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2013-07-21remove __libc_csu_* cruftRich Felker-10/+0
these functions were mistakenly assumed to be needed to match glibc ABI, but glibc has them as part of the non-shared part of libc that's always statically linked into the main program. moreover, the only place they are referenced from is glibc's crt1.o.
2013-07-21add support for init/fini array in main program, and greatly simplifyRich Felker-26/+33
modern (4.7.x and later) gcc uses init/fini arrays, rather than the legacy _init/_fini function pasting and crtbegin/crtend ctors/dtors system, on most or all archs. some archs had already switched a long time ago. without following this change, global ctors/dtors will cease to work under musl when building with new gcc versions. the most surprising part of this patch is that it actually reduces the size of the init code, for both static and shared libc. this is achieved by (1) unifying the handling main program and shared libraries in the dynamic linker, and (2) eliminating the glibc-inspired rube goldberg machine for passing around init and fini function pointers. to clarify, some background: the function signature for __libc_start_main was based on glibc, as part of the original goal of being able to run some glibc-linked binaries. it worked by having the crt1 code, which is linked into every application, static or dynamic, obtain and pass pointers to the init and fini functions, which __libc_start_main is then responsible for using and recording for later use, as necessary. however, in neither the static-linked nor dynamic-linked case do we actually need crt1.o's help. with dynamic linking, all the pointers are available in the _DYNAMIC block. with static linking, it's safe to simply access the _init/_fini and __init_array_start, etc. symbols directly. obviously changing the __libc_start_main function signature in an incompatible way would break both old musl-linked programs and glibc-linked programs, so let's not do that. instead, the function can just ignore the information it doesn't need. new archs need not even provide the useless args in their versions of crt1.o. existing archs should continue to provide it as long as there is an interest in having newly-linked applications be able to run on old versions of musl; at some point in the future, this support can be removed.
2013-07-21fix order of fini_array execution for shared libsRich Felker-2/+2
2013-07-20add support for init_array/fini_array ctors/dtors to dynamic linkerRich Felker-2/+13
2013-07-20fix shm_open wrongly being cancellableRich Felker-1/+6
2013-07-20fix uninitialized/stale use of alloc (%m modifier) flag in scanfRich Felker-0/+4
for conversion specifiers, alloc is always set when the specifier is parsed. however, if scanf stops due to mismatching literal text, either an uninitialized (if no conversions have been performed yet) or stale (from the previous conversion) of the flag will be used, possibly causing an invalid pointer to be passed to free when the function returns.
2013-07-19harden realloc/free to detect simple overflowsRich Felker-0/+6
the sizes in the header and footer for a chunk should always match. if they don't, the program has definitely invoked undefined behavior, and the most likely cause is a simple overflow, either of a buffer in the block being freed or the one just below it. crashing here should not only improve security of buggy programs, but also aid in debugging, since the crash happens in a context where you have a pointer to the likely-overflowed buffer.
2013-07-19improve [f]stat[v]fs functions, and possibly work around old kernelsRich Felker-2/+5
the main aim of this patch is to ensure that if not all fields are filled in, they contain zeros, so as not to confuse applications. reportedly some older kernels, including commonly used openvz kernels, lack the f_flags field, resulting in applications reading random junk as the mount flags; the common symptom seems to be wrongly considering the filesystem to be mounted read-only and refusing to operate. glibc has some amazingly ugly fallback code to get the mount flags for old kernels, but having them really is not that important anyway; what matters most is not presenting incorrect flags to the application. I have also aimed to fill in some fields of statvfs that were previously missing, and added code to explicitly zero the reserved space at the end of the structure, which will make things easier in the future if this space someday needs to be used.
2013-07-19change uid_t, gid_t, and id_t to unsigned typesRich Felker-6/+20
this change is both to fix one of the remaining type (and thus C++ ABI) mismatches with glibc/LSB and to allow use of the full range of uid and gid values, if so desired. passwd/group access functions were not prepared to deal with unsigned values, so they too have been fixed with this commit.
2013-07-18make the dynamic linker find its path file relative to its own locationRich Felker-1/+20
prior to this change, using a non-default syslibdir was impractical on systems where the ordinary library paths contain musl-incompatible library files. the file containing search paths was always taken from /etc, which would either correspond to a system-wide musl installation, or fail to exist at all, resulting in searching of the default library path. the new search strategy is safe even for suid programs because the pathname used comes from the PT_INTERP header of the program being run, rather than any external input. as part of this change, I have also begun differentiating the names of arch variants that differ by endianness or floating point calling convention. the corresponding changes in the build system and and gcc wrapper script (to use an alternate dynamic linker name) for these configurations have not yet been made.
