When compiled with GCC 11.1 and -march=z14 -O3 build flags, running
ld.so (or any dynamically linked program) prints:
Fatal glibc error: CPU lacks VXE support (z14 or later required)
Co-Authored-By: Stefan Liebler <stli@linux.ibm.com>
Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
When built with GCC 11.1 and -mcpu=power9, ld.so prints this error
message when running on POWER8:
Fatal glibc error: CPU lacks ISA 3.00 support (POWER9 or later required)
No bug. This commit optimizes memcmp-evex.S. The optimizations include
adding a new vec compare path for small sizes, reorganizing the entry
control flow, removing some unnecissary ALU instructions from the main
loop, and most importantly replacing the heavy use of vpcmp + kand
logic with vpxor + vptern. test-memcmp and test-wmemcmp are both
passing.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
No bug. This commit optimizes memcmp-avx2.S. The optimizations include
adding a new vec compare path for small sizes, reorganizing the entry
control flow, and removing some unnecissary ALU instructions from the
main loop. test-memcmp and test-wmemcmp are both passing.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
No bug. This commit adds some additional performance test cases to
bench-memcmp.c and test-memcmp.c. The new benchtests include some
medium range sizes, as well as small sizes near page cross. The new
correctness tests correspond with the new benchtests though add some
additional cases for checking the page cross logic.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
The tst-timespec_getres (e5ac7bd679) triggers an issue on 32-bit
architecture on Linux older than 5.1, where the fallback syscall
is used.
Checked on powerpc-linux-gnu.
ISO C2X added the asctime_r, ctime_r, gmtime_r and localtime_r
functions from POSIX. It's now removed asctime_r and ctime_r again,
reflecting that they are marked obsolescent in POSIX; update glibc's
time.h accordingly.
The same change that removed those two functions from C2X also marked
asctime and ctime as deprecated (reflecting how POSIX shows them as
obsolescent), i.e. using the [[deprecated]] attribute in the
prototypes shown in C2X. It's less clear if we should explicitly
deprecate those functions like that in the glibc headers; this patch
does nothing regarding such a deprecation (there's no normative
requirement from C2X showing the functions as deprecated).
Tested for x86_64 and x86.
Starting with commit
26492c0a14
"Annotate additional APIs with GCC attribute access.",
gcc emits this warning on s390x:
In function 'do_one_test',
inlined from 'do_mb_tests' at bug-regex19.c:385:11:
bug-regex19.c:271:9: error: 're_search' specified size 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Werror=stringop-overflow=]
271 | res = re_search (®buf, test->string, strlen (test->string),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
272 | test->start, strlen (test->string) - test->start, NULL);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ../include/regex.h:2,
from bug-regex19.c:22:
bug-regex19.c: In function 'do_mb_tests':
../posix/regex.h:554:17: note: in a call to function 're_search' declared with attribute 'read_only (2, 3)'
554 | extern regoff_t re_search (struct re_pattern_buffer *__buffer,
| ^~~~~~~~~
...
The function do_one_test is inlined into do_mb_tests on s390x (at least with
gcc 10). If do_one_test is marked with __attribute__ ((noinline)), there are
no warnings on s390x. If do_one_test is marked with
__attribute__ ((always_inline)), there are the same warnings on x86_64.
test->string points to a variable length array on stack of do_mb_tests
and the content is generated based on the passed test struct.
According to Martin Sebor, this is a false positive caused by the same bug as
the one in nss/makedb.c. It's fixed in GCC 11 and will also be available in
the next GCC 10.4 release.
This updates IBM256, IBM277, IBM278, IBM280, IBM284, IBM297, IBM424
in the same way that IBM273 was updated for bug 23290.
IBM256 and IBM424 still have holes after this change, so HAS_HOLES
is not updated.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Coverity discovered that paths allocated by chroot_canon are not freed
in a couple of routines in ldconfig.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
A coverity run identified a number of resource leaks in cache.c.
There are a couple of simple memory leaks where a local allocation is
not freed before function return. Then there is a mmap leak and a
file descriptor leak where a map is not unmapped in the error case and
a file descriptor remains open respectively.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Fix trivial leak identified by coverity. The program runs to exit and
the leak doesn't grow, but it's just cleaner to free the allocated
memory.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
ISO C2X adds a timespec_getres function alongside the C11
timespec_get, with functionality similar to that of POSIX clock_getres
(including allowing a NULL pointer to be passed to the function).
Implement this function for glibc, similarly to the implementation of
timespec_get.
This includes a basic test like that of timespec_get, but no
documentation in the manual, given that TIME_UTC and timespec_get
aren't documented in the manual at all. The handling of 64-bit time
follows that in timespec_get; people maintaining patch series for
64-bit time will need to update them accordingly (to export
__timespec_getres64, redirect calls in time.h and run the test for
_TIME_BITS=64).
Tested for x86_64 and x86, and (previous version; only testcase
differs) with build-many-glibcs.py.
When MALLOC_CHECK_ is non-zero, the realloc hook missed to set errno to
ENOMEM when called with too big size. Run the test tst-malloc-too-large
also with MALLOC_CHECK_=3 to catch that.
Convert the output of benchtests/bench-rawmemchr to JSON like other string
benchmarks. This makes the output more parseable and allows usage of
compare_strings.py, for example.
Reviewed-by: Lucas A. M. Magalhaes <lamm@linux.ibm.com>
Reuse code for optimized strlen to implement a faster version of rawmemchr.
This takes advantage of the same benefits provided by the strlen implementation,
but needs some extra steps. __strlen_power10 code should be unchanged after this
change.
rawmemchr returns a pointer to the char found, while strlen returns only the
length, so we have to take that into account when preparing the return value.
