The kernel version check is used to avoid glibc to run on older
kernels where some syscall are not available and fallback code are
not enabled to handle graciously fail. However, it does not prevent
if the kernel does not correctly advertise its version through
vDSO note, uname or procfs.
Also kernel version checks are sometime not desirable by users,
where they want to deploy on different system with different kernel
version knowing the minimum set of syscall is always presented on
such systems.
The kernel version check has been removed along with the
LD_ASSUME_KERNEL environment variable. The minimum kernel used to
built glibc is still provided through NT_GNU_ABI_TAG ELF note and
also printed when libc.so is issued.
Checked on x86_64-linux-gnu.
On 32-bit machines this has no affect. On 64-bit machines
{u}int_fast{16|32} are set as {u}int64_t which is often not
ideal. Particularly x86_64 this change both saves code size and
may save instruction cost.
Full xcheck passes on x86_64.
And optimize it slightly.
This is commit 8c8510ab27 revised.
In _dl_aux_init in elf/dl-support.c, use an explicit loop
and -fno-tree-loop-distribute-patterns to avoid memset.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Otherwise, <dl-auxv.h> on POWER ends up being included twice,
once in dl-sysdep.c, once in dl-support.c. That leads to a linker
failure due to multiple definitions of _dl_cache_line_size.
Fixes commit d96d2995c1
("Revert "Linux: Consolidate auxiliary vector parsing").
This reverts commit 8c8510ab27. The
revert is not perfect because the commit included a bug fix for
_dl_sysdep_start with an empty argv, introduced in commit
2d47fa6862 ("Linux: Remove
DL_FIND_ARG_COMPONENTS"), and this bug fix is kept.
The revert is necessary because the reverted commit introduced an
early memset call on aarch64, which leads to crash due to lack of TCB
initialization.
And optimize it slightly.
The large switch statement in _dl_sysdep_start can be replaced with
a large array. This reduces source code and binary size. On
i686-linux-gnu:
Before:
text data bss dec hex filename
7791 12 0 7803 1e7b elf/dl-sysdep.os
After:
text data bss dec hex filename
7135 12 0 7147 1beb elf/dl-sysdep.os
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The generic version is the de-facto Linux implementation. It
requires an auxiliary vector, so Hurd does not use it.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
Neither the <dlfcn.h> entry points, nor lazy symbol resolution, nor
initial shared library load-up, are cancellation points, so ld.so
should exclusively use I/O primitives that are not cancellable. We
currently achieve this by having the cancellation hooks compile as
no-ops when IS_IN(rtld); this patch changes to using exclusively
_nocancel primitives in the source code instead, which makes the
intent clearer and significantly reduces the amount of code compiled
under IS_IN(rtld) as well as IS_IN(libc) -- in particular,
elf/Makefile no longer thinks we require a copy of unwind.c in
rtld-libc.a. (The older mechanism is preserved as a backstop.)
The bulk of the change is splitting up the files that define the
_nocancel I/O functions, so they don't also define the variants that
*are* cancellation points; after which, the existing logic for picking
out the bits of libc that need to be recompiled as part of ld.so Just
Works. I did this for all of the _nocancel functions, not just the
ones used by ld.so, for consistency.
fcntl was a little tricky because it's only a cancellation point for
certain opcodes (F_SETLKW(64), which can block), and the existing
__fcntl_nocancel wasn't applying the FCNTL_ADJUST_CMD hook, which
strikes me as asking for trouble, especially as the only nontrivial
definition of FCNTL_ADJUST_CMD (for powerpc64) changes F_*LK* opcodes.
To fix this, fcntl_common moves to fcntl_nocancel.c along with
__fcntl_nocancel, and changes its name to the extern (but hidden)
symbol __fcntl_nocancel_adjusted, so that regular fcntl can continue
calling it. __fcntl_nocancel now applies FCNTL_ADJUST_CMD; so that
both both fcntl.c and fcntl_nocancel.c can see it, the only nontrivial
definition moves from sysdeps/u/s/l/powerpc/powerpc64/fcntl.c to
.../powerpc64/sysdep.h and becomes entirely a macro, instead of a macro
that calls an inline function.
The nptl version of libpthread also changes a little, because its
"compat-routines" formerly included files that defined all the
_nocancel functions it uses; instead of continuing to duplicate them,
I exported the relevant ones from libc.so as GLIBC_PRIVATE. Since the
Linux fcntl.c calls a function defined by fcntl_nocancel.c, it can no
longer be used from libpthread.so; instead, introduce a custom
forwarder, pt-fcntl.c, and export __libc_fcntl from libc.so as
GLIBC_PRIVATE. The nios2-linux ABI doesn't include a copy of vfork()
in libpthread, and it was handling that by manipulating
libpthread-routines in .../linux/nios2/Makefile; it is cleaner to do
what other such ports do, and have a pt-vfork.S that defines no symbols.
