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* fix missing comma in sh setjmp asmTrutz Behn2015-01-301-1/+1
| | | | | | this typo did not result in an erroneous setjmp with at least binutils 2.22 but fix it for clarity and compatibility with potentially stricter sh assemblers.
* fix erroneous return of partial username matches by getspnam[_r]Rich Felker2015-01-211-1/+1
| | | | | | | | | when using /etc/shadow (rather than tcb) as its backend, getspnam_r matched any username starting with the caller-provided string rather than requiring an exact match. in practice this seems to have affected only systems where one valid username is a prefix for another valid username, and where the longer username appears first in the shadow file.
* simplify part of getopt_longRich Felker2015-01-211-13/+11
| | | | | | | as a result of commit e8e4e56a8ce1f3d7e4a027ff5478f2f8ea70c46b, the later code path for setting optarg to a null pointer is no longer necessary, and removing it eliminates an indention level and arguably makes the code more readable.
* always set optarg in getopt_longRich Felker2015-01-211-1/+1
| | | | | | | | | | | the standard getopt does not touch optarg unless processing an option with an argument. however, programs using the GNU getopt API, which we attempt to provide in getopt_long, expect optarg to be a null pointer after processing an option without an argument. before argument permutation support was added, such programs typically detected its absence and used their own replacement getopt_long, masking the discrepency in behavior.
* overhaul __synccall and fix AS-safety and other issues in set*idRich Felker2015-01-152-45/+138
| | | | | | | | | | | | | | | | | | | | | multi-threaded set*id and setrlimit use the internal __synccall function to work around the kernel's wrongful treatment of these process properties as thread-local. the old implementation of __synccall failed to be AS-safe, despite POSIX requiring setuid and setgid to be AS-safe, and was not rigorous in assuring that all threads were caught. in a worst case, threads late in the process of exiting could retain permissions after setuid reported success, in which case attacks to regain dropped permissions may have been possible under the right conditions. the new implementation of __synccall depends on the presence of /proc/self/task and will fail if it can't be opened, but is able to determine that it has caught all threads, and does not use any locks except its own. it thereby achieves AS-safety simply by blocking signals to preclude re-entry in the same thread. with this commit, all known conformance and safety issues in set*id functions should be fixed.
* add FUTEX_PRIVATE macro to internal futex.hRich Felker2015-01-151-0/+2
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* suppress EINTR in sem_wait and sem_timedwaitRich Felker2015-01-151-1/+1
| | | | | | | per POSIX, the EINTR condition is an optional error for these functions, not a mandatory one. since old kernels (pre-2.6.22) failed to honor SA_RESTART for the futex syscall, it's dangerous to trust EINTR from the kernel. thankfully POSIX offers an easy way out.
* for multithreaded set*id/setrlimit, handle case where callback does not runRich Felker2015-01-152-4/+4
| | | | | | | | in the current version of __synccall, the callback is always run, so failure to handle this case did not matter. however, the upcoming overhaul of __synccall will have failure cases, in which case the callback does not run and errno is already set. the changes being committed now are in preparation for that.
* increase syslog message limit from 256 to 1024Rich Felker2015-01-131-1/+1
| | | | | this addresses alpine linux issue #3692 and brings the syslog message length limit in alignment with uclibc's implementation.
* remove rlimit hacks from multi-threaded set*id() codeRich Felker2015-01-121-23/+15
| | | | | | | | | | | | | | | | | | | | | | | the code being removed was introduced to work around "partial failure" of multi-threaded set*id() operations, where some threads would succeed in changing their ids but an RLIMIT_NPROC setting would prevent the rest from succeeding, leaving the process in an inconsistent and dangerous state. however, the workaround code did not handle important usage cases like swapping real and effective uids then restoring their original values, and the wrongful kernel enforcement of RLIMIT_NPROC at setuid time was removed in Linux 3.1, making the workaround obsolete. since the partial failure still is dangerous on old kernels, and could in principle happen on post-fix kernels as well if set*id() syscalls fail for another spurious reason such as resource-related failures, new code is added to detect and forcibly kill the process if/when such a situation arises. future documentation releases should be updated to reflect that setting RLIMIT_NPROC to RLIM_INFINITY is necessary to avoid this forced-kill on old kernels. ideally, at some point the kernel will get proper multi-threaded set*id() syscalls capable of performing their actions atomically, and all of the userspace code to emulate them can be treated as a fallback for outdated kernels.
