AgeCommit message (Collapse)AuthorLines
2015-06-09in malloc, refuse to use brk if it grows into stackRich Felker-1/+9
the linux/nommu fdpic ELF loader sets up the brk range to overlap entirely with the main thread's stack (but growing from opposite ends), so that the resulting failure mode for malloc is not to return a null pointer but to start returning pointers to memory that overlaps with the caller's stack. needless to say this extremely dangerous and makes brk unusable. since it's non-trivial to detect execution environments that might be affected by this kernel bug, and since the severity of the bug makes any sort of detection that might yield false-negatives unsafe, we instead check the proximity of the brk to the stack pointer each time the brk is to be expanded. both the main thread's stack (where the real known risk lies) and the calling thread's stack are checked. an arbitrary gap distance of 8 MB is imposed, chosen to be larger than linux default main-thread stack reservation sizes and larger than any reasonable stack configuration on nommu. the effeciveness of this patch relies on an assumption that the amount by which the brk is being grown is smaller than the gap limit, which is always true for malloc's use of brk. reliance on this assumption is why the check is being done in malloc-specific code and not in __brk.
2015-06-09fix spurious errors from pwd/grp functions when nscd backend is absentRich Felker-4/+8
for several pwd/grp functions, the only way the caller can distinguish between a successful negative result ("no such user/group") and an internal error is by clearing errno before the call and checking errno afterwards. the nscd backend support code correctly simulated a not-found response on systems where such a backend is not running, but failed to restore errno. this commit also fixed an outdated/incorrect comment.
2015-06-07fix regression in pre-v7 arm on kernels with kuser helper removedRich Felker-17/+14
the arm atomics/TLS runtime selection code is called from __set_thread_area and depends on having libc.auxv and __hwcap available. commit 71f099cb7db821c51d8f39dfac622c61e54d794c moved the first call to __set_thread_area to the top of dynamic linking stage 3, before this data is made available, causing the runtime detection code to always see __hwcap as zero and thereby select the atomics/TLS implementations based on kuser helper. upcoming work on superh will use similar runtime detection. ideally this early-init code should be cleanly refactored and shared between the dynamic linker and static-linked startup.
2015-06-07add multiple inclusion guard to locale_impl.hRich Felker-0/+5
2015-06-07remove redefinition of MB_CUR_MAX in locale_impl.hRich Felker-3/+0
unless/until the byte-based C locale is implemented, defining MB_CUR_MAX to 1 in the C locale is wrong. no internal code currently uses the MB_CUR_MAX macro, but having it defined inconsistently is error-prone. applications get the value from stdlib.h and were unaffected.
2015-06-06make static C and C.UTF-8 locales available outside of newlocaleRich Felker-21/+28
2015-06-06remove another invalid skip of locking in ungetwcRich Felker-3/+1
2015-06-06add macro version of ctype.h isascii functionRich Felker-0/+2
presumably internal code (ungetwc and fputwc) was written assuming a macro implementation existed; otherwise use of isascii is just a pessimization.
2015-06-06remove invalid skip of locking in ungetwcRich Felker-6/+3
aside from being invalid, the early check only optimized the error case, and likely pessimized the common case by separating the two branches on isascii(c) at opposite ends of the function.
2015-06-05fix uselocale((locale_t)0) not to modify localeTimo Teräs-3/+1
commit 68630b55c0c7219fe9df70dc28ffbf9efc8021d8 made the new locale to be assigned unconditonally resulting in crashes later on.
2015-06-04release 1.1.10v1.1.10Rich Felker-1/+34
2015-06-04fix dynamic linker regression processing R_*_NONE type relocationsRich Felker-0/+1
commit f3ddd173806fd5c60b3f034528ca24542aecc5b9 inadvertently removed the early check for "none" type relocations, causing the address dso->base+0 to be dereferenced to obtain an addend. shared libraries, (including and PIE executables were unaffected, since their base addresses are the actual address of their mappings and are readable. non-PIE main executables, however, have a base address of 0 because their load addresses are absolute and not offset at load time. in practice none-type relocations do not arise with toolchains that are in use except on mips, and on mips it's moderately rare for a non-PIE executable to have a relocation table, since the mips-specific got processing serves in its place for most purposes.