Right now, it appears that Hurd does not implement _nocancel I/O, so
sysdeps/generic/not-cancel.h will forward everything back to the
regular functions. This changed the names of some of the functions
that sysdeps/mach/hurd/dl-sysdep.c needs to interpose.
* elf/dl-load.c, elf/dl-misc.c, elf/dl-profile.c, elf/rtld.c
* sysdeps/unix/sysv/linux/dl-sysdep.c
Include not-cancel.h. Use __close_nocancel instead of __close,
__open64_nocancel instead of __open, __read_nocancel instead of
__libc_read, and __write_nocancel instead of __libc_write.
* csu/check_fds.c (check_one_fd)
* sysdeps/posix/fdopendir.c (__fdopendir)
* sysdeps/posix/opendir.c (__alloc_dir): Use __fcntl_nocancel
instead of __fcntl and/or __libc_fcntl.
* sysdeps/unix/sysv/linux/pthread_setname.c (pthread_setname_np)
* sysdeps/unix/sysv/linux/pthread_getname.c (pthread_getname_np)
* sysdeps/unix/sysv/linux/i386/smp.h (is_smp_system):
Use __open64_nocancel instead of __open_nocancel.
* sysdeps/unix/sysv/linux/not-cancel.h: Move all of the
hidden_proto declarations to the end and issue them if either
IS_IN(libc) or IS_IN(rtld).
* sysdeps/unix/sysv/linux/Makefile [subdir=io] (sysdep_routines):
Add close_nocancel, fcntl_nocancel, nanosleep_nocancel,
open_nocancel, open64_nocancel, openat_nocancel, pause_nocancel,
read_nocancel, waitpid_nocancel, write_nocancel.
* io/Versions [GLIBC_PRIVATE]: Add __libc_fcntl,
__fcntl_nocancel, __open64_nocancel, __write_nocancel.
* posix/Versions: Add __nanosleep_nocancel, __pause_nocancel.
* nptl/pt-fcntl.c: New file.
* nptl/Makefile (pthread-compat-wrappers): Remove fcntl.
(libpthread-routines): Add pt-fcntl.
* include/fcntl.h (__fcntl_nocancel_adjusted): New function.
(__libc_fcntl): Remove attribute_hidden.
* sysdeps/unix/sysv/linux/fcntl.c (__libc_fcntl): Call
__fcntl_nocancel_adjusted, not fcntl_common.
(__fcntl_nocancel): Move to new file fcntl_nocancel.c.
(fcntl_common): Rename to __fcntl_nocancel_adjusted; also move
to fcntl_nocancel.c.
* sysdeps/unix/sysv/linux/fcntl_nocancel.c: New file.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/fcntl.c: Remove file.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h:
Define FCNTL_ADJUST_CMD here, as a self-contained macro.
* sysdeps/unix/sysv/linux/close.c: Move __close_nocancel to...
* sysdeps/unix/sysv/linux/close_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/nanosleep.c: Move __nanosleep_nocancel to...
* sysdeps/unix/sysv/linux/nanosleep_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/open.c: Move __open_nocancel to...
* sysdeps/unix/sysv/linux/open_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/open64.c: Move __open64_nocancel to...
* sysdeps/unix/sysv/linux/open64_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/openat.c: Move __openat_nocancel to...
* sysdeps/unix/sysv/linux/openat_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/openat64.c: Move __openat64_nocancel to...
* sysdeps/unix/sysv/linux/openat64_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/pause.c: Move __pause_nocancel to...
* sysdeps/unix/sysv/linux/pause_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/read.c: Move __read_nocancel to...
* sysdeps/unix/sysv/linux/read_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/waitpid.c: Move __waitpid_nocancel to...
* sysdeps/unix/sysv/linux/waitpid_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/write.c: Move __write_nocancel to...
* sysdeps/unix/sysv/linux/write_nocancel.c: ...this new file.
* sysdeps/unix/sysv/linux/nios2/Makefile: Don't override
libpthread-routines.
* sysdeps/unix/sysv/linux/nios2/pt-vfork.S: New file which
defines nothing.
* sysdeps/mach/hurd/dl-sysdep.c: Define __read instead of
__libc_read, and __write instead of __libc_write. Define
__open64 in addition to __open.
GCC 4.5 warns about "extern void _end; &end;".
Use char[] instead, as that also doesn't fall foul
of a target's .sdata optimizations.
Signed-off-by: Richard Henderson <rth@twiddle.net>
2004-08-15 Roland McGrath <roland@redhat.com>
[BZ #227]
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_BRK_PAGE_ROUNDED): New macro.
* sysdeps/unix/sysv/linux/dl-sysdep.c (frob_brk)
[! __ASSUME_BRK_PAGE_ROUNDED]: Adjust the break up if it falls within
the partial page after the dynamic linker's own data segment.
2001-07-01 Andreas Jaeger <aj@suse.de>
* sysdeps/unix/sysv/linux/dl-sysdep.c (frob_brk): Remove duplicate
sbrk. Closes PR libc/2312.