2013-07-18fix off-by-one error in checks for implementation-internal signal numbersRich Felker-3/+3
2013-07-17make posix_spawn (and functions that use it) use CLONE_VFORK flagRich Felker-1/+2
this is both a minor scheduling optimization and a workaround for a difficult-to-fix bug in qemu app-level emulation. from the scheduling standpoint, it makes no sense to schedule the parent thread again until the child has exec'd or exited, since the parent will immediately block again waiting for it. on the qemu side, as regular application code running on an underlying libc, qemu cannot make arbitrary clone syscalls itself without confusing the underlying implementation. instead, it breaks them down into either fork-like or pthread_create-like cases. it was treating the code in posix_spawn as pthread_create-like, due to CLONE_VM, which caused horribly wrong behavior: CLONE_FILES broke the synchronization mechanism, CLONE_SIGHAND broke the parent's signals, and CLONE_THREAD caused the child's exec to end the parent -- if it hadn't already crashed. however, qemu special-cases CLONE_VFORK and emulates that with fork, even when CLONE_VM is also specified. this also gives incorrect semantics for code that really needs the memory sharing, but posix_spawn does not make use of the vm sharing except to avoid momentary double commit charge. programs using posix_spawn (including via popen) should now work correctly under qemu app-level emulation.
2013-07-17fix missing argument in variadic syscall macrosRich Felker-1/+1
for 0-argument syscalls (1 argument to the macro, the syscall number), the __SYSCALL_NARGS_X macro's ... argument was not satisfied. newer compilers seem to care about this.
2013-07-17fix error code on time conversion overflowsRich Felker-4/+4
POSIX mandates EOVERFLOW for this condition.
2013-07-17fix fd leak in file mapping code used in new zoneinfo supportRich Felker-1/+1
2013-07-17the big time handling overhaulRich Felker-348/+649
this commit has two major user-visible parts: zoneinfo-format time zones are now supported, and overflow handling is intended to be complete in the sense that all functions return a correct result if and only if the result fits in the destination type, and otherwise return an error. also, some noticable bugs in the way DST detection and normalization worked have been fixed, and performance may be better than before, but it has not been tested.
2013-07-13fix omission of dtv setup in static linked programs on TLS variant I archsRich Felker-1/+1
apparently this was never noticed before because the linker normally optimizes dynamic TLS models to non-dynamic ones when static linking, thus eliminating the calls to __tls_get_addr which crash when the dtv is missing. however, some libsupc++ code on ARM was calling __tls_get_addr when static linked and crashing. the reason is unclear to me, but with this issue fixed it should work now anyway.
2013-07-10fix invalid library phdr pointers passed to callback from dl_iterate_phdrRich Felker-9/+16
map_library was saving pointers to an automatic-storage buffer rather than pointers into the mapping. this should be a fairly simple fix, but the patch here is slightly complicated by two issues: 1. supporting gratuitously obfuscated ELF files where the program headers are not right at the beginning of the file. 2. cleaning up the map_library function so that data isn't clobbered by the time we need it.
2013-07-09fix a couple misleading/wrong signal descriptions in strsignalRich Felker-2/+2
there are still several more that are misleading, but SIGFPE (integer division error misdescribed as floating point) and and SIGCHLD (possibly non-exit status change events described as exiting) were the worst offenders.
2013-07-09add realtime signals to strsignalRich Felker-3/+19
the name format RTnn/RTnnn was chosen to minimized bloat while uniquely identifying the signal.
2013-07-09fix off-by-one array bound in strsignalRich Felker-1/+1
2013-07-09fix bogus lazy allocation in ctermid and missing malloc failure checkRich Felker-10/+7
also clean up, optimize, and simplify the code, removing branches by simply pre-setting the result string to an empty string, which will be preserved if other operations fail.
2013-07-09fix fd leak on races and cancellation in ctermidRich Felker-2/+3
2013-07-09fix missing SOCK_CLOEXEC in various functions that use sockets internallyRich Felker-4/+4
2013-07-04move core memalign code from aligned_alloc to __memalignRich Felker-49/+55
there are two motivations for this change. one is to avoid gratuitously depending on a C11 symbol for implementing a POSIX function. the other pertains to the documented semantics. C11 does not define any behavior for aligned_alloc when the length argument is not a multiple of the alignment argument. posix_memalign on the other hand places no requirements on the length argument. using __memalign as the implementation of both, rather than trying to implement one in terms of the other when their documented contracts differ, eliminates this confusion.
2013-07-04move alignment check from aligned_alloc to posix_memalignRich Felker-1/+2
C11 has no requirement that the alignment be a multiple of sizeof(void*), and in fact seems to require any "valid alignment supported by the implementation" to work. since the alignment of char is 1 and thus a valid alignment, an alignment argument of 1 should be accepted.
2013-07-01add stubs for additional legacy ether.h functionsRich Felker-0/+15
these would not be expensive to actually implement, but reading /etc/ethers does not sound like a particularly useful feature, so for now I'm leaving them as stubs.