2015-06-03add additional Makefile dependency rules for rcrt1.o PIE start fileRich Felker-2/+4
2015-05-29fix failure of ungetc and ungetwc to work on files in eof statusRich Felker-10/+11
these functions were written to handle clearing eof status, but failed to account for the __toread function's handling of eof. with this patch applied, __toread still returns EOF when the file is in eof status, so that read operations will fail, but it also sets up valid buffer pointers for read mode, which are set to the end of the buffer rather than the beginning in order to make the whole buffer available to ungetc/ungetwc. minor changes to __uflow were needed since it's now possible to have non-zero buffer pointers while in eof status. as made, these changes remove a 'fast path' bypassing the function call to __toread, which could be reintroduced with slightly different logic, but since ordinary files have a syscall in f->read, optimizing the code path does not seem worthwhile. the __stdio_read function is also updated not to zero the read buffer pointers on eof/error. while not necessary for correctness, this change avoids the overhead of calling __toread in ungetc after reaching eof, and it also reduces code size and increases consistency with the fmemopen read operation which does not zero the pointers.
2015-05-28add missing legacy LFS64 macros in sys/resource.hRich Felker-0/+3
based on patch by Felix Janda, with RLIM64_SAVED_CUR and RLIM64_SAVED_MAX added for completeness.
2015-05-28configure: work around compilers that merely warn for unknown optionsShiz-2/+12
some compilers (such as clang) accept unknown options without error, but then print warnings on each invocation, cluttering the build output and burying meaningful warnings. this patch makes configure's tryflag and tryldflag functions use additional options to turn the unknown-option warnings into errors, if available, but only at check time. these options are not output in config.mak to avoid the risk of spurious build breakage; if they work, they will have already done their job at configure time.
2015-05-27implement fail-safe static locales for newlocaleRich Felker-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.
2015-05-27rename internal locale file handling locale mapsRich Felker-0/+0
since the __setlocalecat function was removed, the filename __setlocalecat.c no longer made sense.
2015-05-27overhaul locale internals to treat categories roughly uniformlyRich Felker-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.
2015-05-27replace atomics with locks in locale-setting codeRich Felker-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.
2015-05-26add rcrt1 start file for fully static-linked PIERich Felker-2/+17
static-linked PIE files need startup code to relocate themselves, much like the dynamic linker does. rcrt1.c reuses the code in dlstart.c, stage 1 of the dynamic linker, which in turn reuses crt_arch.h, to achieve static PIE with no new code. only relative relocations are supported. existing toolchains that don't yet support static PIE directly can be repurposed by passing "-shared -Wl,-Bstatic -Wl,-Bsymbolic" instead of "-static -pie" and substituting rcrt1.o in place of crt1.o. all libraries being linked must be built as PIC/PIE; TEXTRELs are not supported at this time.
2015-05-26fix incorrect application of visibility to Scrt1.oRich Felker-1/+1
commit de2b67f8d41e08caa56bf6540277f6561edb647f attempted to avoid having vis.h affect crt files, but the Makefile variable used, CRT_LIBS, refers to the final output copies in the lib directory, not the copies in the crt build directory, and thus the -DCRT was not applied. while unlikely to be noticed, this regression probably broke production of PIE executables whose main functions are not in the executable but rather a shared library.
2015-05-25reprocess all libc/ldso symbolic relocations in dynamic linking stage 3Rich Felker-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, 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 build.
2015-05-25move call to dynamic linker stage-3 into stage-2 functionRich Felker-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.
2015-05-25mark mips crt code as codeRich Felker-0/+4
otherwise disassemblers treat it as data.
2015-05-25mark mips cancellable syscall code as codeRich Felker-0/+3
otherwise disassemblers treat it as data.
2015-05-25simplify/shrink relocation processing in dynamic linker stage 1Rich Felker-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.
2015-05-25remove processing of DT_JMPREL from dynamic linker stage 1 bootstrapRich Felker-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.
2015-05-24fix stack alignment code in mips crt_arch.hRich Felker-2/+2
the instruction used to align the stack, "and $sp, $sp, -8", does not actually exist; it's expanded to 2 instructions using the 'at' (assembler temporary) register, and thus cannot be used in a branch delay slot. since alignment mod 16 commutes with subtracting 8, simply swapping these two operations fixes the problem. crt1.o was not affected because it's still being generated from a dedicated asm source file. dlstart.lo was not affected because the stack pointer it receives is already aligned by the kernel. but Scrt1.o was affected in cases where the dynamic linker gave it a misaligned stack pointer.