* simplify ctermidRich Felker2015-01-121-14/+2
| | | | | | | | | | opening /dev/tty then using ttyname_r on it does not produce a canonical terminal name; it simply yields "/dev/tty". it would be possible to make ctermid determine the actual controlling terminal device via field 7 of /proc/self/stat, but doing so would introduce a buffer overflow into applications built with L_ctermid==9, which glibc defines, adversely affecting the quality of ABI compat.
* fix regression in getopt_long support for non-option argumentsRich Felker2015-01-111-7/+6
| | | | | | | | | | | | | | | | commit b72cd07f176b876aa51864d93aa8101477b1d732 added support for a this feature in getopt, but it was later broken in the case where getopt_long is used as a side effect of the changes made in commit 91184c4f16b143107fa9935edebe5d2b20bd70d8, which prevented the underlying getopt call from seeing the leading '-' or '+' character in optstring. this commit changes the logic in the getopt_long core to check for a leading colon, possibly after the leading '-' or '+', without depending on the latter having been skipped by the caller. a minor incorrectness in the return value for one error condition in getopt_long is also fixed when opterr has been set to zero but optstring has no leading ':'.
* check for connect failure in syslog log openingRich Felker2015-01-091-2/+6
| | | | | | | based on patch by Dima Krasner, with minor improvements for code size. connect can fail if there is no listening syslogd, in which case a useless socket was kept open, preventing subsequent syslog call from attempting to connect again.
* overhaul forkpty function using new login_ttyRich Felker2014-12-211-26/+45
| | | | | | | | | | | | | | | | | based on discussion with and patches by Felix Janda. these changes started as an effort to factor forkpty in terms of login_tty, which returns an error and skips fd reassignment and closing if setting the controlling terminal failed. the previous forkpty code was unable to handle errors in the child, and did not attempt to; it just silently ignored them. but this would have been unacceptable when switching to using login_tty, since the child would start with the wrong stdin, stdout, and stderr and thereby clobber the parent's files. the new code uses the same technique as the posix_spawn implementation to convey any possible error in the child to the parent so that the parent can report failure to the caller. it is also safe against thread cancellation and against signal delivery in the child prior to the determination of success.
* block pthread cancellation in openpty functionRich Felker2014-12-201-9/+14
| | | | | | | being a nonstandard function, this isn't strictly necessary, but it's inexpensive and avoids unpleasant surprises. eventually I would like all functions in libc to be safe against cancellation, either ignoring it or acting on it cleanly.
* don't write openpty results until success is determinedRich Felker2014-12-201-10/+12
| | | | | | not only is this semantically more correct; it also reduces code size slightly by eliminating the need for the compiler to assume the possibility of aliasing.
* add login_tty functionFelix Janda2014-12-201-0/+14
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* set optopt in getopt_longRich Felker2014-12-201-0/+1
| | | | | | this is undocumented but possibly expected behavior of GNU getopt_long, and useful when error message printing has been suppressed.
* add error message printing to getopt_long and make related improvementsRich Felker2014-12-202-6/+32
| | | | | some related changes are also made to getopt, and the return value of getopt_long in the case of missing arguments is fixed.
* support translation for getopt error messagesRich Felker2014-12-201-0/+2
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* fix stderr locking and ferror semantics in getopt message printingRich Felker2014-12-191-12/+16
| | | | | | | | | | if writing the error message fails, POSIX requires that ferror(stderr) be set. and as a function that operates on a stdio stream, getopt is required to lock the stream it uses, stderr. fwrite calls are used instead of fprintf since there is a demand from some users not to pull in heavy stdio machinery via getopt. this mimics the original code using write.
* use tkill instead of tgkill in implementing raiseRich Felker2014-12-181-3/+2
| | | | | | | | | | this shaves off a useless syscall for getting the caller's pid and brings raise into alignment with other functions which were adapted to use tkill rather than tgkill. commit 83dc6eb087633abcf5608ad651d3b525ca2ec35e documents the rationale for this change, and in particular why the tgkill syscall is useless for its designed purpose of avoiding races.
* don't suppress sign output for NANs in printfRich Felker2014-12-181-1/+1
| | | | | | | | | formally, it seems a sign is only required when the '+' modifier appears in the format specifier, in which case either '+' or '-' must be present in the output. but the specification is written such that an optional negative sign is part of the output format anyway, and the simplest approach to fixing the problem is removing the code that was suppressing the sign.
* fix return value computation in one code path of wcsnrtombsRich Felker2014-12-181-1/+1
| | | | the affected code was wrongly counting characters instead of bytes.
* provide CMPLX macros in implementation-internal libm.hRich Felker2014-12-171-0/+12
| | | | | | this avoids assuming the presence of C11 macro definitions in the public complex.h, which need changes potentially incompatible with the way these macros are being used internally.
