| Commit message (Expand) | Author | Age | Files | Lines |
|---|
| * | fix pshared barrier wrong return value.•••i set the return value but then never used it... oops!
| Rich Felker | 2011-09-27 | 1 | -1/+1 |
| * | convert the barrier pshared option back to 0/1 values when getting it | Rich Felker | 2011-09-27 | 1 | -1/+1 |
| * | improve error handling in mntent stuff...•••not sure if this is correct/ideal. it needs further attention.
| Rich Felker | 2011-09-27 | 1 | -2/+9 |
| * | fix missing va_end in prctl syscall wrapper | Rich Felker | 2011-09-27 | 1 | -0/+1 |
| * | fix clobbering of errno in get(pw|gr)([ug]id|nam) by fclose | Rich Felker | 2011-09-27 | 2 | -0/+12 |
| * | process-shared barrier support, based on discussion with bdonlan•••this implementation is rather heavy-weight, but it's the first
solution i've found that's actually correct. all waiters actually wait
twice at the barrier so that they can synchronize exit, and they hold
a "vm lock" that prevents changes to virtual memory mappings (and
blocks pthread_barrier_destroy) until all waiters are finished
inspecting the barrier.
thus, it is safe for any thread to destroy and/or unmap the barrier's
memory as soon as pthread_barrier_wait returns, without further
synchronization.
| Rich Felker | 2011-09-27 | 7 | -16/+102 |
| * | fix incorrect allocation failure check in pthread_create•••mmap returns MAP_FAILED not 0 because some idiot thought the ability
to mmap the null pointer page would be a good idea...
| Rich Felker | 2011-09-27 | 1 | -1/+1 |
| * | fix ctype macros to cast argument to (unsigned) first•••issue reported by nsz, but it's actually not just pedantic. the
functions can take input of any arithmetic type, including floating
point, and the behavior needs to be as if the conversion implicit in
the function call took place.
| Rich Felker | 2011-09-26 | 2 | -7/+7 |
| * | another cond var fix: requeue count race condition•••lock out new waiters during the broadcast. otherwise the wait count
added to the mutex might be lower than the actual number of waiters
moved, and wakeups may be lost.
this issue could also be solved by temporarily setting the mutex
waiter count higher than any possible real count, then relying on the
kernel to tell us how many waiters were requeued, and updating the
counts afterwards. however the logic is more complex, and i don't
really trust the kernel. the solution here is also nice in that it
replaces some atomic cas loops with simple non-atomic ops under lock.
| Rich Felker | 2011-09-26 | 2 | -15/+13 |
| * | fix lost signals in cond vars•••due to moving waiters from the cond var to the mutex in bcast, these
waiters upon wakeup would steal slots in the count from newer waiters
that had not yet been signaled, preventing the signal function from
taking any action.
to solve the problem, we simply use two separate waiter counts, and so
that the original "total" waiters count is undisturbed by broadcast
and still available for signal.
| Rich Felker | 2011-09-26 | 3 | -14/+17 |
| * | cleanup various minor issues reported by nsz•••the changes to syscall_ret are mostly no-ops in the generated code,
just cleanup of type issues and removal of some implementation-defined
behavior. the one exception is the change in the comparison value,
which is fixed so that 0xf...f000 (which in principle could be a valid
return value for mmap, although probably never in reality) is not
treated as an error return.
| Rich Felker | 2011-09-26 | 6 | -9/+9 |
| * | redo cond vars again, use sequence numbers•••testing revealed that the old implementation, while correct, was
giving way too many spurious wakeups due to races changing the value
of the condition futex. in a test program with 5 threads receiving
broadcast signals, the number of returns from pthread_cond_wait was
roughly 3 times what it should have been (2 spurious wakeups for every
legitimate wakeup). moreover, the magnitude of this effect seems to
grow with the number of threads.
the old implementation may also have had some nasty race conditions
with reuse of the cond var with a new mutex.
the new implementation is based on incrementing a sequence number with
each signal event. this sequence number has nothing to do with the
number of threads intended to be woken; it's only used to provide a
value for the futex wait to avoid deadlock. in theory there is a
danger of race conditions due to the value wrapping around after 2^32
signals. it would be nice to eliminate that, if there's a way.
testing showed no spurious wakeups (though they are of course
possible) with the new implementation, as well as slightly improved
performance.
| Rich Felker | 2011-09-26 | 4 | -48/+52 |
| * | revert previous change in cond var waiter move•••using swap has a race condition: the waiters must be added to the
mutex waiter count *before* they are taken off the cond var waiter
count, or wake events can be lost.
