| Message ID | 87zhfngjot.fsf@oldenburg2.str.redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce <elf-initfini.h> and ELF_INITFINI for all architectures | expand |
On 20/12/2019 11:23, Florian Weimer wrote: > This change is desirable for a rework of the statically linked startup > code to remove the generic ROP trampoline in it (bug 23323). > > I verified that the *crt*.o files are unchanged by this change after > stripping (although my binutils dispatcher fails to determine the > correct ABI for some of the MIPS gcrt1.o files, so those have not been > checked). > > Thanks, > Florian > 8<------------------------------------------------------------------8< > > This supersedes the init_array sysdeps directory. It allows us to > check for ELF_INITFINI in both C and assembler code, and skip DT_INIT > and DT_FINI processing completely on newer architectures. > > A new header file is needed because <dl-machine.h> is incompatible > with assembler code. <sysdep.h> is compatible with assembler code, > but it cannot be included in all assembler files because on some > architectures, it redefines register names, and some assembler files > conflict with that. > > <elf-initfini.h> is replicated for legacy architectures which need > DT_INIT/DT_FINI support. New architectures follow the generic default > and disable it. LGTM, with only a small clarification below. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > > ----- > csu/elf-init.c | 7 ++-- > csu/gmon-start.c | 8 +++++ > elf/dl-fini.c | 5 +-- > elf/dl-init.c | 8 ++--- > nptl/pt-crti.S | 13 +++++-- > .../pt-crti.S => aarch64/elf-initfini.h} | 13 +++---- > sysdeps/alpha/elf-initfini.h | 20 +++++++++++ > sysdeps/arm/elf-initfini.h | 20 +++++++++++ > sysdeps/csky/Implies | 1 - > sysdeps/{init_array => generic}/crti.S | 12 +++++-- > sysdeps/{init_array => generic}/crtn.S | 6 ++++ > sysdeps/generic/elf-initfini.h | 24 +++++++++++++ > sysdeps/hppa/elf-initfini.h | 20 +++++++++++ > sysdeps/ia64/elf-initfini.h | 20 +++++++++++ > sysdeps/init_array/elf-init.c | 37 ------------------- > sysdeps/init_array/gmon-start.c | 41 ---------------------- > sysdeps/m68k/elf-initfini.h | 20 +++++++++++ > sysdeps/microblaze/elf-initfini.h | 20 +++++++++++ > sysdeps/mips/elf-initfini.h | 20 +++++++++++ > sysdeps/nios2/elf-initfini.h | 20 +++++++++++ > sysdeps/powerpc/elf-initfini.h | 20 +++++++++++ > sysdeps/riscv/Implies | 2 -- > sysdeps/s390/elf-initfini.h | 20 +++++++++++ > sysdeps/sh/elf-initfini.h | 20 +++++++++++ > sysdeps/sparc/elf-initfini.h | 20 +++++++++++ > sysdeps/x86/elf-initfini.h | 20 +++++++++++ > 26 files changed, 331 insertions(+), 106 deletions(-) > > diff --git a/csu/elf-init.c b/csu/elf-init.c > index 6112dca379..c16029aa08 100644 > --- a/csu/elf-init.c > +++ b/csu/elf-init.c > @@ -34,6 +34,7 @@ > <https://www.gnu.org/licenses/>. */ > > #include <stddef.h> > +#include <elf-initfini.h> > > > /* These magic symbols are provided by the linker. */ Ok. > @@ -49,7 +50,7 @@ extern void (*__fini_array_start []) (void) attribute_hidden; > extern void (*__fini_array_end []) (void) attribute_hidden; > > > -#ifndef NO_INITFINI > +#if ELF_INITFINI > /* These function symbols are provided for the .init/.fini section entry > points automagically by the linker. */ > extern void _init (void); > @@ -79,7 +80,7 @@ __libc_csu_init (int argc, char **argv, char **envp) > } > #endif > > -#ifndef NO_INITFINI > +#if ELF_INITFINI > _init (); > #endif > Ok. > @@ -99,7 +100,7 @@ __libc_csu_fini (void) > while (i-- > 0) > (*__fini_array_start [i]) (); > > -# ifndef NO_INITFINI > +# if ELF_INITFINI > _fini (); > # endif > #endif Ok. > diff --git a/csu/gmon-start.c b/csu/gmon-start.c > index 9e427342df..1a4fc655ba 100644 > --- a/csu/gmon-start.c > +++ b/csu/gmon-start.c > @@ -37,6 +37,7 @@ > #include <sys/gmon.h> > #include <stdlib.h> > #include <unistd.h> > +#include <elf-initfini.h> > #define __ASSEMBLY__ > #include <entry.h> > > @@ -59,6 +60,13 @@ extern char etext[]; > # endif > #endif > > +#if !ELF_INITFINI > +/* Instead of defining __gmon_start__ globally in gcrt1.o, we make it > + static and just put a pointer to it into the .preinit_array > + section. */ > +# define GMON_START_ARRAY_SECTION ".preinit_array" > +#endif > + > #ifdef GMON_START_ARRAY_SECTION > static void __gmon_start__ (void); > static void (*const gmon_start_initializer) (void) > diff --git a/elf/dl-fini.c b/elf/dl-fini.c > index 70e7346304..e33cf4db96 100644 > --- a/elf/dl-fini.c > +++ b/elf/dl-fini.c > @@ -19,6 +19,7 @@ > #include <assert.h> > #include <string.h> > #include <ldsodefs.h> > +#include <elf-initfini.h> > > > /* Type of the constructor functions. */ > @@ -117,7 +118,7 @@ _dl_fini (void) > > /* Is there a destructor function? */ > if (l->l_info[DT_FINI_ARRAY] != NULL > - || l->l_info[DT_FINI] != NULL) > + || (ELF_INITFINI && l->l_info[DT_FINI] != NULL)) > { > /* When debugging print a message first. */ > if (__builtin_expect (GLRO(dl_debug_mask) > @@ -139,7 +140,7 @@ _dl_fini (void) > } > > /* Next try the old-style destructor. */ > - if (l->l_info[DT_FINI] != NULL) > + if (ELF_INITFINI && l->l_info[DT_FINI] != NULL) > DL_CALL_DT_FINI > (l, l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr); > } > diff --git a/elf/dl-init.c b/elf/dl-init.c > index 3721bca81e..9ac8bafdf9 100644 > --- a/elf/dl-init.c > +++ b/elf/dl-init.c > @@ -18,6 +18,7 @@ > > #include <stddef.h> > #include <ldsodefs.h> > +#include <elf-initfini.h> > > > /* Type of the initializer. */ > @@ -40,11 +41,6 @@ call_init (struct link_map *l, int argc, char **argv, char **env) > && l->l_type == lt_executable) > return; > > - /* Are there any constructors? */ > - if (l->l_info[DT_INIT] == NULL > - && __builtin_expect (l->l_info[DT_INIT_ARRAY] == NULL, 1)) > - return; > - Is the idea of removing the early return to always print the debug message below? > /* Print a debug message if wanted. */ > if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS)) > _dl_debug_printf ("\ncalling init: %s\n\n", > @@ -54,7 +50,7 @@ call_init (struct link_map *l, int argc, char **argv, char **env) > - the one named by DT_INIT > - the others in the DT_INIT_ARRAY. > */ > - if (l->l_info[DT_INIT] != NULL) > + if (ELF_INITFINI && l->l_info[DT_INIT] != NULL) > DL_CALL_DT_INIT(l, l->l_addr + l->l_info[DT_INIT]->d_un.d_ptr, argc, argv, env); > > /* Next see whether there is an array with initialization functions. */ Ok. > diff --git a/nptl/pt-crti.S b/nptl/pt-crti.S > index b389442a15..ef006a0437 100644 > --- a/nptl/pt-crti.S > +++ b/nptl/pt-crti.S > @@ -33,11 +33,18 @@ > License along with the GNU C Library; if not, see > <https://www.gnu.org/licenses/>. */ > > +#include <elf-initfini.h> > + > /* Arrange for __pthread_initialize_minimal_internal to be called at > libpthread startup, instead of conditionally calling > __gmon_start__. */ > > -#define PREINIT_FUNCTION __pthread_initialize_minimal_internal > -#define PREINIT_FUNCTION_WEAK 0 > +#if ELF_INITFINI > +# define PREINIT_FUNCTION __pthread_initialize_minimal_internal > +# define PREINIT_FUNCTION_WEAK 0 > > -#include <crti.S> > +# include <crti.S> > +#else > + .section .init_array,"a",%init_array > + .dc.a __pthread_initialize_minimal_internal > +#endif Ok. > diff --git a/sysdeps/init_array/pt-crti.S b/sysdeps/aarch64/elf-initfini.h > similarity index 67% > rename from sysdeps/init_array/pt-crti.S > rename to sysdeps/aarch64/elf-initfini.h > index 3955298eca..660964ccda 100644 > --- a/sysdeps/init_array/pt-crti.S > +++ b/sysdeps/aarch64/elf-initfini.h > @@ -1,5 +1,5 @@ > -/* Special initializer support for libpthread. > - Copyright (C) 2015-2019 Free Software Foundation, Inc. > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. AArch64 version. > + Copyright (C) 2019 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 > @@ -14,10 +14,7 @@ > > 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/>. */ > + <http://www.gnu.org/licenses/>. */ > > -/* This arranges for libpthread.so's special initializer to be called as > - soon as the library is loaded. */ > - > - .section .init_array,"a",%init_array > - .dc.a __pthread_initialize_minimal_internal > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 Ok. > diff --git a/sysdeps/alpha/elf-initfini.h b/sysdeps/alpha/elf-initfini.h > new file mode 100644 > index 0000000000..f3203cf173 > --- /dev/null > +++ b/sysdeps/alpha/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. Alpha version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 Ok. > diff --git a/sysdeps/arm/elf-initfini.h b/sysdeps/arm/elf-initfini.h > new file mode 100644 > index 0000000000..b4406f1003 > --- /dev/null > +++ b/sysdeps/arm/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. Arm version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 Ok. > diff --git a/sysdeps/csky/Implies b/sysdeps/csky/Implies > index fd80b4826e..f8c3a7586e 100644 > --- a/sysdeps/csky/Implies > +++ b/sysdeps/csky/Implies > @@ -1,4 +1,3 @@ > -init_array > wordsize-32 > # C-SKY uses IEEE 754 floating point. > ieee754/flt-32 Ok. > diff --git a/sysdeps/init_array/crti.S b/sysdeps/generic/crti.S > similarity index 80% > rename from sysdeps/init_array/crti.S > rename to sysdeps/generic/crti.S > index 145c918f93..82d6dc0d91 100644 > --- a/sysdeps/init_array/crti.S > +++ b/sysdeps/generic/crti.S > @@ -12,11 +12,17 @@ > toolchains without .init_array support can use this to avoid the > superfluous .init and .fini boilerplate code. */ > > +#include <elf-initfini.h> > + > +#if ELF_INITFINI > +# error Cannot use default crti.S because it lacks _init code > +#endif > + Ok. > #ifdef PREINIT_FUNCTION > > -#if PREINIT_FUNCTION_WEAK > -# error PREINIT_FUNCTION_WEAK is unsupported > -#endif > +# if PREINIT_FUNCTION_WEAK > +# error PREINIT_FUNCTION_WEAK is unsupported > +# endif > > /* This arranges for PREINIT_FUNCTION to be called upon loading a library that > contains crti.o. */ Ok. > diff --git a/sysdeps/init_array/crtn.S b/sysdeps/generic/crtn.S > similarity index 82% > rename from sysdeps/init_array/crtn.S > rename to sysdeps/generic/crtn.S > index 6f70e77160..d92b07dd0b 100644 > --- a/sysdeps/init_array/crtn.S > +++ b/sysdeps/generic/crtn.S > @@ -11,3 +11,9 @@ > But new configurations without compatibility concerns for > toolchains without .init_array support can use this to avoid the > superfluous .init and .fini boilerplate code. */ > + > +#include <elf-initfini.h> > + > +#if ELF_INITFINI > +# error Cannot use genetric crtn.S because it lacks _fini code > +#endif Ok. > diff --git a/sysdeps/generic/elf-initfini.h b/sysdeps/generic/elf-initfini.h > new file mode 100644 > index 0000000000..2f4d172765 > --- /dev/null > +++ b/sysdeps/generic/elf-initfini.h > @@ -0,0 +1,24 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Legacy platforms define this to 1. If 0, the dynamic linker > + ignores the DT_INIT and DT_FINI tags, and static binaries will not > + call the _init or _fini functions. If 1, the old constructor > + mechanisms are used in addition to the initarray/finiarray > + support. */ > +#define ELF_INITFINI 0 Ok. > diff --git a/sysdeps/hppa/elf-initfini.h b/sysdeps/hppa/elf-initfini.h > new file mode 100644 > index 0000000000..18e3df5aff > --- /dev/null > +++ b/sysdeps/hppa/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. HPPA version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 Ok. > diff --git a/sysdeps/ia64/elf-initfini.h b/sysdeps/ia64/elf-initfini.h > new file mode 100644 > index 0000000000..9b45ce3c7e > --- /dev/null > +++ b/sysdeps/ia64/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. IA64 version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 Ok. > diff --git a/sysdeps/init_array/elf-init.c b/sysdeps/init_array/elf-init.c > deleted file mode 100644 > index d928e6997c..0000000000 > --- a/sysdeps/init_array/elf-init.c > +++ /dev/null > @@ -1,37 +0,0 @@ > -/* Startup support for ELF initializers/finalizers in the main executable. > - Copyright (C) 2013-2019 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. > - > - In addition to the permissions in the GNU Lesser General Public > - License, the Free Software Foundation gives you unlimited > - permission to link the compiled version of this file with other > - programs, and to distribute those programs without any restriction > - coming from the use of this file. (The GNU Lesser General Public > - License restrictions do apply in other respects; for example, they > - cover modification of the file, and distribution when not linked > - into another program.) > - > - Note that people who make modified versions of this file are not > - obligated to grant this special exception for their modified > - versions; it is their choice whether to do so. The GNU Lesser > - General Public License gives permission to release a modified > - version without this exception; this exception also makes it > - possible to release a modified version which carries forward this > - exception. > - > - 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/>. */ > - > -#define NO_INITFINI > -#include <csu/elf-init.c> Ok. > diff --git a/sysdeps/init_array/gmon-start.c b/sysdeps/init_array/gmon-start.c > deleted file mode 100644 > index 9ea40b44b6..0000000000 > --- a/sysdeps/init_array/gmon-start.c > +++ /dev/null > @@ -1,41 +0,0 @@ > -/* gmon startup hook using .preinit_array. > - Copyright (C) 2013-2019 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. > - > - In addition to the permissions in the GNU Lesser General Public > - License, the Free Software Foundation gives you unlimited > - permission to link the compiled version of this file with other > - programs, and to distribute those programs without any restriction > - coming from the use of this file. (The GNU Lesser General Public > - License restrictions do apply in other respects; for example, they > - cover modification of the file, and distribution when not linked > - into another program.) > - > - Note that people who make modified versions of this file are not > - obligated to grant this special exception for their modified > - versions; it is their choice whether to do so. The GNU Lesser > - General Public License gives permission to release a modified > - version without this exception; this exception also makes it > - possible to release a modified version which carries forward this > - exception. > - > - 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/>. */ > - > -/* Instead of defining __gmon_start__ globally in gcrt1.o, we make it > - static and just put a pointer to it into the .preinit_array section. */ > - > -#define GMON_START_ARRAY_SECTION ".preinit_array" > - > -#include <csu/gmon-start.c> Ok. > diff --git a/sysdeps/m68k/elf-initfini.h b/sysdeps/m68k/elf-initfini.h > new file mode 100644 > index 0000000000..6ae56c16c3 > --- /dev/null > +++ b/sysdeps/m68k/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. m68k version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 Ok. > diff --git a/sysdeps/microblaze/elf-initfini.h b/sysdeps/microblaze/elf-initfini.h > new file mode 100644 > index 0000000000..e36e664762 > --- /dev/null > +++ b/sysdeps/microblaze/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader, for Microblaze. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 Ok. > diff --git a/sysdeps/mips/elf-initfini.h b/sysdeps/mips/elf-initfini.h > new file mode 100644 > index 0000000000..83fe8025b7 > --- /dev/null > +++ b/sysdeps/mips/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. MIPS version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 OK. > diff --git a/sysdeps/nios2/elf-initfini.h b/sysdeps/nios2/elf-initfini.h > new file mode 100644 > index 0000000000..56c510da71 > --- /dev/null > +++ b/sysdeps/nios2/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. nios2 version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 OK. > diff --git a/sysdeps/powerpc/elf-initfini.h b/sysdeps/powerpc/elf-initfini.h > new file mode 100644 > index 0000000000..c1c38efe1f > --- /dev/null > +++ b/sysdeps/powerpc/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader, for powerpc. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 OK. > diff --git a/sysdeps/riscv/Implies b/sysdeps/riscv/Implies > index c88325b8be..1945b1f4bb 100644 > --- a/sysdeps/riscv/Implies > +++ b/sysdeps/riscv/Implies > @@ -1,5 +1,3 @@ > -init_array > - > ieee754/ldbl-128 > ieee754/dbl-64 > ieee754/flt-32 OK. > diff --git a/sysdeps/s390/elf-initfini.h b/sysdeps/s390/elf-initfini.h > new file mode 100644 > index 0000000000..b300881236 > --- /dev/null > +++ b/sysdeps/s390/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. S/390 version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 OK. > diff --git a/sysdeps/sh/elf-initfini.h b/sysdeps/sh/elf-initfini.h > new file mode 100644 > index 0000000000..de44d0bb6a > --- /dev/null > +++ b/sysdeps/sh/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. SH version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 OK. > diff --git a/sysdeps/sparc/elf-initfini.h b/sysdeps/sparc/elf-initfini.h > new file mode 100644 > index 0000000000..9a983c5501 > --- /dev/null > +++ b/sysdeps/sparc/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. SPARC version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 OK. > diff --git a/sysdeps/x86/elf-initfini.h b/sysdeps/x86/elf-initfini.h > new file mode 100644 > index 0000000000..ba4b5a5b47 > --- /dev/null > +++ b/sysdeps/x86/elf-initfini.h > @@ -0,0 +1,20 @@ > +/* Determine DT_INIT/DT_FINI support in the dynamic loader. x86 version. > + Copyright (C) 2019 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 > + <http://www.gnu.org/licenses/>. */ > + > +/* Enable DT_INIT/DT_FINI support. */ > +#define ELF_INITFINI 1 > OK.
* Adhemerval Zanella: >> @@ -40,11 +41,6 @@ call_init (struct link_map *l, int argc, char **argv, char **env) >> && l->l_type == lt_executable) >> return; >> >> - /* Are there any constructors? */ >> - if (l->l_info[DT_INIT] == NULL >> - && __builtin_expect (l->l_info[DT_INIT_ARRAY] == NULL, 1)) >> - return; >> - > > Is the idea of removing the early return to always print the debug > message below? Yes, I think this message is helpful to show what is going on, although like so many dynamic linker log messages, its wording could probably be improved. I do not think it matters today because every object linked by current GCC contains an ELF constructor (the _ITM_registerTMCloneTable stuff).
* Adhemerval Zanella: > On 20/12/2019 11:23, Florian Weimer wrote: >> This change is desirable for a rework of the statically linked startup >> code to remove the generic ROP trampoline in it (bug 23323). >> >> I verified that the *crt*.o files are unchanged by this change after >> stripping (although my binutils dispatcher fails to determine the >> correct ABI for some of the MIPS gcrt1.o files, so those have not been >> checked). >> >> Thanks, >> Florian >> 8<------------------------------------------------------------------8< >> >> This supersedes the init_array sysdeps directory. It allows us to >> check for ELF_INITFINI in both C and assembler code, and skip DT_INIT >> and DT_FINI processing completely on newer architectures. >> >> A new header file is needed because <dl-machine.h> is incompatible >> with assembler code. <sysdep.h> is compatible with assembler code, >> but it cannot be included in all assembler files because on some >> architectures, it redefines register names, and some assembler files >> conflict with that. >> >> <elf-initfini.h> is replicated for legacy architectures which need >> DT_INIT/DT_FINI support. New architectures follow the generic default >> and disable it. > > LGTM, with only a small clarification below. > > Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> I've fixed up the years and URLs and pushed this. Thanks, Florian
This breaks riscv64. Andreas.
* Andreas Schwab:
> This breaks riscv64.
How so?
Thanks,
Florian
On Feb 20 2020, Florian Weimer wrote: > * Andreas Schwab: > >> This breaks riscv64. > > How so? It crashes. Andreas.
environ is empty. Andreas.
* Andreas Schwab:
> environ is empty.
That's because libc.so.6 still has DT_INIT, from which _environ and
other variables are set up. I assumed binutils would convert that into
DT_INITARRAY because the architecture is not supposed to have DT_INIT.
Without that, it's hard to declare that there is no DT_INIT, and the
patch essentially breaks ABI (because DT_INIT processing is gone).
This should fix the breakage:
Subject: Use ELF constructor instead of _init in libc.so
On !ELF_INITFINI architectures, _init is no longer called by the dynamic
linker. We can use an ELF constructor instead because the constructor
order does not matter. (The other constructors are used to set up libio
vtable bypasses and do not depend on this initialization routine.)
diff --git a/csu/init-first.c b/csu/init-first.c
index 1cd8a75098..1fa1633657 100644
--- a/csu/init-first.c
+++ b/csu/init-first.c
@@ -46,9 +46,8 @@ __libc_init_first (int argc, char **argv, char **envp)
/* For DSOs we do not need __libc_init_first but instead _init. */
}
-void
-attribute_hidden
-_init (int argc, char **argv, char **envp)
+static void __attribute__ ((constructor))
+init (int argc, char **argv, char **envp)
{
#endif
But I'm no longer sure if RISC-V is actually an !ELF_INITFINI
architecture.
