It was added on Linux 5.10 (ecb8ac8b1f146915aa6b96449b66dd48984caacc)
with the same functionality as madvise but using a pidfd of the target
process.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was added on Linux 5.4 (3695eae5fee0605f316fbaad0b9e3de791d7dfaf)
to extend waitid to wait on pidfd.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
The posix_spawnattr_tcsetpgrp_np works on a file descriptor (the
controlling terminal), so it would make more sense to actually fit
it on the file actions API.
Also, POSIX_SPAWN_TCSETPGROUP is not really required since it is
implicit by the presence of tcsetpgrp file action.
The posix/tst-spawn6.c is also fixed when TTY can is not present.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Currently there is no proper way to set the controlling terminal through
posix_spawn in race free manner [1]. This forces shell implementations
to keep using fork+exec when launching background process groups,
even when using posix_spawn yields better performance.
This patch adds a new GNU extension so the creating process can
configure the created process terminal group. This is done with a new
flag, POSIX_SPAWN_TCSETPGROUP, along with two new attribute functions:
posix_spawnattr_tcsetpgrp_np, and posix_spawnattr_tcgetpgrp_np.
The function sets a new attribute, spawn-tcgroupfd, that references to
the controlling terminal.
The controlling terminal is set after the spawn-pgroup attribute, and
uses the spawn-tcgroupfd along with current creating process group
(so it is composable with POSIX_SPAWN_SETPGROUP).
To create a process and set the controlling terminal, one can use the
following sequence:
posix_spawnattr_t attr;
posix_spawnattr_init (&attr);
posix_spawnattr_setflags (&attr, POSIX_SPAWN_TCSETPGROUP);
posix_spawnattr_tcsetpgrp_np (&attr, tcfd);
If the idea is also to create a new process groups:
posix_spawnattr_t attr;
posix_spawnattr_init (&attr);
posix_spawnattr_setflags (&attr, POSIX_SPAWN_TCSETPGROUP
| POSIX_SPAWN_SETPGROUP);
posix_spawnattr_tcsetpgrp_np (&attr, tcfd);
posix_spawnattr_setpgroup (&attr, 0);
The controlling terminal file descriptor is ignored if the new flag is
not set.
This interface is slight different than the one provided by QNX [2],
which only provides the POSIX_SPAWN_TCSETPGROUP flag. The QNX
documentation does not specify how the controlling terminal is obtained
nor how it iteracts with POSIX_SPAWN_SETPGROUP. Since a glibc
implementation is library based, it is more straightforward and avoid
requires additional file descriptor operations to request the caller
to setup the controlling terminal file descriptor (and it also allows
a bit less error handling by posix_spawn).
Checked on x86_64-linux-gnu and i686-linux-gnu.
[1] https://github.com/ksh93/ksh/issues/79
[2] https://www.qnx.com/developers/docs/7.0.0/index.html#com.qnx.doc.neutrino.lib_ref/topic/p/posix_spawn.html
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
When fnmatch processes a bracket expression, and eventually finds it to be
unterminated, it should rescan it, treating the starting bracket as a
normal character. That didn't happen when a matching character was found
while scanning the bracket expression.
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
This patch simplifies the memory allocation code and uses the sched
routines instead of reimplement it. This still uses a stack
allocation buffer, so it can be used on malloc initialization code.
