glibc/posix/glob64-lstat-compat.c

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posix: Add compat glob symbol to not follow dangling symbols This patch follows commit 5554304f0 (posix: Allow glob to match dangling symlinks [BZ #866]) by adding a compat symbol that follow previous semantic of not following dangling symlinks and thus avoiding call gl_lstat with GLOB_ALTDIRFUNC. It avoids failure with old binaries that not set the alternate function pointer for lstat (GNUmake for instance). The following scenario, for instance, fails with current GNUmake because glibc will access unitialized memory when calling gl_lstat: $ cat src/t/t.c int main () { return 0; } $ cat Makefile SRC = $(wildcard src/*/t.c) OBJ = $(patsubst src/%.c, obj/%.o, $(SRC)) prog: $(OBJ) $(CC) $(CFLAGS) $(LDFLAGS) $(LIBS) $(OBJ) -o prog obj/%.o: src/%.c $(CC) $(CFLAGS) -c $< -o $@ $ make This works as expected with the patch applied. Since it is for generic ABI, default compat symbols are added with override for Linux due LFS. Now we have two compat symbols for glob on Linux: 1. sysdeps/unix/sysv/linux/oldglob.c which implements glob64 with the old dirent layout. For this implementation I also set it to not follow dangling symlinks (which is the safest path). 2. sysdeps/unix/sysv/linux/glob{64}-lstat-compat.c which implements the compat symbol for dangling symlinks. As for generic glob, the implementation uses XSTAT_IS_XSTAT64 to define whether both __glob_lstat_compat and __glob64_lstat_compat should be different implementations. For archictures that define XSTAT_IS_XSTAT64, __glob_lstat_compat is aliased to __glob64_lstat_compat. 3. sysdeps/unix/sysv/linux/alpha/oldglob.c with a different glob_t layout. As for 1. this patch changes it to not follow dangling symlinks. The patch also bumps _GNU_GLOB_INTERFACE_VERSION to 2 to advertise the new semantic. On GNUmake, for instance, it will force to it use its internal glob implementation instead and avoiding triggering the same failure on builds against newer GLIBCs. Checked on x86_64-linux-gnu and i686-linux-gnu. I also checked with a build against the major ABIs required to check for the abilist. The changes should also work on gnulib (I run gnulib-tool.py check glob and it shown no regressions). [BZ #22183] * include/gnu-versions.h (_GNU_GLOB_INTERFACE_VERSION): Increase version to 2. * posix/Makefile (routines): Add glob-lstat-compat and glob64-lstat-compat. * posix/Versions (GLIBC_2.27, glob, glob64): Add symbol version. * posix/glob-lstat-compat.c: New file. * posix/glob64-lstat-compat.c: Likewise. * posix/tst-glob_lstat_compat.c: Likewise. * sysdeps/unix/sysv/linux/glob-lstat-compat.c: Likewise. * sysdeps/unix/sysv/linux/alpha/glob-lstat-compat.c: Likewise. * sysdeps/unix/sysv/linux/glob64-lstat-compat.c: Likewise. * sysdeps/unix/sysv/linux/alpha/glob.c: Remove file. * posix/glob.c (glob_lstat): New function. (glob): Rename to __glob and add versioned symbol to 2.27. (glob_in_dir): Use glob_lstat. * posix/glob64.c (glob64): Add GLOB_ATTRIBUTE. * sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/glob.c (glob): Add versioned symbol for 2.27. * sysdeps/unix/sysv/linux/glob64.c (glob64): Likewise. * sysdeps/unix/sysv/linux/oldglob.c (GLOB_NO_LSTAT): Define. * sysdeps/unix/sysv/linux/alpha/oldglob.c (__old_glob): Do not use gl_lstat on glob call. * sysdeps/unix/sysv/linux/aarch64/libc.abilist: Add GLIBC_2.27 glob and glob64 symbols. * sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist: Likewise. * sysdeps/unix/linux/powerpc/powerpc32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
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/* Compat glob which does not use gl_lstat for GLOB_ALTDIRFUNC.
