about summary refs log tree commit diff
path: root/src
Commit message (Collapse)AuthorAgeFilesLines
* move aio queue allocation from io thread to submitting threadRich Felker2018-12-111-16/+21
| | | | | | | | | | | | | | | since commit c9f415d7ea2dace5bf77f6518b6afc36bb7a5732, it has been possible that the allocator is application-provided code, which cannot necessarily run safely on io thread stacks, and which should not be able to see the existence of io threads, since they are an implementation detail. instead of having the io thread request and possibly allocate its queue (and the map structures leading to it), make the submitting thread responsible for this, and pass the queue pointer into the io thread via its args structure. this eliminates the only early error case in io threads, making it no longer necessary to pass an error status back to the submitting thread via the args structure.
* fix and future-proof against stack overflow in aio io threadsRich Felker2018-12-091-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | aio threads not using SIGEV_THREAD notification are created with small stacks and no guard page, which is possible since they only run the code for the requested io operation, not any application code. the motivation is not creating a lot of VMAs. however, the io thread needs to be able to receive a cancellation signal in case aio_cancel (implemented via pthread_cancel) is called. this requires sufficient stack space for a signal frame, which PTHREAD_STACK_MIN does not necessarily include. in principle MINSIGSTKSZ from signal.h should give us sufficient space for a signal frame, but the value is incorrect on some existing archs due to kernel addition of new vector register support without consideration for impact on ABI. some powerpc models exceed MINSIGSTKSZ by about 0.5k, and x86[_64] with AVX-512 can exceed it by up to about 1.5k. so use MINSIGSTKSZ+2048 to allow for the discrepancy plus some working space. unfortunately, it's possible that signal frame sizes could continue to grow, and some archs (aarch64) explicitly specify that they may. passing of a runtime value for MINSIGSTKSZ via AT_MINSIGSTKSZ in the aux vector was added to aarch64 linux, and presumably other archs will use this mechanism to report if they further increase the signal frame size. when AT_MINSIGSTKSZ is present, assume it's correct, so that we only need a small amount of working space in addition to it; in this case just add 512.
* add namespace-safe version of getauxval for internal useRich Felker2018-12-092-1/+13
|
* fix wordexp not to read past end of string ending with lone backslashRich Felker2018-12-091-1/+1
|
* fix memccpy to not access buffer past given sizeQuentin Rameau2018-12-021-1/+1
| | | | | memccpy would return a pointer over the given size when c is not found in the source buffer and n reaches 0.
* optimize two-way strstr and memmem bad character shiftRich Felker2018-11-082-2/+2
| | | | | | | | | | | | | | | | first, the condition (mem && k < p) is redundant, because mem being nonzero implies the needle is periodic with period exactly p, in which case any byte that appears in the needle must appear in the last p bytes of the needle, bounding the shift (k) by p. second, the whole point of replacing the shift k by mem (=l-p) is to prevent shifting by less than mem when discarding the memory on shift, in which case linear time could not be guaranteed. but as written, the check also replaced shifts greater than mem by mem, reducing the benefit of the shift. there is no possible benefit to this reduction of the shift; since mem is being cleared, the full shift is valid and more optimal. so only replace the shift by mem when it would be less than mem.
* fix regression in setlocale for LC_ALL with per-category settingRich Felker2018-11-021-1/+1
| | | | | | commit d88e5dfa8b989dafff4b748bfb3cba3512c8482e inadvertently changed the argument pased to __get_locale from part (the current ;-delimited component) to name (the full string).
* fix failure to flush stderr when fflush(0) is calledRich Felker2018-11-021-1/+4
| | | | | | | | commit ddc947eda311331959c73dbc4491afcfe2326346 fixed the corresponding bug for exit which was introduced when commit 0b80a7b0404b6e49b0b724e3e3fe0ed5af3b08ef added support for caller-provided buffers, making it possible for stderr to be a buffered stream.
