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* add system for resetting TLS to initial valuesRich Felker2013-08-034-14/+56
| | | | | | | | | | | | | | | this is needed for reused threads in the SIGEV_THREAD timer notification system, and could be reused elsewhere in the future if needed, though it should be refactored for such use. for static linking, __init_tls.c is simply modified to export the TLS info in a structure with external linkage, rather than using statics. this perhaps makes the code more clear, since the statics were poorly named for statics. the new __reset_tls.c is only linked if it is used. for dynamic linking, the code is in dynlink.c. sharing code with __copy_tls is not practical since __reset_tls must also re-zero thread-local bss.
* fix multiple bugs in SIGEV_THREAD timersRich Felker2013-08-036-22/+36
| | | | | | | | | | | | | | | | | | 1. the thread result field was reused for storing a kernel timer id, but would be overwritten if the application code exited or cancelled the thread. 2. low pointer values were used as the indicator that the timer id is a kernel timer id rather than a thread id. this is not portable, as mmap may return low pointers on some conditions. instead, use the fact that pointers must be aligned and kernel timer ids must be non-negative to map pointers into the negative integer space. 3. signals were not blocked until after the timer thread started, so a race condition could allow a signal handler to run in the timer thread when it's not supposed to exist. this is mainly problematic if the calling thread was the only thread where the signal was unblocked and the signal handler assumes it runs in that thread.
* fix faccessat to support AT_EACCESS flagRich Felker2013-08-031-1/+46
| | | | | | | | | | | | | | this is another case of the kernel syscall failing to support flags where it needs to, leading to horrible workarounds in userspace. this time the workaround requires changing uid/gid, and that's not safe to do in the current process. in the worst case, kernel resource limits might prevent recovering the original values, and then there would be no way to safely return. so, use the safe but horribly inefficient alternative: forking. clone is used instead of fork to suppress signals from the child. fortunately this worst-case code is only needed when effective and real ids mismatch, which mainly happens in suid programs.
* collapse euidaccess to a call to faccessatRich Felker2013-08-031-9/+1
| | | | | | it turns out Linux is buggy for faccessat, just like fchmodat: the kernel does not actually take a flags argument. so we're going to have to emulate it there.
* add legacy euidaccess function and eaccess alias for itRich Felker2013-08-031-0/+18
| | | | this is mainly for ABI compat purposes.
* make tdestroy allow null function pointer if no destructor is neededRich Felker2013-08-021-1/+1
| | | | this change is to align with a change in the glibc interface.
* fix aliasing violations in tsearch functionsRich Felker2013-08-021-2/+10
| | | | | | | patch by nsz. the actual object the caller has storing the tree root has type void *, so accessing it as struct node * is not valid. instead, simply access the value, move it to a temporary of the appropriate type and work from there, then move the result back.
* protect against long double type mismatches (mainly powerpc for now)Rich Felker2013-08-021-0/+7
| | | | | | check in configure to be polite (failing early if we're going to fail) and in vfprintf.c since that is the point at which a mismatching type would be extremely dangerous.
* add legacy function vallocRich Felker2013-08-021-0/+8
| | | | it was already declared in stdlib.h, but not defined anywhere.
* add wcsftime_t aliasRich Felker2013-08-021-0/+3
| | | | this is a nonstandard extension.
* make fchdir, fchmod, fchown, and fstat support O_PATH file descriptorsRich Felker2013-08-024-5/+37
| | | | | | | | | on newer kernels, fchdir and fstat work anyway. this same fix should be applied to any other syscalls that are similarly affected. with this change, the current definitions of O_SEARCH and O_EXEC as O_PATH are mostly conforming to POSIX requirements. the main remaining issue is that O_NOFOLLOW has different semantics.
* debloat code that depends on /proc/self/fd/%d with shared functionRich Felker2013-08-025-6/+26
| | | | | | | I intend to add more Linux workarounds that depend on using these pathnames, and some of them will be in "syscall" functions that, from an anti-bloat standpoint, should not depend on the whole snprintf framework.
* work around linux's lack of flags argument to fchmodat syscallRich Felker2013-08-021-1/+29
| | | | | | | | | | | | | | | | | | | previously, the AT_SYMLINK_NOFOLLOW flag was ignored, giving dangerously incorrect behavior -- the target of the symlink had its modes changed to the modes (usually 0777) intended for the symlink). this issue was amplified by the fact that musl provides lchmod, as a wrapper for fchmodat, which some archival programs take as a sign that symlink modes are supported and thus attempt to use. emulating AT_SYMLINK_NOFOLLOW was a difficult problem, and I originally believed it could not be solved, at least not without depending on kernels newer than 3.5.x or so where O_PATH works halfway well. however, it turns out that accessing O_PATH file descriptors via their pseudo-symlink entries in /proc/self/fd works much better than trying to use the fd directly, and works even on older kernels. moreover, the kernel has permanently pegged these references to the inode obtained by the O_PATH open, so there should not be race conditions with the file being moved, deleted, replaced, etc.
