Rich Felker [Thu, 29 Sep 2011 02:07:58 +0000 (22:07 -0400)]
don't crash on null strings in printf
passing null pointer for %s is UB but lots of broken programs do it anyway
Rich Felker [Wed, 28 Sep 2011 23:45:37 +0000 (19:45 -0400)]
fix excessive/insufficient wakes in __vm_unlock
there is no need to send a wake when the lock count does not hit zero,
but when it does, all waiters must be woken (since all with the same
sign are eligible to obtain the lock).
Rich Felker [Wed, 28 Sep 2011 23:37:14 +0000 (19:37 -0400)]
make getmntent_r discard long lines when it returns error, not seek back
seeking back can be performed by the caller, but if the caller doesn't
expect it, it will result in an infinite loop of failures.
Rich Felker [Wed, 28 Sep 2011 22:57:18 +0000 (18:57 -0400)]
improve pshared barriers
eliminate the sequence number field and instead use the counter as the
futex because of the way the lock is held, sequence numbers are
completely useless, and this frees up a field in the barrier structure
to be used as a waiter count for the count futex, which lets us avoid
some syscalls in the best case.
as of now, self-synchronized destruction and unmapping should be fully
safe. before any thread can return from the barrier, all threads in
the barrier have obtained the vm lock, and each holds a shared lock on
the barrier. the barrier memory is not inspected after the shared lock
count reaches 0, nor after the vm lock is released.
Rich Felker [Wed, 28 Sep 2011 22:00:02 +0000 (18:00 -0400)]
next step making barrier self-sync'd destruction safe
i think this works, but it can be simplified. (next step)
Rich Felker [Wed, 28 Sep 2011 16:47:15 +0000 (12:47 -0400)]
barrier destroy must also wait for threads in other processes exiting barrier
the vm lock only waits for threads in the same process exiting.
actually this fix is not enough, but it's a start...
Rich Felker [Wed, 28 Sep 2011 15:36:11 +0000 (11:36 -0400)]
stupid typo (caused by rather ugly spelling in POSIX..) in aio
Rich Felker [Wed, 28 Sep 2011 03:08:59 +0000 (23:08 -0400)]
correctly handle the degenerate barrier in the pshared case
Rich Felker [Tue, 27 Sep 2011 22:56:29 +0000 (18:56 -0400)]
fix crash in pthread_cond_wait mutex-locked check
it was assuming the result of the condition it was supposed to be
checking for, i.e. that the thread ptr had already been initialized by
pthread_mutex_lock. use the slower call to be safe.
Rich Felker [Tue, 27 Sep 2011 22:39:49 +0000 (18:39 -0400)]
fix crash in pthread_testcancel if pthread_self has not been called
Rich Felker [Tue, 27 Sep 2011 22:22:31 +0000 (18:22 -0400)]
improve/debloat mutex unlock error checking in pthread_cond_wait
we're not required to check this except for error-checking mutexes,
but it doesn't hurt. the new test is actually simpler/lighter, and it
also eliminates the need to later check that pthread_mutex_unlock
succeeds.
Rich Felker [Tue, 27 Sep 2011 22:17:27 +0000 (18:17 -0400)]
check mutex owner in pthread_cond_wait
when used with error-checking mutexes, pthread_cond_wait is required
to fail with EPERM if the mutex is not locked by the caller.
previously we relied on pthread_mutex_unlock to generate the error,
but this is not valid, since in the case of such invalid usage the
internal state of the cond variable has already been potentially
corrupted (due to access outside the control of the mutex). thus, we
have to check first.
Rich Felker [Tue, 27 Sep 2011 21:03:44 +0000 (17:03 -0400)]
fix pshared barrier wrong return value.
i set the return value but then never used it... oops!
Rich Felker [Tue, 27 Sep 2011 21:02:19 +0000 (17:02 -0400)]
convert the barrier pshared option back to 0/1 values when getting it
Rich Felker [Tue, 27 Sep 2011 21:00:38 +0000 (17:00 -0400)]
improve error handling in mntent stuff...
not sure if this is correct/ideal. it needs further attention.