2001-07-01 Andreas Jaeger <aj@suse.de>
* sysdeps/generic/segfault.c (install_handler): Handle case that
the output file does not exists. Closes PR libc/2345.
2001-07-11 Ulrich Drepper <drepper@redhat.com>
* intl/locale.alias: Use he language code for hebrew, not il
[PR libc/2382].
2001-07-11 Jakub Jelinek <jakub@redhat.com>
* iconv/gconv_int.h: Fix comment typo.
* hurd/hurdsig.c (_hurdsig_init): Remove a useless line of code.
backwards conditional in test for x == 1.0.
2001-07-06 Paul Eggert <eggert@twinsun.com>
* manual/argp.texi: Remove ignored LGPL copyright notice; it's
not appropriate for documentation anyway.
* manual/libc-texinfo.sh: "Library General Public License" ->
"Lesser General Public License".
2001-07-06 Andreas Jaeger <aj@suse.de>
* All files under GPL/LGPL version 2: Place under LGPL version
2.1.
1997-07-26 04:14 Ulrich Drepper <drepper@cygnus.com>
* elf/Makefile (distribute): Add genrtldtbl.awk.
(before-compile): Add rtldtbl.h.
(GAWK): New variable.
(generated): Add trusted-dirs.h and rtldtbl.h.
($(objpfx)rtldtbl.h): New rule. File is needed by dl-load.c.
* elf/dl-load.c: Rewrite. Now use cache and look for shared
objects in machine dependent directories.
* elf/dl-object.c (_dl_new_object): Initialize l_rpath_dirs member.
* elf/dl-support.c: Rename function to non_dynamic_init and add
initialization for _dl_platform, _dl_platformlen, _dl_pagesize
and call to initializer for search path.
* elf/elf.h: Add AT_PLATFORM and AT_HWCAP.
* elf/genrtldtbl.awk: New file.
* elf/link.h: Add type definitions and declarations for search
path cache.
* elf/rtld.c: Add definitions of variables used for search path cache.
* sysdeps/generic/dl-sysdep.c: Let auxiliary vector initialize
_dl_platform. Initialize _dl_pagesize early and use this value.
* sysdeps/i386/dl-machine.h: Add code for _dl_platform handling.
* sysdeps/mach/hurd/dl-sysdep.c: Initialize _dl_pagesize.
* sysdeps/unix/sysv/linux/dl-sysdep.c: Use _dl_pagesize instead
of calling getpagesize.
* elf/dl-error.c (_dl_signal_error): Make message nicer.
* nss/libnss_files.map: Fix typo.
Reported by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>.
* sysdeps/generic/strsep.c: Optimize case where separator set contains
only one character.
* sysdeps/libm-ieee754/s_ccosh.c: Correct sign of result for real
== +-Inf.
* sysdeps/libm-ieee754/s_ccoshf.c: Likewise.
* sysdeps/libm-ieee754/s_ccoshl.c: Likewise.
1997-07-25 09:15 H.J. Lu <hjl@gnu.ai.mit.edu>
* sysdeps/sparc/udiv_qrnnd.S: Check PIC instead of __PIC__.
* sysdeps/unix/sysv/linux/sparc/__sigtrampoline.S: Likewise.
* sysdeps/unix/mips/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/mips/clone.S: Likewise.
* sysdeps/mips/bsd-_setjmp.S: Remove __PIC__ comment.
* sysdeps/mips/bsd-setjmp.S: Likewise.
* sysdeps/mips/dl-machine.h: Remove extra stuff.
* sysdeps/mips/mips64/dl-machine.h: Likewise.
1997-07-25 18:55 Philip Blundell <Philip.Blundell@pobox.com>
* sysdeps/standalone/arm/sysdep.c: New file.
1997-07-25 13:25 Philip Blundell <Philip.Blundell@pobox.com>
* aout/Makefile: New file.
* Makeconfig (binfmt-subdir): Assume a.out when not ELF.
* sysdeps/generic/machine-gmon.h: Add warning about limitations of
__builtin_return_address().
* sysdeps/arm/machine-gmon.h: New file, use assembly to avoid
above problem.
1997-07-25 16:24 H.J. Lu <hjl@gnu.ai.mit.edu>
* elf/dl-deps.c (_dl_map_object_deps): Fix a typo.
1997-07-22 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
* math/libm-test.c (ccos_test, ccosh_test): Fix sign in some
tests.
1997-07-24 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
* sunrpc/clnt_udp.c (clntudp_call): Rename cu_wait from timeout to
not shadow the variable in the outer scope.
(_hurd_set_brk): Try to allocate more space when we run out.
* sysdeps/generic/sbrk.c: If __curbrk is zero, call __brk with
zero and examine it again.
* sysdeps/unix/sysv/linux/i386/brk.c: New file.
* sysdeps/unix/sysv/linux/i386/brk.S: File removed.
* sysdeps/unix/sysv/linux/i386/sbrk.S: File removed.
* sysdeps/unix/sysv/linux/dl-sysdep.c: New file.