* move RPATH search after LD_LIBRARY_PATH searchRich Felker2013-08-021-2/+2
| | | | | | | | | this is the modern way, and the only way that makes any sense. glibc has this complicated mechanism with RPATH and RUNPATH that controls whether RPATH is processed before or after LD_LIBRARY_PATH, presumably to support legacy binaries, but there is no compelling reason to support this, and better behavior is obtained by just fixing the search order.
* if map_library has allocated a buffer for phdrs, free it on success tooRich Felker2013-08-021-0/+1
| | | | this fixes an oversight in the previous commit.
* improve error handling in map_library and support long phdrsRich Felker2013-08-021-12/+21
| | | | | | | previously, errno could be meaningless when the caller wrote it to the dlerror string or stderr. try to make it meaningful. also, fix incorrect check for over-long program headers and instead actually support them by allocating memory if needed.
* fix uninitialized dyn variable in map_libraryRich Felker2013-08-021-1/+1
| | | | | this can only happen for invalid library files, but they were not detected reliably because the variable was uninitialized.
* fix (deprecated) mktemp logic and update it to match other temp functionsRich Felker2013-08-021-4/+11
| | | | | | | | the access function cannot be used to check for existence, because it operates using real uid/gid rather than effective to determine accessibility; this matters for the non-final path components. instead, use stat. failure of stat is success if only the final component is missing (ENOENT) and otherwise is failure.
* remove (no longer useful) namespace-protected __mktemp symbolRich Felker2013-08-021-4/+1
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* make mkdtemp and mkstemp family leave template unchanged on failRich Felker2013-08-022-13/+18
| | | | | | also refactor mkdtemp based on new shared temp code, removing dependency on the deprecated mktemp, whose behavior made this logic more difficult.
* optimized memset asm for i386 and x86_64Rich Felker2013-08-012-0/+88
| | | | | | | | | | | | | | | | | | | | the concept of both versions is the same; they differ only in details. for long runs, they use "rep movsl" or "rep movsq", and for small runs, they use a trick, writing from both ends towards the middle, that reduces the number of branches needed. in addition, if memset is called multiple times with the same length, all branches will be predicted; there are no loops. for larger runs, there are likely faster approaches than "rep", at least on some cpu models. for 32-bit, it's unlikely that there is any faster approach that does not require non-baseline instructions; doing anything fancier would require inspecting cpu capabilities. for 64-bit, there may very well be faster versions that work on all models; further optimization could be explored in the future. with these changes, memset is anywhere between 50% faster and 6 times faster, depending on the cpu model and the length and alignment of the destination buffer.
* in pthread_getattr_np, use mremap rather than madvise to measure stackRich Felker2013-07-311-1/+2
| | | | | | | | | | | the original motivation for this patch was that qemu (and possibly other syscall emulators) nop out madvise, resulting in an infinite loop. however, there is another benefit to this change: madvise may actually undo an explicit madvise the application intended for its stack, whereas the mremap operation is a true nop. the logic here is that mremap must fail if it cannot resize the mapping in-place, and the caller knows that it cannot resize in-place because it knows the next page of virtual memory is already occupied.
* fix theoretical out-of-bound access in dynamic linkerRich Felker2013-07-311-1/+1
| | | | | | | | one of the arguments to memcmp may be shorter than the length l-3, and memcmp is under no obligation not to access past the first byte that differs. instead use strncmp which conveys the correct semantics. the performance difference is negligible here and since the code is only use for shared libc, both functions are already linked anyway.
* prevent passing PT_INTERP name to dlopen from double-loading libcRich Felker2013-07-311-6/+11
| | | | | | | | | | | | | the dev/inode for the main app and the dynamic linker ("interpreter") are not available, so the subsequent checks don't work. in general we don't want to make exact string matches to existing libraries prevent loading new ones, since this breaks loading upgraded modules in module-loading systems. so instead, special-case it. the motivation for this fix is that calling dlopen on the names returned by dl_iterate_phdr or walking the link map (obtained by dlinfo) seem to be the only methods available to an application to actually get a list of open dso handles.
* add some sanity checks in dynamic loader codeRich Felker2013-07-311-0/+10
| | | | | | | | reject elf files which are not ET_EXEC/ET_DYN type as bad exec format, and reject ET_EXEC files when they cannot be loaded at the correct address, since they are not relocatable at runtime. the main practical benefit of this is to make dlopen of the main program fail rather than producing an unsafe-to-use handle.
* fix bug where read error was treated as success reading library headersRich Felker2013-07-311-1/+1
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* don't call null pointer if DT_INIT/DT_FINI are nullRich Felker2013-07-311-2/+2
| | | | | | | | it's not clear to me why the linker even outputs these headers if they are null, but apparently it does so. with the default startfiles, they will never be null anyway, but this patch allows eliminating crti, crtn, crtbegin, and crtend (leaving only crt1) if the toolchain is using init_array/fini_array (or for a C-only, no-ctor environment).
* use separate sigaction buffers for old and new dataTimo Teräs2013-07-302-8/+8
| | | | | | in signal() it is needed since __sigaction uses restrict in parameters and sharing the buffer is technically an aliasing error. do the same for the syscall, as at least qemu-user does not handle it properly.