Rich Felker [Tue, 27 Sep 2011 20:47:00 +0000 (16:47 -0400)]
fix missing va_end in prctl syscall wrapper
Rich Felker [Tue, 27 Sep 2011 20:45:29 +0000 (16:45 -0400)]
fix clobbering of errno in get(pw|gr)([ug]id|nam) by fclose
Rich Felker [Tue, 27 Sep 2011 17:50:29 +0000 (13:50 -0400)]
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 [Tue, 27 Sep 2011 16:18:44 +0000 (12:18 -0400)]
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 [Mon, 26 Sep 2011 22:56:56 +0000 (18:56 -0400)]
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 [Mon, 26 Sep 2011 17:14:41 +0000 (13:14 -0400)]
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 [Mon, 26 Sep 2011 16:54:28 +0000 (12:54 -0400)]
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 [Mon, 26 Sep 2011 04:59:28 +0000 (00:59 -0400)]
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 [Mon, 26 Sep 2011 04:25:13 +0000 (00:25 -0400)]
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 [Mon, 26 Sep 2011 01:14:40 +0000 (21:14 -0400)]
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 [Mon, 26 Sep 2011 01:10:50 +0000 (21:10 -0400)]
optimize cond waiter move using atomic swap instead of cas loop
Rich Felker [Sun, 25 Sep 2011 06:56:01 +0000 (02:56 -0400)]
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 [Sun, 25 Sep 2011 06:38:03 +0000 (02:38 -0400)]
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 [Sat, 24 Sep 2011 02:58:45 +0000 (22:58 -0400)]
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 [Sat, 24 Sep 2011 02:24:33 +0000 (22:24 -0400)]
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 [Fri, 23 Sep 2011 18:24:57 +0000 (14:24 -0400)]
sys/user.h may need stdint.h
Rich Felker [Fri, 23 Sep 2011 02:56:06 +0000 (22:56 -0400)]
"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 [Fri, 23 Sep 2011 01:08:55 +0000 (21:08 -0400)]
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 [Thu, 22 Sep 2011 19:36:25 +0000 (15:36 -0400)]
fix x86_64 user.h (previously was just a copy of i386)
Rich Felker [Thu, 22 Sep 2011 19:35:57 +0000 (15:35 -0400)]
cleanup/debloat i386 user.h
Rich Felker [Thu, 22 Sep 2011 19:25:07 +0000 (15:25 -0400)]
wrong __WORDSIZE in x86_64 header
Rich Felker [Thu, 22 Sep 2011 03:57:51 +0000 (23:57 -0400)]
protect against/handle cancellation reading shadow passwords
Rich Felker [Thu, 22 Sep 2011 03:27:17 +0000 (23:27 -0400)]
make dns lookups (and thus getaddrinfo) cancellable
Rich Felker [Thu, 22 Sep 2011 03:17:45 +0000 (23:17 -0400)]
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 [Thu, 22 Sep 2011 02:25:31 +0000 (22:25 -0400)]
fix missing SIG_DFL, SIG_IGN, SIG_ERR without posix in signal.h
Rich Felker [Thu, 22 Sep 2011 01:30:45 +0000 (21:30 -0400)]
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 [Thu, 22 Sep 2011 01:01:56 +0000 (21:01 -0400)]
gnu search.h has struct qelem...
Rich Felker [Thu, 22 Sep 2011 00:24:12 +0000 (20:24 -0400)]
release notes for 0.8.3
Rich Felker [Thu, 22 Sep 2011 00:11:10 +0000 (20:11 -0400)]
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 [Wed, 21 Sep 2011 23:40:55 +0000 (19:40 -0400)]
new gcc wrapper now supports pre-4.4 gcc versions and is more robust
Rich Felker [Wed, 21 Sep 2011 23:39:40 +0000 (19:39 -0400)]
new installation guide with alternate and primary libc setups
Rich Felker [Wed, 21 Sep 2011 00:02:48 +0000 (20:02 -0400)]
fix some header typos
Rich Felker [Tue, 20 Sep 2011 18:51:56 +0000 (14:51 -0400)]
make stdbool.h conform to c99
Rich Felker [Tue, 20 Sep 2011 16:14:06 +0000 (12:14 -0400)]
fix incorrect include guard in mqueue.h
Rich Felker [Tue, 20 Sep 2011 15:18:13 +0000 (11:18 -0400)]
fix statvfs.c to match new fsid_t definition
Rich Felker [Tue, 20 Sep 2011 15:16:27 +0000 (11:16 -0400)]
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 [Tue, 20 Sep 2011 14:58:18 +0000 (10:58 -0400)]
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 [Tue, 20 Sep 2011 03:35:48 +0000 (23:35 -0400)]
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 [Tue, 20 Sep 2011 02:27:02 +0000 (22:27 -0400)]
add some more siginfo aliases broken software expects...
