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* implement fail-safe static locales for newlocaleRich Felker2015-05-273-13/+46
| | | | | | | | this frees applications which need to make temporary use of the C locale (via uselocale) from the possibility that newlocale might fail. the C.UTF-8 locale is also provided as a static locale. presently they behave the same, but this may change in the future.
* rename internal locale file handling locale mapsRich Felker2015-05-271-0/+0
| | | | | since the __setlocalecat function was removed, the filename __setlocalecat.c no longer made sense.
* overhaul locale internals to treat categories roughly uniformlyRich Felker2015-05-278-136/+112
| | | | | | | | | | | | | | | | | | | | previously, LC_MESSAGES was treated specially as the only category which could be set to a locale name without a definition file, in order to facilitate gettext message translations when no libc locale was available. LC_NUMERIC was completely un-settable, and LC_CTYPE stored a flag intended to be used for a possible future byte-based C locale, instead of storing a __locale_map pointer like the other categories use. this patch changes all categories to be represented by pointers to __locale_map structures, and allows locale names without definition files to be treated as valid locales with trivial definition when used in any category. outwardly visible functional changes should be minor, limited mainly to the strings read back from setlocale and the way gettext handles translations in categories other than LC_MESSAGES. various internal refactoring has also been performed, and improvements in const correctness have been made.
* replace atomics with locks in locale-setting codeRich Felker2015-05-272-32/+51
| | | | | | | | | this is part of a general program of removing direct use of atomics where they are not necessary to meet correctness or performance needs, but in this case it's also an optimization. only the global locale needs synchronization; allocated locales referenced with locale_t handles are immutable during their lifetimes, and using atomics to initialize them increases their cost of setup.
* reprocess all libc/ldso symbolic relocations in dynamic linking stage 3Rich Felker2015-05-251-11/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f3ddd173806fd5c60b3f034528ca24542aecc5b9 introduced early relocations and subsequent reprocessing as part of the dynamic linker bootstrap overhaul, to allow use of arbitrary libc functions before the main application and libraries are loaded, but only reprocessed GOT/PLT relocation types. commit c093e2e8201524db0d638920e76bcb6b1d925f3a added reprocessing of non-GOT/PLT relocations to fix an actual regression that was observed on powerpc, but only for RELA format tables with out-of-line addends. REL table (inline addends at the relocation address) reprocessing is trickier because the first relocation pass clobbers the addends. this patch extends symbolic relocation reprocessing for libc/ldso to support all relocation types, whether REL or RELA format tables are used. it is believed not to alter behavior on any existing archs for the current dynamic linker and libc code. the motivations for this change are consistency and future-proofing. it ensures that behavior does not differ depending on whether REL or RELA tables are used, which could lead to undetected arch-specific bugs. it also ensures that, if in the future code depending on additional relocation types is added to libc.so, either at the source level or as part of the compiler runtime that gets pulled in (for example, soft-float with TLS for fenv), the new code will work properly. the implementation concept is simple: stage 2 of the dynamic linker counts the number of symbolic relocations in the libc/ldso REL table and allocates a VLA to save their addends into; stage 3 then uses the saved addends in place of the inline ones which were clobbered. for stack safety, a hard limit (currently 4k) is imposed on the number of such addends; this should be a couple orders of magnitude larger than the actual need. this number is not a runtime variable that could break fail-safety; it is constant for a given libc.so build.
* move call to dynamic linker stage-3 into stage-2 functionRich Felker2015-05-253-12/+9
| | | | | | | | | this move eliminates a duplicate "by-hand" symbol lookup loop from the stage-1 code and replaces it with a call to find_sym, which can be used once we're in stage 2. it reduces the size of the stage 1 code, which is helpful because stage 1 will become the crt start file for static-PIE executables, and it will allow stage 3 to access stage 2's automatic storage, which will be important in an upcoming commit.
* mark mips cancellable syscall code as codeRich Felker2015-05-251-0/+3
| | | | otherwise disassemblers treat it as data.