Thanks,
Florian
On Thu, Feb 20, 2020 at 10:53 AM Florian Weimer <fweimer@redhat.com> wrote: > That's because libc.so.6 still has DT_INIT, from which _environ and > other variables are set up. I assumed binutils would convert that into > DT_INITARRAY because the architecture is not supposed to have DT_INIT. > Without that, it's hard to declare that there is no DT_INIT, and the > patch essentially breaks ABI (because DT_INIT processing is gone). DT_INIT is a function address. DT_INITARRAY is a pointer to a table of addresses. I don't see how the linker can easily convert between them. We would have to increase the size of the init_array table at link time, and I don't think we have any linker support for that. Maybe we could modify the startfiles to put a weak reference to _init at the end of init_array, right before the zero that normally ends the list, and fix the linker to stop creating DT_INIT for _init. But that sounds a little risky, and defeats the purpose of dropping support for _init to reduce code size. I would prefer that glibc not create an _init function in the first place. > But I'm no longer sure if RISC-V is actually an !ELF_INITFINI > architecture. gcc will not create .init sections. Newlib does not create them or run them in the startfiles. The linux kernel does not run DT_INIT. That is probably why your patch failed for Andreas. But there is a problem with GNU ld which automatically creates DT_INIT when it sees a function called _init. We missed that. This is in target dependent code. The default function name can be overridden but that isn't quite right for RISC-V either. Maybe we should give a linker error if someone gives a _init or _fini function to the linker? That way they get a link time error instead of a run-time error. Jim
* Jim Wilson: > On Thu, Feb 20, 2020 at 10:53 AM Florian Weimer <fweimer@redhat.com> wrote: >> That's because libc.so.6 still has DT_INIT, from which _environ and >> other variables are set up. I assumed binutils would convert that into >> DT_INITARRAY because the architecture is not supposed to have DT_INIT. >> Without that, it's hard to declare that there is no DT_INIT, and the >> patch essentially breaks ABI (because DT_INIT processing is gone). > > DT_INIT is a function address. DT_INITARRAY is a pointer to a table > of addresses. I don't see how the linker can easily convert between > them. We would have to increase the size of the init_array table at > link time, and I don't think we have any linker support for that. > Maybe we could modify the startfiles to put a weak reference to _init > at the end of init_array, right before the zero that normally ends the > list, and fix the linker to stop creating DT_INIT for _init. But that > sounds a little risky, and defeats the purpose of dropping support for > _init to reduce code size. I would prefer that glibc not create an > _init function in the first place. I'm not worried about glibc here. It's easy to make glibc consistent with itself. The patch I posted seems to do the trick, without regressing anywhere else. What I don't know is whether this binutils bug has resulted in DT_INIT being used *elsewhere*. I don't have a RISC-V distribution to analyze, so I really don't know. Fedora RISC-V seems dead, this hasn't been updated in a while: <https://dl.fedoraproject.org/pub/alt/risc-v/repo/fedora/rawhide/latest/riscv64/> (I have existing tools for RPM-based distributions, so having one would be most useful to me to check for DT_INIT references.) >> But I'm no longer sure if RISC-V is actually an !ELF_INITFINI >> architecture. > > gcc will not create .init sections. Newlib does not create them or > run them in the startfiles. The linux kernel does not run DT_INIT. The kernel never runs DT_INIT on any architecture as far as I know, but currently released glibc does, even on RISC-V. > That is probably why your patch failed for Andreas. Yes, looks like it. > But there is a problem with GNU ld which automatically creates DT_INIT > when it sees a function called _init. We missed that. This is in > target dependent code. The default function name can be overridden > but that isn't quite right for RISC-V either. Maybe we should give a > linker error if someone gives a _init or _fini function to the linker? > That way they get a link time error instead of a run-time error. I would expect the toolchain to treat _init just like any other function, so without DT_INIT support, it would turn into dead code. Thanks, Florian
* Florian Weimer: > * Jim Wilson: > >> On Thu, Feb 20, 2020 at 10:53 AM Florian Weimer <fweimer@redhat.com> wrote: >>> That's because libc.so.6 still has DT_INIT, from which _environ and >>> other variables are set up. I assumed binutils would convert that into >>> DT_INITARRAY because the architecture is not supposed to have DT_INIT. >>> Without that, it's hard to declare that there is no DT_INIT, and the >>> patch essentially breaks ABI (because DT_INIT processing is gone). >> >> DT_INIT is a function address. DT_INITARRAY is a pointer to a table >> of addresses. I don't see how the linker can easily convert between >> them. We would have to increase the size of the init_array table at >> link time, and I don't think we have any linker support for that. >> Maybe we could modify the startfiles to put a weak reference to _init >> at the end of init_array, right before the zero that normally ends the >> list, and fix the linker to stop creating DT_INIT for _init. But that >> sounds a little risky, and defeats the purpose of dropping support for >> _init to reduce code size. I would prefer that glibc not create an >> _init function in the first place. > > I'm not worried about glibc here. It's easy to make glibc consistent > with itself. The patch I posted seems to do the trick, without > regressing anywhere else. > > What I don't know is whether this binutils bug has resulted in DT_INIT > being used *elsewhere*. I don't have a RISC-V distribution to analyze, > so I really don't know. Fedora RISC-V seems dead, this hasn't been > updated in a while: > > <https://dl.fedoraproject.org/pub/alt/risc-v/repo/fedora/rawhide/latest/riscv64/> > > (I have existing tools for RPM-based distributions, so having one would > be most useful to me to check for DT_INIT references.) I loaded the repository <http://fedora.riscv.rocks/repos/rawhide/latest/riscv64/> and ran this query: SELECT symboldb.nevra(package), file.name FROM symboldb.elf_dynamic dt JOIN symboldb.elf_file hdr USING (contents_id) JOIN symboldb.file USING (contents_id) JOIN symboldb.package USING (package_id) WHERE hdr.e_machine = 243 AND dt.tag = 12 ORDER BY 1, 2; nevra | name -----------------------------------------------+---------------------------------------------------- glibc-2.30.9000-31.fc32.riscv64 | /lib64/libc-2.30.9000.so jamin-0.97.16-19.20111031cvs.fc31.riscv64 | /usr/lib64/ladspa/jamincont_1912.so ladspa-1.13-23.fc31.riscv64 | /usr/lib64/ladspa/amp.so ladspa-1.13-23.fc31.riscv64 | /usr/lib64/ladspa/delay.so ladspa-1.13-23.fc31.riscv64 | /usr/lib64/ladspa/filter.so ladspa-1.13-23.fc31.riscv64 | /usr/lib64/ladspa/noise.so ladspa-autotalent-plugins-0.2-20.fc31.riscv64 | /usr/lib64/ladspa/autotalent.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/adsr_1653.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/adsr_1680.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/amp_1654.