Commit Graph

1069 Commits

Author SHA1 Message Date
Florian Weimer
2ba3cfa160 malloc: Remove __malloc_initialize_hook from the API [BZ #19564]
__malloc_initialize_hook is interposed by application code, so
the usual approach to define a compatibility symbol does not work.
This commit adds a new mechanism based on #pragma GCC poison in
<stdc-predef.h>.
2016-06-10 10:46:05 +02:00
Paul Pluzhnikov
b9f5c3acc0 2016-06-05 Paul Pluzhnikov <ppluzhnikov@google.com>
* manual/install.texi: Remove mention of --without-tls
	* INSTALL: Regenerate.
2016-06-05 08:41:13 -07:00
Roland McGrath
c30c3f46a5 stpcpy is part of POSIX.1-2008 [BZ #3629] 2016-05-30 13:28:25 +02:00
ricaljasan@pacific.net
b56e416f72 manual: fix typos in error reporting 2016-05-19 23:25:06 -04:00
ricaljasan@pacific.net
5a1021e885 manual: fix typo in the introduction 2016-05-19 23:22:59 -04:00
Stephen Gallagher
ced8f89336 NSS: Implement group merging support.
https://sourceware.org/glibc/wiki/Proposals/GroupMerging

== Justification ==
It is common today for users to rely on centrally-managed user stores for
handling their user accounts. However, much software existing today does
not have an innate understanding of such accounts. Instead, they commonly
rely on membership in known groups for managing access-control (for
example the "wheel" group on Fedora and RHEL systems or the "adm" group
on Debian-derived systems). In the present incarnation of nsswitch, the
only way to have such groups managed by a remote user store such as
FreeIPA or Active Directory would be to manually remove the groups from
/etc/group on the clients so that nsswitch would then move past nss_files
and into the SSSD, nss-ldap or other remote user database.

== Solution ==
With this patch, a new action is introduced for nsswitch:
NSS_ACTION_MERGE. To take advantage of it, one will add [SUCCESS=merge]
between two database entries in the nsswitch.conf file. When a group is
located in the first of the two group entries, processing will continue
on to the next one. If the group is also found in the next entry (and the
group name and GID are an exact match), the member list of the second
entry will be added to the group object to be returned.

== Implementation ==
After each DL_LOOKUP_FN() returns, the next action is checked. If the
function returned NSS_STATUS_SUCCESS and the next action is
NSS_ACTION_MERGE, a copy of the result buffer is saved for the next pass
through the loop. If on this next pass through the loop the database
returns another instance of a group matching both the group name and GID,
the member list is added to the previous list and it is returned as a
single object. If the following database does not contain the same group,
then the original is copied back into the destination buffer.

This patch implements merge functionality only for the group database.
For other databases, there is a default implementation that will return
the EINVAL errno if a merge is requested. The merge functionality can be
implemented for other databases at a later time if such is needed. Each
database must provide a unique implementation of the deep-copy and merge
functions.

If [SUCCESS=merge] is present in nsswitch.conf for a glibc version that
does not support it, glibc will process results up until that operation,
at which time it will return results if it has found them or else will
simply return an error. In practical terms, this ends up behaving like
the remainder of the nsswitch.conf line does not exist.

== Iterators ==
This feature does not modify the iterator functionality from its current
behavior. If getgrnam() or getgrgid() is called, glibc will iterate
through all entries in the `group` line in nsswitch.conf and display the
list of members without attempting to merge them. This is consistent with
the behavior of nss_files where if two separate lines are specified for
the same group in /etc/groups, getgrnam()/getgrgid() will display both.
Clients are already expected to handle this gracefully.

== No Premature Optimizations ==
The following is a list of places that might be eligible for
optimization, but were not overengineered for this initial contribution:
 * Any situation where a merge may occur will result in one malloc() of
   the same size as the input buffer.
 * Any situation where a merge does occur will result in a second
   malloc() to hold the list of pointers to member name strings.
 * The list of members is simply concatenated together and is not tested
   for uniqueness (which is identical to the behavior for nss_files,
   which will simply return identical values if they both exist on the
   line in the file. This could potentially be optimized to reduce space
   usage in the buffer, but it is both complex and computationally
   expensive to do so.