Linux currently supports at maximum of 4096 cpus for most architectures:
$ find -iname Kconfig | xargs git grep -A10 -w NR_CPUS | grep -w range
arch/alpha/Kconfig- range 2 32
arch/arc/Kconfig- range 2 4096
arch/arm/Kconfig- range 2 16 if DEBUG_KMAP_LOCAL
arch/arm/Kconfig- range 2 32 if !DEBUG_KMAP_LOCAL
arch/arm64/Kconfig- range 2 4096
arch/csky/Kconfig- range 2 32
arch/hexagon/Kconfig- range 2 6 if SMP
arch/ia64/Kconfig- range 2 4096
arch/mips/Kconfig- range 2 256
arch/openrisc/Kconfig- range 2 32
arch/parisc/Kconfig- range 2 32
arch/riscv/Kconfig- range 2 32
arch/s390/Kconfig- range 2 512
arch/sh/Kconfig- range 2 32
arch/sparc/Kconfig- range 2 32 if SPARC32
arch/sparc/Kconfig- range 2 4096 if SPARC64
arch/um/Kconfig- range 1 1
arch/x86/Kconfig-# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
arch/x86/Kconfig- range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
arch/xtensa/Kconfig- range 2 32
With x86 supporting 8192:
arch/x86/Kconfig
976 config NR_CPUS_RANGE_END
977 int
978 depends on X86_64
979 default 8192 if SMP && CPUMASK_OFFSTACK
980 default 512 if SMP && !CPUMASK_OFFSTACK
981 default 1 if !SMP
So using a maximum of 32k cpu should cover all cases (and I would
expect once we start to have many more CPUs that Linux would provide
a more straightforward way to query for such information).
A test is added to check if sched_getaffinity can successfully return
with large buffers.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
We add a new C.UTF-8 locale. This locale is not builtin to glibc, but
is provided as a distinct locale. The locale provides full support for
UTF-8 and this includes full code point sorting via STRCMP-based
collation (strcmp or wcscmp).
The collation uses a new keyword 'codepoint_collation' which drops all
collation rules and generates an empty zero rules collation to enable
STRCMP usage in collation. This ensures that we get full code point
sorting for C.UTF-8 with a minimal 1406 bytes of overhead (LC_COLLATE
structure information and ASCII collating tables).
The new locale is added to SUPPORTED. Minimal test data for specific
code points (minus those not supported by collate-test) is provided in
C.UTF-8.in, and this verifies code point sorting is working reasonably
across the range. The locale was tested manually with the full set of
code points without failure.
The locale is harmonized with locales already shipping in various
downstream distributions. A new tst-iconv9 test is added which verifies
the C.UTF-8 locale is generally usable.
Testing for fnmatch, regexec, and recomp is provided by extending
bug-regex1, bugregex19, bug-regex4, bug-regex6, transbug, tst-fnmatch,
tst-regcomp-truncated, and tst-regex to use C.UTF-8.
Tested on x86_64 or i686 without regression.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Split the mcheck implementation into the debugging hooks and API so
that the API can be replicated in libc and libc_malloc_debug.so. The
libc APIs always result in failure.
The mcheck implementation has also been moved entirely into
libc_malloc_debug.so and with it, all of the hook initialization code
can now be moved into the debug library. Now the initialization can
be done independently of libc internals.
With this patch, libc_malloc_debug.so can no longer be used with older
libcs, which is not its goal anyway. tst-vfork3 breaks due to this
since it spawns shell scripts, which in turn execute using the system
glibc. Move the test to tests-container so that only the built glibc
is used.
This move also fixes bugs in the mcheck version of memalign and
realloc, thus allowing removal of the tests from tests-mcheck
exclusion list.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Remove all malloc hook uses from core malloc functions and move it
into a new library libc_malloc_debug.so. With this, the hooks now no
longer have any effect on the core library.
libc_malloc_debug.so is a malloc interposer that needs to be preloaded
to get hooks functionality back so that the debugging features that
depend on the hooks, i.e. malloc-check, mcheck and mtrace work again.
Without the preloaded DSO these debugging features will be nops.
These features will be ported away from hooks in subsequent patches.
Similarly, legacy applications that need hooks functionality need to
preload libc_malloc_debug.so.
The symbols exported by libc_malloc_debug.so are maintained at exactly
the same version as libc.so.
Finally, static binaries will no longer be able to use malloc
debugging features since they cannot preload the debugging DSO.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This patch adds a way to close a range of file descriptors on
posix_spawn as a new file action. The API is similar to the one
provided by Solaris 11 [1], where the file action causes the all open
file descriptors greater than or equal to input on to be closed when
the new process is spawned.