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/blop_files/parabola_1649_data.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/blop_files/sawtooth_1641_data.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/blop_files/square_1643_data.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/branch_1673.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/dahdsr_2021.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/difference_2030.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/fmod_1656.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/interpolator_1660.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/lp4pole_1671.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/product_1668.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/pulse_1645.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/quantiser100_2029.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/quantiser20_2027.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/quantiser50_2028.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/random_1661.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/ratio_2034.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/sawtooth_1641.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/sequencer16_1677.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/sequencer32_1676.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/sequencer64_1675.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/square_1643.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/sum_1665.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/sync_pulse_2023.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/sync_square_1678.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/tracker_2025.so ladspa-blop-plugins-0.2.8-26.fc31.riscv64 | /usr/lib64/ladspa/triangle_1649.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_autopan.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_chorusflanger.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_deesser.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_doubler.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_dynamics_m.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_dynamics_st.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_echo.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_eq.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_eqbw.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_limiter.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_pinknoise.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_pitch.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_reflector.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_reverb.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_rotspeak.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_sigmoid.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_tremolo.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_tubewarmth.so ladspa-tap-plugins-0.7.0-24.fc31.riscv64 | /usr/lib64/ladspa/tap_vibrato.so ladspa-wasp-plugins-0.9.7-10.fc31.riscv64 | /usr/lib64/ladspa/libwasp_booster.so ladspa-wasp-plugins-0.9.7-10.fc31.riscv64 | /usr/lib64/ladspa/libwasp_noisifier.so ladspa-wasp-plugins-0.9.7-10.fc31.riscv64 | /usr/lib64/ladspa/libwasp_xshaper.so nekobee-dssi-0.1.7-22.fc31.riscv64 | /usr/lib64/dssi/nekobee.so numactl-libs-2.0.12-3.fc32.riscv64 | /usr/lib64/libnuma.so.1.0.0 sblim-cmpi-rpm-1.0.1-25.fc31.riscv64 | /usr/lib64/libcimrpm.so.0.0.0 sblim-cmpi-rpm-1.0.1-25.fc31.riscv64 | /usr/lib64/libcimrpmv4.so.0.0.0 (62 rows) So there are a few packages which have been built in such a way that they have a DT_INIT tag. I don't know if this qualifies as use, and I haven't disassembled the objects to see if the init routine does anything meaningful. Thoughts? Should we still label RISC-V as an !ELF_INITFINI architecture? Thanks, Florian
On Fri, Feb 21, 2020 at 10:34 AM Florian Weimer <fweimer@redhat.com> wrote: > So there are a few packages which have been built in such a way that > they have a DT_INIT tag. I looked at numactl. In the Makefile.am I see -Wl,-init,numa_init -Wl,-fini,numa_fini So the DT_INIT and DT_FINI are doing something useful, but can be fixed by porting the package to use init_array/fini_array instead, or maybe adding some trickiness to the linker. But I'd rather the package be fixed, and that the linker should give an error when -init or -fini are used. It is at least the intent that we don't have init/fini support for RISC-V, and we should drop DT_INIT if we can do so without causing an ABI break. It looks like glibc is the only important package with DT_INIT so maybe that is the only one we have to worry about. > Thoughts? Should we still label RISC-V as an !ELF_INITFINI > architecture? I created an ABI issue to start a discussion with other RISC-V developers https://github.com/riscv/riscv-elf-psabi-doc/issues/132 Jim
On Fri, Feb 21, 2020 at 2:42 PM Florian Weimer <fweimer@redhat.com> wrote: > > * Jim Wilson: > > > On Thu, Feb 20, 2020 at 10:53 AM Florian Weimer <fweimer@redhat.com> wrote: > >> That's because libc.so.6 still has DT_INIT, from which _environ and > >> other variables are set up. I assumed binutils would convert that into > >> DT_INITARRAY because the architecture is not supposed to have DT_INIT. > >> Without that, it's hard to declare that there is no DT_INIT, and the > >> patch essentially breaks ABI (because DT_INIT processing is gone). > > > > DT_INIT is a function address. DT_INITARRAY is a pointer to a table > > of addresses. I don't see how the linker can easily convert between > > them. We would have to increase the size of the init_array table at > > link time, and I don't think we have any linker support for that. > > Maybe we could modify the startfiles to put a weak reference to _init > > at the end of init_array, right before the zero that normally ends the > > list, and fix the linker to stop creating DT_INIT for _init. But that > > sounds a little risky, and defeats the purpose of dropping support for > > _init to reduce code size. I would prefer that glibc not create an > > _init function in the first place. > > I'm not worried about glibc here. It's easy to make glibc consistent > with itself. The patch I posted seems to do the trick, without > regressing anywhere else. > > What I don't know is whether this binutils bug has resulted in DT_INIT > being used *elsewhere*. I don't have a RISC-V distribution to analyze, > so I really don't know. Fedora RISC-V seems dead, this hasn't been > updated in a while: > > <https://dl.fedoraproject.org/pub/alt/risc-v/repo/fedora/rawhide/latest/riscv64/> > We are still alive, but the mirroring of the repository to dl.fedoraproject.org was disabled. I will look into enabling it again.
Can you please revert your change until the issue is resolved one way or the other? Andreas.
On Feb 21 2020, Florian Weimer wrote: > What I don't know is whether this binutils bug has resulted in DT_INIT > being used *elsewhere*. I don't have a RISC-V distribution to analyze, > so I really don't know. Fedora RISC-V seems dead, this hasn't been > updated in a while: > > <https://dl.fedoraproject.org/pub/alt/risc-v/repo/fedora/rawhide/latest/riscv64/> > > (I have existing tools for RPM-based distributions, so having one would > be most useful to me to check for DT_INIT references.) You can take a look here: https://download.opensuse.org/ports/riscv/tumbleweed/repo/oss/ Andreas.