2015-05-22add .text section directive to all crt_arch.h files missing itRich Felker-0/+7
i386 and x86_64 versions already had the .text directive; other archs did not. normally, top-level (file scope) __asm__ starts in the .text section anyway, but problems were reported with some versions of clang, and it seems preferable to set it explicitly anyway, at least for the sake of consistency between archs.
2015-05-21remove outdated and misleading comment in iconv.cRich Felker-6/+0
the comment claimed that EUC/GBK/Big5 are not implemented, which has been incorrect since commit 19b4a0a20efc6b9df98b6a43536ecdd628ba4643.
2015-05-21in iconv_open, accept "CHAR" and "" as aliases for "UTF-8"Rich Felker-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.
2015-05-20fix inconsistency in a_and and a_or argument types on x86[_64]Rich Felker-12/+12
conceptually, and on other archs, these functions take a pointer to int, but in the i386, x86_64, and x32 versions of atomic.h, they took a pointer to void instead.
2015-05-19inline llsc atomics when building for sh4aBobby Bingham-90/+128
If we're building for sh4a, the compiler is already free to use instructions only available on sh4a, so we can do the same and inline the llsc atomics. If we're building for an older processor, we still do the same runtime atomics selection as before.
2015-05-18reprocess libc/ldso RELA relocations in stage 3 of dynamic linkingRich Felker-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.
2015-05-18fix null pointer dereference in dcngettext under specific conditionsRich Felker-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.
2015-05-16eliminate costly tricks to avoid TLS access for current locale stateRich Felker-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.
2015-05-16in i386 __set_thread_area, don't assume %gs register is initially zeroRich Felker-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.
2015-05-14make arm reloc.h CRTJMP macro compatible with thumbRich Felker-0/+5
compilers targeting armv7 may be configured to produce thumb2 code instead of arm code by default, and in the future we may wish to support targets where only the thumb instruction set is available. the instructions this patch omits in thumb mode are needed only for non-thumb versions of armv4 or earlier, which are not supported by any current compilers/toolchains and thus rather pointless to have. at some point these compatibility return sequences may be removed from all asm source files, and in that case it would make sense to remove them here too and remove the ifdef.
2015-05-14make arm crt_arch.h compatible with thumb code generationRich Felker-4/+6
compilers targeting armv7 may be configured to produce thumb2 code instead of arm code by default, and in the future we may wish to support targets where only the thumb instruction set is available. the changes made here avoid operating directly on the sp register, which is not possible in thumb code, and address an issue with the way the address of _DYNAMIC is computed. previously, the relative address of _DYNAMIC was stored with an additional offset of -8 versus the pc-relative add instruction, since on arm the pc register evaluates to ".+8". in thumb code, it instead evaluates to ".+4". both are two (normal-size) instructions beyond "." in the current execution mode, so the numbered label 2 used in the relative address expression is simply moved two instructions ahead to be compatible with both instruction sets.
2015-05-12release 1.1.9v1.1.9Rich Felker-1/+40
2015-05-08fix netinet/ether.h for c++Szabolcs Nagy-0/+8
2015-05-06fix futimes legacy function with null tv pointerRich Felker-0/+1
a null pointer is valid here and indicates that the current time should be used. based on patch by Felix Janda, simplified.
2015-05-06fix stack protector crashes on x32 & powerpc due to misplaced TLS canaryRich Felker-3/+11
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.
2015-05-02improve iswdigit macro to diagnose errorsRich Felker-2/+2
this is analogous to commit 2ca55a93f2a11185d72dcb69006fd2c30b5c3144 for the macros in ctype.h.
2015-05-02fix broken cancellation on x32 due to incorrect saved-PC offsetRich Felker-1/+1
2015-05-02fix crash in x32 sigsetjmpRich Felker-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.
2015-05-02fix x32 __set_thread_area failure due to junk in upper bitsRich Felker-1/+1
the kernel does not properly clear the upper bits of the syscall argument, so we have to do it before the syscall.
2015-05-01fix dangling pointers in x32 syscall timespec fixup codeRich Felker-10/+23
the lifetime of compound literals is the block in which they appear. the temporary struct __timespec_kernel objects created as compound literals no longer existed at the time their addresses were passed to the kernel.
2015-05-01add IPTOS_CLASS_* macros to netinet/ip.hSzabolcs Nagy-0/+12
These macros were introduced in glibc 2.12 to follow RFC 2474 which deprecates "IP Precedence" in favor of "Class Selector Codepoints".