path: root/src
AgeCommit message (Collapse)AuthorLines
2017-12-14fix data race in at_quick_exitRich Felker-3/+4
aside from theoretical arbitrary results due to UB, this could practically cause unbounded overflow of static array if hit, but hitting it depends on having more than 32 calls to at_quick_exit and having them sufficiently often.
2017-12-12add ibm1047 codepage (ebcdic representation of latin1) to iconvRich Felker-0/+20
2017-12-11implement strftime padding specifier extensionsTimo Teräs-8/+14
notes added by maintainer: the '-' specifier allows default padding to be suppressed, and '_' allows padding with spaces instead of the default (zeros). these extensions seem to be included in several other implementations including FreeBSD and derivatives, and Solaris. while portable software should not depend on them, time format strings are often exposed to the user for configurable time display. reportedly some python programs also use and depend on them.
2017-12-06implement the fopencookie extension to stdioWilliam Pitcock-0/+138
notes added by maintainer: this function is a GNU extension. it was chosen over the similar BSD function funopen because the latter depends on fpos_t being an arithmetic type as part of its public API, conflicting with our definition of fpos_t and with the intent that it be an opaque type. it was accepted for inclusion because, despite not being widely used, it is usually very difficult to extricate software using it from the dependency on it. calling pattern for the read and write callbacks is not likely to match glibc or other implementations, but should work with any reasonable callbacks. in particular the read function is never called without at least one byte being needed to satisfy its caller, so that spurious blocking is not introduced. contracts for what callbacks called from inside libc/stdio can do are always complicated, and at some point still need to be specified explicitly. at the very least, the callbacks must return or block indefinitely (they cannot perform nonlocal exits) and they should not make calls to stdio using their own FILE as an argument.
2017-11-20make fgetwc handling of encoding errors consistent with/without bufferRich Felker-14/+14
previously, fgetwc left all but the first byte of an illegal sequence unread (available for subsequent calls) when reading out of the FILE buffer, but dropped all bytes contibuting to the error when falling back to reading a byte at a time. neither behavior was ideal. in the buffered case, each malformed character produced one error per byte, rather than one per character. in the unbuffered case, consuming the last byte that caused the transition from "incomplete" to "invalid" state potentially dropped (and produced additional spurious encoding errors for) the next valid character. to handle both cases uniformly without duplicate code, revise the buffered case to only cover situations where a complete and valid character is present in the buffer, and fall back to byte-at-a-time for all other cases. this allows using mbtowc (stateless) instead of mbrtowc, which may slightly improve performance too. when an encoding error has been hit in the byte-at-a-time case, leave the final byte that produced the error unread (via ungetc) except in the case of single-byte errors (for UTF-8, bytes c0, c1, f5-ff, and continuation bytes with no lead byte). single-byte errors are fully consumed so as not to leave the caller in an infinite loop repeating the same error. none of these changes are distinguished from a conformance standpoint, since the file position is unspecified after encoding errors. they are intended merely as QoI/consistency improvements.
2017-11-20fix treatment by fgetws of encoding errors as eofRich Felker-1/+6
fgetwc does not set the stream's error indicator on encoding errors, making ferror insufficient to distinguish between error and eof conditions. feof is also insufficient, since it will return true if the file ended with a partial character encoding error. whether fgetwc should be setting the error indicator itself is a question with conflicting answers. the POSIX text for the function states it as a requirement, but the ISO C text seems to require that it not. this may be revisited in the future based on the outcome of Austin Group issue #1170.
2017-11-18fix fgetwc when decoding a character that crosses buffer boundarySzabolcs Nagy-0/+1
Update the buffer position according to the bytes consumed into st when decoding an incomplete character at the end of the buffer.
2017-11-14add reverse iconv mappings for JIS-based encodingsRich Felker-1/+612
these encodings are still commonly used in messaging protocols and such. the reverse mapping is implemented as a binary search of a list of the jis 0208 characters in unicode order; the existing forward table is used to perform the comparison in the search.