* Andreas Schwab: > Can you please revert your change until the issue is resolved one way or > the other? I'm going resubmit the actual fix after testing on more architectures. Thanks, Florian
* Andreas Schwab: > On Feb 21 2020, Florian Weimer wrote: > >> What I don't know is whether this binutils bug has resulted in DT_INIT >> being used *elsewhere*. I don't have a RISC-V distribution to analyze, >> so I really don't know. Fedora RISC-V seems dead, this hasn't been >> updated in a while: >> >> <https://dl.fedoraproject.org/pub/alt/risc-v/repo/fedora/rawhide/latest/riscv64/> >> >> (I have existing tools for RPM-based distributions, so having one would >> be most useful to me to check for DT_INIT references.) > > You can take a look here: > > https://download.opensuse.org/ports/riscv/tumbleweed/repo/oss/ Nice, I could just point my tool at it and it got some data (despite not having ported it to openSUSE or riscv64 at all): nevra | name ----------------------------------+-------------------------------------- authbind-2.1.2-2.1.riscv64 | /usr/lib/authbind/libauthbind.so.1.0 glibc-2.31-2.1.riscv64 | /lib64/libc-2.31.so jamin-0.95.0-259.1.riscv64 | /usr/lib64/ladspa/jamincont_1912.so ladspa-caps-0.4.4-4.2.riscv64 | /usr/lib64/ladspa/caps.so ladspa-pvoc-0.1.12-3.2.riscv64 | /usr/lib64/ladspa/pvoc.so libnuma1-2.0.13-1.1.riscv64 | /usr/lib64/libnuma.so.1.0.0 segv_handler-0.0.1-161.2.riscv64 | /usr/lib64/segv_handler.so vde2-2.3.2+svn587-3.2.riscv64 | /usr/lib64/vde2/libvdetap.so (8 rows) This still looks rather manageable to me, so perhaps we can go ahead with the removal of DT_INIT support on riscv64. Thanks, Florian
Hi Florian, On 2/20/20 10:48 AM, Florian Weimer wrote: > * Andreas Schwab: > >> environ is empty. > > That's because libc.so.6 still has DT_INIT, from which _environ and > other variables are set up. I assumed binutils would convert that into > DT_INITARRAY because the architecture is not supposed to have DT_INIT. > Without that, it's hard to declare that there is no DT_INIT, and the > patch essentially breaks ABI (because DT_INIT processing is gone). > > This should fix the breakage: > > Subject: Use ELF constructor instead of _init in libc.so > > On !ELF_INITFINI architectures, _init is no longer called by the dynamic > linker. We can use an ELF constructor instead because the constructor > order does not matter. (The other constructors are used to set up libio > vtable bypasses and do not depend on this initialization routine.) > > diff --git a/csu/init-first.c b/csu/init-first.c > index 1cd8a75098..1fa1633657 100644 > --- a/csu/init-first.c > +++ b/csu/init-first.c > @@ -46,9 +46,8 @@ __libc_init_first (int argc, char **argv, char **envp) > /* For DSOs we do not need __libc_init_first but instead _init. */ > } > > -void > -attribute_hidden > -_init (int argc, char **argv, char **envp) > +static void __attribute__ ((constructor)) > +init (int argc, char **argv, char **envp) > { > #endif > This (or lack thereof) turned out to be the nasty busbox sh crash (and kernel init panic) on ARC based off rebased upstream (latest RV32 from Alistair) containing the original patch f4349837d93b4df. I tried this fixup and it seems to work. The DT_INIT entry goes away and init does run as part of init_array. It seems that commit also removed init_array from sysdeps/{riscv,csky}/Implies - so newer arches. I suppose I need to do that for ARC as well - but could you please explain (or point to documentation) which explains how this the Implies stuff works. > But I'm no longer sure if RISC-V is actually an !ELF_INITFINI > architecture. And an arch is !ELF_INITFINI if it supports initarray ? I did switch ARC gcc [1] / binutils [2]to initarray last year [1] http://lists.infradead.org/pipermail/linux-snps-arc/2019-January/005318.html [2] http://lists.infradead.org/pipermail/linux-snps-arc/2019-February/005388.html Thx, -Vineet
* Vineet Gupta: > It seems that commit also removed init_array from > sysdeps/{riscv,csky}/Implies - so newer arches. I suppose I need to do > that for ARC as well - but could you please explain (or point to > documentation) which explains how this the Implies stuff works. You are very lucky. The mechanism is explained in the section Porting the GNU C Library in the manual: <https://www.gnu.org/software/libc/manual/html_node/Porting.html> It's one of the few aspects of our build systems that's documented. However, in commit f4349837d93b4dfe9ba09791e280ee2d6c99919f ("Introduce <elf-initfini.h> and ELF_INITFINI for all architectures") I replaced the use of the implies mechanism with a new header file, <elf-initfini.h>. This allows us to control the default for new targets in a more explicit way. Previously, new ports had to include initarray explicitly, and we know from past experience (the lack of removal of the sysctl function comes to my mind) that this does not work. >> But I'm no longer sure if RISC-V is actually an !ELF_INITFINI >> architecture. > > And an arch is !ELF_INITFINI if it supports initarray ? Not necessarily. glibc always supports DT_INITARRAY for all targets, but on some targets, it is necessary to honor DT_INIT/DT_FINI for legacy binaries at least. (I hope no targets are left where binutils produces DT_INIT for regular ELF constructors, but I haven't checked.) > I did switch ARC gcc [1] / binutils [2]to initarray last year > > [1] http://lists.infradead.org/pipermail/linux-snps-arc/2019-January/005318.html > [2] http://lists.infradead.org/pipermail/linux-snps-arc/2019-February/005388.html I haven't followed the ARC contribution process closely, sorry. Do you plan to contribute the port with a GLIBC_2.32 ABI baseline, or do you want to support older binaries for an earlier non-upstream port, backdating the baseline? This matters because in the GLIBC_2.32 case, old binaries will not work anyway, so we may as well require that they are rebuilt without DT_INIT/DT_FINI. In this case, the glibc master defaults should work. If you want to support old binaries (which use older symbol versions such as GLIBC_2.17), it may make sense to keep DT_INIT/DT_FINI support as well. To achieve this, you need to add an <elf-initifini.h> header file with /* Enable DT_INIT/DT_FINI support. */ #define ELF_INITFINI 1 and keep the crti.S and crtn.S files you already have. Thanks, Florian
On 2/26/20 11:27 AM, Florian Weimer wrote: > I haven't followed the ARC contribution process closely, sorry. Do you > plan to contribute the port with a GLIBC_2.32 ABI baseline, or do you > want to support older binaries for an earlier non-upstream port, > backdating the baseline? No we don't need to support old binaries: 2.32 will be baseline > This matters because in the GLIBC_2.32 case, old binaries will not work > anyway, so we may as well require that they are rebuilt without > DT_INIT/DT_FINI. In this case, the glibc master defaults should work. Understood ! > If you want to support old binaries (which use older symbol versions > such as GLIBC_2.17), it may make sense to keep DT_INIT/DT_FINI support > as well. To achieve this, you need to add an <elf-initifini.h> header > file with > > /* Enable DT_INIT/DT_FINI support. */ > #define ELF_INITFINI 1 > > and keep the crti.S and crtn.S files you already have. Per the review comments on ARC port last year [1], I was advised to remove the ARC specific crt*.S so those are anyhow gone. [1] https://sourceware.org/ml/libc-alpha/2019-01/msg00654.html
