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* 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.
* release 1.1.6 v1.1.6Rich Felker2015-01-132-1/+43
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* 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.
* add new prctl command PR_SET_MM_MAP to sys/prctl.hSzabolcs Nagy2014-12-231-0/+21
| | | | | | | | | | | | | | | | | PR_SET_MM_MAP was introduced as a subcommand for PR_SET_MM in linux v3.18 commit f606b77f1a9e362451aca8f81d8f36a3a112139e the associated struct type is replicated in sys/prctl.h using libc types. example usage: struct prctl_mm_map *p; ... prctl(PR_SET_MM, PR_SET_MM_MAP, p, sizeof *p); the kernel side supported struct size may be queried with the PR_SET_MM_MAP_SIZE subcommand.
* add new syscall numbers for bpf and kexec_file_loadSzabolcs Nagy2014-12-238-0/+20
| | | | | | | | | | | these syscalls are new in linux v3.18, bpf is present on all supported archs except sh, kexec_file_load is only allocted for x86_64 and x32 yet. bpf was added in linux commit 99c55f7d47c0dc6fc64729f37bf435abf43f4c60 kexec_file_load syscall number was allocated in commit f0895685c7fd8c938c91a9d8a6f7c11f22df58d2
* move wint_t definition to the shared part of alltypes.h.inRich Felker2014-12-2110-9/+1
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* fix signedness of UINT32_MAX and UINT64_MAX at the preprocessor levelRich Felker2014-12-211-2/+2
| | | | | | | | per the rules for hexadecimal integer constants, the previous definitions were correctly treated as having unsigned type except possibly when used in preprocessor conditionals, where all artithmetic takes place as intmax_t or uintmax_t. the explicit 'u' suffix ensures that they are treated as unsigned in all contexts.
* 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 Janda2014-12-202-0/+16
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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.
* fix signedness of WINT_MIN expressionRich Felker2014-12-171-1/+1
| | | | since wint_t is unsigned, WINT_MIN needs to expand to an unsigned zero.
* make the definition of _Complex_I explicitly complexRich Felker2014-12-171-2/+2
| | | | | | | it's unclear whether compilers which provide pure imaginary types might produce a pure imaginary expression for 1.0fi. using 0.0f+1.0fi ensures that the result is explicitly complex and makes this obvious to human readers too.
* make the result of the cimag macro a non-lvalueRich Felker2014-12-171-1/+1
| | | | | this change is not necessary but helps diagnose invalid code. based on patch by Jens Gustedt.
* fix definition of CMPLX macros in complex.h to work in constant expressionsRich Felker2014-12-171-3/+9
| | | | | | | | | | | | | | | | | based on patches by Jens Gustedt. these macros need to be usable in static initializers, and the old definitions were not. there is no portable way to provide correct definitions for these macros unless the compiler supports pure imaginary types. a portable definition is provided for this case even though there are presently no compilers that can use it. gcc and compatible compilers provide a builtin function that can be used, but clang fails to support this and instead requires a construct which is a constraint violation and which is only a constant expression as a clang-specific extension. since these macros are a namespace violation in pre-C11 profiles, and since no known pre-C11 compilers provide any way to define them correctly anyway, the definitions have been made conditional on C11.
* 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 Felker2014-12-172-35/+194
| | | | | | | | | | | | 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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* don't shadow functions with macros in C++Bobby Bingham2014-12-093-0/+6
| | | | | | | | | | C++ programmers typically expect something like "::function(x,y)" to work and may be surprised to find that "(::function)(x,y)" is actually required due to the headers declaring a macro version of some standard functions. We already omit function-like macros for C++ in most cases where there is a real function available. This commit extends this to the remaining function-like macros which have a real function version.
* 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 ':'.
* add arm private syscall numbersTimo Teräs2014-12-031-0/+5
| | | | it is part of kernel uapi, and some programs (e.g. nodejs) do use them
* 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.