dl-ifunc-generic.h | 28 ++++++++++++++ > >> .../unix/sysv/linux/s390/dl-ifunc-generic.h | 31 ++++++++++++++++ > >> .../unix/sysv/linux/sparc/dl-ifunc-generic.h | 26 +++++++++++++ > >> .../unix/sysv/linux/x86_64/dl-ifunc-generic.h | 32 ++++++++++++++++ > >> 11 files changed, 237 insertions(+), 5 deletions(-) > >> create mode 100644 elf/dl-symbol-hacks.h > >> create mode 100644 sysdeps/generic/dl-ifunc-generic.h > >> create mode 100644 sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h > >> create mode 100644 sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h > >> create mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h > >> create mode 100644 sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h > >> create mode 100644 sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h > >> create mode 100644 sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h > >> > >> diff --git a/elf/Makefile b/elf/Makefile > >> index 3386f0ce77..4b992bd348 100644 > >> --- a/elf/Makefile > >> +++ b/elf/Makefile > >> @@ -162,11 +162,6 @@ ifeq (yes,$(have-loop-to-function)) > >> CFLAGS-rtld.c += -fno-tree-loop-distribute-patterns > >> endif > >> > >> -ifeq (yes,$(have-loop-to-function)) > >> -# Likewise, during static library startup, memset is not yet available. > >> -CFLAGS-dl-support.c = -fno-tree-loop-distribute-patterns > >> -endif > >> - > >> # Compile rtld itself without stack protection. > >> # Also compile all routines in the static library that are elided from > >> # the shared libc because they are in libc.a in the same way. > >> diff --git a/elf/dl-support.c b/elf/dl-support.c > >> index 4af0b5b2ce..6d1996ae6e 100644 > >> --- a/elf/dl-support.c > >> +++ b/elf/dl-support.c > >> @@ -44,6 +44,7 @@ > >> #include <dl-auxv.h> > >> #include <dl-find_object.h> > >> #include <array_length.h> > >> +#include <dl-symbol-hacks.h> > >> > >> extern char *__progname; > >> char **_dl_argv = &__progname; /* This is checked for some error messages. */ > >> diff --git a/elf/dl-symbol-hacks.h b/elf/dl-symbol-hacks.h > >> new file mode 100644 > >> index 0000000000..6b9d24ed03 > >> --- /dev/null > >> +++ b/elf/dl-symbol-hacks.h > >> @@ -0,0 +1,31 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_SYMBOL_HACKS_H > >> +#define _DL_SYMBOL_HACKS_H > >> + > >> +#include <dl-ifunc-generic.h> > >> + > >> +/* Some compiler optimizations may transform loops into memset/memmove > >> + calls and without proper redirection it might call PLT throught > >> + ifunc without relocations being processed. */ > >> +#if !IS_IN(rtld) && defined HAVE_MEMSET_IFUNC_GENERIC > >> +asm ("memset = " HAVE_MEMSET_IFUNC_GENERIC); > >> +#endif > >> + > >> +#endif > >> diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c > >> index 8e7ee9df10..c797484522 100644 > >> --- a/elf/dl-tunables.c > >> +++ b/elf/dl-tunables.c > >> @@ -32,6 +32,7 @@ > >> #include <ldsodefs.h> > >> #include <array_length.h> > >> #include <dl-minimal-malloc.h> > >> +#include <dl-symbol-hacks.h> > >> > >> #define TUNABLES_INTERNAL 1 > >> #include "dl-tunables.h" > >> diff --git a/sysdeps/generic/dl-ifunc-generic.h b/sysdeps/generic/dl-ifunc-generic.h > >> new file mode 100644 > >> index 0000000000..5e1d5c1fd8 > >> --- /dev/null > >> +++ b/sysdeps/generic/dl-ifunc-generic.h > >> @@ -0,0 +1,37 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_IFUNC_GENERIC_H > >> +#define _DL_IFUNC_GENERIC_H > >> + > >> +/* The compiler might optimize loops or other constructs to library calls even > >> + in freestanding mode. Although it is safe in most scenarios, on program > >> + loading and static startup, iFUNC resolution might require other dynamic > >> + relocation that are not yet done. > >> + > >> + Instead of adding per-file compiler flags to avoid the libcall generation, > >> + this header defines generic symbols that will be routed instead of the > >> + default symbols name. > >> + > >> + Each port can then define the following macro to the expected generic > >> + implementation if the symbol is provided as iFUNC: > >> + > >> + HAVE_MEMSET_IFUNC_GENERIC - the generic memset call. > >> + */ > >> + > >> +#endif > >> diff --git a/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h > >> new file mode 100644 > >> index 0000000000..1278a06ff0 > >> --- /dev/null > >> +++ b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h > >> @@ -0,0 +1,24 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_IFUNC_GENERIC_H > >> +#define _DL_IFUNC_GENERIC_H > >> + > >> +#define HAVE_MEMSET_IFUNC_GENERIC "__memset_generic" > >> + > >> +#endif > >> diff --git a/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h > >> new file mode 100644 > >> index 0000000000..c8e294b3c9 > >> --- /dev/null > >> +++ b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h > >> @@ -0,0 +1,26 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_IFUNC_GENERIC_H > >> +#define _DL_IFUNC_GENERIC_H > >> + > >> +#ifdef USE_MULTIARCH > >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ia32" > >> +#endif > >> + > >> +#endif > > > > This file should be in sysdeps/i386/i686/multiarch. > > > > My understanding is we only support iFUNC for Linux, but it seems that multiarch > directory is not Linux specific. I will change it. > > >> diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h > >> new file mode 100644 > >> index 0000000000..b0f9401670 > >> --- /dev/null > >> +++ b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h > >> @@ -0,0 +1,28 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_IFUNC_GENERIC_H > >> +#define _DL_IFUNC_GENERIC_H > >> + > >> +/* powerpc and powerpc64 provides the default memset as 'memset', so > >> + no need to redirect it. */ > >> +#if defined USE_MULTIARCH && defined __powerpc64__ && _CALL_ELF != 2 > >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_power8" > >> +#endif > >> + > >> +#endif > >> diff --git a/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h > >> new file mode 100644 > >> index 0000000000..f664ac07a7 > >> --- /dev/null > >> +++ b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h > >> @@ -0,0 +1,31 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_IFUNC_GENERIC_H > >> +#define _DL_IFUNC_GENERIC_H > >> + > >> +#ifdef USE_MULTIARCH > >> +# include <ifunc-memset.h> > >> + > >> +# define IFUNC_SYMBOL_STR1(s) #s > >> +# define IFUNC_SYMBOL_STR(s) IFUNC_SYMBOL_STR1(s) > >> + > >> +# define HAVE_MEMSET_IFUNC_GENERIC IFUNC_SYMBOL_STR(MEMSET_DEFAULT) > >> +#endif > >> + > >> +#endif > >> diff --git a/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h > >> new file mode 100644 > >> index 0000000000..86815317a9 > >> --- /dev/null > >> +++ b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h > >> @@ -0,0 +1,26 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_IFUNC_GENERIC_H > >> +#define _DL_IFUNC_GENERIC_H > >> + > >> +#ifdef USE_MULTIARCH > >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ultra1" > >> +#endif > >> + > >> +#endif > >> diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h > >> new file mode 100644 > >> index 0000000000..7b7cf1c3d6 > >> --- /dev/null > >> +++ b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h > >> @@ -0,0 +1,32 @@ > >> +/* Symbol rediretion for loader/static initialization code. > >> + Copyright (C) 2022 Free Software Foundation, Inc. > >> + This file is part of the GNU C Library. > >> + > >> + The GNU C Library is free software; you can redistribute it and/or > >> + modify it under the terms of the GNU Lesser General Public > >> + License as published by the Free Software Foundation; either > >> + version 2.1 of the License, or (at your option) any later version. > >> + > >> + The GNU C Library is distributed in the hope that it will be useful, > >> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> + Lesser General Public License for more details. > >> + > >> + You should have received a copy of the GNU Lesser General Public > >> + License along with the GNU C Library; if not, see > >> + <https://www.gnu.org/licenses/>. */ > >> + > >> +#ifndef _DL_IFUNC_GENERIC_H > >> +#define _DL_IFUNC_GENERIC_H > >> + > >> +#include <isa-level.h> > >> + > >> +#if MINIMUM_X86_ISA_LEVEL >= 4 > >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_evex_unaligned" > >> +#elif MINIMUM_X86_ISA_LEVEL == 3 > >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_avx2_unaligned" > >> +#else > >> +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_sse2_unaligned" > >> +#endif > >> + > >> +#endif > >> -- > >> 2.34.1 > >> > > > > This file should be in sysdeps/x86_64/multiarch and the generic > > memset should follow sysdeps/x86_64/memset.S: > > > > #define DEFAULT_IMPL_V1 "multiarch/memset-sse2-unaligned-erms.S" > > #define DEFAULT_IMPL_V3 "multiarch/memset-avx2-unaligned-erms.S" > > #define DEFAULT_IMPL_V4 "multiarch/memset-evex-unaligned-erms.S" > > Right, my understading it does follow the provided implementation based > on the MINIMUM_X86_ISA_LEVEL. What I am missing here? You are right. The file content is OK. But it should be in sysdeps/x86_64/multiarch.
diff --git a/elf/Makefile b/elf/Makefile index 3386f0ce77..4b992bd348 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -162,11 +162,6 @@ ifeq (yes,$(have-loop-to-function)) CFLAGS-rtld.c += -fno-tree-loop-distribute-patterns endif -ifeq (yes,$(have-loop-to-function)) -# Likewise, during static library startup, memset is not yet available. -CFLAGS-dl-support.c = -fno-tree-loop-distribute-patterns -endif - # Compile rtld itself without stack protection. # Also compile all routines in the static library that are elided from # the shared libc because they are in libc.a in the same way. diff --git a/elf/dl-support.c b/elf/dl-support.c index 4af0b5b2ce..6d1996ae6e 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -44,6 +44,7 @@ #include <dl-auxv.h> #include <dl-find_object.h> #include <array_length.h> +#include <dl-symbol-hacks.h> extern char *__progname; char **_dl_argv = &__progname; /* This is checked for some error messages. */ diff --git a/elf/dl-symbol-hacks.h b/elf/dl-symbol-hacks.h new file mode 100644 index 0000000000..6b9d24ed03 --- /dev/null +++ b/elf/dl-symbol-hacks.h @@ -0,0 +1,31 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_SYMBOL_HACKS_H +#define _DL_SYMBOL_HACKS_H + +#include <dl-ifunc-generic.h> + +/* Some compiler optimizations may transform loops into memset/memmove + calls and without proper redirection it might call PLT throught + ifunc without relocations being processed. */ +#if !IS_IN(rtld) && defined HAVE_MEMSET_IFUNC_GENERIC +asm ("memset = " HAVE_MEMSET_IFUNC_GENERIC); +#endif + +#endif diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index 8e7ee9df10..c797484522 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -32,6 +32,7 @@ #include <ldsodefs.h> #include <array_length.h> #include <dl-minimal-malloc.h> +#include <dl-symbol-hacks.h> #define TUNABLES_INTERNAL 1 #include "dl-tunables.h" diff --git a/sysdeps/generic/dl-ifunc-generic.h b/sysdeps/generic/dl-ifunc-generic.h new file mode 100644 index 0000000000..5e1d5c1fd8 --- /dev/null +++ b/sysdeps/generic/dl-ifunc-generic.h @@ -0,0 +1,37 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_IFUNC_GENERIC_H +#define _DL_IFUNC_GENERIC_H + +/* The compiler might optimize loops or other constructs to library calls even + in freestanding mode. Although it is safe in most scenarios, on program + loading and static startup, iFUNC resolution might require other dynamic + relocation that are not yet done. + + Instead of adding per-file compiler flags to avoid the libcall generation, + this header defines generic symbols that will be routed instead of the + default symbols name. + + Each port can then define the following macro to the expected generic + implementation if the symbol is provided as iFUNC: + + HAVE_MEMSET_IFUNC_GENERIC - the generic memset call. + */ + +#endif diff --git a/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h new file mode 100644 index 0000000000..1278a06ff0 --- /dev/null +++ b/sysdeps/unix/sysv/linux/aarch64/dl-ifunc-generic.h @@ -0,0 +1,24 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_IFUNC_GENERIC_H +#define _DL_IFUNC_GENERIC_H + +#define HAVE_MEMSET_IFUNC_GENERIC "__memset_generic" + +#endif diff --git a/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h new file mode 100644 index 0000000000..c8e294b3c9 --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/dl-ifunc-generic.h @@ -0,0 +1,26 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_IFUNC_GENERIC_H +#define _DL_IFUNC_GENERIC_H + +#ifdef USE_MULTIARCH +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ia32" +#endif + +#endif diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h new file mode 100644 index 0000000000..b0f9401670 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/dl-ifunc-generic.h @@ -0,0 +1,28 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_IFUNC_GENERIC_H +#define _DL_IFUNC_GENERIC_H + +/* powerpc and powerpc64 provides the default memset as 'memset', so + no need to redirect it. */ +#if defined USE_MULTIARCH && defined __powerpc64__ && _CALL_ELF != 2 +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_power8" +#endif + +#endif diff --git a/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h new file mode 100644 index 0000000000..f664ac07a7 --- /dev/null +++ b/sysdeps/unix/sysv/linux/s390/dl-ifunc-generic.h @@ -0,0 +1,31 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_IFUNC_GENERIC_H +#define _DL_IFUNC_GENERIC_H + +#ifdef USE_MULTIARCH +# include <ifunc-memset.h> + +# define IFUNC_SYMBOL_STR1(s) #s +# define IFUNC_SYMBOL_STR(s) IFUNC_SYMBOL_STR1(s) + +# define HAVE_MEMSET_IFUNC_GENERIC IFUNC_SYMBOL_STR(MEMSET_DEFAULT) +#endif + +#endif diff --git a/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h new file mode 100644 index 0000000000..86815317a9 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sparc/dl-ifunc-generic.h @@ -0,0 +1,26 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_IFUNC_GENERIC_H +#define _DL_IFUNC_GENERIC_H + +#ifdef USE_MULTIARCH +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_ultra1" +#endif + +#endif diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h new file mode 100644 index 0000000000..7b7cf1c3d6 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/dl-ifunc-generic.h @@ -0,0 +1,32 @@ +/* Symbol rediretion for loader/static initialization code. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_IFUNC_GENERIC_H +#define _DL_IFUNC_GENERIC_H + +#include <isa-level.h> + +#if MINIMUM_X86_ISA_LEVEL >= 4 +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_evex_unaligned" +#elif MINIMUM_X86_ISA_LEVEL == 3 +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_avx2_unaligned" +#else +# define HAVE_MEMSET_IFUNC_GENERIC "__memset_sse2_unaligned" +#endif + +#endif