diff --git a/csu/elf-init.c b/csu/elf-init.c index 6112dca379..c16029aa08 100644 --- a/csu/elf-init.c +++ b/csu/elf-init.c @@ -34,6 +34,7 @@ <https://www.gnu.org/licenses/>. */ #include <stddef.h> +#include <elf-initfini.h> /* These magic symbols are provided by the linker. */ @@ -49,7 +50,7 @@ extern void (*__fini_array_start []) (void) attribute_hidden; extern void (*__fini_array_end []) (void) attribute_hidden; -#ifndef NO_INITFINI +#if ELF_INITFINI /* These function symbols are provided for the .init/.fini section entry points automagically by the linker. */ extern void _init (void); @@ -79,7 +80,7 @@ __libc_csu_init (int argc, char **argv, char **envp) } #endif -#ifndef NO_INITFINI +#if ELF_INITFINI _init (); #endif @@ -99,7 +100,7 @@ __libc_csu_fini (void) while (i-- > 0) (*__fini_array_start [i]) (); -# ifndef NO_INITFINI +# if ELF_INITFINI _fini (); # endif #endif diff --git a/csu/gmon-start.c b/csu/gmon-start.c index 9e427342df..1a4fc655ba 100644 --- a/csu/gmon-start.c +++ b/csu/gmon-start.c @@ -37,6 +37,7 @@ #include <sys/gmon.h> #include <stdlib.h> #include <unistd.h> +#include <elf-initfini.h> #define __ASSEMBLY__ #include <entry.h> @@ -59,6 +60,13 @@ extern char etext[]; # endif #endif +#if !ELF_INITFINI +/* Instead of defining __gmon_start__ globally in gcrt1.o, we make it + static and just put a pointer to it into the .preinit_array + section. */ +# define GMON_START_ARRAY_SECTION ".preinit_array" +#endif + #ifdef GMON_START_ARRAY_SECTION static void __gmon_start__ (void); static void (*const gmon_start_initializer) (void) diff --git a/elf/dl-fini.c b/elf/dl-fini.c index 70e7346304..e33cf4db96 100644 --- a/elf/dl-fini.c +++ b/elf/dl-fini.c @@ -19,6 +19,7 @@ #include <assert.h> #include <string.h> #include <ldsodefs.h> +#include <elf-initfini.h> /* Type of the constructor functions. */ @@ -117,7 +118,7 @@ _dl_fini (void) /* Is there a destructor function? */ if (l->l_info[DT_FINI_ARRAY] != NULL - || l->l_info[DT_FINI] != NULL) + || (ELF_INITFINI && l->l_info[DT_FINI] != NULL)) { /* When debugging print a message first. */ if (__builtin_expect (GLRO(dl_debug_mask) @@ -139,7 +140,7 @@ _dl_fini (void) } /* Next try the old-style destructor. */ - if (l->l_info[DT_FINI] != NULL) + if (ELF_INITFINI && l->l_info[DT_FINI] != NULL) DL_CALL_DT_FINI (l, l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr); } diff --git a/elf/dl-init.c b/elf/dl-init.c index 3721bca81e..9ac8bafdf9 100644 --- a/elf/dl-init.c +++ b/elf/dl-init.c @@ -18,6 +18,7 @@ #include <stddef.h> #include <ldsodefs.h> +#include <elf-initfini.h> /* Type of the initializer. */ @@ -40,11 +41,6 @@ call_init (struct link_map *l, int argc, char **argv, char **env) && l->l_type == lt_executable) return; - /* Are there any constructors? */ - if (l->l_info[DT_INIT] == NULL - && __builtin_expect (l->l_info[DT_INIT_ARRAY] == NULL, 1)) - return; - /* Print a debug message if wanted. */ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS)) _dl_debug_printf ("\ncalling init: %s\n\n", @@ -54,7 +50,7 @@ call_init (struct link_map *l, int argc, char **argv, char **env) - the one named by DT_INIT - the others in the DT_INIT_ARRAY. */ - if (l->l_info[DT_INIT] != NULL) + if (ELF_INITFINI && l->l_info[DT_INIT] != NULL) DL_CALL_DT_INIT(l, l->l_addr + l->l_info[DT_INIT]->d_un.d_ptr, argc, argv, env); /* Next see whether there is an array with initialization functions. */ diff --git a/nptl/pt-crti.S b/nptl/pt-crti.S index b389442a15..ef006a0437 100644 --- a/nptl/pt-crti.S +++ b/nptl/pt-crti.S @@ -33,11 +33,18 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ +#include <elf-initfini.h> + /* Arrange for __pthread_initialize_minimal_internal to be called at libpthread startup, instead of conditionally calling __gmon_start__. */ -#define PREINIT_FUNCTION __pthread_initialize_minimal_internal -#define PREINIT_FUNCTION_WEAK 0 +#if ELF_INITFINI +# define PREINIT_FUNCTION __pthread_initialize_minimal_internal +# define PREINIT_FUNCTION_WEAK 0 -#include <crti.S> +# include <crti.S> +#else + .section .init_array,"a",%init_array + .dc.a __pthread_initialize_minimal_internal +#endif diff --git a/sysdeps/init_array/pt-crti.S b/sysdeps/aarch64/elf-initfini.h similarity index 67% rename from sysdeps/init_array/pt-crti.S rename to sysdeps/aarch64/elf-initfini.h index 3955298eca..660964ccda 100644 --- a/sysdeps/init_array/pt-crti.S +++ b/sysdeps/aarch64/elf-initfini.h @@ -1,5 +1,5 @@ -/* Special initializer support for libpthread. - Copyright (C) 2015-2019 Free Software Foundation, Inc. +/* Determine DT_INIT/DT_FINI support in the dynamic loader. AArch64 version. + Copyright (C) 2019 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 @@ -14,10 +14,7 @@ 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/>. */ + <http://www.gnu.org/licenses/>. */ -/* This arranges for libpthread.so's special initializer to be called as - soon as the library is loaded. */ - - .section .init_array,"a",%init_array - .dc.a __pthread_initialize_minimal_internal +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/alpha/elf-initfini.h b/sysdeps/alpha/elf-initfini.h new file mode 100644 index 0000000000..f3203cf173 --- /dev/null +++ b/sysdeps/alpha/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. Alpha version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/arm/elf-initfini.h b/sysdeps/arm/elf-initfini.h new file mode 100644 index 0000000000..b4406f1003 --- /dev/null +++ b/sysdeps/arm/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. Arm version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/csky/Implies b/sysdeps/csky/Implies index fd80b4826e..f8c3a7586e 100644 --- a/sysdeps/csky/Implies +++ b/sysdeps/csky/Implies @@ -1,4 +1,3 @@ -init_array wordsize-32 # C-SKY uses IEEE 754 floating point. ieee754/flt-32 diff --git a/sysdeps/init_array/crti.S b/sysdeps/generic/crti.S similarity index 80% rename from sysdeps/init_array/crti.S rename to sysdeps/generic/crti.S index 145c918f93..82d6dc0d91 100644 --- a/sysdeps/init_array/crti.S +++ b/sysdeps/generic/crti.S @@ -12,11 +12,17 @@ toolchains without .init_array support can use this to avoid the superfluous .init and .fini boilerplate code. */ +#include <elf-initfini.h> + +#if ELF_INITFINI +# error Cannot use default crti.S because it lacks _init code +#endif + #ifdef PREINIT_FUNCTION -#if PREINIT_FUNCTION_WEAK -# error PREINIT_FUNCTION_WEAK is unsupported -#endif +# if PREINIT_FUNCTION_WEAK +# error PREINIT_FUNCTION_WEAK is unsupported +# endif /* This arranges for PREINIT_FUNCTION to be called upon loading a library that contains crti.o. */ diff --git a/sysdeps/init_array/crtn.S b/sysdeps/generic/crtn.S similarity index 82% rename from sysdeps/init_array/crtn.S rename to sysdeps/generic/crtn.S index 6f70e77160..d92b07dd0b 100644 --- a/sysdeps/init_array/crtn.S +++ b/sysdeps/generic/crtn.S @@ -11,3 +11,9 @@ But new configurations without compatibility concerns for toolchains without .init_array support can use this to avoid the superfluous .init and .fini boilerplate code. */ + +#include <elf-initfini.h> + +#if ELF_INITFINI +# error Cannot use genetric crtn.S because it lacks _fini code +#endif diff --git a/sysdeps/generic/elf-initfini.h b/sysdeps/generic/elf-initfini.h new file mode 100644 index 0000000000..2f4d172765 --- /dev/null +++ b/sysdeps/generic/elf-initfini.h @@ -0,0 +1,24 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Legacy platforms define this to 1. If 0, the dynamic linker + ignores the DT_INIT and DT_FINI tags, and static binaries will not + call the _init or _fini functions. If 1, the old constructor + mechanisms are used in addition to the initarray/finiarray + support. */ +#define ELF_INITFINI 0 diff --git a/sysdeps/hppa/elf-initfini.h b/sysdeps/hppa/elf-initfini.h new file mode 100644 index 0000000000..18e3df5aff --- /dev/null +++ b/sysdeps/hppa/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. HPPA version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/ia64/elf-initfini.h b/sysdeps/ia64/elf-initfini.h new file mode 100644 index 0000000000..9b45ce3c7e --- /dev/null +++ b/sysdeps/ia64/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. IA64 version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/init_array/elf-init.c