The function posix_spawn_file_actions_addclosefrom_np is safe to be
implemented by iterating over /proc/self/fd, since the Linux spawni.c
helper process does not use CLONE_FILES, so its has own file descriptor
table and any failure (in /proc operation) aborts the process creation
and returns an error to the caller.
I am aware that this file action might be redundant to the current
approach of POSIX in promoting O_CLOEXEC in more interfaces. However
O_CLOEXEC is still not the default and for some specific usages, the
caller needs to close all possible file descriptors to avoid them
leaking. Some examples are CPython (discussed in BZ#10353) and OpenJDK
jspawnhelper [2] (where OpenJDK spawns a helper process to exactly
closes all file descriptors). Most likely any environment which calls
functions that might open file descriptor under the hood and aim to use
posix_spawn might face the same requirement.
Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15.
[1] https://docs.oracle.com/cd/E36784_01/html/E36874/posix-spawn-file-actions-addclosefrom-np-3c.html
[2] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
Austin Group issue 62 [1] dropped the async-signal-safe requirement
for fork and provided a async-signal-safe _Fork replacement that
does not run the atfork handlers. It will be included in the next
POSIX standard.
It allow to close a long standing issue to make fork AS-safe (BZ#4737).
As indicated on the bug, besides the internal lock for the atfork
handlers itself; there is no guarantee that the handlers itself will
not introduce more AS-safe issues.
The idea is synchronize fork with the required internal locks to allow
children in multithread processes to use mostly of standard function
(even though POSIX states only AS-safe function should be used). On
signal handles, _Fork should be used intead and only AS-safe functions
should be used.
For testing, the new tst-_Fork only check basic usage. I also added
a new tst-mallocfork3 which uses the same strategy to check for
deadlock of tst-mallocfork2 but using threads instead of subprocesses
(and it does deadlock if it replaces _Fork with fork).
[1] https://austingroupbugs.net/view.php?id=62
The Linux nptl implementation is used as base for generic fork
implementation to handle the internal locks and mutexes. The
system specific bits are moved a new internal _Fork symbol.
(This new implementation will be used to provide a async-signal-safe
_Fork now that POSIX has clarified that fork might not be
async-signal-safe [1]).
For Hurd it means that the __nss_database_fork_prepare_parent and
__nss_database_fork_subprocess will be run in a slight different
order.
[1] https://austingroupbugs.net/view.php?id=62
The glob might pass a different stat struct for gl_stat and gl_lstat
when GLOB_ALTDIRFUNC is used. This requires add a new 64-bit time
version that also uses 64-bit time stat functions.
Checked on i686-linux-gnu and x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
It operates similar to execve and it is is already used to implement
fexecve without requiring /proc to be mounted. However, different
than fexecve, if the syscall is not supported by the kernel an error
is returned instead of trying a fallback.
Checked on x86_64-linux-gnu and powerpc64le-linux-gnu.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The tst-wait4 is moved to common file and used for wait3
tests.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Both htl and nptl uses a different data structure to implement atfork
handlers. The nptl one was refactored by 27761a1042 to use a dynarray
which simplifies the code.
This patch moves the nptl one to be the generic implementation and
replace Hurd linked one. Different than previous NPTL, Hurd also uses
a global lock, so performance should be similar.
Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build for
i686-gnu.
compat_symbol_reference now works for non-internal tests, too.
Also stop building and running the tests on those architectures
that lack the test symbol versions.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
compat_symbol_reference is now available for regular tests as well.
Also avoid building and running the tests in case the pre-2.27
symbol version of glob is not available. This avoids a spurious
UNSUPPORTED result.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This change adds new test to assess sched_rr_get_interval's
functionality.
To be more specific - following use cases are checked:
- If the read interval is correct
- If the proper ABI is used - to check if adjacent data is not
overwritten
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Previously, glibc would pick an arbitrary tmpfs file system from
/proc/mounts if /dev/shm was not available. This could lead to
an unsuitable file system being picked for the backing storage for
shm_open, sem_open, and related functions.