2017-11-13generalize iconv framework for 8-bit codepagesRich Felker-246/+273
previously, 8-bit codepages could only remap the high 128 bytes; the low range was assumed/forced to agree with ascii. interpretation of codepage table headers has been changed so that it's possible to represent mappings for up to 256 slots (fewer if the initial portion of the map is elided because it coincides with unicode codepoints). this requires consuming a bit more of the 10-bit space of characters that can be represented in 8-bit codepages, but there's still a plenty left. the size of the legacy_chars table is actually reduced now by eliding the first 256 entries and considering them to map implicitly via the identity map. before these changes, there seem to have been minor bugs/omissions in codepage table generation, so it's likely that some actual bug fixes are silently included in this commit. round-trip testing of a few codepages was performed on the new version of the code, but no differential testing against the old version was done.
2017-11-11reformat cjk iconv tables to be diff-friendly, match tool outputRich Felker-2755/+2808
the new version of the code used to generate these tables forces a newline every 256 entries, whereas at the time these files were originally generated and committed, it only wrapped them at 80 columns. the new behavior ensures that localized changes to the tables, if they are ever needed, will produce localized diffs. other tables including hkscs were already committed in the new format. binary comparison of the generated object files was performed to confirm that no spurious changes slipped in.
2017-11-10prevent fork's errno from being clobbered by atfork handlersBobby Bingham-3/+3
If the syscall fails, errno must be set correctly for the caller. There's no guarantee that the handlers registered with pthread_atfork won't clobber errno, so we need to ensure it gets set after they are called.
2017-11-10add iso-2022-jp support (decoding only) to iconvRich Felker-2/+45
this implementation aims to match the baseline defined by rfc1468 (the original mime charset definition) plus the halfwidth katakana extension included in the whatwg definition of the charset. rejection of si/so controls and newlines in doublebyte state are not currently enforced. the jis x 0201 mode is currently interpreted as having the yen sign and overline character in place of backslash and tilde; ascii mode has the standard ascii characters in those slots.
2017-11-10add iconv framework for decoding stateful encodingsRich Felker-3/+24
assuming pointers obtained from malloc have some nonzero alignment, repurpose the low bit of iconv_t as an indicator that the descriptor is a stateless value representing the source and destination character encodings.
2017-11-10simplify/optimize iconv utf-8 caseRich Felker-4/+3
the special case where mbrtowc returns 0 but consumed 1 byte of input does not need to be considered, because the short-circuit for low bytes already covered that case.
2017-11-10handle ascii range individually in each iconv caseRich Felker-2/+10
short-circuiting low bytes before the switch precluded support for character encodings that don't coincide with ascii in this range. this limitation affected iso-2022 encodings, which use the esc byte to introduce a shift sequence, and things like ebcdic.
2017-11-10move iconv_close to its own translation unitRich Felker-5/+6
this is in preparation to support stateful conversion descriptors, which are necessarily allocated and thus must be freed in iconv_close. putting it in a separate TU will avoid pulling in free if iconv_close is not referenced.
2017-11-10refactor iconv conversion descriptor encoding/decodingRich Felker-6/+20
this change is made to avoid having assumptions about the encoding spread out across the file, and to facilitate future change to a form that can accommodate allocted, stateful descriptors when needed. this commit should not produce any functional changes; with the compiler tested the only change to code generation was minor reordering of local variables on stack.
2017-11-09fix getaddrinfo error code for non-numeric service with AI_NUMERICSERVA. Wilcox-1/+1
If AI_NUMERICSERV is specified and a numeric service was not provided, POSIX mandates getaddrinfo return EAI_NONAME. EAI_SERVICE is only for services that cannot be used on the specified socket type.
2017-11-09fix mismatched type of __pthread_tsd_run_dtors weak definitionRich Felker-2/+2
commit a6054e3c94aa0491d7366e4b05ae0d73f661bfe2 changed this function not to take an argument, but the weak definition used by timer_create was not updated to match. reported by Pascal Cuoq.
2017-11-05adjust posix_spawn dup2 action behavior to match future requirementsRich Felker-8/+12
the resolution to Austin Group issue #411 defined new semantics for the posix_spawn dup2 file action in the (previously useless) case where src and dest fd are equal. future issues will require the dup2 file action to remove the close-on-exec flag. without this change, passing fds to a child with posix_spawn while avoiding fd-leak races in a multithreaded parent required a complex dance with temporary fds. based on patch by Petr Skocik. changes were made to preserve the 80-column formatting of the function and to remove code that became unreachable as a result of the new functionality.