b/sysdeps/init_array/elf-init.c deleted file mode 100644 index d928e6997c..0000000000 --- a/sysdeps/init_array/elf-init.c +++ /dev/null @@ -1,37 +0,0 @@ -/* Startup support for ELF initializers/finalizers in the main executable. - Copyright (C) 2013-2019 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. - - In addition to the permissions in the GNU Lesser General Public - License, the Free Software Foundation gives you unlimited - permission to link the compiled version of this file with other - programs, and to distribute those programs without any restriction - coming from the use of this file. (The GNU Lesser General Public - License restrictions do apply in other respects; for example, they - cover modification of the file, and distribution when not linked - into another program.) - - Note that people who make modified versions of this file are not - obligated to grant this special exception for their modified - versions; it is their choice whether to do so. The GNU Lesser - General Public License gives permission to release a modified - version without this exception; this exception also makes it - possible to release a modified version which carries forward this - exception. - - 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/>. */ - -#define NO_INITFINI -#include <csu/elf-init.c> diff --git a/sysdeps/init_array/gmon-start.c b/sysdeps/init_array/gmon-start.c deleted file mode 100644 index 9ea40b44b6..0000000000 --- a/sysdeps/init_array/gmon-start.c +++ /dev/null @@ -1,41 +0,0 @@ -/* gmon startup hook using .preinit_array. - Copyright (C) 2013-2019 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. - - In addition to the permissions in the GNU Lesser General Public - License, the Free Software Foundation gives you unlimited - permission to link the compiled version of this file with other - programs, and to distribute those programs without any restriction - coming from the use of this file. (The GNU Lesser General Public - License restrictions do apply in other respects; for example, they - cover modification of the file, and distribution when not linked - into another program.) - - Note that people who make modified versions of this file are not - obligated to grant this special exception for their modified - versions; it is their choice whether to do so. The GNU Lesser - General Public License gives permission to release a modified - version without this exception; this exception also makes it - possible to release a modified version which carries forward this - exception. - - 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/>. */ - -/* Instead of defining __gmon_start__ globally in gcrt1.o, we make it - static and just put a pointer to it into the .preinit_array section. */ - -#define GMON_START_ARRAY_SECTION ".preinit_array" - -#include <csu/gmon-start.c> diff --git a/sysdeps/m68k/elf-initfini.h b/sysdeps/m68k/elf-initfini.h new file mode 100644 index 0000000000..6ae56c16c3 --- /dev/null +++ b/sysdeps/m68k/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. m68k version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/microblaze/elf-initfini.h b/sysdeps/microblaze/elf-initfini.h new file mode 100644 index 0000000000..e36e664762 --- /dev/null +++ b/sysdeps/microblaze/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader, for Microblaze. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/mips/elf-initfini.h b/sysdeps/mips/elf-initfini.h new file mode 100644 index 0000000000..83fe8025b7 --- /dev/null +++ b/sysdeps/mips/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. MIPS version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/nios2/elf-initfini.h b/sysdeps/nios2/elf-initfini.h new file mode 100644 index 0000000000..56c510da71 --- /dev/null +++ b/sysdeps/nios2/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. nios2 version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/powerpc/elf-initfini.h b/sysdeps/powerpc/elf-initfini.h new file mode 100644 index 0000000000..c1c38efe1f --- /dev/null +++ b/sysdeps/powerpc/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader, for powerpc. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/riscv/Implies b/sysdeps/riscv/Implies index c88325b8be..1945b1f4bb 100644 --- a/sysdeps/riscv/Implies +++ b/sysdeps/riscv/Implies @@ -1,5 +1,3 @@ -init_array - ieee754/ldbl-128 ieee754/dbl-64 ieee754/flt-32 diff --git a/sysdeps/s390/elf-initfini.h b/sysdeps/s390/elf-initfini.h new file mode 100644 index 0000000000..b300881236 --- /dev/null +++ b/sysdeps/s390/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. S/390 version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/sh/elf-initfini.h b/sysdeps/sh/elf-initfini.h new file mode 100644 index 0000000000..de44d0bb6a --- /dev/null +++ b/sysdeps/sh/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. SH version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/sparc/elf-initfini.h b/sysdeps/sparc/elf-initfini.h new file mode 100644 index 0000000000..9a983c5501 --- /dev/null +++ b/sysdeps/sparc/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. SPARC version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1 diff --git a/sysdeps/x86/elf-initfini.h b/sysdeps/x86/elf-initfini.h new file mode 100644 index 0000000000..ba4b5a5b47 --- /dev/null +++ b/sysdeps/x86/elf-initfini.h @@ -0,0 +1,20 @@ +/* Determine DT_INIT/DT_FINI support in the dynamic loader. x86 version. + Copyright (C) 2019 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 + <http://www.gnu.org/licenses/>. */ + +/* Enable DT_INIT/DT_FINI support. */ +#define ELF_INITFINI 1
This change is desirable for a rework of the statically linked startup code to remove the generic ROP trampoline in it (bug 23323). I verified that the *crt*.o files are unchanged by this change after stripping (although my binutils dispatcher fails to determine the correct ABI for some of the MIPS gcrt1.o files, so those have not been checked). Thanks, Florian 8<------------------------------------------------------------------8< This supersedes the init_array sysdeps directory. It allows us to check for ELF_INITFINI in both C and assembler code, and skip DT_INIT and DT_FINI processing completely on newer architectures. A new header file is needed because <dl-machine.h> is incompatible with assembler code. <sysdep.h> is compatible with assembler code, but it cannot be included in all assembler files because on some architectures, it redefines register names, and some assembler files conflict with that. <elf-initfini.h> is replicated for legacy architectures which need DT_INIT/DT_FINI support. New architectures follow the generic default and disable it. ----- csu/elf-init.c | 7 ++-- csu/gmon-start.c | 8 +++++ elf/dl-fini.c | 5 +-- elf/dl-init.c | 8 ++--- nptl/pt-crti.S | 13 +++++-- .../pt-crti.S => aarch64/elf-initfini.h} | 13 +++---- sysdeps/alpha/elf-initfini.h | 20 +++++++++++ sysdeps/arm/elf-initfini.h | 20 +++++++++++ sysdeps/csky/Implies | 1 - sysdeps/{init_array => generic}/crti.S | 12 +++++-- sysdeps/{init_array => generic}/crtn.S | 6 ++++ sysdeps/generic/elf-initfini.h | 24 +++++++++++++ sysdeps/hppa/elf-initfini.h | 20 +++++++++++ sysdeps/ia64/elf-initfini.h | 20 +++++++++++ sysdeps/init_array/elf-init.c | 37 ------------------- sysdeps/init_array/gmon-start.c | 41 ---------------------- sysdeps/m68k/elf-initfini.h | 20 +++++++++++ sysdeps/microblaze/elf-initfini.h | 20 +++++++++++ sysdeps/mips/elf-initfini.h | 20 +++++++++++ sysdeps/nios2/elf-initfini.h | 20 +++++++++++ sysdeps/powerpc/elf-initfini.h | 20 +++++++++++ sysdeps/riscv/Implies | 2 -- sysdeps/s390/elf-initfini.h | 20 +++++++++++ sysdeps/sh/elf-initfini.h | 20 +++++++++++ sysdeps/sparc/elf-initfini.h | 20 +++++++++++ sysdeps/x86/elf-initfini.h | 20 +++++++++++ 26 files changed, 331 insertions(+), 106 deletions(-)