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2018-02-24use idiomatic safe form for FUNLOCK macroRich Felker-1/+1
previously this macro used an odd if/else form instead of the more idiomatic do/while(0), making it unsafe against omission of trailing semicolon. the omission would make the following statement conditional instead of producing an error.
2018-02-24in vswprintf, initialize the FILE rather than memset-and-assignRich Felker-9/+8
this is the idiom that's used elsewhere and should be more efficient or at least no worse.
2018-02-24remove unused MIN macro from getdelim source fileRich Felker-2/+0
2018-02-24remove useless null check before call to free in fcloseRich Felker-1/+1
2018-02-24remove useless and confusing parentheses in stdio __towrite functionRich Felker-1/+1
they seem to be relics of e3cd6c5c265cd481db6e0c5b529855d99f0bda30 where this code was refactored from a check that previously masked against (F_ERR|F_NOWR) instead of just F_NOWR.
2018-02-24avoid use of readv syscall in __stdio_read backend when not neededRich Felker-1/+2
formally, calling readv with a zero-length first iov component should behave identically to calling read on just the second component, but presence of a zero-length iov component has triggered bugs in some kernels and performs significantly worse than a simple read on some file types.
2018-02-24consistently return number of bytes read from stdio read backendRich Felker-2/+2
the stdio FILE read backend's return type is size_t, not ssize_t, and all of the special (non-fd-backed) FILE types already return the number of bytes read (zero) on error or eof. only __stdio_read leaked a syscall error return into its return value. fread had a workaround for this behavior going all the way back to the original check-in. remove the workaround since it's no longer needed.
2018-02-24remove obfuscated flags bit-twiddling logic in __stdio_readRich Felker-1/+1
replace with simple conditional that doesn't rely on assumption that cnt is either 0 or -1.
2018-02-24fix getopt wrongly treating colons in optstring as valid option charsRich Felker-1/+1
the ':' in optstring has special meaning as a flag applying to the previous option character, or to getopt's error handling behavior when it appears at the beginning. don't also accept a "-:" option based on its presence.
2018-02-23add getentropy functionRich Felker-0/+31
based loosely on patch by Hauke Mehrtens; converted to wrap the public API of the underlying getrandom function rather than direct syscalls, so that if/when a fallback implementation of getrandom is added it will automatically get picked up by getentropy too.
2018-02-22add getrandom syscall wrapperHauke Mehrtens-0/+7
This syscall is available since Linux 3.17 and was also implemented in glibc in version 2.25 using the same interfaces.
2018-02-21convert execvp error handling to switch statementRich Felker-2/+9
this is more extensible if we need to consider additional errors, and more efficient as long as the compiler does not know it can cache the result of __errno_location (a surprisingly complex issue detailed in commit a603a75a72bb469c6be4963ed1b55fabe675fe15).
2018-02-21fix execvp failing on not-dir entries in PATH.Przemyslaw Pawelczyk-1/+1
It's better to make execvp continue PATH search on ENOTDIR rather than issuing an error. Bogus entries should not render rest of PATH invalid. Maintainer's note: POSIX seems to require the search to continue like this as part of XBD 8.3 Other Environment Variables. Only errors that conclusively determine non-existence are candidates for continuing; otherwise for consistency we have to report the error.
2018-02-11fix incorrect overflow check for allocation in fmemopenRich Felker-1/+1
when a null buffer pointer is passed to fmemopen, requesting it allocate its own memory buffer, extremely large size arguments near SIZE_MAX could overflow and result in underallocation. this results from omission of the size of the cookie structure in the overflow check but inclusion of it in the calloc call. instead of accounting for individual small contributions to the total allocation size needed, simply reject sizes larger than PTRDIFF_MAX, which will necessarily fail anyway. then adding arbitrary fixed-size structures is safe without matching up the expressions in the comparison and the allocation.