| Rich Felker | 2011-09-25 | 1 | -2/+6 |
| * | optimize cond waiter move using atomic swap instead of cas loop | Rich Felker | 2011-09-25 | 1 | -6/+2 |
| * | fix logic for when wakeup is not desired on cond bcast•••somehow i forgot that normal-type mutexes don't store the owner tid.
| Rich Felker | 2011-09-25 | 1 | -3/+4 |
| * | new futex-requeue-based pthread_cond_broadcast implementation•••this avoids the "stampede effect" where pthread_cond_broadcast would
result in all waiters waking up simultaneously, only to immediately
contend for the mutex and go back to sleep.
| Rich Felker | 2011-09-25 | 4 | -7/+69 |
| * | fix ABA race in cond vars, improve them overall•••previously, a waiter could miss the 1->0 transition of block if
another thread set block to 1 again after the signal function set
block to 0. we now use the caller's thread id as a unique token to
store in block, which no other thread will ever write there. this
ensures that if block still contains the tid, no signal has occurred.
spurious wakeups will of course occur whenever there is a spurious
return from the futex wait and another thread has begun waiting on the
cond var. this should be a rare occurrence except perhaps in the
presence of interrupting signal handlers.
signal/bcast operations have been improved by noting that they need
not avoid inspecting the cond var's memory after changing the futex
value. because the standard allows spurious wakeups, there is no way
for an application to distinguish between a spurious wakeup just
before another thread called signal/bcast, and the deliberate wakeup
resulting from the signal/bcast call. thus the woken thread must
assume that the signalling thread may still be waiting to act on the
cond var, and therefore it cannot destroy/unmap the cond var.
| Rich Felker | 2011-09-23 | 3 | -11/+12 |
| * | FD_ISSET must return an int. this is the easiest way.•••casting to int would not be correct because high bits could be lost.
mapping the high bits down onto low bits would be costlier in the
common case where the result is just used in a conditional. changing
the type of the bit array elements to int would permute the order of
the bit array on 64-bit big endian systems, so that's not an option
either.
| Rich Felker | 2011-09-23 | 1 | -1/+1 |
| * | sys/user.h may need stdint.h | Rich Felker | 2011-09-23 | 1 | -0/+1 |
| * | "optimize" arm __pthread_self•••actually this is just to avoid gcc being stupid and refusing to inline
the function version, even when the size cost is essentially identical
whether it's inlined or not.
| Rich Felker | 2011-09-22 | 1 | -4/+1 |
| * | fix deadlock in condition wait whenever there are multiple waiters•••it's amazing none of the conformance tests i've run even bothered to
check whether something so basic works...
| Rich Felker | 2011-09-22 | 4 | -5/+18 |
| * | fix x86_64 user.h (previously was just a copy of i386) | Rich Felker | 2011-09-22 | 1 | -48/+13 |
| * | cleanup/debloat i386 user.h | Rich Felker | 2011-09-22 | 1 | -43/+11 |
| * | wrong __WORDSIZE in x86_64 header | Rich Felker | 2011-09-22 | 1 | -1/+1 |
| * | protect against/handle cancellation reading shadow passwords | Rich Felker | 2011-09-21 | 1 | -1/+11 |
| * | make dns lookups (and thus getaddrinfo) cancellable | Rich Felker | 2011-09-21 | 1 | -4/+11 |
| * | use poll rather than select in dns lookups (also clock_gettime)•••if the file descriptor resource limit has been increased past
FD_SETSIZE, this is actually a security issue; we could write past the
end of the fd_set object. using poll makes it a non-issue, and
simplifies the code at the same time.
also, use clock_gettime instead of gettimeofday, for reduced bloat
and better entropy.
| Rich Felker | 2011-09-21 | 1 | -12/+10 |
| * | fix missing SIG_DFL, SIG_IGN, SIG_ERR without posix in signal.h | Rich Felker | 2011-09-21 | 1 | -5/+6 |
| * | avoid setting FILE lock count when not using flockfile•••for now this is just a tiny optimization, but later if we support
cancellation from __stdio_read and __stdio_write, it will be necessary
for the recusrive lock count to be zero in order for these functions
to know they are responsible for unlocking the FILE on cancellation.