Rich Felker [Tue, 20 Sep 2011 00:02:12 +0000 (20:02 -0400)]
cleanup redundancy in bits/signal.h versions
Rich Felker [Mon, 19 Sep 2011 21:39:51 +0000 (17:39 -0400)]
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 [Mon, 19 Sep 2011 20:59:10 +0000 (16:59 -0400)]
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 [Mon, 19 Sep 2011 15:56:09 +0000 (11:56 -0400)]
fix broken multi-inclusion guard in sys/reg.h
Rich Felker [Sun, 18 Sep 2011 20:44:54 +0000 (16:44 -0400)]
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 [Sun, 18 Sep 2011 20:42:06 +0000 (16:42 -0400)]
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 [Sun, 18 Sep 2011 20:34:13 +0000 (16:34 -0400)]
cleanup more bits cruft (sysmacros and socket)
Rich Felker [Sun, 18 Sep 2011 19:39:52 +0000 (15:39 -0400)]
more bits junk (tcp.h)
Rich Felker [Sun, 18 Sep 2011 19:31:44 +0000 (15:31 -0400)]
move invariant netinet/in.h stuff out of bits/in.h
Rich Felker [Sun, 18 Sep 2011 14:14:37 +0000 (10:14 -0400)]
overhaul clone syscall wrapping
several things are changed. first, i have removed the old __uniclone
function signature and replaced it with the "standard" linux
__clone/clone signature. this was necessary to expose clone to
applications anyway, and it makes it easier to port __clone to new
archs, since it's now testable independently of pthread_create.
secondly, i have removed all references to the ugly ldt descriptor
structure (i386 only) from the c code and pthread structure. in places
where it is needed, it is now created on the stack just when it's
needed, in assembly code. thus, the i386 __clone function takes the
desired thread pointer as its argument, rather than an ldt descriptor
pointer, just like on all other sane archs. this should not affect
applications since there is really no way an application can use clone
with threads/tls in a way that doesn't horribly conflict with and
clobber the underlying implementation's use. applications are expected
to use clone only for creating actual processes, possibly with new
namespace features and whatnot.
Rich Felker [Sat, 17 Sep 2011 15:41:11 +0000 (11:41 -0400)]
release notes for 0.8.2
Rich Felker [Sat, 17 Sep 2011 15:37:46 +0000 (11:37 -0400)]
dummy implementation of set_thread_area
eventually we may have a working "generic" implementation for archs
that don't need anything special. in any case, the goal of having
stubs like this is to allow early testing of new ports before all the
details needed for threads have been filled in. more functions like
this will follow.
Rich Felker [Fri, 16 Sep 2011 18:39:15 +0000 (14:39 -0400)]
fix assumptions that char is signed
Rich Felker [Fri, 16 Sep 2011 18:33:51 +0000 (14:33 -0400)]
fix more instances of old a_xchg (use new a_swap name)
Rich Felker [Fri, 16 Sep 2011 18:29:24 +0000 (14:29 -0400)]
use a_swap rather than old name a_xchg
Rich Felker [Fri, 16 Sep 2011 16:44:39 +0000 (12:44 -0400)]
fix generic sigsetjmp (unused anyway) pointer signedness error
Rich Felker [Fri, 16 Sep 2011 16:08:20 +0000 (12:08 -0400)]
fix idiotic const-correctness error in lio_listio
i blame this one on posix for using hideous const-qualified double
pointers which are unusable without hideous casts.
Rich Felker [Fri, 16 Sep 2011 14:13:00 +0000 (10:13 -0400)]
fix ptrace (maybe)
Rich Felker [Thu, 15 Sep 2011 17:03:13 +0000 (13:03 -0400)]
implement ptrace syscall wrapper (untested)
Rich Felker [Wed, 14 Sep 2011 23:11:15 +0000 (19:11 -0400)]
0.8.1 release notes
Rich Felker [Wed, 14 Sep 2011 13:37:01 +0000 (09:37 -0400)]
remove incorrectly-made-visible internal dst offset variable
Rich Felker [Wed, 14 Sep 2011 13:36:38 +0000 (09:36 -0400)]
fix inconsistent signature for aio_error
Rich Felker [Wed, 14 Sep 2011 01:21:53 +0000 (21:21 -0400)]
fix return types for aio_read and aio_write again
previous fix was backwards and propagated the wrong type rather than
the right one...
Rich Felker [Wed, 14 Sep 2011 01:09:35 +0000 (21:09 -0400)]
fix various errors in function signatures/prototypes found by nsz
Rich Felker [Tue, 13 Sep 2011 20:12:57 +0000 (16:12 -0400)]
fix cruft left in release notes
Rich Felker [Tue, 13 Sep 2011 19:39:58 +0000 (15:39 -0400)]
fix prototypes for aio_read and aio_write
Rich Felker [Tue, 13 Sep 2011 18:45:59 +0000 (14:45 -0400)]
add missing posix_spawnattr_init/destroy functions
Rich Felker [Tue, 13 Sep 2011 17:41:40 +0000 (13:41 -0400)]
0.8.0 release
Rich Felker [Tue, 13 Sep 2011 13:53:41 +0000 (09:53 -0400)]
remove some stray trailing space characters
Rich Felker [Mon, 12 Sep 2011 04:00:30 +0000 (00:00 -0400)]
implement gnu sigisemptyset
Rich Felker [Mon, 12 Sep 2011 02:50:02 +0000 (22:50 -0400)]
add prototypes for GNU *_unlocked stdio functions
actually these are just weak aliases for the normal locking versions
right now, and they will probably stay that way since making them
lock-free without slowing down the normal versions would require
significant code duplication for no benefit.
