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* remove a_ctz_l from arch specific atomic_arch.hAndre McCurdy2018-04-191-19/+23
| | | | | | | | Update atomic.h to provide a_ctz_l in all cases (atomic_arch.h should now only provide a_ctz_32 and/or a_ctz_64). The generic version of a_ctz_32 now takes advantage of a_clz_32 if available and the generic a_ctz_64 now makes use of a_ctz_32.
* fix out of bounds write for zero length buffer in gethostnameMarc André Tanner2018-04-191-1/+1
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* add support for caller-provided buffers to setvbufRich Felker2018-04-181-11/+14
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* clean up allocation/setup logic for open_[w]memstreamRich Felker2018-04-182-38/+50
| | | | | bring these functions up to date with the current idioms we use/prefer in fmemopen and fopencookie.
* clean up allocation/setup logic for fmemopenRich Felker2018-04-181-21/+31
| | | | | | rather than manually performing pointer arithmetic to carve multiple objects out of one allocation, use a containing struct that encompasses them all.
* minor cleanup in fopencookieRich Felker2018-04-181-5/+2
| | | | | assign entire struct rather than member-at-a-time. don't repeat buffer sizes; always use sizeof to ensure consistency.
* allow interposition/replacement of allocator (malloc)Rich Felker2018-04-184-23/+30
| | | | | | | | | | | | | | | | | | | | | | | replacement is subject to conditions on the replacement functions. they may only call functions which are async-signal-safe, as specified either by POSIX or as an implementation-defined extension. if any allocator functions are replaced, at least malloc, realloc, and free must be provided. if calloc is not provided, it will behave as malloc+memset. any of the memalign-family functions not provided will fail with ENOMEM. in order to implement the above properties, calloc and __memalign check that they are using their own malloc or free, respectively. choice to check malloc or free is based on considerations of supporting __simple_malloc. in order to make this work, calloc is split into separate versions for __simple_malloc and full malloc; commit ba819787ee93ceae94efd274f7849e317c1bff58 already did most of the split anyway, and completing it saves an extra call frame. previously, use of -Bsymbolic-functions made dynamic interposition impossible. now, we are using an explicit dynamic-list, so add allocator functions to the list. most are not referenced anyway, but all are added for completeness.
* refactor flockfile not to duplicate lock mechanism logicRich Felker2018-04-182-12/+14
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* fix stdio lock dependency on read-after-free not faultingRich Felker2018-04-183-20/+24
| | | | | | | instead of using a waiters count, add a bit to the lock field indicating that the lock may have waiters. threads which obtain the lock after contending for it will perform a potentially-spurious wake when they release the lock.
* remove unused __brk function/source fileRich Felker2018-04-171-7/+0
| | | | | commit e3bc22f1eff87b8f029a6ab31f1a269d69e4b053 removed all references to __brk.
* comment __malloc_donate overflow logicRich Felker2018-04-171-0/+3
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* ldso, malloc: implement reclaim_gaps via __malloc_donateAlexander Monakov2018-04-171-18/+43
| | | | | Split 'free' into unmap_chunk and bin_chunk, use the latter to introduce __malloc_donate and use it in reclaim_gaps instead of calling 'free'.
* malloc: fix an over-allocation bugAlexander Monakov2018-04-171-4/+4
| | | | | Fix an instance where realloc code would overallocate by OVERHEAD bytes amount. Manually arrange for reuse of memcpy-free-return exit sequence.
* fix return value of nice functionRich Felker2018-04-171-5/+9
| | | | | | | the Linux SYS_nice syscall is unusable because it does not return the newly set priority. always use SYS_setpriority. also avoid overflows in addition of inc by handling large inc values directly without examining the old nice value.
* optimize malloc0Alexander Monakov2018-04-111-6/+23
| | | | | | | | | | | | | Implementation of __malloc0 in malloc.c takes care to preserve zero pages by overwriting only non-zero data. However, malloc must have already modified auxiliary heap data just before and beyond the allocated region, so we know that edge pages need not be preserved. For allocations smaller than one page, pass them immediately to memset. Otherwise, use memset to handle partial pages at the head and tail of the allocation, and scan complete pages in the interior. Optimize the scanning loop by processing 16 bytes per iteration and handling rest of page via memset as soon as a non-zero byte is found.
