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2014-03-13semctl: fix UB causing crashes on powerpcrofl0r-4/+8
it's UB to fetch variadic args when none are passed, and this caused real crashes on ppc due to its calling convention, which defines that for variadic functions aggregate types be passed as pointers. the assignment caused that pointer to get dereferenced, resulting in a crash.
2014-01-08fix inadvertent use of struct in place of union for semunRich Felker-3/+3
2014-01-08fix type of semctl variadic argumentRich Felker-4/+10
per POSIX, the variadic argument has type union semun, which may contain a pointer or int; the type read depends on the command being issued. this allows the userspace part of the implementation to be type-correct without requiring special-casing for different commands. the kernel always expects to receive the argument interpreted as unsigned long (or equivalently, a pointer), and does its own handling of extracting the int portion from the representation, as needed. this change fixes two possible issues: most immediately, reading the argument as a (signed) long and passing it to the syscall would perform incorrect sign-extension of pointers on the upcoming x32 target. the other possible issue is that some archs may use different (user-space) argument-passing convention for unions, preventing va_arg from correctly obtaining the argument when the type long (or even unsigned long or void *) is passed to it.
2013-11-09fix harmless inconsistency in semtimedopRich Felker-1/+1
this should not matter since the reality is that either all the sysv sem syscalls are individual syscalls, or all of them are multiplexed on the SYS_ipc syscall (depending on arch). but best to be consistent anyway.
2013-11-09implement semtimedopRich Felker-0/+14
this is a Linux-specific extension to the sysv semaphore api.
2013-06-29prevent shmget from allocating objects that overflow ptrdiff_tRich Felker-0/+2
rather than returning an error, we have to increase the size argument so high that the kernel will have no choice but to fail. this is because POSIX only permits the EINVAL error for size errors when a new shared memory segment would be created; if it already exists, the size argument must be ignored. unfortunately Linux is non-conforming in this regard, but I want to keep the code correct in userspace anyway so that if/when Linux is fixed, the behavior applications see will be conforming.
2013-06-28work around wrong kernel type for sem_nsems member of struct semid_dsRich Felker-0/+7
rejecting invalid values for n is fine even in the case where a new sem will not be created, since the kernel does its range checks on n even in this case as well. by default, the kernel will bound the limit well below USHRT_MAX anyway, but it's presumably possible that an administrator could override this limit and break things.
2012-10-28fix shmdt syscall calling convention on old archsRich Felker-1/+1
2012-09-22fix remaining IPC_64 issue (shmctl)Rich Felker-4/+2
also cleanup cruft related to the issue
2012-09-22fix IPC_64 in msgctl tooRich Felker-6/+2
2012-09-22fix broken semctl on systems that don't use IPC_64 flagRich Felker-2/+6
not tested on mips and arm; they may still be broken. x86_64 should be ok now.
2011-04-17overhaul pthread cancellationRich Felker-12/+4
this patch improves the correctness, simplicity, and size of cancellation-related code. modulo any small errors, it should now be completely conformant, safe, and resource-leak free. the notion of entering and exiting cancellation-point context has been completely eliminated and replaced with alternative syscall assembly code for cancellable syscalls. the assembly is responsible for setting up execution context information (stack pointer and address of the syscall instruction) which the cancellation signal handler can use to determine whether the interrupted code was in a cancellable state. these changes eliminate race conditions in the previous generation of cancellation handling code (whereby a cancellation request received just prior to the syscall would not be processed, leaving the syscall to block, potentially indefinitely), and remedy an issue where non-cancellable syscalls made from signal handlers became cancellable if the signal handler interrupted a cancellation point. x86_64 asm is untested and may need a second try to get it right.
2011-04-13numerous fixes to sysv ipcRich Felker-5/+5
some of these definitions were just plain wrong, others based on outdated ancient "non-64" versions of the kernel interface. as much as possible has now been moved out of bits/* these changes break abi (the old abi for these functions was wrong), but since they were not working anyway it can hardly matter.
2011-04-06consistency: change all remaining syscalls to use SYS_ rather than __NR_ prefixRich Felker-11/+11
2011-04-06fix incorrect (and conflicting on LP64 archs) types for sysv ipc msgq functionsRich Felker-1/+1
2011-04-05add sysv ipc message queues (completely untested)Rich Felker-0/+58
2011-03-20global cleanup to use the new syscall interfaceRich Felker-14/+14
2011-02-13fixed missing cast in the non-i386 version of shmat (preparation for ports)Rich Felker-1/+1
2011-02-12initial check-in, version 0.5.0v0.5.0Rich Felker-0/+118