The commit 'sparc: Use Linux kABI for syscall return'
(86c5d2cf0c) did not take into account
a subtle sparc syscall kABI constraint. For syscalls that might block
indefinitely, on an interrupt (like SIGCONT) the kernel will set the
instruction pointer to just before the syscall:
arch/sparc/kernel/signal_64.c
476 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
477 {
[...]
525 if (restart_syscall) {
526 switch (regs->u_regs[UREG_I0]) {
527 case ERESTARTNOHAND:
528 case ERESTARTSYS:
529 case ERESTARTNOINTR:
530 /* replay the system call when we are done */
531 regs->u_regs[UREG_I0] = orig_i0;
532 regs->tpc -= 4;
533 regs->tnpc -= 4;
534 pt_regs_clear_syscall(regs);
535 fallthrough;
536 case ERESTART_RESTARTBLOCK:
537 regs->u_regs[UREG_G1] = __NR_restart_syscall;
538 regs->tpc -= 4;
539 regs->tnpc -= 4;
540 pt_regs_clear_syscall(regs);
541 }
However, on a SIGCONT it seems that 'g1' register is being clobbered after the
syscall returns. Before 86c5d2cf0c, the 'g1' was always placed jus
before the 'ta' instruction which then reloads the syscall number and restarts
the syscall.
On master, where 'g1' might be placed before 'ta':
$ cat test.c
#include <unistd.h>
int main ()
{
pause ();
}
$ gcc test.c -o test
$ strace -f ./t
[...]
ppoll(NULL, 0, NULL, NULL, 0
On another terminal
$ kill -STOP 2262828
$ strace -f ./t
[...]
--- SIGSTOP {si_signo=SIGSTOP, si_code=SI_USER, si_pid=2521813, si_uid=8289} ---
--- stopped by SIGSTOP ---
And then
$ kill -CONT 2262828
Results in:
--- SIGCONT {si_signo=SIGCONT, si_code=SI_USER, si_pid=2521813, si_uid=8289} ---
restart_syscall(<... resuming interrupted ppoll ...>) = -1 EINTR (Interrupted system call)
Where the expected behaviour would be:
$ strace -f ./t
[...]
ppoll(NULL, 0, NULL, NULL, 0) = ? ERESTARTNOHAND (To be restarted if no handler)
--- SIGSTOP {si_signo=SIGSTOP, si_code=SI_USER, si_pid=2521813, si_uid=8289} ---
--- stopped by SIGSTOP ---
--- SIGCONT {si_signo=SIGCONT, si_code=SI_USER, si_pid=2521813, si_uid=8289} ---
ppoll(NULL, 0, NULL, NULL, 0
Just moving the 'g1' setting near the syscall asm is not suffice,
the compiler might optimize it away (as I saw on cancellation.c by
trying this fix). Instead, I have change the inline asm to put the
'g1' setup in ithe asm block. This would require to change the asm
constraint for INTERNAL_SYSCALL_NCS, since the syscall number is not
constant.
Checked on sparc64-linux-gnu.
Reported-by: René Rebe <rene@exactcode.de>
Tested-by: Sam James <sam@gentoo.org>
Reviewed-by: Sam James <sam@gentoo.org>
(cherry picked from commit 2c1903cbba)
So caller can check which state was found if multiple ones are
asked.
Checked on x86_64-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 38316352e0)
Starting from glibc 2.1, crt1.o contains _IO_stdin_used which is checked
by _IO_check_libio to provide binary compatibility for glibc 2.0. Add
crt1-2.0.o for tests against glibc 2.0. Define tests-2.0 for glibc 2.0
compatibility tests. Add and update glibc 2.0 compatibility tests for
stderr, matherr and pthread_kill.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 5f245f3bfb)
There is very little test coverage of inputs to strtod-family
functions that don't contain anything that can be parsed as a number
(one test of ".y" in tst-strtod2), and none that I can see of skipping
initial whitespace. Add some tests of these things to tst-strtod2.
