diff options
| -rw-r--r-- | NEWS | 4 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h | 45 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/64/mmap_internal.h | 42 | ||||
| -rw-r--r-- | sysdeps/x86/cpu-tunables.c | 7 | ||||
| -rw-r--r-- | sysdeps/x86/include/cpu-features-preferred_feature_index_1.def | 1 |
5 files changed, 4 insertions, 95 deletions
diff --git a/NEWS b/NEWS index 3a04befe8e..bf2b6846fc 100644 --- a/NEWS +++ b/NEWS @@ -9,6 +9,10 @@ Version 2.35 Major new features: +* The LD_PREFER_MAP_32BIT_EXEC environment variable support has been + removed since the first PT_LOAD segment is no longer executable due + to defaulting to -z separate-code. + * Unicode 14.0.0 Support: Character encoding, character type info, and transliteration tables are all updated to Unicode 14.0.0, using generator scripts contributed by Mike FABIAN (Red Hat). diff --git a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h b/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h deleted file mode 100644 index 5b9696e2de..0000000000 --- a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h +++ /dev/null @@ -1,45 +0,0 @@ -/* Optional code to distinguish library flavours. x86-64 version. - Copyright (C) 2015-2021 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <https://www.gnu.org/licenses/>. */ - -#ifndef _DL_LIBRECON_H - -#include <sysdeps/unix/sysv/linux/dl-librecon.h> - -/* Recognizing extra environment variables. For 64-bit applications, - branch prediction performance may be negatively impacted when the - target of a branch is more than 4GB away from the branch. Add the - Prefer_MAP_32BIT_EXEC bit so that mmap will try to map executable - pages with MAP_32BIT first. NB: MAP_32BIT will map to lower 2GB, - not lower 4GB, address. Prefer_MAP_32BIT_EXEC reduces bits available - for address space layout randomization (ASLR). Prefer_MAP_32BIT_EXEC - is always disabled for SUID programs and can be enabled by setting - environment variable, LD_PREFER_MAP_32BIT_EXEC. */ -#define EXTRA_LD_ENVVARS \ - case 21: \ - if (!__libc_enable_secure \ - && memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0) \ - GLRO(dl_x86_cpu_features).preferred[index_arch_Prefer_MAP_32BIT_EXEC] \ - |= bit_arch_Prefer_MAP_32BIT_EXEC; \ - break; - -/* Extra unsecure variables. The names are all stuffed in a single - string which means they have to be terminated with a '\0' explicitly. */ -#define EXTRA_UNSECURE_ENVVARS \ - "LD_PREFER_MAP_32BIT_EXEC\0" - -#endif /* dl-librecon.h */ diff --git a/sysdeps/unix/sysv/linux/x86_64/64/mmap_internal.h b/sysdeps/unix/sysv/linux/x86_64/64/mmap_internal.h deleted file mode 100644 index 18177d2cb3..0000000000 --- a/sysdeps/unix/sysv/linux/x86_64/64/mmap_internal.h +++ /dev/null @@ -1,42 +0,0 @@ -/* Linux mmap system call. x86-64 version. - Copyright (C) 2015-2021 Free Software Foundation, Inc. - - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public License as - published by the Free Software Foundation; either version 2.1 of the - License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <https://www.gnu.org/licenses/>. */ - -#ifndef MMAP_X86_64_INTERNAL_H -#define MMAP_X86_64_INTERNAL_H - -#include <ldsodefs.h> - -/* If the Prefer_MAP_32BIT_EXEC bit is set, try to map executable pages - with MAP_32BIT first. */ -#define MMAP_PREPARE(addr, len, prot, flags, fd, offset) \ - if ((addr) == NULL \ - && ((prot) & PROT_EXEC) != 0 \ - && HAS_ARCH_FEATURE (Prefer_MAP_32BIT_EXEC)) \ - { \ - void *ret = (void*) INLINE_SYSCALL_CALL (mmap, (addr), (len), \ - (prot), \ - (flags) | MAP_32BIT, \ - (fd), (offset)); \ - if (ret != MAP_FAILED) \ - return ret; \ - } - -#include_next <mmap_internal.h> - -#endif diff --git a/sysdeps/x86/cpu-tunables.c b/sysdeps/x86/cpu-tunables.c index 61b05e5b1d..957db3ad22 100644 --- a/sysdeps/x86/cpu-tunables.c +++ b/sysdeps/x86/cpu-tunables.c @@ -258,13 +258,6 @@ TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp) 20); } break; - case 21: - { - CHECK_GLIBC_IFUNC_PREFERRED_BOTH (n, cpu_features, - Prefer_MAP_32BIT_EXEC, - disable, 21); - } - break; case 23: { CHECK_GLIBC_IFUNC_PREFERRED_NEED_BOTH diff --git a/sysdeps/x86/include/cpu-features-preferred_feature_index_1.def b/sysdeps/x86/include/cpu-features-preferred_feature_index_1.def index 1530d594b3..8250bfcbec 100644 --- a/sysdeps/x86/include/cpu-features-preferred_feature_index_1.def +++ b/sysdeps/x86/include/cpu-features-preferred_feature_index_1.def @@ -26,7 +26,6 @@ BIT (I586) BIT (I686) BIT (Slow_SSE4_2) BIT (AVX_Fast_Unaligned_Load) -BIT (Prefer_MAP_32BIT_EXEC) BIT (Prefer_No_VZEROUPPER) BIT (Prefer_ERMS) BIT (Prefer_No_AVX512) |