* add missing erfcl wrapper for archs where long double is plain doubleRich Felker2013-07-281-0/+4
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* fix semantically incorrect use of LC_GLOBAL_LOCALERich Felker2013-07-287-7/+7
| | | | | | | | | | | | | LC_GLOBAL_LOCALE refers to the global locale, controlled by setlocale, not the thread-local locale in effect which these functions should be using. neither LC_GLOBAL_LOCALE nor 0 has an argument to the *_l functions has behavior defined by the standard, but 0 is a more logical choice for requesting the callee to lookup the current locale. in the future I may move the current locale lookup the the caller (the non-_l-suffixed wrapper). at this point, all of the locale logic is dummied out, so no harm was done, but it should at least avoid misleading usage.
* fix indention-with-spacesRich Felker2013-07-271-1/+1
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* reorder strftime to eliminate the incorrect indention levelRich Felker2013-07-271-5/+5
| | | | | this change is in preparation for possibly adding support for the field width and padding specifiers added in POSIX 2008.
* a few more fixes for unistd/sysconf feature reportingRich Felker2013-07-271-7/+7
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* report presence of ADV and MSG options in unistd.h and sysconfRich Felker2013-07-261-2/+2
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* report that posix_spawn is supported in unistd.h and sysconfRich Felker2013-07-261-1/+1
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* add ABI symbols for strtol family functionsRich Felker2013-07-261-0/+8
| | | | | these odd names are actually generated by mess in glibc's stdlib.h, so any glibc-linked program using strtol needs them to run against musl.
* make ldd report the libc/dynamic linker itselfRich Felker2013-07-261-0/+22
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* fix computation of entry point and main app phdrs when invoking via ldsoRich Felker2013-07-261-3/+1
| | | | | | | | | | | entry point was wrong for PIE. e_entry was being treated as an absolute value, whereas it's actually relative to the load address (which is zero for non-PIE). phdr pointer was wrong for non-PIE. e_phoff was being treated as load-address-relative, whereas it's actually a file offset in the ELF file. in any case, map_library was already computing it correctly, and the incorrect code in __dynlink was overwriting it with junk.
* fix undefined strcpy call in inet_ntopRich Felker2013-07-251-1/+1
| | | | | source and dest arguments for strcpy cannot overlap, so memmove must be used here. the length is already known from the above loop.
* make inet_ntop format v4-mapped ipv6 addresses properlyRich Felker2013-07-251-8/+14
| | | | | | | | | | | | | | based on a patch by orc. POSIX actually fails to specify the format of the ntop conversion; presumably, any output that will correctly round-trip back via the (well-specified) pton operation is acceptable. the new behavior is much more convenient than the old, however. this patch also affects getnameinfo, which is implemented in terms of inet_ntop and which is the preferred interface for performing this conversion. I've also removed some inexplicable cruft (filling the buffer with 'x' before doing anything) whose origin I was unable to track down.
* rework langinfo code for ABI compat and for use by time codeRich Felker2013-07-244-17/+17
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* update strxfrm/wcsxfrm for future LC_COLLATE support and ABI compatRich Felker2013-07-244-14/+20
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* add ABI compat aliases for a number of locale_t functionsRich Felker2013-07-248-0/+24
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* prepare strcoll/wcscoll for LC_COLLATE support and add ABI symbolsRich Felker2013-07-244-15/+20
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* add _l versions of strtod family functions, purely as aliasesRich Felker2013-07-241-0/+8
| | | | | | | | this is a cheat since the _l versions take an extra argument, but since these functions are only here for ABI purposes, it doesn't really matter as long as the ABI matches. if the non-__-prefixed versions are eventually made public, they should proabably be real functions rather than hacks like this.
* add __wcsftime_l symbolRich Felker2013-07-241-3/+9
| | | | | | unlike the strftime commit, this one is purely an ABI compatibility issue. the previous version of the code would have worked just as well with LC_TIME once LC_TIME support is added.
* move strftime_l into strftime.c and add __-prefixed versionRich Felker2013-07-242-8/+10
| | | | | | the latter is both for ABI purposes, and to facilitate eventually adding LC_TIME support. it's also nice to eliminate an extra source file.
* make getaddrinfo with AF_UNSPEC and null host return both IPv4 and v6Rich Felker2013-07-241-14/+23
| | | | | | based on a patch by orc, with indexing and flow control cleaned up a little bit. this code is all going to be replaced at some point in the near future.
* support STB_GNU_UNIQUE symbol bindings in dynamic linkerRich Felker2013-07-241-1/+1
| | | | | | | | | these are needed for some C++ library binaries including most builds of libstdc++. I'm not entirely clear on the rationale. this patch does not implement any special semantics for them, but as far as I can tell, no special treatment is needed in correctly-linked programs; this binding seems to exist only for catching incorrectly-linked programs.
* move the dynamic linker's jmp_buf from static to automatic storageRich Felker2013-07-241-5/+7
| | | | | this more than compensates for the size increase of jmp_buf, and greatly reduces bss/data size on archs with huge jmp_buf.