* simplify/shrink relocation processing in dynamic linker stage 1Rich Felker2015-05-251-24/+16
| | | | | | | | | the outer-loop approach made sense when we were also processing DT_JMPREL, which might be in REL or RELA form, to avoid major code duplication. commit 09db855b35709aa627d7055c57a98e1e471920ab removed processing of DT_JMPREL, and in the remaining two tables, the format (REL or RELA) is known by the name of the table. simply writing two versions of the loop results in smaller and simpler code.
* remove processing of DT_JMPREL from dynamic linker stage 1 bootstrapRich Felker2015-05-251-1/+0
| | | | | | | the DT_JMPREL relocation table necessarily consists entirely of JMP_SLOT (REL_PLT in internal nomenclature) relocations, which are symbolic; they cannot be resolved in stage 1, so there is no point in processing them.
* remove outdated and misleading comment in iconv.cRich Felker2015-05-211-6/+0
| | | | | the comment claimed that EUC/GBK/Big5 are not implemented, which has been incorrect since commit 19b4a0a20efc6b9df98b6a43536ecdd628ba4643.
* in iconv_open, accept "CHAR" and "" as aliases for "UTF-8"Rich Felker2015-05-211-1/+2
| | | | | | | | while not a requirement, it's common convention in other iconv implementations to accept "CHAR" as an alias for nl_langinfo(CODESET), meaning the encoding used for char[] strings in the current locale, and also "" as an alternate form. supporting this is not costly and improves compatibility.
* reprocess libc/ldso RELA relocations in stage 3 of dynamic linkingRich Felker2015-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | this fixes a regression on powerpc that was introduced in commit f3ddd173806fd5c60b3f034528ca24542aecc5b9. global data accesses on powerpc seem to be using a translation-unit-local GOT filled via R_PPC_ADDR32 relocations rather than R_PPC_GLOB_DAT. being a non-GOT relocation type, these were not reprocessed after adding the main application and its libraries to the chain, causing libc code not to see copy relocations in the main program, and therefore to use the pre-copy-relocation addresses for global data objects (like environ). the motivation for the dynamic linker only reprocessing GOT/PLT relocation types in stage 3 is that these types always have a zero addend, making them safe to process again even if the storage for the addend has been clobbered. other relocation types which can be used for address constants in initialized data objects may have non-zero addends which will be clobbered during the first pass of relocation processing if they're stored inline (REL form) rather than out-of-line (RELA form). powerpc generally uses only RELA, so this patch is sufficient to fix the regression in practice, but is not fully general, and would not suffice if an alternate toolchain generated REL for powerpc.
* fix null pointer dereference in dcngettext under specific conditionsRich Felker2015-05-181-1/+1
| | | | | | | | | | if setlocale has not been called, the current locale's messages_name may be a null pointer. the code path where it's assumed to be non-null was only reachable if bindtextdomain had already been called, which is normally not done in programs which do not call setlocale, so the omitted check went unnoticed. patch from Void Linux, with description rewritten.
* eliminate costly tricks to avoid TLS access for current locale stateRich Felker2015-05-165-27/+4
| | | | | | | | | | | | | | | the code being removed used atomics to track whether any threads might be using a locale other than the current global locale, and whether any threads might have abstract 8-bit (non-UTF-8) LC_CTYPE active, a feature which was never committed (still pending). the motivations were to support early execution prior to setup of the thread pointer, to partially support systems (ancient kernels) where thread pointer setup is not possible, and to avoid high performance cost on archs where accessing the thread pointer may be very slow. since commit 19a1fe670acb3ab9ead0fe31859ca7d4fe40dd54, the thread pointer is always available, so these hacks are no longer needed. removing them greatly simplifies the affected code.