* fix incorrect results for catan with some inputsRich Felker2018-04-111-13/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the catan implementation from OpenBSD includes a FIXME-annotated "overflow" branch that produces a meaningless and incorrect large-magnitude result. it was reachable via three paths, corresponding to gotos removed by this commit, in order: 1. pure imaginary argument with imaginary component greater than 1 in magnitude. this case does not seem at all exceptional and is handled (at least with the quality currently expected from our complex math functions) by the existing non-exceptional code path. 2. arguments on the unit circle, including the pure-real argument 1.0. these are not exceptional except for ±i, which should produce results with infinite imaginary component and which lead to computation of atan2(±0,0) in the existing non-exceptional code path. such calls to atan2() however are well-defined by POSIX. 3. the specific argument +i. this route should be unreachable due to the above (2), but subtle rounding effects might have made it possible in rare cases. continuing on the non-exceptional code path in this case would lead to computing the (real) log of an infinite argument, then producing a NAN when multiplying it by I. for now, remove the exceptional code paths entirely. replace the multiplication by I with construction of a complex number using the CMPLX macro so that the NAN issue (3) prevented cannot arise. with these changes, catan should give reasonably correct results for real arguments, and should no longer give completely-wrong results for pure-imaginary arguments outside the interval (-i,+i).
* fix wrong result in casin and many related complex functionsRich Felker2018-04-093-3/+6
| | | | | | | | | | | the factor of -i noted in the comment at the top of casin.c was omitted from the actual code, yielding a result rotated 90 degrees and propagating into errors in other functions defined in terms of casin. implement multiplication by -i as a rotation of the real and imaginary parts of the result, rather than by actual multiplication, since the latter cannot be optimized without knowledge that the operand is finite. here, the rotation is the actual intent, anyway.
* implement wcsftime padding specifier extensionsSamuel Holland2018-04-071-3/+5
| | | | | | | | | | | | | | Commit 8a6bd7307da3fc4d08dd6a9277b611ccb4971354 added support for padding specifier extensions to strftime, but did not modify wcsftime. In the process, it added a parameter to __strftime_fmt_1 in strftime.c, but failed to update the prototype in wcsftime.c. This was found by compiling musl with LTO: src/time/wcsftime.c:7:13: warning: type of '__strftime_fmt_1' does \ not match original declaration [-Wlto-type-mismatch] Fix the prototype of __strftime_fmt_1 in wcsftime.c, and generate the 'pad' argument the same way as it is done in strftime.
* prevent bypass of guarantee that suids start with fd 0/1/2 openRich Felker2018-04-051-0/+2
| | | | | | | | | | | | | | | it was reported by Erik Bosman that poll fails without setting revents when the nfds argument exceeds the current value for RLIMIT_NOFILE, causing the subsequent open calls to be bypassed. if the rlimit is either 1 or 2, this leaves fd 0 and 1 potentially closed but openable when the application code is reached. based on a brief reading of the poll syscall documentation and code, it may be possible for poll to fail under other attacker-controlled conditions as well. if it turns out these are reasonable conditions that may happen in the real world, we may have to go back and implement fallbacks to probe each fd individually if poll fails, but for now, keep things simple and treat all poll failures as fatal.
* fix fmaf wrong resultSzabolcs Nagy2018-04-021-1/+1
| | | | | | | | | | | | | if double precision r=x*y+z is not a half way case between two single precision floats or it is an exact result then fmaf returns (float)r. however the exactness check was wrong when |x*y| < |z| and could cause incorrectly rounded result in nearest rounding mode when r is a half way case. fmaf(-0x1.26524ep-54, -0x1.cb7868p+11, 0x1.d10f5ep-29) was incorrectly rounded up to 0x1.d117ap-29 instead of 0x1.d1179ep-29. (exact result is 0x1.d1179efffffffecp-29, r is 0x1.d1179fp-29)
* fix nl_langinfo_l(CODESET, loc) reporting wrong locale's valueRich Felker2018-03-071-1/+1
| | | | | | use of MB_CUR_MAX encoded a hidden dependency on the currently active locale for the calling thread, whereas nl_langinfo_l is supposed to report for the locale passed as an argument.