Tested for x86_64.
(cherry picked from commit 378039ca57)
Although there are some tests in tst-strtod2 and tst-strtod3 for the
end pointer provided by strtod when it doesn't parse the whole string,
they aren't very thorough. Add tests of more such cases to
tst-strtod2.
Tested for x86_64.
(cherry picked from commit b5d3737b30)
Some of the strtod tests use type-generic machinery in tst-strtod.h to
test the strto* functions for all floating types, while others only
test double even when the tests are in fact meaningful for all
floating types.
Convert tst-strtod2 and tst-strtod5 to use the type-generic machinery
so they test all floating types. I haven't tried to convert them to
use newer test interfaces in other ways, just made the changes
necessary to use the type-generic machinery.
Tested for x86_64.
(cherry picked from commit 8de031bcb9)
As reported in bug 32045, it's incorrect for strtod/nan functions to
set errno based on overflowing payload (strtod should only set errno
for overflow / underflow of its actual result, and potentially if
nothing in the string can be parsed as a number at all; nan should be
a pure function that never sets it). Save and restore errno around
the internal strtoull call and add associated test coverage.
Tested for x86_64.
(cherry picked from commit 64f62c47e9)
There are two separate sets of tests of NaN payloads in glibc:
* libm-test-{get,set}payload* verify that getpayload, setpayload,
setpayloadsig and __builtin_nan functions are consistent in their
payload handling.
* test-nan-payload verifies that strtod-family functions and the
not-built-in nan functions are consistent in their payload handling.
Nothing, however, connects the two sets of functions (i.e., verifies
that strtod / nan are consistent with getpayload / setpayload /
__builtin_nan).
Improve test-nan-payload to check actual payload value with getpayload
rather than just verifying that the strtod and nan functions produce
the same NaN. Also check that the NaNs produced aren't signaling and
extend the tests to cover _FloatN / _FloatNx.
Tested for x86_64.
(cherry picked from commit be77d5ae41)
Some of the strtod tests use type-generic machinery in tst-strtod.h to
test the strto* functions for all floating types, while others only
test double even when the tests are in fact meaningful for all
floating types.
Convert the tests of the internal __strtod_internal interface to cover
all floating types. I haven't tried to convert them to use newer test
interfaces in other ways, just made the changes necessary to use the
type-generic machinery. As an internal interface, there are no
aliases for different types with the same ABI (however,
__strtold_internal is defined even if long double has the same ABI as
double), so macros used by the type-generic testing code are redefined
as needed to avoid expecting such aliases to be present.
Tested for x86_64.
(cherry picked from commit 3fc063dee0)
As reported in bug 30220, the implementation of strtod-family
functions has a bug in the following case: the input string would,
with infinite exponent range, take one more bit to represent than is
available in the normal precision of the return type; the value
represented is in the subnormal range; and there are no nonzero bits
in the value, below those that can be represented in subnormal
precision, other than the least significant bit and possibly the
0.5ulp bit. In this case, round_and_return ends up discarding the
least significant bit.
Fix by saving that bit to merge into more_bits (it can't be merged in
at the time it's computed, because more_bits mustn't include this bit
in the case of after-rounding tininess detection checking if the
result is still subnormal when rounded to normal precision, so merging
this bit into more_bits needs to take place after that check).
Tested for x86_64.
(cherry picked from commit 457622c2fa)
Add tests of underflow in tst-strtod-round, and thus also test for
errno being unchanged when there is neither overflow nor underflow.
The errno setting before the function call to test for being unchanged
is adjusted to set errno to 12345 instead of 0, so that any bugs where
strtod sets errno to 0 would be detected.
This doesn't add any new test inputs for tst-strtod-round, and in
particular doesn't cover the edge cases of underflow the way
tst-strtod-underflow does (none of the existing test inputs for
tst-strtod-round actually exercise cases that have underflow with
before-rounding tininess detection but not with after-rounding
tininess detection), but at least it provides some coverage (as per
the recent discussions) that ordinary non-overflowing non-underflowing
inputs to these functions do not set errno.