* in i386 __set_thread_area, don't assume %gs register is initially zeroRich Felker2015-05-161-4/+9
| | | | | | | | | | | | | | | | | | | | | | | commit f630df09b1fd954eda16e2f779da0b5ecc9d80d3 added logic to handle the case where __set_thread_area is called more than once by reusing the GDT slot already in the %gs register, and only setting up a new GDT slot when %gs is zero. this created a hidden assumption that %gs is zero when a new process image starts, which is true in practice on Linux, but does not seem to be documented ABI, and fails to hold under qemu app-level emulation. while it would in theory be possible to zero %gs in the entry point code, this code is shared between static and dynamic binaries, and dynamic binaries must not clobber the value of %gs already setup by the dynamic linker. the alternative solution implemented in this commit simply uses global data to store the GDT index that's selected. __set_thread_area should only be called in the initial thread anyway (subsequent threads get their thread pointer setup by __clone), but even if it were called by another thread, it would simply read and write back the same GDT index that was already assigned to the initial thread, and thus (in the x86 memory model) there is no data race.
* fix futimes legacy function with null tv pointerRich Felker2015-05-061-0/+1
| | | | | a null pointer is valid here and indicates that the current time should be used. based on patch by Felix Janda, simplified.
* fix stack protector crashes on x32 & powerpc due to misplaced TLS canaryRich Felker2015-05-063-3/+8
| | | | | | | | | | | | | | | | | | | i386, x86_64, x32, and powerpc all use TLS for stack protector canary values in the default stack protector ABI, but the location only matched the ABI on i386 and x86_64. on x32, the expected location for the canary contained the tid, thus producing spurious mismatches (resulting in process termination) upon fork. on powerpc, the expected location contained the stdio_locks list head, so returning from a function after calling flockfile produced spurious mismatches. in both cases, the random canary was not present, and a predictable value was used instead, making the stack protector hardening much less effective than it should be. in the current fix, the thread structure has been expanded to have canary fields at all three possible locations, and archs that use a non-default location must define a macro in pthread_arch.h to choose which location is used. for most archs (which lack TLS canary ABI) the choice does not matter.
* fix crash in x32 sigsetjmpRich Felker2015-05-021-0/+1
| | | | | | | | | | | the 64-bit push reads not only the 32-bit return address but also the first 32 signal mask bits. if any were nonzero, the return address obtained will be invalid. at some point storage of the return address should probably be moved to follow the saved mask so that there's plenty room and the same code can be used on x32 and regular x86_64, but for now I want a fix that does not risk breaking x86_64, and this simple re-zeroing works.
* fix x32 __set_thread_area failure due to junk in upper bitsRich Felker2015-05-021-1/+1
| | | | | the kernel does not properly clear the upper bits of the syscall argument, so we have to do it before the syscall.
* complex: fix ctanh(+-0+i*nan) and ctanh(+-0+-i*inf)Szabolcs Nagy2015-05-012-2/+4
| | | | | These cases were incorrect in C11 as described by http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1886.htm
* fix mishandling of ENOMEM return case in internal getgrent_a functionRich Felker2015-05-011-1/+2
| | | | | | | | due to an incorrect return statement in this error case, the previously blocked cancellation state was not restored and no result was stored. this could lead to invalid (read) accesses in the caller resulting in crashes or nonsensical result data in the event of memory exhaustion.
* fix sh jmp_buf size to match ABIRich Felker2015-04-271-2/+2
| | | | | | | | | | | | | | | | | while the sh port is still experimental and subject to ABI instability, this is not actually an application/libc boundary ABI change. it only affects third-party APIs where jmp_buf is used in a shared structure at the ABI boundary, because nothing anywhere near the end of the jmp_buf object (which includes the oversized sigset_t) is accessed by libc. both glibc and uclibc have 15-slot jmp_buf for sh. presumably the smaller version was used in musl because the slots for fpu status register and thread pointer register (gbr) were incorrect and must not be restored by longjmp, but the size should have been preserved, as it's generally treated as a libc-agnostic ABI property for the arch, and having extra slots free in case we ever need them for something is useful anyway.
* fix build regression in aarch64 sigsetjmpRich Felker2015-04-241-2/+2
| | | | | at least some assembler versions do not accept the register name lr. use the name x30 instead.
* fix build regression in sh-nofpu subarch due to missing symbolRich Felker2015-04-241-0/+3
| | | | | | commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 switched sigsetjmp to use the new hidden ___setjmp symbol for setjmp, but the nofpu variant of setjmp.s was not updated to match.