* implement FNM_CASEFOLD extension to fnmatch functionNagy Szabolcs2014-12-171-11/+25
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* add basic dns record parsing functionsRich Felker2014-12-171-0/+171
| | | | | | | | | | | | based on patch by Timo Teräs, with some corrections to bounds checking code and other minor changes. while they are borderline scope creep, the functions added are fairly small and are roughly the minimum code needed to use the results of the res_query API without re-implementing error-prone DNS packet parsing, and they are used in practice by some kerberos related software and possibly other things. at this time there is no intent to implement further nameser.h API functions.
* correctly handle write errors encountered by printf-family functionsRich Felker2014-12-172-2/+12
| | | | | | | | | | | | | | | | | | previously, write errors neither stopped further output attempts nor caused the function to return an error to the caller. this could result in silent loss of output, possibly in the middle of output in the event of a non-permanent error. the simplest solution is temporarily clearing the error flag for the target stream, then suppressing further output when the error flag is set and checking/restoring it at the end of the operation to determine the correct return value. since the wide version of the code internally calls the narrow fprintf to perform some of its underlying operations, initial clearing of the error flag is suppressed when performing a narrow vfprintf on a wide-oriented stream. this is not a problem since the behavior of narrow operations on wide-oriented streams is undefined.
* simplify getopt_long argv permutation loop logicRich Felker2014-12-131-3/+1
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* fix handling of "--" with getopt_long argv permutationRich Felker2014-12-131-1/+0
| | | | | | if argv permutation is used, the option terminator "--" should be moved before any skipped non-option arguments rather than being left in the argv tail where the caller will see and interpret it.
* accept null longopts pointer in getopt_longRich Felker2014-12-111-1/+1
| | | | | this is an undocumented feature of GNU getopt_long that the BSD version also mimics, and is reportedly needed by some programs.
* fix getopt handling of initial '+' in optstringRich Felker2014-12-101-1/+1
| | | | | | | in the case where an initial '+' was passed in optstring (a getopt_long feature to suppress argv permutation), getopt would fail to see a possible subsequent ':', resulting in incorrect handling of missing arguments.
* support abbreviated options in getopt_longRich Felker2014-12-101-7/+18
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* support options after non-option arguments in getopt_long (argv permutation)Rich Felker2014-12-101-0/+39
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* use direct syscall rather than write function in posix_spawn childRich Felker2014-12-051-1/+1
| | | | | | | | the write function is a cancellation point and accesses thread-local state belonging to the calling thread in the parent process. since cancellation is blocked for the duration of posix_spawn, this is probably safe, but it's fragile and unnecessary. making the syscall directly is just as easy and clearly safe.
* don't fail posix_spawn on failed closeRich Felker2014-12-051-2/+1
| | | | | | | the resolution of austin group issue #370 removes the requirement that posix_spawn fail when the close file action is performed on an already-closed fd. since there are no other meaningful errors for close, just ignoring the return value completely is the simplest fix.
* fix getopt handling of ':' modifier for multibyte option charactersRich Felker2014-12-041-4/+9
| | | | | | | | | the previous hard-coded offsets of +1 and +2 contained a hidden assumption that the option character matched was single-byte, despite this implementation of getopt attempting to support multibyte option characters. this patch reworks the matching logic to leave the final index pointing just past the matched character so that fixed offsets can be used to check for ':'.
* fix return value of pthread_getaffinity_np and pthread_setaffinity_npRich Felker2014-12-021-8/+11
| | | | | these functions are expected to return an error code rather than setting errno and returning -1.
* fix uninitialized output from sched_getaffinityRich Felker2014-12-021-1/+5
| | | | | | | the sched_getaffinity syscall only fills a cpu set up to the set size used/supported by the kernel. the rest is left untouched and userspace is responsible for zero-filling it based on the return value of the syscall.
* add support for non-option arguments extension to getoptGianluca Anzolin2014-12-022-4/+20
| | | | | | | this is a GNU extension, activated by including '-' as the first character of the options string, whereby non-option arguments are processed as if they were arguments to an option character '\1' rather than ending option processing.
* adapt dynamic linker for new binutils versions that omit DT_RPATHRich Felker2014-11-231-0/+2
| | | | | | | | the new DT_RUNPATH semantics for search order are always used, and since binutils had always set both DT_RPATH and DT_RUNPATH when the latter was used, processing only DT_RPATH worked fine. however, recent binutils has stopped generating DT_RPATH when DT_RUNPATH is used, which broke support for this feature completely.