Copyright (C) 2017-2019 Free Software Foundation, Inc.
posix: Add compat glob symbol to not follow dangling symbols This patch follows commit 5554304f0 (posix: Allow glob to match dangling symlinks [BZ #866]) by adding a compat symbol that follow previous semantic of not following dangling symlinks and thus avoiding call gl_lstat with GLOB_ALTDIRFUNC. It avoids failure with old binaries that not set the alternate function pointer for lstat (GNUmake for instance). The following scenario, for instance, fails with current GNUmake because glibc will access unitialized memory when calling gl_lstat: $ cat src/t/t.c int main () { return 0; } $ cat Makefile SRC = $(wildcard src/*/t.c) OBJ = $(patsubst src/%.c, obj/%.o, $(SRC)) prog: $(OBJ) $(CC) $(CFLAGS) $(LDFLAGS) $(LIBS) $(OBJ) -o prog obj/%.o: src/%.c $(CC) $(CFLAGS) -c $< -o $@ $ make This works as expected with the patch applied. Since it is for generic ABI, default compat symbols are added with override for Linux due LFS. Now we have two compat symbols for glob on Linux: 1. sysdeps/unix/sysv/linux/oldglob.c which implements glob64 with the old dirent layout. For this implementation I also set it to not follow dangling symlinks (which is the safest path). 2. sysdeps/unix/sysv/linux/glob{64}-lstat-compat.c which implements the compat symbol for dangling symlinks. As for generic glob, the implementation uses XSTAT_IS_XSTAT64 to define whether both __glob_lstat_compat and __glob64_lstat_compat should be different implementations. For archictures that define XSTAT_IS_XSTAT64, __glob_lstat_compat is aliased to __glob64_lstat_compat. 3. sysdeps/unix/sysv/linux/alpha/oldglob.c with a different glob_t layout. As for 1. this patch changes it to not follow dangling symlinks. The patch also bumps _GNU_GLOB_INTERFACE_VERSION to 2 to advertise the new semantic. On GNUmake, for instance, it will force to it use its internal glob implementation instead and avoiding triggering the same failure on builds against newer GLIBCs. Checked on x86_64-linux-gnu and i686-linux-gnu. I also checked with a build against the major ABIs required to check for the abilist. The changes should also work on gnulib (I run gnulib-tool.py check glob and it shown no regressions). [BZ #22183] * include/gnu-versions.h (_GNU_GLOB_INTERFACE_VERSION): Increase version to 2. * posix/Makefile (routines): Add glob-lstat-compat and glob64-lstat-compat. * posix/Versions (GLIBC_2.27, glob, glob64): Add symbol version. * posix/glob-lstat-compat.c: New file. * posix/glob64-lstat-compat.c: Likewise. * posix/tst-glob_lstat_compat.c: Likewise. * sysdeps/unix/sysv/linux/glob-lstat-compat.c: Likewise. * sysdeps/unix/sysv/linux/alpha/glob-lstat-compat.c: Likewise. * sysdeps/unix/sysv/linux/glob64-lstat-compat.c: Likewise. * sysdeps/unix/sysv/linux/alpha/glob.c: Remove file. * posix/glob.c (glob_lstat): New function. (glob): Rename to __glob and add versioned symbol to 2.27. (glob_in_dir): Use glob_lstat. * posix/glob64.c (glob64): Add GLOB_ATTRIBUTE. * sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/glob.c (glob): Add versioned symbol for 2.27. * sysdeps/unix/sysv/linux/glob64.c (glob64): Likewise. * sysdeps/unix/sysv/linux/oldglob.c (GLOB_NO_LSTAT): Define. * sysdeps/unix/sysv/linux/alpha/oldglob.c (__old_glob): Do not use gl_lstat on glob call. * sysdeps/unix/sysv/linux/aarch64/libc.abilist: Add GLIBC_2.27 glob and glob64 symbols. * sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist: Likewise. * sysdeps/unix/linux/powerpc/powerpc32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
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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/>. */
#include <shlib-compat.h>
#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_27)
# include <glob.h>
# define glob(pattern, flags, errfunc, pglob) \
__glob64_lstat_compat (pattern, flags, errfunc, pglob)
# define GLOB_ATTRIBUTE attribute_compat_text_section
/* Avoid calling gl_lstat with GLOB_ALTDIRFUNC. */
# define GLOB_NO_LSTAT
# include <posix/glob64.c>
compat_symbol (libc, __glob64_lstat_compat, glob64, GLIBC_2_0);
#endif