explicit_bzero(s, n) is the same as memset(s, 0, n), except that the
compiler is not allowed to delete a call to explicit_bzero even if the
memory pointed to by 's' is dead after the call. Right now, this effect
is achieved externally by having explicit_bzero be a function whose
semantics are unknown to the compiler, and internally, with a no-op
asm statement that clobbers memory. This does mean that small
explicit_bzero operations cannot be expanded inline as small memset
operations can, but on the other hand, small memset operations do get
deleted by the compiler. Hopefully full compiler support for
explicit_bzero will happen relatively soon.
There are two new tests: test-explicit_bzero.c verifies the
visible semantics in the same way as the existing test-bzero.c,
and tst-xbzero-opt.c verifies the not-being-optimized-out property.
The latter is conceptually based on a test written by Matthew Dempsky
for the OpenBSD regression suite.
The crypt() implementation has an immediate use for this new feature.
We avoid having to add a GLIBC_PRIVATE alias for explicit_bzero
by running all of libcrypt's calls through the fortified variant,
__explicit_bzero_chk, which is in the impl namespace anyway. Currently
I'm not aware of anything in libc proper that needs this, but the
glue is all in place if it does become necessary. The legacy DES
implementation wasn't bothering to clear its buffers, so I added that,
mostly for consistency's sake.
* string/explicit_bzero.c: New routine.
* string/test-explicit_bzero.c, string/tst-xbzero-opt.c: New tests.
* string/Makefile (routines, strop-tests, tests): Add them.
* string/test-memset.c: Add ifdeffage for testing explicit_bzero.
* string/string.h [__USE_MISC]: Declare explicit_bzero.
* debug/explicit_bzero_chk.c: New routine.
* debug/Makefile (routines): Add it.
* debug/tst-chk1.c: Test fortification of explicit_bzero.
* string/bits/string3.h: Fortify explicit_bzero.
* manual/string.texi: Document explicit_bzero.
* NEWS: Mention addition of explicit_bzero.
* crypt/crypt-entry.c (__crypt_r): Clear key-dependent intermediate
data before returning, using explicit_bzero.
* crypt/md5-crypt.c (__md5_crypt_r): Likewise.
* crypt/sha256-crypt.c (__sha256_crypt_r): Likewise.
* crypt/sha512-crypt.c (__sha512_crypt_r): Likewise.
* include/string.h: Redirect internal uses of explicit_bzero
to __explicit_bzero_chk[_internal].
* string/Versions [GLIBC_2.25]: Add explicit_bzero.
* debug/Versions [GLIBC_2.25]: Add __explicit_bzero_chk.
* sysdeps/arm/nacl/libc.abilist
* sysdeps/unix/sysv/linux/aarch64/libc.abilist
* sysdeps/unix/sysv/linux/alpha/libc.abilist
* sysdeps/unix/sysv/linux/arm/libc.abilist
* sysdeps/unix/sysv/linux/hppa/libc.abilist
* sysdeps/unix/sysv/linux/i386/libc.abilist
* sysdeps/unix/sysv/linux/ia64/libc.abilist
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
* sysdeps/unix/sysv/linux/microblaze/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
* sysdeps/unix/sysv/linux/nios2/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
* sysdeps/unix/sysv/linux/sh/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist:
Add entries for explicit_bzero and __explicit_bzero_chk.
Improve strcspn performance using a much faster algorithm. It is kept simple
so it works well on most targets. It is generally at least 10 times faster
than the existing implementation on bench-strcspn on a few AArch64
implementations, and for some tests 100 times as fast (repeatedly calling
strchr on a small string is extremely slow...).
In fact the string/bits/string2.h inlines make no longer sense, as GCC
already uses strlen if reject is an empty string, strchrnul is 5 times as
fast as __strcspn_c1, while __strcspn_c2 and __strcspn_c3 are slower than
the strcspn main loop for large strings (though reject length 2-4 could be
special cased in the future to gain even more performance).
Tested on x86_64, i686, and aarch64.
* string/Version (libc): Add GLIBC_2.24.
* string/strcspn.c (strcspn): Rewrite function.
* string/bits/string2.h (strcspn): Use __builtin_strcspn.
(__strcspn_c1): Remove inline function.
(__strcspn_c2): Likewise.
(__strcspn_c3): Likewise.
* string/string-inline.c
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c1): Add
compatibility symbol.
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c2):
Likewise.
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c3):
Likewise.
* sysdeps/i386/string-inlines.c: Include generic string-inlines.c.
returning.
(PTR_DEMANGLE): Real definition now that it's not the same as
PRT_MANGLE anymore.
* sysdeps/unix/sysv/linux/x86_64/sysdep.h: Likewise.
* string/strerror_l.c: New file.
* string/Makefile (routines): Add strerror_l.
* string/string.h: Declare strerror_l.
* string/Versions: Export strerror_l for GLIBC_2.6.
* nscd/connections.c (nscd_run): Don't define MAXKEYLEN here.
2004-03-22 Jakub Jelinek <jakub@redhat.com>
* sysdeps/unix/sysv/linux/sparc/sparc32/getpagesize.c
(__getpagesize): Avoid warning about writing into read-only memory.
* string/Makefile (routines): Add xpg-strerror.
* string/string.h (strerror_r): If __USE_XOPEN2K but not __USE_GNU,
redirect strerror_r to __xpg_strerror_r.
* string/Versions (libc): Add __xpg_strerror_r@@GLIBC_2.3.4.