== Testing ==
I performed testing by running the getent utility against my newly-built
glibc and configuring /etc/nsswitch.conf with the following entry:
group: group:      files [SUCCESS=merge] sss

In /etc/group I included the line:
wheel10:sgallagh

I then configured my local SSSD using the id_provider=local to respond
with:
wheel:*:10:localuser,localuser2

I then ran `getent group wheel` against the newly-built glibc in
multiple situations and received the expected output as described
above:
 * When SSSD was running.
 * When SSSD was configured in nsswitch.conf but the daemon was not
   running.
 * When SSSD was configured in nsswitch.conf but nss_sss.so.2 was not
   installed on the system.
 * When the order of 'sss' and 'files' was reversed.
 * All of the above with the [SUCCESS=merge] removed (to ensure no
   regressions).
 * All of the above with `getent group 10`.
 * All of the above with `getent group` with and without
   `enumerate=true` set in SSSD.
 * All of the above with and without nscd enabled on the system.
2016-04-29 22:18:21 -04:00
Florian Weimer
137fe72eca glob: Simplify the interface for the GLOB_ALTDIRFUNC callback gl_readdir
Previously, application code had to set up the d_namlen member if
the target supported it, involving conditional compilation.  After
this change, glob will use the length of the string in d_name instead
of d_namlen to determine the file name length.  All glibc targets
provide the d_type and d_ino members, and setting them as needed for
gl_readdir is straightforward.

Changing the behavior with regards to d_ino is left to a future
cleanup.
2016-04-29 09:35:30 +02:00
Florian Weimer
29d794863c malloc: Run fork handler as late as possible [BZ #19431]
Previously, a thread M invoking fork would acquire locks in this order:

  (M1) malloc arena locks (in the registered fork handler)
  (M2) libio list lock

A thread F invoking flush (NULL) would acquire locks in this order:

  (F1) libio list lock
  (F2) individual _IO_FILE locks

A thread G running getdelim would use this order:

  (G1) _IO_FILE lock
  (G2) malloc arena lock

After executing (M1), (F1), (G1), none of the threads can make progress.

This commit changes the fork lock order to:

  (M'1) libio list lock
  (M'2) malloc arena locks

It explicitly encodes the lock order in the implementations of fork,
and does not rely on the registration order, thus avoiding the deadlock.
2016-04-14 09:17:02 +02:00
Florian Weimer
b49ab5f450 Remove union wait [BZ #19613]
The overloading approach in the W* macros was incompatible with
integer expressions of a type different from int.  Applications
using union wait and these macros will have to migrate to the
POSIX-specified int status type.
2016-04-14 08:54:57 +02:00
Joseph Myers
b55b28e657 Allow spurious underflow / inexact for ldbl-128ibm.
A large number of the test-ldouble failures seen for ldbl-128ibm are
spurious "underflow" and "inexact" exceptions.  These arise from such
exceptions in the underlying arithmetic; unlike other spurious
exceptions from that arithmetic, they do not in general relate to
cases where the returned result is also substantially inaccurate, are
not so readily avoidable by appropriately conditional libgcc patches,
and are widespread enough to be hard to handle through individual
XFAILing of the affected tests.

Thus, this patch documents relaxed accuracy goals for libm functions
for IBM long double and makes libm-test.inc reflect these spurious
exceptions in ldbl-128ibm arithmetic and always allow them in
ldbl-128ibm testing (while still not allowing these exceptions to be
missing where required to be present).  Tested for powerpc.

	* manual/math.texi (Errors in Math Functions): Document relaxed
	accuracy goals for IBM long double.
	* math/libm-test.inc (test_exceptions): Always allow spurious
	"underflow" and "inexact" exceptions for IBM long double.
2016-03-10 23:48:46 +00:00
Joseph Myers
5b4ecd3f95 Require Linux 3.2 except on x86 / x86_64, 3.2 headers everywhere.
In <https://sourceware.org/ml/libc-alpha/2016-01/msg00885.html> I
proposed a minimum Linux kernel version of 3.2 for glibc 2.24, since
Linux 2.6.32 has reached EOL.

In the discussion in February, some concerns were expressed about
compatibility with OpenVZ containers.  It's not clear that these are
real issues, given OpenVZ backporting kernel features and faking the
kernel version for guest software, as discussed in
<https://sourceware.org/ml/libc-alpha/2016-02/msg00278.html>.  It's
also not clear that supporting running GNU/Linux distributions from
late 2016 (at the earliest) on a kernel series from 2009 is a sensible
expectation.  However, as an interim step, this patch increases the
requirement everywhere except x86 / x86_64 (since the controversy was
only about those architectures); the special caveats and settings can
easily be removed later when we're ready to increase the requirements
on x86 / x86_64 (and if someone would like to raise the issue on LWN
as suggested in the previous discussion, that would be welcome).  3.2
kernel headers are required everywhere by this patch.

(x32 already requires 3.4 or later, so is unaffected by this patch.)

As usual for such a change, this patch only changes the configure
scripts and associated documentation.  The intent is to follow up with
removal of dead __LINUX_KERNEL_VERSION conditionals.  Each __ASSUME_*
or other macro that becomes dead can then be removed independently.

Tested for x86_64 and x86.