* add public interface headers to implementation filesRich Felker2018-02-256-0/+11
| | | | | | | | | general policy is that all source files defining a public API or an ABI mechanism referenced by a public header should include the public header that declares the interface, so that the compiler or analysis tools can check the consistency of the declarations. Alexander Monakov pointed out a number of violations of this principle a few years back. fix them now.
* fix aliasing violations in fgetpos/fsetposRich Felker2018-02-242-2/+2
| | | | | | | | | | | | | add a member of appropriate type to the fpos_t union so that accesses are well-defined. use long long instead of off_t since off_t is not always exposed in stdio.h and there's no namespace-clean alias for it. access is still performed using pointer casts rather than by naming the union member as a matter of style; to the extent possible, the naming of fields in opaque types defined in the public headers is not treated as an API contract with the implementation. access via the pointer cast is valid as long as the union has a member of matching type.
* use idiomatic safe form for FUNLOCK macroRich Felker2018-02-241-1/+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.
* in vswprintf, initialize the FILE rather than memset-and-assignRich Felker2018-02-241-9/+8
| | | | | this is the idiom that's used elsewhere and should be more efficient or at least no worse.
* remove unused MIN macro from getdelim source fileRich Felker2018-02-241-2/+0
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* remove useless null check before call to free in fcloseRich Felker2018-02-241-1/+1
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* remove useless and confusing parentheses in stdio __towrite functionRich Felker2018-02-241-1/+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.
* avoid use of readv syscall in __stdio_read backend when not neededRich Felker2018-02-241-1/+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.
* consistently return number of bytes read from stdio read backendRich Felker2018-02-242-2/+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.
* remove obfuscated flags bit-twiddling logic in __stdio_readRich Felker2018-02-241-1/+1
| | | | | replace with simple conditional that doesn't rely on assumption that cnt is either 0 or -1.
* fix getopt wrongly treating colons in optstring as valid option charsRich Felker2018-02-241-1/+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.
* add getentropy functionRich Felker2018-02-231-0/+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.
* add getrandom syscall wrapperHauke Mehrtens2018-02-221-0/+7
| | | | | This syscall is available since Linux 3.17 and was also implemented in glibc in version 2.25 using the same interfaces.
* convert execvp error handling to switch statementRich Felker2018-02-211-2/+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).
* fix execvp failing on not-dir entries in PATH.Przemyslaw Pawelczyk2018-02-211-1/+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.
* fix incorrect overflow check for allocation in fmemopenRich Felker2018-02-111-1/+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.
* make getcwd fail if it cannot obtain an absolute pathDmitry V. Levin2018-02-071-1/+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
* adjust strftime + modifier to match apparent intent of POSIXRich Felker2018-02-061-6/+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.
* fix strftime field widths with %F format and zero yearRich Felker2018-02-051-1/+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.
* document pthread structure ABI constraints in commentsRich Felker2018-02-051-0/+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.
* re-fix child reaping in wordexpAlexander Monakov2018-02-051-7/+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.
* revert regression in faccessat AT_EACCESS robustnessRich Felker2018-02-051-21/+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.
* store pthread stack guard sizes for pthread_getattr_npWilliam Pitcock2018-02-033-1/+4
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* getopt_long: accept prefix match of long options containing equals signsSamuel Holland2018-01-311-1/+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.
* fix getopt_long arguments to partial matchesSamuel Holland2018-01-311-1/+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".
* fix printf alt-form octal with value 0 and no explicit precisionRich Felker2018-01-101-2/+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.
* revise the definition of multiple basic locks in the codeJens Gustedt2018-01-0915-16/+16
| | | | In all cases this is just a change from two volatile int to one.
* consistently use the LOCK an UNLOCK macrosJens Gustedt2018-01-096-12/+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.
* new lock algorithm with state and congestion count in one atomic intJens Gustedt2018-01-093-8/+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.
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