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2013-08-01optimized memset asm for i386 and x86_64Rich Felker2-0/+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.
2013-08-01work around gcc 4.8's generation of self-referential mem* functions at -O3Rich Felker2-0/+13
2013-07-31in pthread_getattr_np, use mremap rather than madvise to measure stackRich Felker1-1/+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.
2013-07-31fix theoretical out-of-bound access in dynamic linkerRich Felker1-1/+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.
2013-07-31prevent passing PT_INTERP name to dlopen from double-loading libcRich Felker1-6/+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.
2013-07-31add some sanity checks in dynamic loader codeRich Felker1-0/+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.
2013-07-31fix bug where read error was treated as success reading library headersRich Felker1-1/+1
2013-07-31don't call null pointer if DT_INIT/DT_FINI are nullRich Felker1-2/+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).
2013-07-30add macros for new(ish) prctl commandsRich Felker1-0/+37
2013-07-30fix some prctl macros that were incorrectly copied into this fileRich Felker1-3/+3
2013-07-30use separate sigaction buffers for old and new dataTimo Teräs2-8/+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.
2013-07-29release notes for 0.9.12v0.9.12Rich Felker1-0/+39
2013-07-28add missing erfcl wrapper for archs where long double is plain doubleRich Felker1-0/+4
2013-07-28fix semantically incorrect use of LC_GLOBAL_LOCALERich Felker7-7/+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.
2013-07-27fix indention-with-spacesRich Felker1-1/+1
2013-07-27reorder strftime to eliminate the incorrect indention levelRich Felker1-5/+5
this change is in preparation for possibly adding support for the field width and padding specifiers added in POSIX 2008.
2013-07-27add wrapper headers, with warnings, for various incorrect names under sysRich Felker6-0/+11
also add a warning to the existing sys/poll.h. the warning is absent from sys/dir.h because it is actually providing a slightly different API to the program, and thus just replacing the #include directive is not a valid fix to programs using this one.
2013-07-27a few more fixes for unistd/sysconf feature reportingRich Felker2-7/+8
2013-07-26report presence of ADV and MSG options in unistd.h and sysconfRich Felker2-2/+4
2013-07-26report that posix_spawn is supported in unistd.h and sysconfRich Felker2-1/+2
2013-07-26add ABI symbols for strtol family functionsRich Felker1-0/+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.
2013-07-26make ldd report the libc/dynamic linker itselfRich Felker1-0/+22
2013-07-26fix computation of entry point and main app phdrs when invoking via ldsoRich Felker1-3/+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.
2013-07-26fix powerpc build breakage from dynamic linker path search changesRich Felker1-1/+1
2013-07-26new mostly-C crt1 implementationRich Felker9-0/+96
the only immediate effect of this commit is enabling PIE support on some archs that did not previously have any Scrt1.s, since the existing asm files for crt1 override this C code. so some of the crt_arch.h files committed are only there for the sake of documenting what their archs "would do" if they used the new C-based crt1. the expectation is that new archs should use this new system rather than using heavy asm for crt1. aside from being easier and less error-prone, it also ensures that PIE support is available immediately (since Scrt1.o is generated from the same C source, using -fPIC) rather than having to be added as an afterthought in the porting process.
2013-07-25fix undefined strcpy call in inet_ntopRich Felker1-1/+1
source and dest arguments for strcpy cannot overlap, so memmove must be used here. the length is already known from the above loop.
2013-07-25make inet_ntop format v4-mapped ipv6 addresses properlyRich Felker1-8/+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.
2013-07-24do not include math modules in the default -O3 optimization setRich Felker1-1/+1
it's not clear that -O3 helps them, and gcc seems to have floating point optimization bugs that introduce additional failures when -O3 is used on some of these files.
2013-07-24fix incorrect type for new si_call_addr in siginfo_tRich Felker1-3/+3
apparently the original kernel commit's i386 version of siginfo.h defined this field as unsigned int, but the asm-generic file always had void *. unsigned int is obviously not a suitable type for an address, in a non-arch-specific file, and glibc also has void * here, so I think void * is the right type for it. also fix redundant type specifiers.