	* sysdeps/unix/sysv/linux/configure.ac (LIBC_LINUX_VERSION):
	Define to 3.2.0.
	(arch_minimum_kernel): Likewise.
	* sysdeps/unix/sysv/linux/configure: Regenerated.
	* sysdeps/unix/sysv/linux/i386/configure.ac (arch_minimum_kernel):
	Define to 2.6.32.
	* sysdeps/unix/sysv/linux/i386/configure: Regenerated.
	* sysdeps/unix/sysv/linux/x86_64/64/configure.ac
	(arch_minimum_kernel): Define to 2.6.32.
	* sysdeps/unix/sysv/linux/x86_64/64/configure: Regenerated.
	* README: Document Linux 3.2 requirement.
	* manual/install.texi (Linux): Document Linux 3.2 headers
	requirement.
	* INSTALL: Regenerated.
2016-02-24 17:15:12 +00:00
Florian Weimer
7584a3f96d Deprecate readdir_r, readdir64_r [BZ #19056] 2016-02-20 12:56:55 +01:00
Florian Weimer
ca135f824b malloc: Remove max_total_mem member form struct malloc_par
Also note that sumblks in struct mallinfo is always 0.
No functional change.
2016-02-19 17:07:04 +01:00
Carlos O'Donell
2c8f75f79b Update INSTALL with latest versions tested to work. 2016-02-14 20:54:29 -05:00
Paul Eggert
97ee300903 Fix doc quoting problems with Texinfo 5
Without this change, in the info file output, Texinfo 5 quotes code
in text with undirected single quotes 'like this' and generates
code examples that with many PDF readers cannot be cut out of PDFs
and pasted into code.
* manual/libc.texinfo: Configure the libc manual like the GNU
Emacs manual, by using @documentencoding and setting
txicodequoteundirected and txicodequotebacktick.  This way,
Texinfo 5 quotes code in text with directed single quotes ‘like
this’ and produces examples that can be cut out of PDFs.  This
change causes Texinfo 5 to generate info files that contain UTF-8
characters in the set {'‘', '’', '“', '”', 'Ä', 'ä', 'ö', '−',
'–', '—', '©', '⇒', '•', '…'}, which is OK nowadays.
2016-01-10 00:20:51 -08:00
Marko Myllynen
48d0341cdd Make shebang interpreter directives consistent 2016-01-07 04:03:21 -05:00
Joseph Myers
084e7d57bb Update miscellaneous files from upstream sources.
This patch updates texinfo.tex, config.guess, config.sub and
move-if-change from their respective upstream sources.

	* manual/texinfo.tex: Update to version 2016-01-04.21 with
	trailing whitespace removed.
	* scripts/config.guess: Update to version 2016-01-01.
	* scripts/config.sub: Update to version 2016-01-01.
	* scripts/move-if-change: Update from gnulib.
2016-01-05 18:04:06 +00:00
Joseph Myers
1979f3c1ad Update copyright dates not handled by scripts/update-copyrights.
I've updated copyright dates in glibc for 2016.  This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files.

	* NEWS: Update copyright dates.
	* catgets/gencat.c (print_version): Likewise.
	* csu/version.c (banner): Likewise.
	* debug/catchsegv.sh: Likewise.
	* debug/pcprofiledump.c (print_version): Likewise.
	* debug/xtrace.sh (do_version): Likewise.
	* elf/ldconfig.c (print_version): Likewise.
	* elf/ldd.bash.in: Likewise.
	* elf/pldd.c (print_version): Likewise.
	* elf/sotruss.sh: Likewise.
	* elf/sprof.c (print_version): Likewise.
	* iconv/iconv_prog.c (print_version): Likewise.
	* iconv/iconvconfig.c (print_version): Likewise.
	* locale/programs/locale.c (print_version): Likewise.
	* locale/programs/localedef.c (print_version): Likewise.
	* login/programs/pt_chown.c (print_version): Likewise.
	* malloc/memusage.sh (do_version): Likewise.
	* malloc/memusagestat.c (print_version): Likewise.
	* malloc/mtrace.pl: Likewise.
	* manual/libc.texinfo: Likewise.
	* nptl/version.c (banner): Likewise.
	* nscd/nscd.c (print_version): Likewise.
	* nss/getent.c (print_version): Likewise.
	* nss/makedb.c (print_version): Likewise.
	* posix/getconf.c (main): Likewise.
	* scripts/test-installation.pl: Likewise.
	* sysdeps/unix/sysv/linux/lddlibc4.c (main): Likewise.
2016-01-04 16:26:30 +00:00
Joseph Myers
f7a9f785e5 Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
Joseph Myers
eed3e1eb79 Make obsolete syscall wrappers into compat symbols (bug 18472).
Various Linux kernel syscalls have become obsolete over time.
Specifically, the following are obsolete in all kernel versions
supported by glibc, are not present for architectures more recently
added to the kernel, and as such, the wrapper functions for them
should be compat symbols, not in static libc and not available for new
links with shared libc.