* fix deadlock and buffered data loss race in fcloseRich Felker2018-11-021-13/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | fflush(NULL) and __stdio_exit lock individual FILEs while holding the open file list lock to walk the list. since fclose first locked the FILE to be closed, then the ofl lock, it could deadlock with these functions. also, because fclose removed the FILE to be closed from the open file list before flushing and closing it, a concurrent fclose or exit could complete successfully before fclose flushed the FILE it was closing, resulting in data loss. reorder the body of fclose to first flush and close the file, then remove it from the open file list only after unlocking it. this creates a window where consumers of the open file list can see dead FILE objects, but in the absence of undefined behavior on the part of the application, such objects will be in an inactive-buffer state and processing them will have no side effects. __unlist_locked_file is also moved so that it's performed only for non-permanent files. this change is not necessary, but preserves consistency (and thereby provides safety/hardening) in the case where an application uses one of the standard streams after closing it while holding an explicit lock on it. such usage is of course undefined behavior.
* __libc_start_main: slightly simplify stage2 pointer setupAlexander Monakov2018-11-021-3/+4
| | | | | | Use "+r" in the asm instead of implementing a non-transparent copy by applying "0" constraint to the source value. Introduce a typedef for the function type to avoid spelling it out twice.
* remove commented-out debug printf from strstrRich Felker2018-11-021-1/+0
| | | | this was leftover from before the initial commit.
* fix spuriously slow check in twoway strstr/memmem coresRich Felker2018-11-022-2/+2
| | | | | mem0 && mem && ... is redundant since mem can only be nonzero when mem0 is nonzero.
* don't omit setting errno in internal __map_file functionRich Felker2018-10-221-2/+2
| | | | | | a caller needs the reason for open (or fstat, albeit unlikely) failure if it's going to make decisions about continuing a path search or similar.
* make the default locale (& a variant) failure-free cases for newlocaleRich Felker2018-10-221-1/+20
| | | | | | | | | | | | | | | commit aeeac9ca5490d7d90fe061ab72da446c01ddf746 introduced fail-safe invariants that creating a locale_t object for the C locale or C.UTF-8 locale will always succeed. extend the guarantee to also cover the following: - newlocale(LC_ALL_MASK, "", 0) - newlocale(LC_ALL_MASK-LC_CTYPE_MASK, "C", 0) provided that the LANG/LC_* environment variables have not been changed by the program. these usages are idiomatic for getting the default locale, and for getting a locale that behaves as the C locale except for honoring the default locale's character encoding.
* simplify newlocale and allow failure for explicit locale namesRich Felker2018-10-221-23/+14
| | | | | | | | | | | | unify the code paths for allocated and non-allocated locale objects, always using a tmp object. this is necessary to avoid clobbering the base locale object too soon if we allow for the possibility that looking up an explicitly requested locale name may fail, and makes the code simpler and cleaner anyway. eliminate the complex and fragile logic for checking whether one of the non-allocated locale objects can be used for the result, and instead just memcmp against each of them.
* remove volatile qualification from category pointers in __locale_structRich Felker2018-10-201-1/+1
| | | | | | | | | | commit 63c188ec42e76ff768e81f6b65b11c68fc43351e missed making this change when switching from atomics to locking for modification of the global locale, leaving access to locale structures unnecessarily burdened with the restrictions of volatile. the volatile qualification was originally added in commit 56fbaa3bbe73f12af2bfbbcf2adb196e6f9fe264.
* adapt setlocale to support possibility of failureRich Felker2018-10-202-12/+22
| | | | | | | introduce a new LOC_MAP_FAILED sentinel for errors, since null pointers for a category's locale map indicate the C locale. at this time, __get_locale does not fail, so there should be no functional change by this commit.
* adjust types in FILE struct to make line buffering check less expensiveRich Felker2018-10-181-4/+2
| | | | | | | | | | | | | | | | | the choice of signed char for lbf was a theoretically space-saving hack that was not helping, and was unwantedly expensive. while comparing bytes against a byte-sized member sounds easy, the trick here was that the byte to be compared was unsigned while the lbf member was signed, making it possible to set lbf negative to disable line buffering. however, this imposed a requirement to promote both operands, zero-extending one and sign-extending the other, in order to compare them. to fix this, repurpose the waiters count slot (unused since commit c21f750727515602a9e84f2a190ee8a0a2aeb2a1). while we're at it, switch mode (orientation) from signed char to int as well. this makes no semantic difference (its only possible values are -1, 0, and 1) but it might help on archs where byte access is awkward.
* optimize internal putc_unlocked macro used in putcRich Felker2018-10-181-1/+2
| | | | | | | | to check whether flush due to line buffering is needed, the int-type character argument must be truncated to unsigned char for comparison. if the original value is subsequently passed to __overflow, it must be preserved, adding to register pressure. since it doesn't matter, truncate all uses so the original value is no longer live.