2017-10-21fix regression in glob with literal . or .. path componentRich Felker-3/+5
commit 8c4be3e2209d2a1d3874b8bc2b474668fcbbbac6 was written to preclude the GLOB_PERIOD extension from matching these directory entries, but also precluded literal matches. adjust the check that excludes . and .. to check whether the GLOB_PERIOD flag is in effect, so that it cannot alter behavior in cases governed by the standard, and also don't exclude . or .. in any case where normal glob behavior (fnmatch's FNM_PERIOD flag) would have included one or both of them (patterns such as ".*"). it's still not clear whether this is the preferred behavior for GLOB_PERIOD, but at least it's clear that it can no longer break applications which are not relying on quirks of a nonstandard feature.
2017-10-19posix_spawn: use larger stack to cover worst-case in execvpeWill Dietz-1/+1
execvpe stack-allocates a buffer used to hold the full path (combination of a PATH entry and the program name) while searching through $PATH, so at least NAME_MAX+PATH_MAX is needed. The stack size can be made conditionally smaller (the current 1024 appears appropriate) should this larger size be burdensome in those situations.
2017-10-18in dns parsing callback, enforce MAXADDRS to preclude overflowRich Felker-0/+1
MAXADDRS was chosen not to need enforcement, but the logic used to compute it assumes the answers received match the RR types of the queries. specifically, it assumes that only one replu contains A record answers. if the replies to both the A and the AAAA query have their answer sections filled with A records, MAXADDRS can be exceeded and clobber the stack of the calling function. this bug was found and reported by Felix Wilhelm.
2017-10-13fix incorrect base name offset from nftw when pathname ends in slash(es)Rich Felker-3/+9
the rightmost '/' character is not necessarily the delimiter before the basename; it could be a spurious trailing character on the directory name. this change does not introduce any normalization of pathnames or stripping of trailing slashes, contrary to at least glibc and perhaps other implementations; it jusst prevents their presence from breaking things. whether further changes should be made is an open question that may depend on conformance and/or application compatibility considerations. based loosely on patch by Joakim Sindholt.
2017-10-13fix read-after-free type error in pthread_detachRich Felker-1/+2
calling __unlock on t->exitlock is not valid because __unlock reads the waiters count after making the atomic store that could allow pthread_exit to continue and unmap the thread's stack and the object t points to. for now, inline the __unlock logic with an unconditional futex wake operation so that the waiters count is not needed. once __lock/__unlock have been made safe for self-synchronized destruction, we could switch back to using them.
2017-10-13math: rewrite fma with mostly int arithmeticsSzabolcs Nagy-431/+154
the freebsd fma code failed to raise underflow exception in some cases in nearest rounding mode (affects fmal too) e.g. fma(-0x1p-1000, 0x1.000001p-74, 0x1p-1022) and the inexact exception may be raised spuriously since the fenv is not saved/restored around the exact multiplication algorithm (affects x86 fma too). another issue is that the underflow behaviour when the rounded result is the minimal normal number is target dependent, ieee754 allows two ways to raise underflow for inexact results: raise if the result before rounding is in the subnormal range (e.g. aarch64, arm, powerpc) or if the result after rounding with infinite exponent range is in the subnormal range (e.g. x86, mips, sh). to avoid all these issues the algorithm was rewritten with mostly int arithmetics and float arithmetics is only used to get correct rounding and raise exceptions according to the behaviour of the target without any fenv.h dependency. it also unifies x86 and non-x86 fma. fmaf is not affected, fmal need to be fixed too. this algorithm depends on a_clz_64 and it required a few spurious instructions to make sure underflow exception is raised in a particular corner case. (normally FORCE_EVAL(tiny*tiny) would be used for this, but on i386 gcc is broken if the expression is constant and there is no easy portable fix for the macro.)
2017-10-13for executing init array functions, use function type with prototypeRich Felker-1/+1
this is for consistency with the way it's done in in the dynamic linker, avoiding a deprecated C feature (non-prototype function types), and improving code generation. GCC unnecessarily uses the variadic calling convention (e.g. clearing rax on x86_64) when making a call where the argument types are not known for compatibility with wrong code which calls variadic functions this way. (C on the other hand is clear that such calls have undefined behavior.)