* bdflush: in Linux 2.6, does nothing if present.

* create_module get_kernel_syms query_module: Linux 2.4 module
  interface, syscalls not present in Linux 2.6.

* uselib: part of the mechanism for loading a.out shared libraries,
  irrelevant with ELF.

This patch adds support for syscalls.list to list syscall aliases of
the form NAME@VERSION:OBSOLETED, with SHLIB_COMPAT conditionals being
generated for such aliases.  Those five syscalls are then made into
compat symbols (obsoleted in glibc 2.23, so future ports won't have
these symbols at all), with the header <sys/kdaemon.h> declaring
bdflush being removed.  When we move to 3.2 as minimum kernel version,
the same can be done for nfsservctl (removed in Linux 3.1) as well.

Tested for x86_64 and x86 (testsuite, as well as checking that the
symbols in question indeed become compat symbols, that they are indeed
omitted from static libc, and that the generated SHLIB_COMPAT
conditionals look right).

	[BZ #18472]
	* sysdeps/unix/Makefile ($(objpfx)stub-syscalls.c): Handle entries
	for the form NAME@VERSION:OBSOLETED and generate SHLIB_COMPAT
	conditionals for them.
	* sysdeps/unix/make-syscalls.sh (emit_weak_aliases): Likewise.
	* sysdeps/unix/sysv/linux/sys/kdaemon.h: Remove file.
	* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Remove
	sys/kdaemon.h.
	* sysdeps/unix/sysv/linux/syscalls.list (bdflush): Make into
	compat-only syscall, obsoleted in glibc 2.23.
	(create_module): Likewise.
	(get_kernel_syms): Likewise.
	(query_module): Likewise.
	(uselib): Likewise.
	* manual/sysinfo.texi (System Parameters): Do not mention bdflush.
2015-12-14 22:52:15 +00:00
Paul Eggert
0a13c9e9de Split large string section; add truncation advice
* manual/examples/strncat.c: Remove.
This example was misleading, as the code would have undefined
behavior if "hello" was longer than SIZE.  Anyway, the manual
shouldn't encourage strncpy+strncat for this sort of thing.
* manual/string.texi (Copying Strings and Arrays): Split into
three sections Copying Strings and Arrays, Concatenating Strings,
and Truncating Strings, as this section was way too long.  All
cross-referenced changed.  Add advice about string-truncation
functions.  Remove misleading strncat example.
2015-12-10 08:29:30 -08:00
Carlos O'Donell
d4e301c5c6 Document best practice for disconnected NSS modules.
NSS modules which can run in disconnected modes should
return NSS_STATUS_NOTFOUND and SUCCESS in order to follow
best practice for such modules and ensure user applications
can have these modules configured without causing problems
if the data sources are not connected.
2015-12-10 00:48:15 -05:00
Paul Eggert
5d1d4918ee Fix typo in strncat, wcsncat manual entries
* manual/string.texi (Copying and Concatenation): Fix typos in
sample implementations of strncat and wcsncat, by having them use
the old value of the destination length, not the new one.
2015-12-04 15:24:35 -08:00
Paul Eggert
2cc4b9cce5 Consistency about byte vs character in string.texi
* manual/string.texi (String and Array Utilities):
Distinguish more carefully among bytes, multibyte characters,
and wide characters.  Use "byte" when talking about C 'char',
to distinguish it more clearly from multibyte characters.
Say "wide character" or "multibyte character" instead of
"character", when a wide or multibyte character is intended.
Similarly for "multibyte string" versus "string".
Define these terms more carefully.
2015-12-04 08:28:34 -08:00
Florian Weimer
2359035ac5 Remove CPU set size checking from affinity functions [BZ #19143]
With current kernel versions, the check does not reliably detect that
unavailable CPUs are requested, for these reasons:

(1) The kernel will silently ignore non-allowed CPUs, that is, CPUs
    which are physically present but disallowed for the thread
    based on system configuration.

(2) Similarly, CPU bits which lack an online CPU (possible CPUs)
    are ignored.

(3) The existing probing code assumes that the CPU mask size is a
    power of two and at least 1024.  Neither has it to be a power
    of two, nor is the minimum possible value 1024, so the value
    determined is often too large.  This means that the CPU set
    size check in glibc accepts CPU bits beyond the actual hard
    system limit.

(4) Future kernel versions may not even have a fixed CPU set size.

After the removal of the probing code, the kernel still returns
EINVAL if no CPU in the requested set remains which can run the
thread after the affinity change.

Applications which care about the exact affinity mask will have
to query it using sched_getaffinity after setting it.  Due to the
effects described above, this commit does not change this.

