| Commit message (Expand) | Author | Files | Lines |
|---|
| 2011-08-02 | fix stubbed-out reboot call | Rich Felker | 1 | -3/+2 |
| 2011-08-02 | correctly handle old kernels without FUTEX_WAIT_BITSET•••futex returns EINVAL, not ENOSYS, when op is not supported.
unfortunately this looks just like EINVAL from other causes, and we
end up running the fallback code and getting EINVAL again. fortunately
this case should be rare since correct code should not generate EINVAL
anyway.
| Rich Felker | 1 | -1/+1 |
| 2011-08-02 | fix sem_timedwait bug introduced in timedwait unification•••this dec used to be performed by the cancellation handler, which was
called when popped.
| Rich Felker | 1 | -0/+1 |
| 2011-08-02 | unify and overhaul timed futex waits•••new features:
- FUTEX_WAIT_BITSET op will be used for timed waits if available. this
saves a call to clock_gettime.
- error checking for the timespec struct is now inside __timedwait so
it doesn't need to be duplicated everywhere. cond_timedwait still
needs to duplicate it to avoid unlocking the mutex, though.
- pushing and popping the cancellation handler is delegated to
__timedwait, and cancellable/non-cancellable waits are unified.
| Rich Felker | 10 | -53/+56 |
| 2011-08-02 | avoid accessing mutex memory after atomic unlock•••this change is needed to fix a race condition and ensure that it's
possible to unlock and destroy or unmap the mutex as soon as
pthread_mutex_lock succeeds. POSIX explicitly gives such an example in
the rationale and requires an implementation to allow such usage.
| Rich Felker | 4 | -34/+31 |
| 2011-08-02 | fix breakage in cancellation due to signal functions overhaul•••sigaddset was not accepting SIGCANCEL as a valid signal number.
| Rich Felker | 1 | -1/+7 |
| 2011-08-02 | overhaul posix semaphores to fix destructability race•••the race condition these changes address is described in glibc bug
report number 12674:
http://sourceware.org/bugzilla/show_bug.cgi?id=12674
up until now, musl has shared the bug, and i had not been able to
figure out how to eliminate it. in short, the problem is that it's not
valid for sem_post to inspect the waiters count after incrementing the
semaphore value, because another thread may have already successfully
returned from sem_wait, (rightly) deemed itself the only remaining
user of the semaphore, and chosen to destroy and free it (or unmap the
shared memory it's stored in). POSIX is not explicit in blessing this
usage, but it gives a very explicit analogous example with mutexes
(which, in musl and glibc, also suffer from the same race condition
bug) in the rationale for pthread_mutex_destroy.
the new semaphore implementation augments the waiter count with a
redundant waiter indication in the semaphore value itself,
representing the presence of "last minute" waiters that may have
arrived after sem_post read the waiter count. this allows sem_post to
read the waiter count prior to incrementing the semaphore value,
rather than after incrementing it, so as to avoid accessing the
semaphore memory whatsoever after the increment takes place.
a similar, but much simpler, fix should be possible for mutexes and
other locking primitives whose usage rules are stricter than
semaphores.
| Rich Felker | 3 | -27/+23 |
| 2011-08-01 | fix wrong messages in gai_strerror•••i had missed the fact that a couple values were unassigned...
| Rich Felker | 1 | -0/+2 |
| 2011-08-01 | port numbers should always be interpreted as decimal•••per POSIX and RFC 3493:
If the specified address family is AF_INET, AF_INET6, or AF_UNSPEC,
the service can be specified as a string specifying a decimal port
number.
021 is a valid decimal number, therefore, interpreting it as octal
seems to be non-conformant.
| Rich Felker | 1 | -1/+1 |
| 2011-08-01 | fix crash in dns code with new stdio locking code | Rich Felker | 1 | -0/+1 |
| 2011-07-31 | consistency: use struct __ucontext instead of ucontext_t in prototypes•••this is necessary to avoid build errors if feature test macros are not
properly defined when including ucontext.h
| Rich Felker | 1 | -1/+1 |
| 2011-07-30 | fix race condition in sigqueue•••this race is fundamentally due to linux's bogus requirement that
userspace, rather than kernelspace, fill in the siginfo structure. an
intervening signal handler that calls fork could cause both the parent
and child process to send signals claiming to be from the parent,
which could in turn have harmful effects depending on what the
recipient does with the signal. we simply block all signals for the
interval between getuid and sigqueue syscalls (much like what raise()
does already) to prevent the race and make the getuid/sigqueue pair
atomic.
this will be a non-issue if linux is fixed to validate the siginfo
structure or fill it in from kernelspace.
| Rich Felker | 1 | -2/+8 |
| 2011-07-30 | clean up pthread_sigmask/sigprocmask dependency order•••it's nicer for the function that doesn't use errno to be independent,
and have the other one call it. saves some time and avoids clobbering
errno.
| Rich Felker | 2 | -11/+7 |
| 2011-07-30 | fix some bugs in setxid and update setrlimit to use __synccall•••setrlimit is supposed to be per-process, not per-thread, but again
linux gets it wrong. work around this in userspace. not only is it
needed for correctness; setxid also depends on the resource limits for
all threads being the same to avoid situations where temporarily
unlimiting the limit succeeds in some threads but fails in others.
| Rich Felker | 2 | -10/+33 |
| 2011-07-30 | add proper fuxed-based locking for stdio•••previously, stdio used spinlocks, which would be unacceptable if we
ever add support for thread priorities, and which yielded
pathologically bad performance if an application attempted to use
flockfile on a key file as a major/primary locking mechanism.
i had held off on making this change for fear that it would hurt
performance in the non-threaded case, but actually support for
recursive locking had already inflicted that cost. by having the
internal locking functions store a flag indicating whether they need
to perform unlocking, rather than using the actual recursive lock
counter, i was able to combine the conditionals at unlock time,
eliminating any additional cost, and also avoid a nasty corner case
where a huge number of calls to ftrylockfile could cause deadlock
later at the point of internal locking.
this commit also fixes some issues with usage of pthread_self
conflicting with __attribute__((const)) which resulted in crashes with
some compiler versions/optimizations, mainly in flockfile prior to
pthread_create.
| Rich Felker | 20 | -46/+71 |
| 2011-07-30 | eliminate dependence of perror on printf | Rich Felker | 1 | -10/+5 |
| 2011-07-30 | fix bug in synccall with no threads: lock was taken but never released | Rich Felker | 1 | -4/+4 |