| Rich Felker | 2011-09-21 | 1 | -1/+1 |
| * | gnu search.h has struct qelem... | Rich Felker | 2011-09-21 | 1 | -0/+7 |
| * | release notes for 0.8.3 | Rich Felker | 2011-09-21 | 1 | -0/+13 |
| * | update syscalls with off_t arguments to handle argument alignment, if needed•••the arm syscall abi requires 64-bit arguments to be aligned on an even
register boundary. these new macros facilitate meeting the abi
requirement without imposing significant ugliness on the code.
| Rich Felker | 2011-09-21 | 9 | -11/+14 |
| * | new gcc wrapper now supports pre-4.4 gcc versions and is more robust | Rich Felker | 2011-09-21 | 1 | -16/+39 |
| * | new installation guide with alternate and primary libc setups | Rich Felker | 2011-09-21 | 1 | -37/+107 |
| * | fix some header typos | Rich Felker | 2011-09-20 | 2 | -2/+2 |
| * | make stdbool.h conform to c99 | Rich Felker | 2011-09-20 | 1 | -1/+2 |
| * | fix incorrect include guard in mqueue.h | Rich Felker | 2011-09-20 | 1 | -2/+2 |
| * | fix statvfs.c to match new fsid_t definition | Rich Felker | 2011-09-20 | 1 | -1/+1 |
| * | fix the fsid_t structure to match name of __val•••this is a case of poorly written man pages not matching the actual
implementation, and why i hate implementing nonstandard interfaces
with no actual documentation of how they're intended to work.
| Rich Felker | 2011-09-20 | 1 | -1/+1 |
| * | fix broken siginfo_t with _GNU_SOURCE defined•••this bug was introduced in a recent patch. the problem we're working
around is that broken GNU software wants to use "struct siginfo"
rather than "siginfo_t", but "siginfo" is not in the reserved
namespace and thus not legal for the standard header to use.
| Rich Felker | 2011-09-20 | 1 | -6/+5 |
| * | fix the definition of struct statvfs to match lsb abi•••at the same time, make struct statfs match the traditional definition
and make it more useful, especially the fsid_t stuff.
| Rich Felker | 2011-09-19 | 7 | -70/+88 |
| * | add some more siginfo aliases broken software expects... | Rich Felker | 2011-09-19 | 1 | -0/+2 |
| * | cleanup redundancy in bits/signal.h versions | Rich Felker | 2011-09-19 | 4 | -376/+139 |
| * | fix the type of wchar_t on arm; support wchar_t varying with arch•••really wchar_t should never vary, but the ARM EABI defines it as an
unsigned 32-bit int instead of a signed one, and gcc follows this
nonsense. thus, to give a conformant environment, we have to follow
(otherwise L""[0] and L'\0' would be 0U rather than 0, but the
application would be unaware due to a mismatched definition for
WCHAR_MIN and WCHAR_MAX, and Bad Things could happen with respect to
signed/unsigned comparisons, promotions, etc.).
fortunately no rules are imposed by the C standard on the relationship
between wchar_t and wint_t, and WEOF has type wint_t, so we can still
make wint_t always-signed and use -1 for WEOF.
| Rich Felker | 2011-09-19 | 6 | -21/+20 |
| * | fix incorrect long double parameters on arm (and other future ports)•••this was the cause of crashes in printf when attempting to print
floating point values.
| Rich Felker | 2011-09-19 | 2 | -10/+22 |
| * | fix broken multi-inclusion guard in sys/reg.h | Rich Felker | 2011-09-19 | 1 | -2/+2 |
| * | initial commit of the arm port•••this port assumes eabi calling conventions, eabi linux syscall
convention, and presence of the kernel helpers at 0xffff0f?0 needed
for threads support. otherwise it makes very few assumptions, and the
code should work even on armv4 without thumb support, as well as on
systems with thumb interworking. the bits headers declare this a
little endian system, but as far as i can tell the code should work
equally well on big endian.
some small details are probably broken; so far, testing has been
limited to qemu/aboriginal linux.
| Rich Felker | 2011-09-18 | 36 | -0/+2225 |
| * | disable dynamic linking/loading code in static libc builds, for now•••it does not work, but some configure scripts will falsely detect
support then generate programs that crash when they call dlopen.
| Rich Felker | 2011-09-18 | 1 | -0/+2 |
| * | cleanup more bits cruft (sysmacros and socket) | Rich Felker | 2011-09-18 | 6 | -414/+199 |
| * | more bits junk (tcp.h) | Rich Felker | 2011-09-18 | 3 | -3/+1 |