Tested for x86_64.
(cherry picked from commit d73ed2601b)
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.
(cherry picked from commit 207d64feb2)
There seem to be no glibc tests specifically for the fread function.
Add basic tests of that function.
Tested for x86_64.
(cherry picked from commit d14c977c65)
_wide_data and _mode are not available in legacy code, so do not attempt
to free the wide backup buffer in legacy code.
Resolves: BZ #32137 and BZ #27821
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit ae4d44b1d5)
The reading loops did not check for read failures. Addresses
a static analysis report.
Manually tested by compiling a program with the GCC's
-finstrument-functions option, running it with
“LD_PRELOAD=debug/libpcprofile.so PCPROFILE_OUTPUT=output-file”,
and reviewing the output of “debug/pcprofiledump output-file”.
(cherry picked from commit 89b088bf70)
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>
(cherry picked from commit 5097cd344f)
Also remove an outdated comment: _dl_allocate_tls_init is
called as part of pthread_create.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit fe06fb313b)
It turns out that quite a few applications use bundled mallocs that
have been built to use global-dynamic TLS (instead of the recommended
initial-exec TLS). The previous workaround from
commit afe42e935b ("elf: Avoid some
free (NULL) calls in _dl_update_slotinfo") does not fix all
encountered cases unfortunatelly.
This change avoids the TLS generation update for recursive use
of TLS from a malloc that was called during a TLS update. This
is possible because an interposed malloc has a fixed module ID and
TLS slot. (It cannot be unloaded.) If an initially-loaded module ID
is encountered in __tls_get_addr and the dynamic linker is already
in the middle of a TLS update, use the outdated DTV, thus avoiding
another call into malloc. It's still necessary to update the
DTV to the most recent generation, to get out of the slow path,
which is why the check for recursion is needed.
The bookkeeping is done using a global counter instead of per-thread
flag because TLS access in the dynamic linker is tricky.
All this will go away once the dynamic linker stops using malloc
for TLS, likely as part of a change that pre-allocates all TLS
during pthread_create/dlopen.
Fixes commit d2123d6827 ("elf: Fix slow
tls access after dlopen [BZ #19924]").
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
(cherry picked from commit 018f0fc3b8)
Remove local FAIL macro in favor to FAIL_EXIT1 from <support/check.h>,
which provides equivalent reporting, with the name of the file and the
line number within of the failure site additionally included. Remove
FAIL_ERR altogether and include ": %m" explicitly with the format string
supplied to FAIL_EXIT1 as there seems little value to have a separate
macro just for this.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 8c98195af6)
Remove local FAIL macro in favor to FAIL_RET from <support/check.h>,
which provides equivalent reporting, with the name of the file of the
failure site additionally included, for the tst-truncate-common core
shared between the tst-truncate and tst-truncate64 tests.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit fe47595504)
If a file descriptor is left unclosed and is cleaned up by _IO_cleanup
on exit, its backup buffer remains unfreed, registering as a leak in
valgrind. This is not strictly an issue since (1) the program should
ideally be closing the stream once it's not in use and (2) the program
is about to exit anyway, so keeping the backup buffer around a wee bit
longer isn't a real problem. Free it anyway to keep valgrind happy
when the streams in question are the standard ones, i.e. stdout, stdin
or stderr.
Also, the _IO_have_backup macro checks for _IO_save_base,
which is a roundabout way to check for a backup buffer instead of
directly looking for _IO_backup_base. The roundabout check breaks when
the main get area has not been used and user pushes a char into the
backup buffer with ungetc. Fix this to use the _IO_backup_base
directly.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 3e1d8d1d1d)
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>
(cherry picked from commit cdf0f88f97)
Complement commit b03e4d7bd2 ("stdio: fix vfscanf with matches longer
than INT_MAX (bug 27650)") and add a test case for the issue, inspired
by the reproducer provided with the bug report.