2018-02-07make getcwd fail if it cannot obtain an absolute pathDmitry V. Levin-1/+7
Currently getcwd(3) can succeed without returning an absolute path because the underlying getcwd syscall, starting with linux commit v2.6.36-rc1~96^2~2, may succeed without returning an absolute path. This is a conformance issue because "The getcwd() function shall place an absolute pathname of the current working directory in the array pointed to by buf, and return buf". Fix this by checking the path returned by syscall and failing with ENOENT if the path is not absolute. The error code is chosen for consistency with the case when the current directory is unlinked. Similar issue was fixed in glibc recently, see https://sourceware.org/bugzilla/show_bug.cgi?id=22679
2018-02-06adjust strftime + modifier to match apparent intent of POSIXRich Felker-6/+12
it's unclear from the specification whether the word "consumes" in "consumes more than four bytes to represent a year" refers just to significant places or includes leading zeros due to field width padding. however the examples in the rationale indicate that the latter was the intent. in particular, the year 270 is shown being formatted by %+5Y as +0270 rather than 00270. previously '+' prefixing was implemented just by comparing the year against 10000. instead, count the number of significant digits and padding bytes to be added, and use the total to determine whether to apply the '+' prefix. based on testing by Dennis Wölfing.
2018-02-05fix strftime field widths with %F format and zero yearRich Felker-1/+2
the code to strip initial sign and leading zeros inadvertently stripped all the zeros and the subsequent '-' separating the month. instead, only strip sign characters from the very first position, and only strip zeros when they are followed by another digit. based on testing by Dennis Wölfing.
2018-02-05document pthread structure ABI constraints in commentsRich Felker-0/+7
in the original submission of the patch that became commit 7c709f2d4f9872d1b445f760b0e68da89e256b9e, and in subsequent reading of it by others, it was not clear that the new member had to be inserted before canary_at_end, or that inserting it at that location was safe. add comments to document.
2018-02-05re-fix child reaping in wordexpAlexander Monakov-7/+1
Do not retry waitpid if the child was terminated by a signal. Do not examine status: since we are not passing any flags, we will not receive stop or continue notifications.
2018-02-05revert regression in faccessat AT_EACCESS robustnessRich Felker-21/+14
commit f9fb20b42da0e755d93de229a5a737d79a0e8f60 switched from using a pipe for the result to conveying it via the child process exit status. Alexander Monakov pointed out that the latter could fail if the application is not expecting faccessat to produce a child and performs a wait operation with __WCLONE or __WALL, and that it is not clear whether it's guaranteed to work when SIGCHLD's disposition has been set to SIG_IGN. in addition, that commit introduced a bug that caused EACCES to be produced instead of EBUSY due to an exit path that was overlooked when the error channel was changed, and introduced a spurious retry loop around the wait operation.
2018-02-03store pthread stack guard sizes for pthread_getattr_npWilliam Pitcock-1/+4
2018-01-31getopt_long: accept prefix match of long options containing equals signsSamuel Holland-1/+2
Consider the first equals sign found in the option to be the delimiter between it and its argument, even if it matches an equals sign in the option name. This avoids consuming the equals sign, which would prevent finding the argument. Instead, it forces a partial match of the part of the option name before the equals sign. Maintainer's note: GNU getopt_long does not explicitly document this behavior, but it can be seen as a consequence of how partial matches are specified, and at least GNU (bfd) ld is known to make use of it.
2018-01-31fix getopt_long arguments to partial matchesSamuel Holland-1/+3
If we find a partial option name match, we need to keep looking for ambiguous/conflicting options. However, we need to remember the position in the candidate argument to find its option-argument later, if there is one. This fixes e.g. option "foobar" being given as "--fooba=baz".