* fix wrong result for putc variants due to operator precedenceRich Felker2018-10-181-1/+1
| | | | | | | the internal putc_unlocked macro was wrongly returning a meaningless boolean result rather than the written character or EOF. bug was found by reading (very surprising) asm.
* further optimize getc/putc when locking is neededRich Felker2018-10-182-10/+10
| | | | | | | | | | | | | | | check whether the lock is free before loading the calling thread's tid. if so, just use a dummy tid value that cannot compare equal to any actual thread id (because it's one bit wider). this also avoids the need to save the tid and pass it to locking_getc or locking_putc, reducing register pressure. this change might slightly hurt the case where the caller already holds the lock, but it does not affect the single-threaded case, and may significantly improve the multi-threaded case, especially on archs where loading the thread pointer is disproportionately expensive like early mips and arm ISA levels. but even on i386 it helps, at least on some machines; I measured roughly a 10-15% improvement.
* use prototype for function pointer in static link libc init barrierRich Felker2018-10-181-1/+1
| | | | | | this is not needed for correctness, but doesn't hurt, and in some cases the compiler may pessimize the call assuming the callee might be variadic when it lacks a prototype.
* fix error in constraints for static link libc init barrierRich Felker2018-10-181-1/+1
| | | | | | | commit 4390383b32250a941ec616e8bff6f568a801b1c0 inadvertently used "r" instead of "0" for the input constraint, which only happened to work for the configuration I tested it on because it usually makes sense for the compiler to choose the same input and output register.
* fix build regression due to missing file for putc changesRich Felker2018-10-181-0/+22
| | | | | commit d664061adb4d7f6647ab2059bc351daa394bf5da inadvertently omitted the new file putc.h.
* bypass indirection through pointer objects to access stdin/out/errRich Felker2018-10-184-9/+33
| | | | | | | | | | | | | | | | | by ABI, the public stdin/out/err macros use extern pointer objects, and this is necessary to avoid copy relocations that would be expensive and make the size of the FILE structure part of the ABI. however, internally it makes sense to access the underlying FILE objects directly. this avoids both an indirection through the GOT to find the address of the stdin/out/err pointer objects (which can't be computed PC-relative because they may have been moved to the main program by copy relocations) and an indirection through the resulting pointer object. in most places this is just a minor optimization, but in the case of getchar and putchar (and the unlocked versions thereof), ipa constant propagation makes all accesses to members of stdin/out PC-relative or GOT-relative, possibly reducing register pressure as well.
* optimize hot paths of putc with manual shrink-wrappingRich Felker2018-10-173-13/+8
| | | | | this is the analog of commit dd8f02b7dce53d6b1c4282439f1636a2d63bee01, but for putc.
* optimize hot paths of getc with manual shrink-wrappingRich Felker2018-10-174-15/+30
| | | | | | | | | | | | | | | | | | | | | | | | with these changes, in a program that has not created any threads besides the main thread and that has not called f[try]lockfile, getc performs indistinguishably from getc_unlocked. this was measured on several i386 and x86_64 models, and should hold on other archs too simply by the properties of the code generation. the case where the caller already holds the lock (via flockfile) is improved significantly as well (40-60% reduction in time on machines tested) and the case where locking is needed is improved somewhat (roughly 10%). the key technique used here is forcing the non-hot path out-of-line and enabling it to be a tail call. a static noinline function (conditional on __GNUC__) is used rather than the extern hiddens used elsewhere for this purpose, so that the compiler can choose non-default calling conventions, making it possible to tail-call to a callee that takes more arguments than the caller on archs where arguments are passed on the stack or must have space reserved on the stack for spilling the. the tid could just be reloaded via the thread pointer in locking_getc, but that would be ridiculously expensive on some archs where thread pointer load requires a trap or syscall.
* document and make explicit desired noinline property for __init_libcRich Felker2018-10-171-0/+6
| | | | | | | | | | | | | on multiple occasions I've started to flatten/inline the code in __init_libc, only to rediscover the reason it was not inlined: GCC fails to deallocate its stack (and now, with the changes in commit 4390383b32250a941ec616e8bff6f568a801b1c0, fails to produce a tail call to the stage 2 function; see PR #87639) before calling main if it was inlined. document this with a comment and use an explicit noinline attribute if __GNUC__ is defined so that even with CFLAGS that heavily favor inlining it won't get inlined.
