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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 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57245 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
2017-07-04unify the use of FUTEX_PRIVATEJens Gustedt-4/+4
The flag 1<<7 is used in several places for different purposes that are not always easy to distinguish. Mark those usages that correspond to the flag that is used by the kernel for futexes.
2017-07-04fix undefined behavior in freeAlexander Monakov-2/+3
2017-07-04reapply va_arg hacks removal to wprintfAlexander Monakov-26/+1
commit 58e2396a9aa23c132faf4198ca4d779c84955b38 missed that the same code was duplicated in implementation of vfwprintf.
2017-06-23powerpc64: add single-instruction math functionsRich Felker-0/+290
while the official elfv2 abi for "powerpc64le" sets power8 as the baseline isa, we use it for both little and big endian powerpc64 targets and need to maintain compatibility with pre-power8 models. the instructions for sqrt, fabs, and fma are in the baseline isa; support for the rest is conditional via predefined isa-level macros. patch by David Edelsohn.
2017-06-23s390x: add single-instruction math functionsRich Felker-0/+360
these were introduced in z196 and not available in the baseline (z900) ISA level. use __HTM__ as an alternate indicator for ISA level, since gcc did not define __ARCH__ until 7.x. patch by David Edelsohn.
2017-06-22fix arm run-time abi string functionsSzabolcs Nagy-36/+76
in arm rtabi these __aeabi_* functions have special abi (they are only allowed to clobber r0,r1,r2,r3,ip,lr,cpsr), so they cannot be simple wrappers around normal string functions (which may clobber other registers), the safest solution is to write them in asm, a minimalistic implementation works because these are not supposed to be emitted by compilers or used in general.
2017-06-21fix regression in getspnam[_r] error code for insufficient buffer sizeRich Felker-1/+1
commit 2d7d05f031e014068a61d3076c6178513395d2ae wrongly changed ERANGE to EINVAL, likely as the result of copy-and-paste error.
2017-06-20fix iconv conversions for iso88592-iso885916Bartosz Brachaczek-1/+1
commit 97bd6b09dbe7478d5a90a06ecd9e5b59389d8eb9 refactored the table lookup into a function and introduced an error in index computation. the error caused garbage to be read from the table if the given charmap had a non-zero number of elided entries.
2017-06-20handle errors from localtime_r in ctime_rRich Felker-3/+2
POSIX requires ctime_r return a null pointer on failure, which can occur if the input time_t value is not representable in broken down form. based on patch by Alexander Monakov.
2017-06-15set errno when getpw*_r, getgr*_r, and getspnam_r failRich Felker-3/+7
these functions return an error code, and are not explicitly documented to set errno, but they are nonstandard and the historical implementations do set errno as well, and some applications expect this behavior. do likewise for compatibility. patch by Rudolph Pereira.
2017-06-15handle localtime errors in ctimeRich Felker-1/+3
ctime passes the result from localtime directly to asctime. But in case of error, localtime returns 0. This causes an error (NULL pointer dereference) in asctime. based on patch by Omer Anson.
2017-06-15handle mremap failure in realloc of mmap-serviced allocationsRich Felker-1/+2
mremap seems to always fail on nommu, and on some non-Linux implementations of the Linux syscall API, it at least fails to increase allocation size, and may fail to move (i.e. defragment) the existing mapping when shrinking it too. instead of failing realloc or leaving an over-sized allocation that may waste a large amount of memory, fallback to malloc-memcpy-free if mremap fails.
2017-06-14getdate: correctly specify error numberA. Wilcox-1/+2
POSIX defines getdate error #5 as: "An I/O error is encountered while reading the template file." POSIX defines getdate error #7 as: "There is no line in the template that matches the input." This change correctly disambiguates between the two error conditions.
2017-06-14catopen: set errno to EOPNOTSUPPA. Wilcox-0/+2
Per 1003.1-2008 (2016 ed.), catopen must set errno on failure. We set errno to EOPNOTSUPP because musl does not currently support message catalogues.
2017-06-08fix glob failure to match plain "/" to root directoryRich Felker-1/+1
the check to prevent matching empty string wrongly blocked matching of "/" due to checking emptiness after stripping leading slashes rather than checking the full original argument string. simplified from patch by Julien Ramseier.
2017-06-08use hard-coded sh4a atomic opcodes to avoid linker errors on shRich Felker-4/+4
when using the sh4a opcodes, the assembler tags the resulting object file as requiring sh4a. the linker then refuses to (static) link it with object files marked as requiring j2, since there is no isa level that includes both sh4a and j2 instructions.
2017-05-31towupper/towlower: fast path for ascii charsNatanael Copa-3/+3
Make a fast path for ascii chars which is assumed to be the most common case. This has significant performance benefit on xml json and similar
2017-05-27fix fchown fallback on arches without chown(2)Samuel Holland-1/+1
The flags argument was missing, causing uninitalized data to be passed to fchownat(2). The correct value of flags should match the fallback for chown(3).
2017-05-27fix iconv conversions to legacy 8bit encodingsRich Felker-9/+12
there was missing reverse-conversion logic for the case, handled specially in the character set tables, where a byte represents a unicode codepoint with the same value. this patch adds code to handle the case, and refactors the two-level 10-bit table lookup for legacy character sets into a function to avoid repeating it yet another time as part of the fix.
2017-04-22have posix_spawnattr_setflags check for supported flagsRich Felker-0/+11
per POSIX, EINVAL is not a mandatory error, only an optional one. but reporting unsupported flags allows an application to fallback gracefully when a requested feature is not supported. this is not helpful now, but it may be in the future if additional flags are added. had this checking been present before, applications would have been able to check for the newly-added POSIX_SPAWN_SETSID feature (added in commit bb439bb17108b67f3df9c9af824d3a607b5b059d) at runtime.
2017-04-22implement new posix_spawn flag POSIX_SPAWN_SETSIDRich Felker-0/+4
this functionality has been adopted for inclusion in the next issue of POSIX as the result of Austin Group issue #1044. based on patch by Daurnimator.
2017-04-22remove va_arg hacks in printf core with undefined behaviorRich Felker-26/+1
the code being removed was written to optimize for size assuming the compiler cannot collapse code paths for different types with the same underlying representation. modern compilers sometimes succeed in making this optimization themselves, but either way it's a small size difference and not worth the source-level complexity or the UB involved in this hack. some incorrect use of va_arg still remains, particularly use of void * where the actual argument has a different pointer type. fixing this requires some actual code additions, rather than just removing cruft, so I'm leaving it to be done later as a separate commit.
2017-04-21make ttyname[_r] return ENODEV rather than ENOENTRich Felker-1/+1
commit 0a950dcf15bb9f7274c804dca490e9e20e475f3e added checking that the pathname a tty device was opened with actually matches the device, which can fail to hold when a container inherits a tty from outside the container. the error code added at the time was ENOENT; however, discussions between affected applications and glibc developers resulted in glibc adopting ENODEV as the error for this condition, and this has now been documented in the man pages project as well. adopt the same error code for consistency. patch by Christian Brauner.