This patch introduces a new function, __shm_get_name, which builds
the file name under the appropriate (now hard-coded) directory. It is
called from the various shm_* and sem_* function. Unlike the
SHM_GET_NAME macro it replaces, the callers handle the return values
and errno updates. shm-directory.c is moved directly into the posix
subdirectory because it can be implemented directly using POSIX
functionality. It resides in libc because it is needed by both
librt and nptl/htl.
In the sem_open implementation, tmpfname is initialized directly
from a string constant. This happens to remove one alloca call.
Checked on x86_64-linux-gnu.
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
Starting with commit 29fddfc7df, the
tests posix/bug-ga2 and resolv/tst-leaks2 are test-container tests.
If test-container.c returns with EXIT_UNSUPPORTED, the tests with
mtrace() are not executed and the mtrace files do not exist.
Therefore the "mtrace-analysis-part" of those tests are marked
UNSUPPORTED if the mtrace files are missing.
Reported-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
The tests posix/bug-ga2-mem and resolv/mtrace-tst-leaks2 are failing on
fedora 33 as mtrace reports memory leaks.
The /etc/nsswitch.conf differs between
Fedora 32: hosts: files dns myhostname
Fedora 33: hosts: files resolve [!UNAVAIL=return] myhostname dns
Therefore /lib64/libnss_resolve.so.2 (from systemd) and the dependencies
libgcc_s.so.1 and libpthread.so.0 are loaded.
Usually all malloc'ed resources from getaddrinfo / gethostbyname are freed
and the libraries are dlclose'd in nss/nsswitch.c:libc_freeres_fn (free_mem).
Unfortunately, /lib64/libnss_resolve.so.2 is marked with DF_1_NODELETE.
As this library is not unmapped, you'll see "Memory not freed".
Therefore those tests are now only relying on libnss_files.so by making
them test-container tests and providing the required configuration files.
By moving the tests to tests-container, those are now running with
"make check". Therefore the mtrace part of the tests are also moved
from "make xcheck" to "make check".
bug-ga2.c is now using test-driver.c in order to support WAIT_FOR_DEBUGGER
environment variable.
The variable idx contains the index into the extra array, whereas wextra
points into the extra array at this index, containing the length of the
following collating sequence in the wide character representation.
Once wordexp switches to posix_spawn, testing for command execution
based on fork handlers will not work anymore. Therefore, move these
subtests into a new test, posix/tst-wordexp-nocmd, which uses a
different form of command execution detection, based on PID
namespaces.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The stub implementations are turned into compat symbols.
Linux actually has two reserved system call numbers (for getpmsg
and putpmsg), but these system calls have never been implemented,
and there are no plans to implement them, so this patch replaces
the wrappers with the generic stubs.
According to <https://bugzilla.redhat.com/show_bug.cgi?id=436349>,
the presence of the XSI STREAMS declarations is a minor portability
hazard because they are not actually implemented.
This commit does not change the TIRPC support code in
sunrpc/rpc_svcout.c. It uses additional XTI functionality and
therefore never worked with glibc.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This commit adds gettid to <unistd.h> on Linux, and not to the
kernel-independent GNU API.
gettid is now supportable on Linux because too many things assume a
1:1 mapping between libpthread threads and kernel threads.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This fixes the same bug in fnmatch that was fixed by commit 7e2f0d2d77 for
regexp matching. As a side effect it also removes the use of an unbound
VLA.
Along with posix_spawn_file_actions_addchdir,
posix_spawn_file_actions_addfchdir is the subject of a change proposal
for POSIX: <http://austingroupbugs.net/view.php?id=1208>
These files were both auto-generated and shipped in the source tree.
We can assume that sed is available and always generate the files
during the build.
This patch syncs the regex implementation with gnulib (commit 0ee5212).