Rich Felker [Mon, 12 Sep 2011 02:45:56 +0000 (22:45 -0400)]
add dummied strverscmp (obnoxious GNU function)
programs that use this tend to horribly botch international text
support, so it's questionable whether we want to support it even in
the long term... for now, it's just a dummy that calls strcmp.
Rich Felker [Mon, 12 Sep 2011 02:43:57 +0000 (22:43 -0400)]
declare alloca in stdlib.h when _GNU_SOURCE is defined
Rich Felker [Sun, 11 Sep 2011 16:35:41 +0000 (12:35 -0400)]
fix serious bug in pthread_join
on spurious wakeups/returns from __timedwait, pthread_join would
"succeed" and unmap the thread's stack while it was still running. at
best this would lead to SIGSEGV when the thread resumed execution, but
in the worst case, the thread would later resume executing on top of
another new thread's stack mapped at the same address.
spent about 4 hours tracking this bug down, chasing rare
difficult-to-reproduce stack corruption in a stress test program.
still no idea *what* caused the spurious wakeups; i suspect it's a
kernel bug.
Rich Felker [Sat, 10 Sep 2011 03:10:27 +0000 (23:10 -0400)]
fix pthread_join wait call: thread termination tid futex is not private
this seeme to be the bug that prevented enabling of private futex
support. i'm going to hold off on switching to private futexes until
after the next release, and until i get a chance to audit all
wait/wake calls to make sure they're using the correct private
argument, but with this change it should be safe to enable private
futex support.
Rich Felker [Fri, 9 Sep 2011 05:07:38 +0000 (01:07 -0400)]
implement POSIX asynchronous io
some features are not yet supported, and only minimal testing has been
performed. should be considered experimental at this point.
Rich Felker [Tue, 6 Sep 2011 02:23:06 +0000 (22:23 -0400)]
fix incorrect overflow errors on strtoul, etc.
Rich Felker [Mon, 5 Sep 2011 19:39:36 +0000 (15:39 -0400)]
strptime: fix use of uninitialized dest field in converting integer
Rich Felker [Mon, 5 Sep 2011 01:53:20 +0000 (21:53 -0400)]
more fmemopen null termination fixes
null termination is only added when current size grows.
in update modes, null termination is not added if it does not fit
(i.e. it is not allowed to clobber data).
these rules make very little sense, but that's how it goes..
Rich Felker [Mon, 5 Sep 2011 01:40:42 +0000 (21:40 -0400)]
fix some fmemopen behaviors
read should not be allowed past "current size".
append mode should write at "current size", not buffer size.
null termination should not be written except when "current size" grows.
Rich Felker [Mon, 5 Sep 2011 01:37:07 +0000 (21:37 -0400)]
handle pending cancellation when enabling async cancellation
this is not strictly required by the standard, but without it, there
is a race condition where cancellation arriving just before async
cancellation is enabled might not be acted upon. it is impossible for
a conforming application to work around this race condition since
calling pthread_testcancel after setting async cancellation mode is
not allowed (pthread_testcancel is not specified to be
async-cancel-safe). thus the implementation should be responsible for
eliminating the race, from a quality-of-implementation standpoint.
Rich Felker [Sun, 4 Sep 2011 20:06:38 +0000 (16:06 -0400)]
fmemopen: fix eof handling, hopefully right this time
Rich Felker [Sun, 4 Sep 2011 20:04:28 +0000 (16:04 -0400)]
fmemopen fixes
disallow seek past end of buffer (per posix)
fix position accounting to include data buffered for read
don't set eof flag when no data was requested
Rich Felker [Sun, 4 Sep 2011 14:29:04 +0000 (10:29 -0400)]
memstreams: fix incorrect handling of file pos > current size
the addition is safe and cannot overflow because both operands are
positive when considered as signed quantities.
Rich Felker [Sun, 4 Sep 2011 04:08:32 +0000 (00:08 -0400)]
optimize seek function for memory streams
Rich Felker [Sun, 4 Sep 2011 04:06:01 +0000 (00:06 -0400)]
fix twos complement overflow bug in mem streams boundary check
the expression -off is not safe in case off is the most-negative
value. instead apply - to base which is known to be non-negative and
bounded within sanity.