From 95a73392580761abc62fc9b1386d232cd55878e9 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 17 Jul 2017 18:11:12 -0300 Subject: [PATCH] tunables: Use direct syscall for access (BZ#21744) The function maybe_enable_malloc_check, which is called by __tunables_init, calls __access_noerrno. It isn't problem when symbol is is in ld.so, which has a special version of __access_noerrno without stack protector. But when glibc is built with stack protector, maybe_enable_malloc_check in libc.a can't call the regular version of __access_noerrno with stack protector. This patch changes how Linux defines the __access_noerrno to be an inline call instead and thus preventing defining different build rules for ld/static and shared. H.J. Lu Adhemerval Zanella [BZ #21744] * elf/dl-tunables.c: Include not-errno.h header. * include/unistd.h (__access_noerrno): Remove definition. * sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise. * sysdeps/generic/not-errno.h: New file. * sysdeps/unix/sysv/linux/not-errno.h: Likewise. --- ChangeLog | 10 +++++++++ elf/dl-tunables.c | 2 ++ include/unistd.h | 7 ------ sysdeps/generic/not-errno.h | 19 ++++++++++++++++ sysdeps/unix/sysv/linux/access.c | 15 ------------- sysdeps/unix/sysv/linux/not-errno.h | 35 +++++++++++++++++++++++++++++ 6 files changed, 66 insertions(+), 22 deletions(-) create mode 100644 sysdeps/generic/not-errno.h create mode 100644 sysdeps/unix/sysv/linux/not-errno.h diff --git a/ChangeLog b/ChangeLog index 7da4510060..554fdac0d9 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2017-07-24 Adhemerval Zanella + H.J. Lu + + [BZ #21744] + * elf/dl-tunables.c: Include not-errno.h header. + * include/unistd.h (__access_noerrno): Remove definition. + * sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise. + * sysdeps/generic/not-errno.h: New file. + * sysdeps/unix/sysv/linux/not-errno.h: Likewise. + 2017-07-24 H.J. Lu [BZ #21752] diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index 44c160cac5..231fb8ca93 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -29,6 +29,8 @@ #define TUNABLES_INTERNAL 1 #include "dl-tunables.h" +#include + #if TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring # define GLIBC_TUNABLES "GLIBC_TUNABLES" #endif diff --git a/include/unistd.h b/include/unistd.h index 5b2a4147dc..7f1c2ccd4b 100644 --- a/include/unistd.h +++ b/include/unistd.h @@ -182,12 +182,5 @@ extern int __getlogin_r_loginuid (char *name, size_t namesize) # include # endif -# if IS_IN (rtld) || !defined SHARED -/* __access variant that does not set errno. Used in very early initialization - code in libc.a and ld.so. It follows access return semantics (zero for - sucess otherwise a value different than 0). */ -extern __typeof (__access) __access_noerrno attribute_hidden; -# endif - # endif #endif diff --git a/sysdeps/generic/not-errno.h b/sysdeps/generic/not-errno.h new file mode 100644 index 0000000000..2aac095e71 --- /dev/null +++ b/sysdeps/generic/not-errno.h @@ -0,0 +1,19 @@ +/* Syscall wrapper that do not set errno. Generic version. + Copyright (C) 2017 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 + . */ + +extern __typeof (__access) __access_noerrno attribute_hidden; diff --git a/sysdeps/unix/sysv/linux/access.c b/sysdeps/unix/sysv/linux/access.c index 67e69bd163..366b6b6461 100644 --- a/sysdeps/unix/sysv/linux/access.c +++ b/sysdeps/unix/sysv/linux/access.c @@ -20,21 +20,6 @@ #include #include -int -__access_noerrno (const char *file, int type) -{ - int res; - INTERNAL_SYSCALL_DECL (err); -#ifdef __NR_access - res = INTERNAL_SYSCALL_CALL (access, err, file, type); -#else - res = INTERNAL_SYSCALL_CALL (faccessat, err, AT_FDCWD, file, type); -#endif - if (INTERNAL_SYSCALL_ERROR_P (res, err)) - return INTERNAL_SYSCALL_ERRNO (res, err); - return 0; -} - int __access (const char *file, int type) { diff --git a/sysdeps/unix/sysv/linux/not-errno.h b/sysdeps/unix/sysv/linux/not-errno.h new file mode 100644 index 0000000000..65f93f331d --- /dev/null +++ b/sysdeps/unix/sysv/linux/not-errno.h @@ -0,0 +1,35 @@ +/* Syscall wrapper that do not set errno. Linux version. + Copyright (C) 2017 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 + . */ + +/* This function is used on maybe_enable_malloc_check (elf/dl-tunables.c) + and to avoid having to build/use multiple versions if stack protection + in enabled it is defined as inline. */ +static inline int +__access_noerrno (const char *pathname, int mode) +{ + int res; + INTERNAL_SYSCALL_DECL (err); +#ifdef __NR_access + res = INTERNAL_SYSCALL_CALL (access, err, pathname, mode); +#else + res = INTERNAL_SYSCALL_CALL (faccessat, err, AT_FDCWD, pathname, mode); +#endif + if (INTERNAL_SYSCALL_ERROR_P (res, err)) + return INTERNAL_SYSCALL_ERRNO (res, err); + return 0; +}