2013-07-25add protocol families PF_IB and PF_VSOCK to socket.hSzabolcs Nagy1-1/+5
linux commit 8d36eb01da5d371feffa280e501377b5c450f5a5 (2013-05-29) added PF_IB for InfiniBand linux commit d021c344051af91f42c5ba9fdedc176740cbd238 (2013-02-06) added PF_VSOCK for VMware sockets
2013-07-24update siginfo according to linux headersSzabolcs Nagy1-1/+13
linux commit a0727e8ce513fe6890416da960181ceb10fbfae6 (2012-04-12) added siginfo fields for SIGSYS (seccomp uses it) linux commit ad5fa913991e9e0f122b021e882b0d50051fbdbc (2009-09-16) added siginfo field and si_code values for SIGBUS (hwpoison signal)
2013-07-24rework langinfo code for ABI compat and for use by time codeRich Felker4-17/+17
2013-07-24update strxfrm/wcsxfrm for future LC_COLLATE support and ABI compatRich Felker4-14/+20
2013-07-24add ABI compat aliases for a number of locale_t functionsRich Felker8-0/+24
2013-07-24add PTRACE_PEEKSIGINFO to ptrace.hSzabolcs Nagy1-0/+11
added in linux-v3.10 commit 84c751bd4aebbaae995fe32279d3dba48327bad4 using stdint.h types for the new ptrace_peeksiginfo_args struct
2013-07-24add if_ether.h constants ETH_P_802_3_MIN and ETH_P_BATMANSzabolcs Nagy1-0/+3
see linux commits 4f99ad51292078cc47343c17d3870764588cff73 and e5c5d22e8dcf7c2d430336cbf8e180bd38e8daf1
2013-07-24add CLOCK_TAI (and CLOCK_SGI_CYCLE) clock ids to time.hSzabolcs Nagy1-0/+2
added in linux-v3.10 commit 1ff3c9677bff7e468e0c487d0ffefe4e901d33f4
2013-07-24remove TCP_COOKIE_TRANSACTIONS from tcp.hSzabolcs Nagy1-1/+0
removed in linux-v3.10 in commit 1a2c6181c4a1922021b4d7df373bba612c3e5f04
2013-07-24add SO_SELECT_ERR_QUEUE to socket.hSzabolcs Nagy1-0/+1
introduced in linux-v3.10 commit 7d4c04fc170087119727119074e72445f2bb192b
2013-07-24prepare strcoll/wcscoll for LC_COLLATE support and add ABI symbolsRich Felker4-15/+20
2013-07-24add _l versions of strtod family functions, purely as aliasesRich Felker1-0/+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.
2013-07-24add __wcsftime_l symbolRich Felker1-3/+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.
2013-07-24move strftime_l into strftime.c and add __-prefixed versionRich Felker2-8/+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.
2013-07-24make getaddrinfo with AF_UNSPEC and null host return both IPv4 and v6Rich Felker1-14/+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.
2013-07-24support STB_GNU_UNIQUE symbol bindings in dynamic linkerRich Felker1-1/+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.
2013-07-24move the dynamic linker's jmp_buf from static to automatic storageRich Felker1-5/+7
this more than compensates for the size increase of jmp_buf, and greatly reduces bss/data size on archs with huge jmp_buf.
2013-07-24change jmp_buf to share an underlying type and struct tag with sigjmp_bufRich Felker9-15/+14
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.
2013-07-23remove redundant check in memalignRich Felker1-1/+1
the case where mem was already aligned is handled earlier in the function now.
2013-07-23fix heap corruption bug in memalignRich Felker1-1/+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.
2013-07-22enhance build process to allow selective -O3 optimizationRich Felker2-12/+57
the motivation for this patch is that the vast majority of libc is code that does not benefit at all from optimizations, but that certain components like string/memory operations can be major performance bottlenecks. at the same time, the old -falign-*=1 options are removed, since they were only beneficial for avoiding bloat when global -O3 was used, and in that case, they may have prevented some of the performance gains. to be the most useful, this patch will need further tuning. in particular, research is needed to determine which components should be built with -O3 by default, and it may be desirable to remove the hard-coded -O3 and instead allow more customization of the optimization level used for selected modules.
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