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* 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.
* change jmp_buf to share an underlying type and struct tag with sigjmp_bufRich Felker2013-07-242-2/+2
| | | | | | | | | | this is necessary to meet the C++ ABI target. alternatives were considered to avoid the size increase for non-sig jmp_buf objects, but they seemed to have worse properties. moreover, the relative size increase is only extreme on x86[_64]; one way of interpreting this is that, if the size increase from this patch makes jmp_buf use too much memory, then the program was already using too much memory when built for non-x86 archs.
* remove redundant check in memalignRich Felker2013-07-231-1/+1
| | | | | the case where mem was already aligned is handled earlier in the function now.
* fix heap corruption bug in memalignRich Felker2013-07-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | this bug was caught by the new footer-corruption check in realloc and free. if the block returned by malloc was already aligned to the desired alignment, memalign's logic to split off the misaligned head was incorrect; rather than writing to a point inside the allocated block, it was overwriting the footer of the previous block on the heap with the value 1 (length 0 plus an in-use flag). fortunately, the impact of this bug was fairly low. (this is probably why it was not caught sooner.) due to the way the heap works, malloc will never return a block whose previous block is free. (doing so would be harmful because it would increase fragmentation with no benefit.) the footer is actually not needed for in-use blocks, except that its in-use bit needs to remain set so that it does not get merged with free blocks, so there was no harm in it being set to 1 instead of the correct value. however, there is one case where this bug could have had an impact: in multi-threaded programs, if another thread freed the previous block after memalign's call to malloc returned, but before memalign overwrote the previous block's footer, the resulting block in the free list could be left in a corrupt state. I have not analyzed the impact of this bad state and whether it could lead to more serious malfunction.
* disable legacy init/fini processing on ARMRich Felker2013-07-221-0/+4
| | | | | | | | | | | since the old, poorly-thought-out musl approach to init/fini arrays on ARM (when it was the only arch that needed them) was to put the code in crti/crtn and have the legacy _init/_fini code run the arrays, adding proper init/fini array support caused the arrays to get processed twice on ARM. I'm not sure skipping legacy init/fini processing is the best solution to the problem, but it works, and it shouldn't break anything since the legacy init/fini system was never used for ARM EABI.
* make pthread attribute types structs, even when they just have one fieldRich Felker2013-07-2211-22/+22
| | | | | this change is to get the right tags for C++ ABI matching. it should have no other effects.
* refactor headers, especially alltypes.h, and improve C++ ABI compatRich Felker2013-07-223-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the arch-specific bits/alltypes.h.sh has been replaced with a generic alltypes.h.in and minimal arch-specific bits/alltypes.h.in. this commit is intended to have no functional changes except: - exposing additional symbols that POSIX allows but does not require - changing the C++ name mangling for some types - fixing the signedness of blksize_t on powerpc (POSIX requires signed) - fixing the limit macros for sig_atomic_t on x86_64 - making dev_t an unsigned type (ABI matching goal, and more logical) in addition, some types that were wrongly defined with long on 32-bit archs were changed to int, and vice versa; this change is non-functional except for the possibility of making pointer types mismatch, and only affects programs that were using them incorrectly, and only at build-time, not runtime. the following changes were made in the interest of moving non-arch-specific types out of the alltypes system and into the headers they're associated with, and also will tend to improve application compatibility: - netdb.h now includes netinet/in.h (for socklen_t and uint32_t) - netinet/in.h now includes sys/socket.h and inttypes.h - sys/resource.h now includes sys/time.h (for struct timeval) - sys/wait.h now includes signal.h (for siginfo_t) - langinfo.h now includes nl_types.h (for nl_item) for the types in stdint.h: - types which are of no interest to other headers were moved out of the alltypes system. - fast types for 8- and 64-bit are hard-coded (at least for now); only the 16- and 32-bit ones have reason to vary by arch. and the following types have been changed for C++ ABI purposes; - mbstate_t now has a struct tag, __mbstate_t - FILE's struct tag has been changed to _IO_FILE - DIR's struct tag has been changed to __dirstream - locale_t's struct tag has been changed to __locale_struct - pthread_t is defined as unsigned long in C++ mode only - fpos_t now has a struct tag, _G_fpos64_t - fsid_t's struct tag has been changed to __fsid_t - idtype_t has been made an enum type (also required by POSIX) - nl_catd has been changed from long to void * - siginfo_t's struct tag has been removed - sigset_t's has been given a struct tag, __sigset_t - stack_t has been given a struct tag, sigaltstack - suseconds_t has been changed to long on 32-bit archs - [u]intptr_t have been changed from long to int rank on 32-bit archs - dev_t has been made unsigned summary of tests that have been performed against these changes: - nsz's libc-test (diff -u before and after) - C++ ABI check symbol dump (diff -u before, after, glibc) - grepped for __NEED, made sure types needed are still in alltypes - built gcc 3.4.6
* remove __libc_csu_* cruftRich Felker2013-07-212-10/+0
| | | | | | | these functions were mistakenly assumed to be needed to match glibc ABI, but glibc has them as part of the non-shared part of libc that's always statically linked into the main program. moreover, the only place they are referenced from is glibc's crt1.o.
* add support for init/fini array in main program, and greatly simplifyRich Felker2013-07-214-26/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | modern (4.7.x and later) gcc uses init/fini arrays, rather than the legacy _init/_fini function pasting and crtbegin/crtend ctors/dtors system, on most or all archs. some archs had already switched a long time ago. without following this change, global ctors/dtors will cease to work under musl when building with new gcc versions. the most surprising part of this patch is that it actually reduces the size of the init code, for both static and shared libc. this is achieved by (1) unifying the handling main program and shared libraries in the dynamic linker, and (2) eliminating the glibc-inspired rube goldberg machine for passing around init and fini function pointers. to clarify, some background: the function signature for __libc_start_main was based on glibc, as part of the original goal of being able to run some glibc-linked binaries. it worked by having the crt1 code, which is linked into every application, static or dynamic, obtain and pass pointers to the init and fini functions, which __libc_start_main is then responsible for using and recording for later use, as necessary. however, in neither the static-linked nor dynamic-linked case do we actually need crt1.o's help. with dynamic linking, all the pointers are available in the _DYNAMIC block. with static linking, it's safe to simply access the _init/_fini and __init_array_start, etc. symbols directly. obviously changing the __libc_start_main function signature in an incompatible way would break both old musl-linked programs and glibc-linked programs, so let's not do that. instead, the function can just ignore the information it doesn't need. new archs need not even provide the useless args in their versions of crt1.o. existing archs should continue to provide it as long as there is an interest in having newly-linked applications be able to run on old versions of musl; at some point in the future, this support can be removed.
* fix order of fini_array execution for shared libsRich Felker2013-07-211-2/+2
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* add support for init_array/fini_array ctors/dtors to dynamic linkerRich Felker2013-07-201-2/+13
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