* impose barrier between thread pointer setup and use for static linkingRich Felker2018-10-171-0/+13
| | | | | | | | | | | | this is the analog of commit 1c84c99913bf1cd47b866ed31e665848a0da84a2 for static linking. unlike with dynamic linking, we don't have symbolic lookup to use as a barrier. use a dummy (target-agnostic) degenerate inline asm fragment instead. this technique has precedent in commit 05ac345f895098657cf44d419b5d572161ebaf43 where it's used for explicit_bzero. if it proves problematic in any way, loading the address of the stage 2 function from a pointer object whose address leaks to kernelspace during thread pointer init could be used as an even stronger barrier.
* move stdio locking MAYBE_WAITERS definition to stdio_impl.hRich Felker2018-10-163-4/+2
| | | | don't repeat definition in two places.
* x86_64: add single instruction fmaSzabolcs Nagy2018-10-154-0/+92
| | | | | | | fma is only available on recent x86_64 cpus and it is much faster than a software fma, so this should be done with a runtime check, however that requires more changes, this patch just adds the code so it can be tested when musl is compiled with -mfma or -mfma4.
* arm: add single instruction fmaSzabolcs Nagy2018-10-152-0/+30
| | | | | | | | | | | | | | vfma is available in the vfpv4 fpu and above, the ACLE standard feature test for double precision hardware fma support is __ARM_FEATURE_FMA && __ARM_FP&8 we need further checks to work around clang bugs (fixed in clang >=7.0) && !__SOFTFP__ because __ARM_FP is defined even with -mfloat-abi=soft && !BROKEN_VFP_ASM to disable the single precision code when inline asm handling is broken. For runtime selection the HWCAP_ARM_VFPv4 hwcap flag can be used, but that requires further work.
* powerpc: add single instruction fabs, fabsf, fma, fmaf, sqrt, sqrtfSzabolcs Nagy2018-10-156-0/+90
| | | | | These are only available on hard float target and sqrt is not available in the base ISA, so further check is used.
* s390x: add single instruction fma and fmafSzabolcs Nagy2018-10-152-0/+14
| | | | These are available in the s390x baseline isa -march=z900.
* allow escaped path-separator slashes in globRich Felker2018-10-131-11/+22
| | | | | | | | | | | | | | | | | | previously (before and after rewrite), spurious escaping of path separators as \/ was not treated the same as /, but rather got split as an unpaired \ at the end of the fnmatch pattern and an unescaped /, resulting in a mismatch/error. for the case of \/ as part of the maximal literal prefix, remove the explicit rejection of it and move the handling of / below escape processing. for the case of \/ after a proper glob pattern, it's hard to parse the pattern, so don't. instead cheat and count repetitions of \ prior to the already-found / character. if there are an odd number, the last is escaping the /, so back up the split position by one. now the char clobbered by null termination is variable, so save it and restore as needed.
* rewrite core of the glob implementation for correctness & optimizationRich Felker2018-10-121-105/+112
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this code has been long overdue for a rewrite, but the immediate cause that necessitated it was total failure to see past unreadable path components. for example, A/B/* would fail to match anything, even though it should succeed, when both A and A/B are searchable but only A/B is readable. this problem both was caught in conformance testing, and impacted users. the old glob implementation insisted on searching the listing of each path component for a match, even if the next component was a literal. it also used considerable stack space, up to length of the pattern, per recursion level, and relied on an artificial bound of the pattern length by PATH_MAX, which was incorrect because a pattern can be much longer than PATH_MAX while having matches shorter (for example, with necessarily long bracket expressions, or with redundancy). in the new implementation, each level of recursion starts by consuming the maximal literal (possibly escaped-literal) path prefix remaining in the pattern, and only opening a directory to read when there is a proper glob pattern in the next path component. it then recurses into each matching entry. the top-level glob function provided automatic storage (up to PATH_MAX) for construction of candidate/result strings, and allocates a duplicate of the pattern that can be modified in-place with temporary null-termination to pass to fnmatch. this allocation is not a big deal since glob already has to perform allocation, and has to link free to clean up if it experiences an allocation failure or other error after some results have already been allocated. care is taken to use the d_type field from iterated dirents when possible; stat is called only when there are literal path components past the last proper-glob component, or when needed to disambiguate symlinks for the purpose of GLOB_MARK. one peculiarity with the new implementation is the manner in which the error handling callback will be called. if attempting to match */B/C/D where a directory A exists that is inaccessible, the error reported will be a stat error for A/B/C/D rather than (previous and wrong implementation) an opendir error for A, or (likely on other implementations) a stat error for A/B. such behavior does not seem to be non-conforming, but if it turns out to be undesirable for any reason, backtracking could be done on error to report the first component producing it. also, redundant slashes are no longer normalized, but preserved as they appear in the pattern; this is probably more correct, and falls out naturally from the algorithm used. since trailing slashes (which force all matches to be directories) are preserved as well, the behavior of GLOB_MARK has been adjusted not to append an additional slash to results that already end in slash.