2018-01-10fix printf alt-form octal with value 0 and no explicit precisionRich Felker-2/+2
commit 78897b0dc00b7cd5c29af5e0b7eebf2396d8dce0 wrongly simplified Dmitry Levin's original submitted patch fixing alt-form octal with the zero flag and field width present, omitting the special case where the value is zero. as a result, printf("%#o",0) wrongly prints "00" rather than "0". the logic prior to this commit was actually better, in that it was aligned with how the alt-form flag (#) for printf is specified ("it shall increase the precision"). at the time there was no good way to avoid the zero flag issue with the old logic, but commit 167dfe9672c116b315e72e57a55c7769f180dffa added tracking of whether an explicit precision was provided. revert commit 78897b0dc00b7cd5c29af5e0b7eebf2396d8dce0 and switch to using the explicit precision indicator for suppressing the zero flag.
2018-01-09revise the definition of multiple basic locks in the codeJens Gustedt-16/+16
In all cases this is just a change from two volatile int to one.
2018-01-09consistently use the LOCK an UNLOCK macrosJens Gustedt-12/+12
In some places there has been a direct usage of the functions. Use the macros consistently everywhere, such that it might be easier later on to capture the fast path directly inside the macro and only have the call overhead on the slow path.
2018-01-09new lock algorithm with state and congestion count in one atomic intJens Gustedt-8/+58
A variant of this new lock algorithm has been presented at SAC'16, see https://hal.inria.fr/hal-01304108. A full version of that paper is available at https://hal.inria.fr/hal-01236734. The main motivation of this is to improve on the safety of the basic lock implementation in musl. This is achieved by squeezing a lock flag and a congestion count (= threads inside the critical section) into a single int. Thereby an unlock operation does exactly one memory transfer (a_fetch_add) and never touches the value again, but still detects if a waiter has to be woken up. This is a fix of a use-after-free bug in pthread_detach that had temporarily been patched. Therefore this patch also reverts c1e27367a9b26b9baac0f37a12349fc36567c8b6 This is also the only place where internal knowledge of the lock algorithm is used. The main price for the improved safety is a little bit larger code. Under high congestion, the scheduling behavior will be different compared to the previous algorithm. In that case, a successful put-to-sleep may appear out of order compared to the arrival in the critical section.
2017-12-18fix iconv output of surrogate pairs in ucs2Rich Felker-1/+1
in the unified code for handling utf-16 and ucs2 output, the check for ucs2 wrongly looked at the source charset rather than the destination charset.
2017-12-18add support for BOM-determined-endian UCS2, UTF-16, and UTF-32 to iconvRich Felker-3/+40
previously, the charset names without endianness specified were always interpreted as big endian. unicode specifies that UTF-16 and UTF-32 have BOM-determined endianness if BOM is present, and are otherwise big endian. since commit 5b546faa67544af395d6407553762b37e9711157 added support for stateful encodings, it is now possible to implement BOM support via the conversion descriptor state. for conversions to these charsets, the output is always big endian and does not have a BOM.
2017-12-18add cp866 (dos cyrillic) to iconvRich Felker-0/+12
2017-12-18update case mappings to unicode 10.0Rich Felker-2/+41
the mapping tables and code are not automatically generated; they were produced by comparing the output of towupper/towlower against the mappings in the UCD, ignoring characters that were previously excluded from case mappings or from alphabetic status (micro sign and circled letters), and adding table entries or code for everything else missing. based very loosely on a patch by Reini Urban.
2017-12-18update ctype tables to unicode 10.0Rich Felker-220/+305
2017-12-18reformat ctype tables to be diff-friendly, match tool outputRich Felker-263/+276
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. commit d060edf6c569ba9df4b52d6bcd93edde812869c9 made the corresponding changes to the iconv tables.
2017-12-14use the name UTC instead of GMT for UTC timezoneNatanael Copa-12/+12
notes by maintainer: both C and POSIX use the term UTC to specify related functionality, despite POSIX defining it as something more like UT1 or historical (pre-UTC) GMT without leap seconds. neither specifies the associated string for %Z. old choice of "GMT" violated principle of least surprise for users and some applications/tests. use "UTC" instead.
2017-12-14fix sysconf for infinite rlimitsNatanael Copa-0/+2
sysconf should return -1 for infinity, not LONG_MAX.
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.