The new tests supersede tst-getcpu, which is removed.  This
addresses bug 19164 because the new tests allocate CPU sets
dynamically.

	* nptl/check-cpuset.h: Remove.
	* nptl/pthread_attr_setaffinity.c (__pthread_attr_setaffinity_new):
	Remove CPU set size check.
	* nptl/pthread_setattr_default_np.c (pthread_setattr_default_np):
	Likewise.
	* sysdeps/unix/sysv/linux/check-cpuset.h: Remove.
	* sysdeps/unix/sysv/linux/pthread_setaffinity.c
	(__kernel_cpumask_size, __determine_cpumask_size): Remove.
	(__pthread_setaffinity_new): Remove CPU set size check.
	* sysdeps/unix/sysv/linux/sched_setaffinity.c
	(__kernel_cpumask_size): Remove.
	(__sched_setaffinity_new): Remove CPU set size check.
	* manual/threads.texi (Default Thread Attributes): Remove stale
	reference to check_cpuset_attr, determine_cpumask_size in comment.
	* sysdeps/unix/sysv/linux/Makefile [$(subdir) == posix] (tests):
	Remove tst-getcpu.  Add tst-affinity, tst-affinity-pid.
	[$(subdir) == nptl] (tests): Add tst-thread-affinity-pthread,
	tst-thread-affinity-pthread2, tst-thread-affinity-sched.
	* sysdeps/unix/sysv/linux/tst-affinity.c: New file.
	* sysdeps/unix/sysv/linux/tst-affinity-pid.c: New file.
	* sysdeps/unix/sysv/linux/tst-skeleton-affinity.c: New skeleton test file.
	* sysdeps/unix/sysv/linux/tst-thread-affinity-sched.c: New file.
	* sysdeps/unix/sysv/linux/tst-thread-affinity-pthread.c: New file.
	* sysdeps/unix/sysv/linux/tst-thread-affinity-pthread2.c: New file.
	* sysdeps/unix/sysv/linux/tst-thread-skeleton-affinity.c: New
	skeleton test file.
	* sysdeps/unix/sysv/linux/tst-getcpu.c: Remove.  Superseded by
	tst-affinity-pid.
2015-11-24 17:21:01 +01:00
Joseph Myers
b08b421835 Require GCC 4.7 or later to build glibc.
This patch implements a requirement of GCC 4.7 or later to build
glibc.

This was discussed in the thread starting at
<https://sourceware.org/ml/libc-alpha/2015-08/msg00851.html>.
Concerns were expressed by Mike and David.  At
<https://sourceware.org/ml/libc-alpha/2015-10/msg00453.html> I have
provided a 14-patch series showing in outline the cleanups facilitated
by this version requirement, as requested by Mike (this patch is the
first in that series, with the addition of a NEWS entry).  Given the
absence of further concerns or alternative proposals for criteria for
updates to this version requirement as requested in
<https://sourceware.org/ml/libc-alpha/2015-10/msg00065.html>, I am
interpreting this as "absence of sustained opposition" under Carlos's
definition at <https://sourceware.org/glibc/wiki/Consensus> and
proposing this patch for inclusion in glibc.  I'd like to remind
people testing with 4.6 that if they move to testing with GCC 5 then
it will probably be about four years before they need to update the
compiler they use to test glibc again.

Although on the principles of time-based updates I think a move to
requiring binutils 2.23 would be reasonable, I'm not currently aware
of any cleanups that would facilitate so am not proposing that at this
time (but would expect to propose a move to requiring binutils 2.24 in
a year's time, as that brings features such as AVX512 support that
should allow some conditionals to be cleaned up).  If someone thinks a
move to requiring 2.23 would help clean things up for their
architecture, please speak up.  (And in general, I suspect there are
lots of architecture-specific configure tests that could be removed on
the basis of current GCC and binutils version requirements, given how
I've found architecture-independent tests obsolete on the basis of
version requirements going back 20 years.)

Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).

	* configure.ac (libc_cv_compiler_ok): Require GCC 4.7 or later.
	* configure: Regenerated.
	* manual/install.texi (Tools for Compilation): Document
	requirement for GCC 4.7 or later.
	* INSTALL: Regenerated.
2015-10-27 16:34:12 +00:00
Joseph Myers
41075ae3e7 Convert 29 more function definitions to prototype style (multiple parameters in one K&R parameter declaration).
This automatically-generated patch converts 29 function definitions in
glibc (including one in an example in the manual) from old-style K&R
to prototype-style.  Following my other recent such patches, this one
deals with the case of function definitions where one K&R parameter
declaration declares multiple parameters, as in:

void
foo (a, b)
     int a, *b;
{
}

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).