Only two changes in GLIBC regex testing are required:
1. posix/bug-regex28.c: as previously discussed [1] the change of
expected results on the pattern should be safe.
2. posix/PCRE.tests: the ERE (a)|\1 is malformed (in the sense that
the \1 doesn't mean anything) and although current GLIBC accepts
it has undefined behavior. This patch removes the specific test.
This sync contains some patches from thread 'Regex: Make libc regex
more usable outside GLIBC.' [2] which have been pushed upstream in
gnulib. This patches also fixes some regex issues (BZ #23233,
BZ #21163, BZ #18986, BZ #13762) and I did not add testcases for
both #23233 and #13762 because I couldn't think a simple way to
trigger the expected failure path to trigger them.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[BZ #23233]
[BZ #21163]
[BZ #18986]
[BZ #13762]
* posix/Makefile (tests): Add bug-regex37 and bug-regex38.
* posix/PCRE.tests: Remove invalid test.
* posix/bug-regex28.c: Fix expected values for used syntax.
* posix/bug-regex37.c: New file.
* posix/bug-regex38.c: Likewise.
* posix/regcomp.c: Sync with gnulib.
* posix/regex.c: Likewise.
* posix/regex.h: Likewise.
* posix/regex_internal.c: Likewise.
* posix/regex_internal.h: Likewise.
* posix/regexec.c: Likewise.
[1] https://sourceware.org/ml/libc-alpha/2017-12/msg00807.html
[2] https://sourceware.org/ml/libc-alpha/2017-12/msg00237.html
As noted in bug 13888, and as I noted previously in
<https://sourceware.org/ml/libc-alpha/2000-10/msg00111.html>, various
tests used hardcoded paths in /tmp, so posing issues for simultaneous
test runs from different build directories.
This patch fixes such uses of hardcoded file names to put them in the
build directory instead (in the case of stdio-common/bug5 the file
names are changed as well, to avoid a conflict with the name bug5.out
also used for the automatic test output redirection). It also fixes
test-installation.pl likewise (that was using filenames with $$ in
them rather than strictly hardcoded names, but that's still not good
practice for temporary file naming).
Note that my list of files changed is not identical to that in bug
13888. I added tst-spawn3.c and test-installation.pl, and removed
some tests that seem to me (now) to create temporary files securely
(simply using /tmp is not itself a problem if the temporary files are
handled properly with mkstemp; I haven't checked whether those tests
used to do things insecurely). conformtest is not changed because the
makefiles always pass a --tmpdir option so the /tmp default is
irrelevant, and for the same reason there is no actual problem with
nptl/tst-umask1.c because again the makefiles always override the
default.
nptl/sockperf.c is ignored because there is no code to run it;
probably that file should actually be removed.
Some tests use the mktemp function, but I think they all use it in a
way that *is* secure (for generating names for directories / sockets /
fifos / symlinks, where the operation using the name will not follow
symlinks and so there is no potential for a symlink attack on the
account running the testsuite).
Some tests use the tmpnam function to generate temporary file names.
This is in principle insecure, but not addressed by this patch (I
consider it a separate issue from the fully hardcoded paths).
Tested for x86_64.
[BZ #13888]
* posix/Makefile (CFLAGS-tst-spawn3.c): New variable.
* posix/tst-spawn3.c (do_test): Put tst-spwan3.pid in OBJPFX, not
/tmp.
* scripts/test-installation.pl: Put temporary files in build
directory, not /tmp.
* stdio-common/Makefile (CFLAGS-bug3.c): New variable.
(CFLAGS-bug4.c): Likewise.
(CFLAGS-bug5.c): Likewise.
(CFLAGS-test-fseek.c): Likewise.
(CFLAGS-test-popen.c): Likewise.
(CFLAGS-test_rdwr.c): Likewise.
* stdio-common/bug3.c (main): Put temporary file in OBJPFX, not
/tmp.
* stdio-common/bug4.c (main): Likewise.
* stdio-common/bug5.c (main): Likewise.