* combine arch ABI's DTP_OFFSET into DTV pointersRich Felker2018-10-124-17/+17
| | | | | | | | | | | | | | | | | | | | | | as explained in commit 6ba5517a460c6c438f64d69464fdfc3269a4c91a, some archs use an offset (typicaly -0x8000) with their DTPOFF relocations, which __tls_get_addr needs to invert. on affected archs, which lack direct support for large immediates, this can cost multiple extra instructions in the hot path. instead, incorporate the DTP_OFFSET into the DTV entries. this means they are no longer valid pointers, so store them as an array of uintptr_t rather than void *; this also makes it easier to access slot 0 as a valid slot count. commit e75b16cf93ebbc1ce758d3ea6b2923e8b2457c68 left behind cruft in two places, __reset_tls and __tls_get_new, from back when it was possible to have uninitialized gap slots indicated by a null pointer in the DTV. since the concept of null pointer is no longer meaningful with an offset applied, remove this cruft. presently there are no archs with both TLSDESC and nonzero DTP_OFFSET, but the dynamic TLSDESC relocation code is also updated to apply an inverted offset to its offset field, so that the offset DTV would not impose a runtime cost in TLSDESC resolver functions.
* fix redundant computations of strlen in glob append functionRich Felker2018-10-111-2/+5
| | | | | len was already passed as an argument, so don't use strcat, and use memcpy instead of strcpy.
* fix invalid substitute of [1] for flexible array member in globRich Felker2018-10-111-2/+2
|
* fix fesetround error checkingSzabolcs Nagy2018-10-101-6/+5
| | | | Rounding modes are not bit flags, but arbitrary non-negative integers.
* fix build regression on armhf in tlsdesc asmRich Felker2018-10-091-0/+1
| | | | | | | | | | | when invoking the assembler, arm gcc does not always pass the right flags to enable use of vfp instruction mnemonics. for C code it produces, it emits the .fpu directive, but this does not help when building asm source files, which tlsdesc needs to be. to fix, use an explicit directive here. commit 0beb9dfbecad38af9759b1e83eeb007e28b70abb introduced this regression. it has not appeared in any release.
* allow freeaddrinfo of arbitrary sublists of addrinfo listRich Felker2018-10-043-8/+25
| | | | | | | | | | | | | | | | | | | | | | | the specification for freeaddrinfo allows it to be used to free "arbitrary sublists" of the list returned by getaddrinfo. it's not clearly stated how such sublists come into existence, but the interpretation seems to be that the application can edit the ai_next pointers to cut off a portion of the list and then free it. actual freeing of individual list slots is contrary to the design of our getaddrinfo implementation, which has no failure paths after making a single allocation, so that light callers can avoid linking realloc/free. freeing individual slots is also incompatible with sharing the string for ai_canonname, which the current implementation does despite no requirement that it be present except on the first result. so, rather than actually freeing individual slots, provide a way to find the start of the allocated array, and reference-count it, freeing the memory all at once after the last slot has been freed. since the language in the spec is "arbitrary sublists", no provision for handling other constructs like multiple lists glued together, circular links, etc. is made. presumably passing such a construct to freeaddrinfo produces undefined behavior.
* inline cp15 thread pointer load in arm dynamic TLSDESC asm when possibleRich Felker2018-10-011-0/+9
| | | | | | | | | | | | the indirect function call is a significant portion of the code path for the dynamic case, and most users are probably building for ISA levels where it can be omitted. we could drop at least one register save/restore (lr) with this change, and possibly another (ip) with some clever shuffling, but it's not clear whether there's a way to do it that's not more expensive, or whether avoiding the save/restore would have any practical effect, so in the interest of avoiding complexity it's omitted for now.