* fix misalignment of dtv in static-linked programs with odd-sized TLSRich Felker2015-04-231-1/+2
| | | | | | | | | | both static and dynamic linked versions of the __copy_tls function have a hidden assumption that the alignment of the beginning or end of the memory passed is suitable for storing an array of pointers for the dtv. pthread_create satisfies this requirement except when libc.tls_size is misaligned, which cannot happen with dynamic linking due to way update_tls_size computes the total size, but could happen with static linking and odd-sized TLS.
* remove dead store from static __init_tlsRich Felker2015-04-231-2/+0
| | | | | | commit dab441aea240f3b7c18a26d2ef51979ea36c301c, which made thread pointer init mandatory for all programs, rendered this store obsolete by removing the early-return path for static programs with no TLS.
* make __init_tp function static when static linkingRich Felker2015-04-231-0/+3
| | | | | | | | this slightly reduces the code size cost of TLS/thread-pointer for static linking since __init_tp can be inlined into its only caller and removed. this is analogous to the handling of __init_libc in __libc_start_main, where the function only has external linkage when it needs to be called from the dynamic linker.
* fix regression in x86_64 math asm with old binutilsRich Felker2015-04-232-6/+6
| | | | | | | | | the implicit-operand form of fucomip is rejected by binutils 2.19 and perhaps other versions still in use. writing both operands explicitly fixes the issue. there is no change to the resulting output. commit a732e80d33b4fd6f510f7cec4f5573ef5d89bc4e was the source of this regression.
* minor optimization to pthread_spin_trylockRich Felker2015-04-222-2/+4
| | | | | | use CAS instead of swap since it's lighter for most archs, and keep EBUSY in the lock value so that the old value obtained by CAS can be used directly as the return value for pthread_spin_trylock.
* optimize spin lock not to dirty cache line while spinningRich Felker2015-04-221-1/+1
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* in visibility preinclude, remove overrides for stdin/stdout/stderrRich Felker2015-04-221-3/+0
| | | | | | | | | | | | the motivation for this change is that the extra declaration (with or without visibility) using "struct _IO_FILE" instead of "FILE" seems to trigger a bug in gcc 3.x where it considers the types mismatched. however, this change also results in slightly better code and it is valid because (1) these three objects are constant, and (2) applying the & operator to any of them is invalid C, since they are not even specified to be objects. thus it does not matter if the application and libc see different addresses for them, as long as the (initial, unchanging) value is seen the same by both.
* fix inconsistent visibility for __hwcap and __sysinfo symbolsRich Felker2015-04-222-5/+3
| | | | | these are used as hidden by asm files (and such use is the whole reason they exist), but their actual definitions were not hidden.
* remove additional libc struct accessor cruftRich Felker2015-04-221-12/+0
| | | | | commit f9cccfc16e58b39ee381fbdfb8688db3bb8e3555 left behind the part in libc.c; remove it too.
* remove useless visibility application from static-linking-only codeRich Felker2015-04-222-3/+2
| | | | | part of the goal here is to eliminate use of the ATTR_LIBC_VISIBILITY macro outside of libc.h, since it was never intended to be 'public'.
* remove libc.h dependency from otherwise-independent multibyte codeRich Felker2015-04-221-2/+4
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* remove cruft for libc struct accessor function and broken visibilityRich Felker2015-04-222-18/+0
| | | | | | | | | these were hacks to work around toolchains that could not properly optimize PIC accesses based on visibility and would generate GOT lookups even for hidden data, which broke the old dynamic linker. since commit f3ddd173806fd5c60b3f034528ca24542aecc5b9 it no longer matters; the dynamic linker does not assume accessibility of this data until stage 3.
* fix duplocale clobbering of new locale struct with memcpy of oldRich Felker2015-04-211-1/+2
| | | | | | | | | | | | | | | when the non-stub duplocale code was added as part of the locale framework in commit 0bc03091bb674ebb9fa6fe69e4aec1da3ac484f2, the old code to memcpy the old locale object to the new one was left behind. the conditional for the memcpy no longer makes sense, because the conditions are now always-true when it's reached, and the memcpy is wrong because it clobbers the new->messages_name pointer setup just above. since the messages_name and ctype_utf8 members have already been copied, all that remains is the cat[] array. these pointers are volatile, so using memcpy to copy them is formally wrong; use a for loop instead.