This has been verified to succeed as from the commit referred and fail
beforehand.
As the test requires 2GiB of data to be passed around its performance
has been evaluated using a choice of systems and the execution time
determined to be respectively in the range of 9s for POWER9@2.166GHz,
24s for FU740@1.2GHz, and 40s for 74Kf@950MHz. As this is on the verge
of and beyond the default timeout it has been increased by the factor of
8. Regardless, following recent practice the test has been added to the
standard rather than extended set.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 89cddc8a70)
Add a FAIL test failure helper analogous to FAIL_RET, that does not
cause the current function to return, providing a standardized way to
report a test failure with a message supplied while permitting the
caller to continue executing, for further reporting, cleaning up, etc.
Update existing test cases that provide a conflicting definition of FAIL
by removing the local FAIL definition and then as follows:
- tst-fortify-syslog: provide a meaningful message in addition to the
file name already added by <support/check.h>; 'support_record_failure'
is already called by 'support_print_failure_impl' invoked by the new
FAIL test failure helper.
- tst-ctype: no update to FAIL calls required, with the name of the file
and the line number within of the failure site additionally included
by the new FAIL test failure helper, and error counting plus count
reporting upon test program termination also already provided by
'support_record_failure' and 'support_report_failure' respectively,
called by 'support_print_failure_impl' and 'adjust_exit_status' also
respectively. However in a number of places 'printf' is called and
the error count adjusted by hand, so update these places to make use
of FAIL instead. And last but not least adjust the final summary just
to report completion, with any error count following as reported by
the test driver.
- test-tgmath2: no update to FAIL calls required, with the name of the
file of the failure site additionally included by the new FAIL test
failure helper. Also there is no need to track the return status by
hand as any call to FAIL will eventually cause the test case to return
an unsuccesful exit status regardless of the return status from the
test function, via a call to 'adjust_exit_status' made by the test
driver.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 1b97a9f23b)
Secondary namespaces have a different malloc. Allocating the
buffer in one namespace and freeing it another results in
heap corruption. Fix this by using a static string (potentially
translated) in secondary namespaces. It would also be possible
to use the malloc from the initial namespace to manage the
buffer, but these functions would still not be safe to use in
auditors etc. because a call to strerror could still free a
buffer while it is used by the application. Another approach
could use proper initial-exec TLS, duplicated in secondary
namespaces, but that would need a callback interface for freeing
libc resources in namespaces on thread exit, which does not exist
today.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 25a5eb4010)
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>
(cherry picked from commit 7da0886247)
Use RXX_LP in RTLD_START_ENABLE_X86_FEATURES. Support shadow stack during
startup for Linux 6.10:
commit 2883f01ec37dd8668e7222dfdb5980c86fdfe277
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Mar 15 07:04:33 2024 -0700
x86/shstk: Enable shadow stacks for x32
1. Add shadow stack support to x32 signal.
2. Use the 64-bit map_shadow_stack syscall for x32.
3. Set up shadow stack for x32.
Add the map_shadow_stack system call to <fixup-asm-unistd.h> and regenerate
arch-syscall.h. Tested on Intel Tiger Lake with CET enabled x32. There
are no regressions with CET enabled x86-64. There are no changes in CET
enabled x86-64 _dl_start_user.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 8344c1f551)
Remove sysdeps/x86_64/x32/dl-machine.h by folding x32 ARCH_LA_PLTENTER,
ARCH_LA_PLTEXIT and RTLD_START into sysdeps/x86_64/dl-machine.h. There
are no regressions on x86-64 nor x32. There are no changes in x86-64
_dl_start_user. On x32, _dl_start_user changes are
<_dl_start_user>:
mov %eax,%r12d
+ mov %esp,%r13d
mov (%rsp),%edx
mov %edx,%esi
- mov %esp,%r13d
and $0xfffffff0,%esp
mov 0x0(%rip),%edi # <_dl_start_user+0x14>
lea 0x8(%r13,%rdx,4),%ecx
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 652c6cf269)
This avoids crashes if a test is passed unknown options.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit c2a474f461)
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>
(cherry picked from commit 942670c81d)
Rename the identifier sz to __sz everywhere.