* add TLSDESC support for 32-bit armRich Felker2018-10-011-0/+62
| | | | | | | | | | | | | | | unlike other asm where the baseline ISA is used, these functions are hot paths and use ISA-level specializations. call-clobbered vfp registers are saved before calling __tls_get_new, since there is no guarantee it won't use them. while setjmp/longjmp have to use hwcap to decide whether to the fpu is in use, since application code could be using vfp registers even if libc was compiled as pure softfloat, __tls_get_new is part of libc and can be assumed not to have access to vfp registers if tlsdesc.S does not. thus it suffices just to check the predefined preprocessor macros. the check for __ARM_PCS_VFP is redundant; !__SOFTFP__ must always be true if the target ISA level includes fpu instructions/registers.
* fix aliasing-based undefined behavior in string functionsRich Felker2018-09-268-19/+46
| | | | | | | | | use the GNU C may_alias attribute if available, and fallback to naive byte-by-byte loops if __GNUC__ is not defined. this patch has been written to minimize changes so that history remains reviewable; it does not attempt to bring the affected code into a more consistent or elegant form.
* optimize nop case of wmemmoveRich Felker2018-09-231-0/+1
|
* fix undefined pointer comparison in wmemmoveRich Felker2018-09-231-1/+2
|
* fix undefined pointer comparison in memmoveRich Felker2018-09-231-1/+1
| | | | | | | | | | | | | | | the comparison must take place in the address space model as an integer type, since comparing pointers that are not pointing into the same array is undefined. the subsequent d<s comparison however is valid, because it's only reached in the case where the source and dest overlap, in which case they are necessarily pointing to parts of the same array. to make the comparison, use an unsigned range check for dist(s,d)>=n, algebraically !(-n<s-d<n). subtracting n yields !(-2*n<s-d-n<0), which mapped into unsigned modular arithmetic is !(-2*n<s-d-n) or rather -2*n>=s-d-n.
* new tsearch implementationSzabolcs Nagy2018-09-207-213/+200
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrote the AVL tree implementation: - It is now non-recursive with fixed stack usage (large enough for worst case tree height). twalk and tdestroy are still recursive as that's smaller/simpler. - Moved unrelated interfaces into separate translation units. - The node structure is changed to use indexed children instead of left/right pointers, this simplifies the balancing logic. - Using void * pointers instead of struct node * in various places, because this better fits the api (node address is passed in a void** argument, so it is tempting to incorrectly cast it to struct node **). - As a further performance improvement the rebalancing now stops when it is not needed (subtree height is unchanged). Otherwise the behaviour should be the same as before (checked over generated random inputs that the resulting tree shape is equivalent). - Removed the old copyright notice (including prng related one: it should be licensed under the same terms as the rest of the project). .text size of pic tsearch + tfind + tdelete + twalk: x86_64 i386 aarch64 arm mips powerpc ppc64le sh4 m68k s390x old 941 899 1220 1068 1852 1400 1600 1008 1008 1488 new 857 881 1040 976 1564 1192 1360 736 820 1408
* fix getaddrinfo regression with AI_ADDRCONFIG on some configurationsRich Felker2018-09-191-1/+10
| | | | | | | | | | | | | | | | | | | | despite not being documented to do so in the standard or Linux documentation, attempts to udp connect to 127.0.0.1 or ::1 generate EADDRNOTAVAIL when the loopback device is not configured and there is no default route for IPv6. this caused getaddrinfo with AI_ADDRCONFIG to fail with EAI_SYSTEM and EADDRNOTAVAIL on some no-IPv6 configurations, rather than the intended behavior of detecting IPv6 as unsuppported and producing IPv4-only results. previously, only EAFNOSUPPORT was treated as unavailability of the address family being probed. instead, treat all errors related to inability to get an address or route as conclusive that the family being probed is unsupported, and only fail with EAI_SYSTEM on other errors. further improvements may be desirable, such as reporting EAI_AGAIN instead of EAI_SYSTEM for errors which are expected to be transient, but this patch should suffice to fix the serious regression.
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-14 00:21:12 +0000