* stdio-common/test-fseek.c (TESTFILE): Likewise.
* stdio-common/test-popen.c (do_test): Likewise.
* stdio-common/test_rdwr.c (main): Likewise.
Current posix_spawnp implementation wrongly tries to execute invalid
binaries (for instance script without shebang) as a shell script in
non compat mode. It was a regression introduced by
9ff72da471 when __spawni started to use
__execvpe instead of __execve (glibc __execvpe try to execute ENOEXEC
as shell script regardless).
This patch fixes it by using an internal symbol (__execvpex) with the
faulty semantic (since compat mode is handled by spawni.c itself).
It was reported by Daniel Drake on libc-help [1].
Checked on x86_64-linux-gnu and i686-linux-gnu.
[BZ #23264]
* include/unistd.h (__execvpex): New prototype.
* posix/Makefile (tests): Add tst-spawn4.
(tests-internal): Add tst-spawn4-compat.
* posix/execvpe.c (__execvpe_common, __execvpex): New functions.
* posix/tst-spawn4-compat.c: New file.
* posix/tst-spawn4.c: Likewise.
* sysdeps/unix/sysv/linux/spawni.c (__spawni): Do not interpret invalid
binaries as shell scripts.
* sysdeps/posix/spawni.c (__spawni): Likewise.
[1] https://sourceware.org/ml/libc-help/2018-06/msg00012.html
* bits/sched.h: Include <bits/types/struct_sched_param.h> and move struct
sched_param definition to it.
* sysdeps/unix/sysv/linux/bits/sched.h: Likewise.
* bits/types/struct_sched_param.h: New file.
* sysdeps/htl/bits/types/struct___pthread_attr.h: Include
<bits/types/struct_sched_param.h> instead of <sched.h>.
* posix/Makefile (headers): Add bits/types/struct_sched_param.h.
Bug 13575 reports that SSIZE_MAX is wrongly defined as LONG_MAX on
32-bit systems where ssize_t is defined as int (which is most 32-bit
systems supported by glibc).
This patch fixes the definition, using a conditional on
__WORDSIZE32_SIZE_ULONG to determine the appropriate type in the
32-bit case. Formally ssize_t need not be the signed type
corresponding to size_t, but as it is for all current glibc
configurations, there is no need for a new macro different from the
one used for defining SIZE_MAX. A testcase is added for both the type
and the value of SSIZE_MAX.
There is a relevant peculiarity in
sysdeps/unix/sysv/linux/s390/bits/typesizes.h:
/* Compatibility with g++ 2.95.x. */
/* size_t is unsigned long int on s390 -m31. */
This has the effect that for GCC 2 for s390, ssize_t does not match
__WORDSIZE32_SIZE_ULONG. I don't think such a conditional on the GCC
version makes sense - to have a well-defined ABI, the choices of
standard types should not depend on the GCC version. It's also the
case that upstream GCC 2.95 did not support s390, and glibc headers
don't in general try to support past development GCC versions - only
actual releases and current mainline development. But whether or not
that GCC 2 case should be removed (with or without a NEWS entry for
such a change), this patch does not result in any changes for s390;
the value is always still LONG_MAX in the s390 case because
__WORDSIZE32_SIZE_ULONG is always defined for 32-bit s390. I don't
think any such oddity in code only active for unofficial or unreleased
old compiler versions should block closing the present bug as fixed
once this patch is in.
Tested for x86_64 and x86, and with build-many-glibcs.py.
[BZ #13575]
* posix/bits/posix1_lim.h: Include <bits/wordsize.h>.
[!SSIZE_MAX && !(__WORDSIZE == 64 || __WORDSIZE32_SIZE_ULONG)]
(SSIZE_MAX): Define to INT_MAX.
* posix/test-ssize-max.c: New file.
* posix/Makefile (tests): Add test-ssize-max.
These tests need a working Internet connection with DNS.
We have additional coverage of getaddrinfo through the resolv tests, so
the loss of default test coverage seems acceptable.