2017-10-13fix access by setjmp and longjmp to __hwcap on arm built as thumb2Rich Felker-0/+2
this is a subtle issue with how the assembler/linker work. for the adr pseudo-instruction used to find __hwcap, the assembler in thumb mode generates a 16-bit thumb add instruction which can only represent word-aligned addresses, despite not knowing the alignment of the label. if the setjmp function is assigned a non-multiple-of-4 address at link time, the load then loads from the wrong address (the last instruction rather than the data containing the offset) and ends up reading nonsense instead of the value of __hwcap. this in turn causes the checks for floating-point/vector register sets (e.g. IWMMX) to evaluate incorrectly, crashing when setjmp/longjmp try to save/restore those registers. fix based on bug report by Felix Hädicke.
2017-09-06work around incorrect EPERM from mmap syscallRich Felker-2/+7
under some conditions, the mmap syscall wrongly fails with EPERM instead of ENOMEM when memory is exhausted; this is probably the result of the kernel trying to fit the allocation somewhere that crosses into the kernel range or below mmap_min_addr. in any case it's a conformance bug, so work around it. for now, only handle the case of anonymous mappings with no requested address; in other cases EPERM may be a legitimate error. this indirectly fixes the possibility of malloc failing with the wrong errno value.
2017-09-06fix glob descent into . and .. with GLOB_PERIODRich Felker-0/+4
GLOB_PERIOD is a gnu extension, and GNU glob does not seem to honor it except in the last path component. it's not clear whether this a bug or intentional, but it seems reasonable that it should exclude the special entries . and .. when walking. changes based on report and analysis by Julien Ramseier.
2017-09-06don't treat numeric port strings as servent records in getservby*()Rich Felker-0/+10
some applications use getservbyport to find port numbers that are not assigned to a service; if getservbyport always succeeds with a numeric string as the result, they fail to find any available ports. POSIX doesn't seem to mandate the behavior one way or another. it specifies an abstract service database, which an implementation could define to include numeric port strings, but it makes more sense to align behavior with traditional implementations. based on patch by A. Wilcox. the original patch only changed getservbyport[_r]. to maintain a consistent view of the "service database", I have also modified getservbyname[_r] to exclude numeric port strings.
2017-09-06fix signal masking race in pthread_create with priority attributesRich Felker-2/+7
if the parent thread was able to set the new thread's priority before it reached the check for 'startlock', the new thread failed to restore its signal mask and thus ran with all signals blocked. concept for patch by Sergei, who reported the issue; unnecessary changes were removed and comments added since the whole 'startlock' thing is non-idiomatic and confusing. eventually it should be replaced with use of idiomatic synchronization primitives.
2017-09-04handle whitespace before %% in scanfBartosz Brachaczek-5/+13
this is mandated by C and POSIX standards and is in accordance with glibc behavior.
2017-09-04fix OOB reads in Xbyte_memmemAlexander Monakov-9/+9
Reported by Leah Neukirchen.
2017-09-04free allocations in clearenvAlexander Monakov-2/+6
This aligns clearenv with the Linux man page by setting 'environ' rather than '*environ' to NULL, and stops it from leaking entries allocated by the libc.
2017-09-04overhaul environment functionsAlexander Monakov-81/+86
Rewrite environment access functions to slim down code, fix bugs and avoid invoking undefined behavior. * avoid using int-typed iterators where size_t would be correct; * use strncmp instead of memcmp consistently; * tighten prologues by invoking __strchrnul; * handle NULL environ. putenv: * handle "=value" input via unsetenv too (will return -1/EINVAL); * rewrite and simplify __putenv; fix the leak caused by failure to deallocate entry added by preceding setenv when called from putenv. setenv: * move management of libc-allocated entries to this translation unit, and use no-op weak symbols in putenv/unsetenv; unsetenv: * rewrite; this fixes UB caused by testing a free'd pointer against NULL on entry to subsequent loops. Not changed: Failure to extend allocation tracking array (previously __env_map, now env_alloced) is ignored rather than causing to report -1/ENOMEM to the caller; the worst-case consequence is leaking this allocation when it is removed or replaced in a subsequent environment access. Initially UB in unsetenv was reported by Alexander Cherepanov. Using a weak alias to avoid pulling in malloc via unsetenv was suggested by Rich Felker.
2017-09-01fix erroneous acceptance of f4 9x xx xx code sequences by utf-8 decoderRich Felker-1/+1
the DFA table controlling accepted ranges for the f4 prefix used an incorrect upper bound of 0xa0 where it should have been 0x90, allowing such sequences to be accepted and decoded as non-Unicode-scalar values 0x110000 through 0x11ffff.