	* crypt/crypt.c (_ufc_doit_r): Convert to prototype-style function
	definition.
	(_ufc_doit_r): Likewise.
	* crypt/crypt_util.c (_ufc_copymem): Likewise.
	(_ufc_output_conversion_r): Likewise.
	* inet/inet_mkadr.c (__inet_makeaddr): Likewise.
	* inet/rcmd.c (rcmd_af): Likewise.
	(rcmd): Likewise.
	(ruserok_af): Likewise.
	(ruserok): Likewise.
	(ruserok2_sa): Likewise.
	(ruserok_sa): Likewise.
	(iruserok_af): Likewise.
	(iruserok): Likewise.
	(__ivaliduser): Likewise.
	(__validuser2_sa): Likewise.
	* inet/rexec.c (rexec_af): Likewise.
	(rexec): Likewise.
	* inet/ruserpass.c (ruserpass): Likewise.
	* locale/programs/xmalloc.c (xcalloc): Likewise.
	* manual/examples/timeval_subtract.c (timeval_subtract): Likewise.
	* math/w_drem.c (__drem): Likewise.
	* math/w_dremf.c (__dremf): Likewise.
	* math/w_dreml.c (__dreml): Likewise.
	* misc/daemon.c (daemon): Likewise.
	* resolv/res_debug.c (p_fqnname): Likewise.
	* stdlib/div.c (div): Likewise.
	* string/memcmp.c (memcmp_bytes): Likewise.
	* sunrpc/pmap_rmt.c (pmap_rmtcall): Likewise.
	* sunrpc/svc_udp.c (svcudp_bufcreate): Likewise.
2015-10-20 11:52:27 +00:00
Mike Frysinger
44f826e317 timezone: polish grammar a bit in documentation
Reported-by: ricaljasan@pacific.net
2015-10-19 14:12:03 -04:00
Florian Weimer
6782806d8f malloc: Rewrite with explicit TLS access using __thread 2015-10-17 12:06:48 +02:00
Florian Weimer
f546f87c4f The va_list pointer is unspecified after a call to vfprintf [BZ #18982]
This adjusts the documentation to the existing implementation.
2015-10-17 12:02:22 +02:00
Namhyung Kim
f45e45a3e0 manual/argp.texi (Specifying Argp Parsers): Fix typo. 2015-10-14 11:49:58 -04:00
Carlos O'Donell
b86b4f5ef2 Fix manual argument order for posix_fallocate64 (Bug 19086).
The argument order for posix_fallocate64 in the manual
was wrong, it was listed as [fd, len, offset] when it
should have been [fd, offset, len].

Verified io/fcntl.h has the right argument order, and it
does. Verified generated PDF.
2015-10-07 14:10:43 -04:00
Carlos O'Donell
032f225008 Files open O_WRONLY not supported in fallocate emulation.
In the posix_fallocate description in the manual we list various
drawbacks with the emulation, including the fact that a file opened
with O_APPEND fails with EBADF. Similarly a file opened with O_WRONLY
fails with EBADF. We must be able to emulate a compare-and-swap via
pread/compare/pwrite in order to make the emulation as safe as possible.
It is not acceptable to ignore the read failure because it could result
in significant data loss across all of the blocks. There is no other way
to make this work without a true atomic CAS and SIGBUS handler (which
is looking more attractive as a way to remove the race condition).

This patch adds O_WRONLY to the manual as another bullet to clarify the
limits of the emulation.

Manual looks good in PDF.
2015-09-29 11:32:36 -04:00
Mike Frysinger
1cba4036b6 timezone: add a configure flag to disable program install
Some distros build+install the timezone tools (zic/zdump/tzselect) outside
of glibc and use the upstream package directly.  Add a configure flag to
glibc so they can disable install of those tools.

This allows tests to run & pass regardless of the configure flag.  Only
the install of them is impacted.
2015-09-18 19:39:46 -04:00
Mike Frysinger
1695cdae06 manual: skip build when perl is unavailable
Do not try to generate the manual when perl is unavailable.  This
matches the behavior when makeinfo is unavailable.  Otherwise the
install step fails when trying to generate the libm section since
it runs a perl script.
2015-08-21 17:10:59 -04:00
Ondřej Bílka
9ceeb27931 Fix exponents in manual.
* manual/macros.texi: Add twoexp macro.
	* manual/filesys.texi: Fix exponents.
	* manual/llio.texi: Likewise.
	* manual/stdio.texi: Likewise.
2015-08-20 09:43:50 +02:00
Gabriel F. T. Gomes
1747fcda49 PowerPC: Extend Program Priority Register support
This patch adds extra inline functions to change the Program Priority
Register from ISA 2.07.