2013-06-29fix failure of mbsrtowcs to record stop position when dest is fullRich Felker-1/+4
2013-06-29implement minimal dlinfo functionRich Felker-0/+20
2013-06-29add some comments about the mips ksigaction structure weirdnessRich Felker-0/+3
2013-06-29fix missing synchronization in calls from dynamic linker to global ctorsRich Felker-0/+4
this change is needed to correctly handle the case where a constructor creates a new thread which calls dlopen. previously, the lock was not held in this case. the reason for the complex logic to avoid locking whenever possible is that, since the mutex is recursive, it will need to inspect the thread pointer to get the current thread's tid, and this requires initializing the thread pointer. we do not want non-multi-threaded programs to attempt to access the thread pointer unnecessarily; doing so could make them crash on ancient kernels that don't support threads but which may otherwise be capable of running the program.
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.
2013-06-28implement week-based-year year numbers in strftimeRich Felker-27/+34
in the process, I refactored the week-number code so it can be used by the week-based-year formats to determine year adjustments at the boundary values. this also improves indention/code readability.
2013-06-28fix breakage in last commit to strftime due to missing INT_MAXRich Felker-0/+1
that's what I get for changing a hard-coded threshold to a proper non-magic-number without testing.
2013-06-28implement week numbers and half of the week-based-year logic for strftimeRich Felker-3/+38
output for plain week numbers (%U and %W) has been sanity-checked, and output for the week-based-year week numbers (%V) has been checked extensively against known-good data for the full non-negative range of 32-bit time_t. year numbers for week-based years (%g and %G) are not yet implemented.
2013-06-27disallow creation of objects larger than PTRDIFF_MAX via mmapRich Felker-0/+5
internally, other parts of the library assume sizes don't overflow ssize_t and/or ptrdiff_t, and the way this assumption is made valid is by preventing creating of such large objects. malloc already does so, but the check was missing from mmap. this is also a quality of implementation issue: even if the implementation internally could handle such objects, applications could inadvertently invoke undefined behavior by subtracting pointers within an object. it is very difficult to guard against this in applications, so a good implementation should simply ensure that it does not happen.
2013-06-26fix syscall argument bug in pthread_getschedparamRich Felker-1/+1
the address of the pointer to the sched param, rather than the pointer, was being passed to the kernel.
2013-06-26fix temp file leak in sem_open on successful creation of new semaphoreRich Felker-2/+2
2013-06-26fix bug whereby sem_open leaked its own internal slots on failureRich Felker-3/+6
2013-06-26in sem_open, don't leak vm mapping if fstat failsRich Felker-2/+2
fstat should not fail under normal circumstances, so this fix is mostly theoretical.
2013-06-26fix failure of pthread_setschedparam to pass correct param to kernelRich Felker-1/+1
the address of the pointer, rather than the pointer, was being passed. this was probably a copy-and-paste error from corresponding get code.
2013-06-26document in sysconf and unistd.h that per-thread cpu clocks existRich Felker-1/+1
2013-06-26fix iconv conversion to legacy 8bit codepagesRich Felker-2/+2
this seems to have been a simple copy-and-paste error from the code for converting from legacy codepages.
2013-06-26remove useless conditional before free from dynamic linker path codeRich Felker-1/+1
2013-06-26fix dynamic linker handling of empty path file or error reading path fileRich Felker-4/+3
previously, the path string was being used despite being invalid. with this change, empty path file or error reading the path file is treated as an empty path. this is preferable to falling back to a default path, so that attacks to prevent reading of the path file could not result in loading incorrect and possibly dangerous (outdated or mismatching ABI) libraries from. the code to strip the final newline has also been removed; now that newline is accepted as a delimiter, it's harmless to leave it in place.
2013-06-25make newline-delimited dynamic linker path file actually workRich Felker-1/+1
apparently the original commit was never tested properly, since getline was only ever reading one line. the intent was to read the entire file, so use getdelim with the null byte as delimiter as a cheap way to read a whole file into memory.
2013-06-25implement inet_lnaof, inet_netof, and inet_makeaddrRich Felker-39/+55
also move all legacy inet_* functions into a single file to avoid wasting object file and compile time overhead on them. the added functions are legacy interfaces for working with classful ipv4 network addresses. they have no modern usefulness whatsoever, but some programs unconditionally use them anyway, and they're tiny.
2013-06-25add ether_aton[_r] and ether_ntoa[_r] functionsRich Felker-0/+43
based on patch by Strake with minor stylistic changes, and combined into a single file. this patch remained open for a long time due to some question as to whether ether_aton would be better implemented in terms of sscanf, and it's time something was committed, so here it is.
2013-06-22fix scanf %c conversion wrongly storing a terminating null byteRich Felker-4/+8
this seems to have been a regression from the refactoring which added the 'm' modifier.