* fix tabs/spaces in memcpy.sRich Felker2014-11-231-279/+279
| | | | | | this file had been a mess that went unnoticed ever since it was imported. some lines used spaces for indention while others used tabs, and tabs were used for alignment.
* fix build regression in arm asm for setjmp/longjmp with old assemblersRich Felker2014-11-232-2/+2
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* fix build regression in arm asm for memcpyRich Felker2014-11-231-30/+30
| | | | | | | | | | | | | | | | | commit 27828f7e9adb6b4f93ca56f6f98ef4c44bb5ed4e fixed compatibility with clang's internal assembler, but broke compatibility with gas and the traditional arm asm syntax by switching to the arm "unified assembler language" (UAL). recent versions of gas also support UAL, but require the .syntax directive to be used to switch to it. clang on the other hand defaults to UAL. and old versions of gas (still relevant) don't support UAL at all. for the conditional ldm/stm instructions, "ia" is default and can just be omitted, resulting in a mnemonic that's compatible with both traditional and UAL syntax. but for byte/halfword loads and stores, there seems to be no mnemonic compatible with both, and thus .word is used to produce the desired opcode explicitly. the .inst directive is not used because it is not compatible with older assemblers.
* arm assembly changes for clang compatibilityJoakim Sindholt2014-11-233-32/+32
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* unify non-inline version of syscall code across archsRich Felker2014-11-221-0/+10
| | | | | | | | | | | | | | except powerpc, which still lacks inline syscalls simply because nobody has written the code, these are all fallbacks used to work around a clang bug that probably does not exist in versions of clang that can compile musl. however, it's useful to have the generic non-inline code anyway, as it eases the task of porting to new archs: writing inline syscall code is now optional. this approach could also help support compilers which don't understand inline asm or lack support for the needed register constraints. mips could not be unified because it has special fixup code for broken layout of the kernel's struct stat.
* fix __aeabi_read_tp oversight in arm atomics/tls overhaulRich Felker2014-11-221-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | calls to __aeabi_read_tp may be generated by the compiler to access TLS on pre-v6 targets. previously, this function was hard-coded to call the kuser helper, which would crash on kernels with kuser helper removed. to fix the problem most efficiently, the definition of __aeabi_read_tp is moved so that it's an alias for the new __a_gettp. however, on v7+ targets, code to initialize the runtime choice of thread-pointer loading code is not even compiled, meaning that defining __aeabi_read_tp would have caused an immediate crash due to using the default implementation of __a_gettp with a HCF instruction. fortunately there is an elegant solution which reduces overall code size: putting the native thread-pointer loading instruction in the default code path for __a_gettp, so that separate default/native code paths are not needed. this function should never be called before __set_thread_area anyway, and if it is called early on pre-v6 hardware, the old behavior (crashing) is maintained. ideally __aeabi_read_tp would not be called at all on v7+ targets anyway -- in fact, prior to the overhaul, the same problem existed, but it was never caught by users building for v7+ with kuser disabled. however, it's possible for calls to __aeabi_read_tp to end up in a v7+ binary if some of the object files were built for pre-v7 targets, e.g. in the case of static libraries that were built separately, so this case needs to be handled.
* overhaul ARM atomics/tls for performance and compatibilityRich Felker2014-11-191-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | previously, builds for pre-armv6 targets hard-coded use of the "kuser helper" system for atomics and thread-pointer access, resulting in binaries that fail to run (crash) on systems where this functionality has been disabled (as a security/hardening measure) in the kernel. additionally, builds for armv6 hard-coded an outdated/deprecated memory barrier instruction which may require emulation (extremely slow) on future models. this overhaul replaces the behavior for all pre-armv7 builds (both of the above cases) to perform runtime detection of the appropriate mechanisms for barrier, atomic compare-and-swap, and thread pointer access. detection is based on information provided by the kernel in auxv: presence of the HWCAP_TLS bit for AT_HWCAP and the architecture version encoded in AT_PLATFORM. direct use of the instructions is preferred when possible, since probing for the existence of the kuser helper page would be difficult and would incur runtime cost. for builds targeting armv7 or later, the runtime detection code is not compiled at all, and much more efficient versions of the non-cas atomic operations are provided by using ldrex/strex directly rather than wrapping cas.
* save auxv pointer into libc struct early in dynamic linker startupRich Felker2014-11-191-0/+1
| | | | | this allows most code to assume it has already been saved, and is a prerequisite for upcoming changes for arm atomic/tls operations.
* getopt: fix optional argument processingFelix Fietkau2014-11-151-2/+2
| | | | | | | Processing an option character with optional argument fails if the option is last on the command line. This happens because the if (optind >= argc) check runs first before testing for optional argument.
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