2015-08-19  Gabriel F. T. Gomes  <gftg@linux.vnet.ibm.com>

	* sysdeps/powerpc/sys/platform/ppc.h (__ppc_set_ppr_med_high,
	__ppc_set_ppr_very_low): New functions.
	* manual/platform.texi: Add documentation about
	__ppc_set_ppr_med_high and __ppc_set_ppr_very_low.
2015-08-19 17:43:26 -03:00
Martin Sebor
a82a3db950 Attempting to install glibc configured with --prefix=/usr into
a non-standard directory specified by the prefix make variable
fails with an error.  Since this is an unsupported use case,
this change makes make install fail early and with a descriptive
error message when either the prefix or the exec_prefix make
variable is overridden on the command line.
2015-06-12 13:15:57 -06:00
Andrew Senkevich
2193311288 Start of series of patches with x86_64 vector math functions.
Here is implementation of cos containing SSE, AVX, AVX2 and AVX512
versions according to Vector ABI which had been discussed in
<https://groups.google.com/forum/#!topic/x86-64-abi/LmppCfN1rZ4>.

Vector math library build and ABI testing enabled by default for x86_64.

    * sysdeps/x86_64/fpu/Makefile: New file.
    * sysdeps/x86_64/fpu/Versions: New file.
    * sysdeps/x86_64/fpu/svml_d_cos_data.S: New file.
    * sysdeps/x86_64/fpu/svml_d_cos_data.h: New file.
    * sysdeps/x86_64/fpu/svml_d_cos2_core.S: New file.
    * sysdeps/x86_64/fpu/svml_d_cos4_core.S: New file.
    * sysdeps/x86_64/fpu/svml_d_cos4_core_avx.S: New file.
    * sysdeps/x86_64/fpu/svml_d_cos8_core.S: New file.
    * sysdeps/x86_64/fpu/svml_d_wrapper_impl.h: New file.
    * sysdeps/x86_64/fpu/multiarch/svml_d_cos2_core.S: New file.
    * sysdeps/x86_64/fpu/multiarch/svml_d_cos2_core_sse4.S: New file.
    * sysdeps/x86_64/fpu/multiarch/svml_d_cos4_core.S: New file.
    * sysdeps/x86_64/fpu/multiarch/svml_d_cos4_core_avx2.S: New file.
    * sysdeps/x86_64/fpu/multiarch/svml_d_cos8_core.S: New file.
    * sysdeps/x86_64/fpu/multiarch/svml_d_cos8_core_avx512.S: New file.
    * sysdeps/x86_64/fpu/multiarch/Makefile (libmvec-sysdep_routines): Added
    build of SSE, AVX2 and AVX512 IFUNC versions.
    * sysdeps/x86/fpu/bits/math-vector.h: Added SIMD declaration for cos.
    * math/bits/mathcalls.h: Added cos declaration with __MATHCALL_VEC.
    * sysdeps/x86_64/configure.ac: Options for libmvec build.
    * sysdeps/x86_64/configure: Regenerated.
    * sysdeps/x86_64/sysdep.h (cfi_offset_rel_rsp): New macro.
    * sysdeps/unix/sysv/linux/x86_64/libmvec.abilist: New file.
    * manual/install.texi (Configuring and compiling): Document
    --disable-mathvec.
    * INSTALL: Regenerated.
    * NEWS: Mention addition of libmvec and x86_64 vector cos.
2015-06-09 14:25:49 +03:00
Florian Weimer
7fe9e2e089 posix_fallocate: Emulation fixes and documentation [BZ #15661]
Handle signed integer overflow correctly.  Detect and reject O_APPEND.
Document drawbacks of emulation.

This does not completely address bug 15661, but improves the situation
somewhat.
2015-06-05 10:50:38 +02:00
Siddhesh Poyarekar
654055e093 Fix typo in safety annotations in envz_remove 2015-05-20 02:36:13 +05:30
Siddhesh Poyarekar
920d70128b Add envz_remove to the libc manual
I was told that Ma Shimao submitted a patch to add envz_remove to the
libc manual, but the patch could not be accepted since he does not
have a copyright assignment in place.  I have been woefully behind on
libc-alpha recently and have not seen the patch or the discussion
thread.  I have also not read the man page for envz_remove, so
Alexandre Oliva asked me if I could write this independently and post
a patch.  The patch below is the result of the same - I have written
it based on the implementation in string/envz.c and Alex told me via
email that the function is AS, AC and MT-safe like envz_strip.

I assume Alex and Carlos cannot review this since they have been
tainted by the original patch (I haven't even tried to look for a link
to it since I don't want to be tainted) so someone else will have to
review this.  If there are no reviewers till the end of the week, I
will commit this since I believe there is a chance that there are no
other reviewers who haven't read that thread.