2017-08-31fix erroneous stop before input limit in mbsnrtowcs and wcsnrtombsRich Felker-2/+6
the value computed as an output limit that bounds the amount of input consumed below the input limit was incorrectly being used as the actual amount of input consumed. instead, compute the actual amount of input consumed as a difference of pointers before and after the conversion. patch by Mikhail Kremnyov.
2017-08-29add a_clz_64 helper functionSzabolcs Nagy-0/+21
counts leading zero bits of a 64bit int, undefined on zero input. (has nothing to do with atomics, added to atomic.h so target specific helper functions are together.) there is a logarithmic generic implementation and another in terms of a 32bit a_clz_32 on targets where that's available.
2017-08-29fix undefined behavior in memset due to missing sequence pointsRich Felker-4/+8
patch by Pascal Cuoq.
2017-08-29__init_libc: add fallbacks for __progname setupAlexander Monakov-4/+4
It is possible for argv[0] to be a null pointer, but the __progname variable is used to implement functions in src/legacy/err.c that do not expect it to be null. It is also available to the user via the program_invocation_name alias as a GNU extension, and the implementation in Glibc initializes it to a pointer to empty string rather than NULL. Since argv[0] is usually non-null and it's preferable to keep those variables in BSS, implement the fallbacks in __init_libc, which also allows to have an intermediate fallback to AT_EXECFN.
2017-08-29fix unsynchronized access to FILE structure in fflush(0)Rich Felker-1/+4
commit c002668eb0352e619ea7064e4940b397b4a6e68d inadvertently moved the check for unflushed write buffer outside of the scope of the existing lock.
2017-08-12fix signed overflow in ftokDaniel Sabogal-1/+1
2017-08-11trap UB from attempts to join a detached threadRich Felker-0/+1
passing to pthread_join the id of a thread which is not joinable results in undefined behavior. in principle the check to trap does not necessarily work if pthread_detach was called after thread creation, since no effort is made here to synchronize access to t->detached, but the check is well-defined and harmless for callers which did not invoke UB, and likely to help catch erroneous code that would otherwise mysteriously hang. patch by William Pitcock.
2017-08-11ppc64: fix setjmp/longjmp handling of TOC pointerBobby Bingham-17/+39
The TOC pointer is constant within a single dso, but needs to be saved and restored around cross-dso calls. The PLT stub saves it to the caller's stack frame, and the linker adds code to the caller to restore it. With a local call, as within a single dso or with static linking, this doesn't happen and the TOC pointer is always in r2. Therefore, setjmp/longjmp need to save/restore the TOC pointer from/to different locations depending on whether the call to setjmp was a local or non-local call. It is always safe for longjmp to restore to both r2 and the caller's stack. If the call to setjmp was local, and only r2 matters and the stack location will be ignored, but is required by the ABI to be reserved for the TOC pointer. If the call was non-local, then only the stack location matters, and whatever is restored into r2 will be clobbered anyway when the caller reloads r2 from the stack. A little extra care is required for sigsetjmp, because it uses setjmp internally. After the second return from this setjmp call, r2 will contain the caller's TOC pointer instead of libc's TOC pointer. We need to save and restore the correct libc pointer before we can tail call to __sigsetjmp_tail.
2017-08-11qsort: add a short comment about the algorithmLeah Neukirchen-0/+3
2017-07-31add _NL_LOCALE_NAME extension to nl_langinfoRich Felker-0/+4
since setlocale(cat, NULL) is required to return the setting for the global locale, there is no standard mechanism to obtain the name of the currently active thread-local locale set by uselocale. this makes it impossible for application/library software to load appropriate translations, etc. unless using the gettext implementation provided by libc, which has privileged access to libc internals. to fill this gap, glibc introduced the _NL_LOCALE_NAME macro which can be used with nl_langinfo to obtain the name. GNU gettext/gnulib code already use this functionality on glibc, and can easily be adapted to make use of it on non-glibc systems if it's available; for other systems they poke at locale implementation internals, which we want to avoid. this patch provides a compatible interface to the one glibc introduced.
2017-07-04fix missing volatile qualifier on lock in __get_localeJens Gustedt-1/+1
2017-07-04remove ineffective compiler assist from printfAlexander Monakov-4/+0
The switch statement has no 'default:' case and the function ends immediately following the switch, so the extra comparison did not communicate any extra information to the compiler.
2017-07-04fix undefined behavior in ptraceAlexander Monakov-2/+6