* remove dead case for F_SETLKW in fcntlRich Felker2015-04-211-1/+0
| | | | | | the first switch already returns in the F_SETLKW code path so it need not be handled in the second switch. moreover the code in the second switch is wrong for the F_SETLKW command: it's not cancellable.
* fix mmap leak in sem_open failure path for link callRich Felker2015-04-211-0/+1
| | | | | | | the leak was found by static analysis (reported by Alexander Monakov), not tested/observed, but seems to have occured both when failing due to O_EXCL, and in a race condition with O_CREAT but not O_EXCL where a semaphore by the same name was created concurrently.
* remove always-true conditional in dynamic linker TLSDESC processingRich Felker2015-04-211-1/+1
| | | | | | the allocating path which can fail is for dynamic TLS, which can only occur at runtime, and the check for runtime was already made in the outer conditional.
* remove redundant code in do_dlsym functionRich Felker2015-04-211-1/+1
| | | | | | | commit 637dd2d383cc1f63bf02a732f03786857b22c7bd introduced the checks for RTLD_DEFAULT and RTLD_NEXT here, claiming they fixed a regression, but the above conditional block clearly already covered these cases, and removing the checks produces no difference in the generated code.
* add optional global visibility overrideRich Felker2015-04-191-0/+40
| | | | | | | | | | | | this is implemented via the build system and does not affect source files. the idea is to use protected or hidden visibility to prevent the compiler from pessimizing function calls within a shared (or position-independent static) libc in the form of overhead setting up for a call through the PLT. the ld-time symbol binding via the -Bsymbolic-functions option already optimized out the PLT itself, but not the code in the caller needed to support a call through the PLT. on some archs this overhead can be substantial; on others it's trivial.
* remove invalid PLT calls from or1k asmRich Felker2015-04-192-3/+7
| | | | analogous to commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 for sh.
* remove possible-textrels from powerpc asmRich Felker2015-04-192-2/+6
| | | | | | | these are perfectly fine with ld-time symbol binding, but otherwise result in textrels. they cannot be replaced with @PLT jump targets because the PLT thunks require a GOT register to be setup, so use a hidden alias instead.
* remove invalid PLT calls from microblaze asmRich Felker2015-04-192-2/+6
| | | | analogous to commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 for sh.
* remove invalid PLT calls from sh asmRich Felker2015-04-192-2/+6
| | | | | | these are perfectly fine with ld-time symbol binding, but if the calls go through a PLT thunk, they are invalid because the caller does not setup a GOT register. use a hidden alias to bypass the issue.
* remove potentially PIC-incompatible relocations from x86_64 and x32 asmRich Felker2015-04-186-7/+11
| | | | analogous to commit 8ed66ecbcba1dd0f899f22b534aac92a282f42d5 for i386.
* remove the last of possible-textrels from i386 asmRich Felker2015-04-186-4/+16
| | | | | | | | | | | | none of these are actual textrels because of ld-time binding performed by -Bsymbolic-functions, but I'm changing them with the goal of making ld-time binding purely an optimization rather than relying on it for semantic purposes. in the case of memmove's call to memcpy, making it explicit that the memmove asm is assuming the forward-copying behavior of the memcpy asm is desirable anyway; in case memcpy is ever changed, the semantic mismatch would be apparent while editing memmcpy.s.
* make dlerror state and message thread-local and dynamically-allocatedRich Felker2015-04-183-32/+65
| | | | | | | | | this fixes truncation of error messages containing long pathnames or symbol names. the dlerror state was previously required by POSIX to be global. the resolution of bug 97 relaxed the requirements to allow thread-safe implementations of dlerror with thread-local state and message buffer.
* add missing 'void' in prototypes of internal pthread functionsAlexander Monakov2015-04-181-6/+6
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