To quickly check 64B, the loop on __strlen_power10 merges the whole block into
16B by using unsigned minimum vector operations (vminub) and checks if there are
any \0 on the resulting vector. The same code is used by rawmemchr if the char c
is 0. However, this approach does not work when c != 0. We first need to
subtract each byte by c, so that the value we are looking for is converted to a
0, then taking the minimum and checking for nulls works again.
The new code branches after it has compared ~256 bytes and chooses which of the
two strategies above will be used in the main loop, based on the char c. This
extra branch adds some overhead (~5%) for length ~256, but is quickly amortized
by the faster loop for larger sizes.
Compared to __rawmemchr_power9, this version is ~20% faster for length < 256.
Because of the optimized main loop, the improvement becomes ~35% for c != 0
and ~50% for c = 0 for strings longer than 256.
Reviewed-by: Lucas A. M. Magalhaes <lamm@linux.ibm.com>
Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
The symbol was moved using scripts/move-symbol-to-libc.py.
The GLIBC_2.11 version is now empty, so add a placeholder symbol.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
The GLIBC_2.3.4 version is now empty, so add a placeholder symbol.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
Add __libpthread_version_placeholder@@GLIBC_2.12 for the targets
that need it.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
__libpthread_version_placeholder@@GLIBC_2.2 is needed by this change;
the Versions entry for GLIBC_2.2 in libpthread had leftover symbols
due to an error in a previous conflict resolution. The condition
for the placeholder symbol is complicated because some architectures
have earlier symbols at the GLIBC_2.2 symbol versions, so the
placeholder is not required there (yet).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
A new placeholder symbol __libpthread_version_placeholder@GLIBC_2.18
is needed to keep the GLIBC_2.18 symbol version in libpthread.
The __pthread_getattr_default_np@@GLIBC_PRIVATE export is used
from pthread_create.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This helps to clarify that the caching of these fields in libpthread
(in __static_tls_size, __static_tls_align_m1) is unnecessary.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
After static dlopen, a copy of ld.so is loaded into the inner
namespace, but that copy is not initialized at all. Some
architectures run into serious problems as result, which is why the
_dl_var_init mechanism was invented. With libpthread moving into
libc and parts into ld.so, more architectures impacted, so it makes
sense to switch to a generic mechanism which performs the partial
initialization.
As a result, getauxval now works after static dlopen (bug 20802).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
In libthread_db, use the exported GLIBC_PRIVATE symbols directly
instead of relying on _thread_db_* variables in libpthread
(which used to be created by the DB_FUNCTION macros).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The initialization of the report_events TCB field is now performed
in __tls_init_tp instead of __pthread_initialize_minimal_internal
(in libpthread).
The events interface is difficult to test because GDB stopped using it
in 2015. The td_thr_get_info change to ignore lookup issues is enough
to support GDB with this change.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To help detect common kinds of memory (and other resource) management
bugs, GCC 11 adds support for the detection of mismatched calls to
allocation and deallocation functions. At each call site to a known
deallocation function GCC checks the set of allocation functions
the former can be paired with and, if the two don't match, issues
a -Wmismatched-dealloc warning (something similar happens in C++
for mismatched calls to new and delete). GCC also uses the same
mechanism to detect attempts to deallocate objects not allocated
by any allocation function (or pointers past the first byte into
allocated objects) by -Wfree-nonheap-object.
This support is enabled for built-in functions like malloc and free.
To extend it beyond those, GCC extends attribute malloc to designate
a deallocation function to which pointers returned from the allocation
function may be passed to deallocate the allocated objects. Another,
optional argument designates the positional argument to which
the pointer must be passed.
This change is the first step in enabling this extended support for
Glibc.
This is similar to the fix for elf/tst-pldd (2f9046fb05):
it checks ptrace_scope value (values higher than 2 are too restrictive
to allow the test to run) and it rearranges the spawned processes
to make the target process the gdb child.
Checked on x86_64-linux-gnu with ptrace_scope set to 1.
Keep __exit_funcs_lock almost all the time and unlock it only to execute
callbacks. This fixed two issues.
1. f->func.cxa was modified outside the lock with rare data race like:
thread 0: __run_exit_handlers unlock __exit_funcs_lock
thread 1: __internal_atexit locks __exit_funcs_lock
thread 0: f->flavor = ef_free;
thread 1: sees ef_free and use it as new
thread 1: new->func.cxa.fn = (void (*) (void *, int)) func;
thread 1: new->func.cxa.arg = arg;
thread 1: new->flavor = ef_cxa;
thread 0: cxafct = f->func.cxa.fn; // it's wrong fn!
thread 0: cxafct (f->func.cxa.arg, status); // it's wrong arg!
thread 0: goto restart;
thread 0: call the same exit_function again as it's ef_cxa
2. Don't unlock in main while loop after *listp = cur->next. If *listp
is NULL and __exit_funcs_done is false another thread may fail in
__new_exitfn on assert (l != NULL):
thread 0: *listp = cur->next; // It can be the last: *listp = NULL.
thread 0: __libc_lock_unlock
thread 1: __libc_lock_lock in __on_exit
thread 1: __new_exitfn
thread 1: if (__exit_funcs_done) // false: thread 0 isn't there yet.
thread 1: l = *listp
thread 1: moves one and crashes on assert (l != NULL);
The test needs multiple iterations to consistently fail without the fix.
Fixes https://sourceware.org/bugzilla/show_bug.cgi?id=27749
Checked on x86_64-linux-gnu.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The error paths of __check_native would leave the socket FD open on
return, resulting in an FD leak. Rework function exit paths so that
the fd is always closed on return.
