When ungetc is called on an unused stream, the backup buffer is
allocated without the main get area being present. This results in
every subsequent ungetc (as the stream remains in the backup area)
checking uninitialized memory in the backup buffer when trying to put a
character back into the stream.
Avoid comparing the input character with buffer contents when in backup
to avoid this uninitialized read. The uninitialized read is harmless in
this context since the location is promptly overwritten with the input
character, thus fulfilling ungetc functionality.
Also adjust wording in the manual to drop the paragraph that says glibc
cannot do multiple ungetc back to back since with this change, ungetc
can actually do this.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The goal of this flag is to allow targets which don't prefer/have ERMS
to still access the non-temporal memset implementation.
There are 4 cases for tuning memset:
1) `Avoid_STOSB && Avoid_Non_Temporal_Memset`
- Memset with temporal stores
2) `Avoid_STOSB && !Avoid_Non_Temporal_Memset`
- Memset with temporal/non-temporal stores. Non-temporal path
goes through `rep stosb` path. We accomplish this by setting
`x86_rep_stosb_threshold` to
`x86_memset_non_temporal_threshold`.
3) `!Avoid_STOSB && Avoid_Non_Temporal_Memset`
- Memset with temporal stores/`rep stosb`
3) `!Avoid_STOSB && !Avoid_Non_Temporal_Memset`
- Memset with temporal stores/`rep stosb`/non-temporal stores.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
This is just a refactor and there should be no behavioral change from
this commit.
The goal is to make `Avoid_Non_Temporal_Memset` a more universal knob
for controlling whether we use non-temporal memset rather than having
extra logic based on vendor.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Issue was we were expecting not matches with CHAR before the start of
the string in the page cross case.
The check code in the page cross case:
```
and $0xffffffffffffffc0,%rax
vmovdqa64 (%rax),%zmm17
vpcmpneqb %zmm17,%zmm16,%k1
vptestmb %zmm17,%zmm17,%k0{%k1}
kmovq %k0,%rax
inc %rax
shr %cl,%rax
je L(continue)
```
expects that all characters that neither match null nor CHAR will be
1s in `rax` prior to the `inc`. Then the `inc` will overflow all of
the 1s where no relevant match was found.
This is incorrect in the page-cross case, as the
`vmovdqa64 (%rax),%zmm17` loads from before the start of the input
string.
If there are matches with CHAR before the start of the string, `rax`
won't properly overflow.
The fix is quite simple. Just replace:
```
inc %rax
shr %cl,%rax
```
With:
```
sar %cl,%rax
inc %rax
```
The arithmetic shift will clear any matches prior to the start of the
string while maintaining the signbit so the 1s can properly overflow
to zero in the case of no matches.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
We have no tests that errno is set to ERANGE on overflow of
strtod-family functions (we do have some tests for underflow, in
tst-strtod-underflow). Add such tests to tst-strtod-round.
Tested for x86_64.
In _dl_tlsdesc_dynamic, there are three 'addi.d sp, sp, -size'
instructions to allocate stack size for Float/LSX/LASX registers.
Every 'addi.d sp, sp, -size' needs a cfi_adjust_cfa_offset because
of sp is used to compute CFA. But only one 'addi.d sp, sp, -size'
will be run according to HWCAP value. And all cfi_adjust_cfa_offset
will be executed in stack unwinding, it result in incorrect CFA.
Change _dl_tlsdesc_dynamic to _dl_tlsdesc_dynamic,
_dl_tlsdesc_dynamic_lsx and _dl_tlsdesc_dynamic_lasx.
Conflicting cfi instructions can be distributed to the three functions.
And cfi instructions can correspond to stack down instructions.
Fix an issue with commit b74121ae4b ("Update.") and prevent a stray
process from being left behind by tst-cancel7 (and also tst-cancelx7,
which is the same test built with '-fexceptions' additionally supplied
to the compiler), which then blocks remote testing until the process has
been killed by hand.
This test case creates a thread that runs an extra copy of the test via
system(3) and using the '--direct' option so that the test wrapper does
not interfere with this instance. This extra copy executes its business
and calls sigsuspend(2) and then never terminates by itself. Instead it
relies on being killed by the main test process directly via a thread
cancellation request or, should that fail, by issuing SIGKILL either at
the conclusion of 'do_test' or by the test driver via 'do_cleanup' where
the test timeout has been hit or the test driver interrupted.
However if the main test process has been instead killed by a signal,
such as due to incorrect execution, before it had a chance to kill the
extra copy of the test case, then the test wrapper will terminate
without running 'do_cleanup' and consequently the extra copy of the test
case will remain forever in its suspended state, and in the remote case
in particular it means that the remote test wrapper will wait forever
for the SSH command to complete.
This has been observed with the 'alpha-linux-gnu' target, where the main
test process triggers SIGSEGV and the test wrapper correctly records:
Didn't expect signal from child: got `Segmentation fault'
in nptl/tst-cancel7.out and terminates, but then the calling SSH command
continues waiting for the remaining process started in the same session
on the remote target to complete.
Address this problem by also registering 'do_cleanup' via atexit(3),
observing that 'support_delete_temp_files' is registered by the test
wrapper before the test initializing function 'do_prepare' is called and
that we call all the functions registered in the reverse of the order in
which they were registered, so it is safe to refer to 'pidfilename' in
'do_cleanup' invoked by exit(3) because by that time temporary files
have not yet been deleted.