* sysdeps/generic/xpg-strerror.c: New file.
* sysdeps/mach/xpg-strerror.c: New file.
2001-10-04 Ben Collins <bcollins@debian.org>
* sysdeps/generic/inttypes.h: Fix typo (define, not defined) in
decleration of __need_wchar_t.
2001-10-03 Jakub Jelinek <jakub@redhat.com>
* string/bits/string2.h (__strsep_g): Add prototype.
(__strsep): Use it.
* string/Versions (__strsep): Remove.
* sysdeps/generic/strsep.c (__strsep_g): Add alias to __strsep.
2001-10-07 Ulrich Drepper <drepper@redhat.com>
* manua/llio.texi: Clarify file references added by mmap.
Patch by Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>.
1999-05-17 Andreas Jaeger <aj@arthur.rhein-neckar.de>
* sysdeps/i386/i486/Versions: New file with inline functions from
sysdeps/i386/i486/bits/string.h for now.
* sysdeps/i386/Versions: Add inline functions from
sysdeps/i386/bits/string.h.
* string/Versions: Add inline functions from <bits/string2.h>.
* string/Makefile (routines): Add string-inlines.
* string/string-inlines.c: New file, used for implementation of
extern inline functions.
* sysdeps/i386/i486/bits/string.h: Use _FORCE_INLINES to generate
non inlined versions of functions.
* string/bits/string2.h: Likewise.
* sysdeps/i386/bits/string.h: Likewise.
1999-05-17 Ulrich Drepper <drepper@cygnus.com>
* inet/arpa/tftp.h: Add second packed attribute.
1998-07-02 21:51 Ulrich Drepper <drepper@cygnus.com>
* Makeconfig: Define list of subdirs as all-subdirs and make subdirs
a copy.
* Makefile: Add rules to generate map files.
(distribute): Remove libc.map, add Versions.def and versions.awk.
* Makerules: Change rules to find map files on common-objpfx.
* elf/Makefile: Likewise.
* md5-crypt/Makefile: Likewise.
* nis/Makefile (libnsl-map): Remove.
* Versions.def: New file.
* versions.awk: New file.
* argp/Versions: New file.
* assert/Versions: New file.
* catgets/Versions: New file.
* csu/Versions: New file.
* ctype/Versions: New file.
* db/Versions: New file.
* debug/Versions: New file.
* dirent/Versions: New file.
* elf/Versions: New file.
* gmon/Versions: New file.
* grp/Versions: New file.
* hesiod/Versions: New file.
* hurd/Versions: New file.
* iconv/Versions: New file.
* inet/Versions: New file.
* intl/Versions: New file.
* io/Versions: New file.
* libio/Versions: New file.
* linuxthreads/Versions: New file.
* locale/Versions: New file.
* login/Versions: New file.
* malloc/Versions: New file.
* math/Versions: New file.
* md5-crypt/Versions: New file.
* misc/Versions: New file.
* nis/Versions: New file.
* nss/Versions: New file.
* posix/Versions: New file.
* pwd/Versions: New file.
* resolv/Versions: New file.
* resource/Versions: New file.
* rt/Versions: New file.
* setjmp/Versions: New file.
* shadow/Versions: New file.
* signal/Versions: New file.
* socket/Versions: New file.
* stdio/Versions: New file.
* stdio-common/Versions: New file.
* stdlib/Versions: New file.
* streams/Versions: New file.
* string/Versions: New file.
* sunrpc/Versions: New file.
* sysdeps/alpha/Versions: New file.
* sysdeps/alpha/fpu/Versions: New file.
* sysdeps/i386/Versions: New file.
* sysdeps/sparc/Versions: New file.
* sysdeps/unix/sysv/Versions: New file.
* sysdeps/unix/sysv/linux/Versions: New file.
* sysdeps/unix/sysv/linux/alpha/Versions: New file.
* sysdeps/unix/sysv/linux/i386/Versions: New file.
* sysdeps/unix/sysv/linux/mips/Versions: New file.
* sysvipc/Versions: New file.
* termios/Versions: New file.
* time/Versions: New file.
* wcsmbs/Versions: New file.
* wctype/Versions: New file.
* libc.map: Removed.
* db/libdb.map: Removed.
* elf/libdl.map: Removed.
* hesiod/libnss_hesiod.map: Removed.
* hurd/libhurduser.map: Removed.
* hurd/libmachuser.map: Removed.
* linuxthreads/libpthread.map: Removed.
* locale/libBrokenLocale.map: Removed.
* login/libutil.map: Removed.
* math/libm.map: Removed.
* md5-crypt/libcrypt.map: Removed.
* nis/libnsl.map: Removed.
* nis/libnsl_compat.map: Removed.
* nis/libnss_nis.map: Removed.
* nis/libnss_nisplus.map: Removed.
* nss/libnss_db.map: Removed.
* nss/libnss_files.map: Removed.
* resolv/libnss_dns.map: Removed.
* resolv/libresolv.map: Removed.
* rt/librt.map: Removed.
* elf/dl-load.c (fillin_rpath): Fix test for trusted directory.
Fix typos.
* elf/rtld.c (process_dl_debug): Recognize 'all'.
(process_envvars): LD_BIND_NOW must be followed by y, Y, or 1.
* sysdeps/generic/elf/backtracesyms.c: Allocate string memory of
correct size.
* sysdeps/unix/sysv/linux/getsysstats.c (get_proc_path): Fix typo
in comment.
Zack Weinberg