Fixes: a643f60c53 ("Make sure that the fortified function conditionals are constant")
(cherry picked from commit 39ca997ab3)
(redone from scratch because of many conflicts)
Previous GCC versions do not support the C23 change that
allows labels on declarations.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit ec119972cb)
Add tests for MREMAP_MAYMOVE and MREMAP_FIXED. On Linux, also test
MREMAP_DONTUNMAP.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit ff0320bec2)
Update the mremap C implementation to support the optional argument for
MREMAP_DONTUNMAP added in Linux 5.7 since it may not always be correct
to implement a variadic function as a non-variadic function on all Linux
targets. Return MAP_FAILED and set errno to EINVAL for unknown flag bits.
This fixes BZ #31968.
Note: A test must be added when a new flag bit is introduced.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 6c40cb0e9f)
Add string/test-strncmp-nonarray and
wcsmbs/test-wcsncmp-nonarray.
This is the test that uncovered bug 31934. Test run time
is more than one minute on a fairly current system, so turn
these into xtests that do not run automatically.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 54252394c2)
This commit adds string/test-strnlen-nonarray and
wcsmbs/test-wcsnlen-nonarray.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 783d4c0b81)
The existing description for setrlimit() has some ambiguity. It could be
understood to have the semantics of getrlimit(), i.e., the limits from the
process are stored in the provided rlp pointer.
Make the description more explicit that rlp are the input values, and that
the limits of the process is changed with this function.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit aedbf08891)
The manual entry for `putc' described what "most systems" do instead of
describing the glibc implementation and its guarantees. This commit
fixes that by warning that putc may be implemented as a macro that
double-evaluates `stream', and removing the performance claim.
Even though the current `putc' implementation does not double-evaluate
`stream', offering this obscure guarantee as an extension to what
POSIX allows does not seem very useful.
The entry for `putwc' is also edited to bring it in line with `putc'.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 10de4a47ef)
Improve aligned_alloc/calloc/malloc test coverage by adding
multi-threaded tests with random memory allocations and with/without
cross-thread memory deallocations.
Perform a number of memory allocation calls with random sizes limited
to 0xffff.
Use the existing DSO ('malloc/tst-aligned_alloc-lib.c') to randomize
allocator selection.
The multi-threaded allocation/deallocation is staged as described below:
- Stage 1: Half of the threads will be allocating memory and the
other half will be waiting for them to finish the allocation.
- Stage 2: Half of the threads will be allocating memory and the
other half will be deallocating memory.
- Stage 3: Half of the threads will be deallocating memory and the
second half waiting on them to finish.
Add 'malloc/tst-aligned-alloc-random-thread.c' where each thread will
deallocate only the memory that was previously allocated by itself.
Add 'malloc/tst-aligned-alloc-random-thread-cross.c' where each thread
will deallocate memory that was previously allocated by another thread.
The intention is to be able to utilize existing malloc testing to ensure
that similar allocation APIs are also exposed to the same rigors.
Reviewed-by: Arjun Shankar <arjun@redhat.com>
(cherry picked from commit b0fbcb7d00)
Make sure the DSO used by aligned_alloc/calloc/malloc tests does not get
a global lock on multithreaded tests.
Reviewed-by: Arjun Shankar <arjun@redhat.com>
(cherry picked from commit 9a27b566b2)
This avoids changing _res.options, which inteferes with change
detection as part of automatic reloading of /etc/resolv.conf.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 868ab8923a)
In single-request mode, there is no second response after an error
because the second query has not been sent yet. Waiting for it
introduces an unnecessary timeout.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit af625987d6)