A minor inconvenience is that if 'signal_handler' is invoked in the test
wrapper as a result of SIGALRM rather than SIGINT, then 'do_cleanup'
will be called twice, once as a cleanup handler and again by exit(3).
In reality it is harmless though, because issuing SIGKILL is guarded by
a record lock, so if the first call has succeeded in killing the extra
copy of the test case, then the subsequent call will do nothing.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Move the release of the semaphore used to synchronize between an extra
copy of the test run as a separate process and the main test process
until after the PID file has been locked. It is so that if the cleanup
function gets called by the test driver due to premature termination of
the main test process, then the function does not get at the PID file
before it has been locked and conclude that the extra copy of the test
has already terminated. This won't usually happen due to a relatively
high amount of time required to elapse before timeout triggers in the
test driver, but it will change with the next change.
There is still a small time window remaining with this change in place
where the main test process gets killed for some reason between the
extra copy of the test has been already started by pthread_create(3) and
a successful return from the call to sem_wait(3), in which case the
cleanup function can be reached before PID has been written to the PID
file and the file locked. It seems that with the test case structured
as it is now and PID-based process management we have no means to avoid
it.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add a new randomized memset test similar to bench-random-memcpy. Instead of
repeating the same call to memset over and over again, it times a large number
of different inputs. The distribution of memset length and alignment is based
on SPEC2017 (length up to 4096 and alignment up to 64).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Improve performance by handling another 16 bytes before entering the loop.
Use ADDHN in the loop to avoid SHRN+FMOV when it terminates. Change final
size computation to avoid increasing latency. On Neoverse V1 performance
of the random strlen benchmark improves by 4.6%.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
These functions are exp10m1, exp2m1, log10p1, log2p1.
Also regenerated ulps on x86_64.
For each format, there are 4 values, one for each rounding mode.
(For the intel96 format, there are 8 values, 4 for Intel hardware,
and 4 for AMD hardware. However, regen-ulps was only run on Intel.
It should be run in a separate patch on a AMD x86_64.)
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This is a follow-up to 10de4a47ef that
reworded the manual entries for putc and putwc and removed any
performance claims.
This commit further clarifies these entries and brings getc and getwc in
line with the descriptions of putc and putwc, removing any performance
claims from them as well.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
As for exit, also allows concurrent quick_exit to avoid race
conditions when it is called concurrently. Since it uses the same
internal function as exit, the __exit_lock lock is moved to
__run_exit_handlers. It also solved a potential concurrent when
calling exit and quick_exit concurrently.
The test case 'expected' is expanded to a value larger than the
minimum required by C/POSIX (32 entries) so at_quick_exit() will
require libc to allocate a new block. This makes the test mre likely to
trigger concurrent issues (through free() at __run_exit_handlers)
if quick_exit() interacts with the at_quick_exit list concurrently.
This is also the latest interpretation of the Austin Ticket [1].
Checked on x86_64-linux-gnu.
[1] https://austingroupbugs.net/view.php?id=1845
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The old code used l_init_called as an indicator for whether TLS
initialization was complete. However, it is possible that
TLS for an object is initialized, written to, and then dlopen
for this object is called again, and l_init_called is not true at
this point. Previously, this resulted in TLS being initialized
twice, discarding any interim writes (technically introducing a
use-after-free bug even).
This commit introduces an explicit per-object flag, l_tls_in_slotinfo.
It indicates whether _dl_add_to_slotinfo has been called for this
object. This flag is used to avoid double-initialization of TLS.
In update_tls_slotinfo, the first_static_tls micro-optimization
is removed because preserving the initalization flag for subsequent
use by the second loop for static TLS is a bit complicated, and
another per-object flag does not seem to be worth it. Furthermore,
the l_init_called flag is dropped from the second loop (for static
TLS initialization) because l_need_tls_init on its own prevents
double-initialization.
The remaining l_init_called usage in resize_scopes and update_scopes
is just an optimization due to the use of scope_has_map, so it is
not changed in this commit.
The isupper check ensures that libc.so.6 is TLS is not reverted.
Such a revert happens if l_need_tls_init is not cleared in
_dl_allocate_tls_init for the main_thread case, now that
l_init_called is not checked anymore in update_tls_slotinfo
in elf/dl-open.c.
Reported-by: Jonathon Anderson <janderson@rice.edu>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Only return __GCONV_INCOMPLETE_INPUT for a partial match when the end of
the input buffer is reached. Otherwise it is a non-match, and other
patterns should be tried.
5476f8cd2e ("htl: move pthread_self info libc.") and
9dfa256216 ("htl: move pthread_equal into libc") to
1dc0bc8f07 ("htl: move pthread_attr_setdetachstate into libc")
moved some pthread_ symbols from libpthread.so to libc.so, but missed
adding the compat version like 5476f8cd2e ("htl: move pthread_self
info libc.") did: libc already had these symbols as forwards,
but versioned GLIBC_2.21, while the symbols in libpthread.so were
versioned GLIBC_2.12.
To fix running executables built before this, we thus have to add the
GLIBC_2.12 version, otherwise execution fails with e.g.
/usr/lib/i386-gnu/libglib-2.0.so: symbol lookup error: /usr/lib/i386-gnu/libglib-2.0.so: undefined symbol: pthread_attr_setinheritsched, version GLIBC_2.12
Previous GCC versions do not support the C23 change that
allows labels on declarations.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
