- 28 5月, 2015 1 次提交
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由 Rich Felker 提交于
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.
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- 27 5月, 2015 3 次提交
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由 Rich Felker 提交于
since the __setlocalecat function was removed, the filename __setlocalecat.c no longer made sense.
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
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.
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- 26 5月, 2015 3 次提交
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由 Rich Felker 提交于
commit f3ddd173 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 c093e2e8 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.
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
otherwise disassemblers treat it as data.
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- 25 5月, 2015 2 次提交
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由 Rich Felker 提交于
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 09db855b 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.
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由 Rich Felker 提交于
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.
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- 22 5月, 2015 2 次提交
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由 Rich Felker 提交于
the comment claimed that EUC/GBK/Big5 are not implemented, which has been incorrect since commit 19b4a0a2.
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由 Rich Felker 提交于
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.
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- 19 5月, 2015 2 次提交
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由 Rich Felker 提交于
this fixes a regression on powerpc that was introduced in commit f3ddd173. 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.
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由 Rich Felker 提交于
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.
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- 16 5月, 2015 2 次提交
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由 Rich Felker 提交于
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 19a1fe67, the thread pointer is always available, so these hacks are no longer needed. removing them greatly simplifies the affected code.
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由 Rich Felker 提交于
commit f630df09 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.
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- 07 5月, 2015 2 次提交
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由 Rich Felker 提交于
a null pointer is valid here and indicates that the current time should be used. based on patch by Felix Janda, simplified.
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由 Rich Felker 提交于
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.
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- 02 5月, 2015 4 次提交
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
the kernel does not properly clear the upper bits of the syscall argument, so we have to do it before the syscall.
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由 Szabolcs Nagy 提交于
These cases were incorrect in C11 as described by http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1886.htm
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由 Rich Felker 提交于
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.
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- 28 4月, 2015 1 次提交
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由 Rich Felker 提交于
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.
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- 25 4月, 2015 1 次提交
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由 Rich Felker 提交于
at least some assembler versions do not accept the register name lr. use the name x30 instead.
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- 24 4月, 2015 4 次提交
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由 Rich Felker 提交于
commit 646cb9a4 switched sigsetjmp to use the new hidden ___setjmp symbol for setjmp, but the nofpu variant of setjmp.s was not updated to match.
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
commit dab441ae, 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.
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由 Rich Felker 提交于
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.
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- 23 4月, 2015 1 次提交
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由 Rich Felker 提交于
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 a732e80d was the source of this regression.
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- 22 4月, 2015 12 次提交
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
these are used as hidden by asm files (and such use is the whole reason they exist), but their actual definitions were not hidden.
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由 Rich Felker 提交于
commit f9cccfc1 left behind the part in libc.c; remove it too.
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由 Rich Felker 提交于
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'.
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由 Rich Felker 提交于
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由 Rich Felker 提交于
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 f3ddd173 it no longer matters; the dynamic linker does not assume accessibility of this data until stage 3.
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由 Rich Felker 提交于
when the non-stub duplocale code was added as part of the locale framework in commit 0bc03091, 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.
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
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.
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由 Rich Felker 提交于
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.
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