	* manual/string.texi (Envz Functions): Add envz_remove.
2015-05-19 06:35:37 +05:30
Florian Weimer
2b028564f1 Avoid SIGFPE in wordexp [BZ #18100]
Check for a zero divisor and integer overflow before performing
division in arithmetic expansion.
2015-03-23 16:12:38 +01:00
Yaakov Selkowitz
af85ebcdf7 manual: fix XPG basename prototype
* manual/string.texi (XPG basename): Fix prototype.
2015-03-12 17:56:46 +01:00
Roland McGrath
4acc27ed0a Document test-wrapper-env-only in INSTALL. 2015-03-06 10:59:15 -08:00
Rical Jasan
7e7af3496e manual: complete example in error message documentation
The manual gives "an example showing how to handle failure to open a
file correctly."  The example function, open_sesame, uses the
newly-introduced strerror function and errno and
program_invocation_short_name variables.  It fails to specify GNU
extensions, however, so attempts to use it in the following way:

    int main (void) {open_sesame ("badname");}

fail during compilation with "error: ‘program_invocation_short_name’
undeclared", indicating the example is incomplete.  The presence of
"#include"s suggest everything neccesary for the function to work should
be present.  For completeness, the example is lacking the following line:

    #define _GNU_SOURCE

as the declarations of program_invocation_*name in errno.h are wrapped
in an "#ifdef __USE_GNU" conditional.

The documentation of the variables is also expanded, adding that their
definition lies in errno.h and noting specifically they are GNU
extensions.
2015-03-06 00:59:49 -05:00
Mike Frysinger
4ca8ddfb05 manual: drop strerror C89 compatibility note
Mentioning systems that are old and don't support C89 is probably
a waste of time nowadays.  Drop the note.
2015-03-06 00:57:43 -05:00
Joseph Myers
18a218b74c Refine documentation of libm exceptions goals.
This patch refines the math.texi documentation of the goals for when
libm function raise the inexact and underflow exceptions.  The
previous text was problematic in some cases around the underflow
threshold.

* Strictly, it would have meant that if the mathematical result of pow
  was very slightly below DBL_MIN, for example, it was required to
  raise the underflow exception; although normally a few ulps error
  would be OK, if that error meant the computed value was slightly
  above DBL_MIN it would fail the previously described underflow
  exception goal.

* Similarly, strict IEEE semantics would imply that sin (DBL_MIN), in
  round-to-nearest mode, underflows on before-rounding but not
  after-rounding architectures, while returning DBL_MIN; the previous
  wording would have required an underflow exception, so preventing
  checks for a result with absolute value below DBL_MIN from being
  sufficient checks to determine whether the exception is required.
  (Under the previous wording, checks for a result with absolute value
  <= DBL_MIN wouldn't have been sufficient either, because in
  FE_TOWARDZERO mode a result of DBL_MIN definitely does not result
  from an underflowing infinite-precision result.)

* The previous wording about rounding infinite-precision values could
  be taken to mean all exceptions including "inexact" must be
  consistent with some such value.  That would mean that a result of
  DBL_MIN in FE_UPWARD mode with "inexact" raised must also have
  "underflow" raised on before-rounding architectures.  Again, that
  would cause problems for computing a result (possibly with spurious
  "inexact" exceptions) and then using a rounding-mode-independent
  test for results with absolute value below DBL_MIN to determine
  whether an underflow exception must be forced in case the underflows
  from intermediate computations happened to be exact.

By refining the documentation, this patch avoids stating goals for
accuracy close to the underflow threshold that were stricter than
applied anywhere else, and allows the implementation strategy of:
compute a result within a few ulps, taking care to avoid underflows in
intermediate computations, then force an underflow exception if that
result was subnormal.  Only fully-defined functions such as fma need
to take greater care about the exact underflow threshold (including
its dependence on whether the architecture is before-rounding or
after-rounding, and on the rounding mode on after-rounding
architectures).

(If the rounding mode is changed as part of the computation, it's
still necessary to ensure that not just intermediate computations, but
the final computation of the result to be returned, do not raise
underflow if that result is the least normal value and underflow would
be inconsistent with the original rounding mode.  Since such code can
readily discard exceptions as part of saving and restoring the
rounding mode - SET_RESTORE_ROUND_NOEX etc. - I don't think that
should be a problem in practice.)

	* manual/math.texi (Errors in Math Functions): Clarify goals
	regarding inexact and underflow exceptions.
2015-02-17 23:41:27 +00:00
Paul Eggert
0d7036bdb1 * manual/time.texi (TZ Variable): glibc no longer comes with tzdata.
Problem reported by J William Piggott.
2015-02-16 15:32:34 -08:00
J William Piggott
3f293d614c [BZ #17969]
* manual/time.texi (TZ Variable): The zoneinfo path is
/usr/share/zoneinfo.
2015-02-12 22:21:13 -05:00