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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/+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.
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.
2015-05-01complex: fix ctanh(+-0+i*nan) and ctanh(+-0+-i*inf)Szabolcs Nagy-2/+4
These cases were incorrect in C11 as described by http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1886.htm
2015-05-01fix mishandling of ENOMEM return case in internal getgrent_a functionRich Felker-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.
2015-04-27fix sh jmp_buf size to match ABIRich Felker-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.
2015-04-24fix build regression in aarch64 sigsetjmpRich Felker-2/+2
at least some assembler versions do not accept the register name lr. use the name x30 instead.
2015-04-24fix build regression in sh-nofpu subarch due to missing symbolRich Felker-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.
2015-04-23fix misalignment of dtv in static-linked programs with odd-sized TLSRich Felker-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.
2015-04-23remove dead store from static __init_tlsRich Felker-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.
2015-04-23make __init_tp function static when static linkingRich Felker-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.
2015-04-23fix regression in x86_64 math asm with old binutilsRich Felker-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.
2015-04-22minor optimization to pthread_spin_trylockRich Felker-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.
2015-04-22optimize spin lock not to dirty cache line while spinningRich Felker-1/+1
2015-04-22in visibility preinclude, remove overrides for stdin/stdout/stderrRich Felker-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.
2015-04-22fix inconsistent visibility for __hwcap and __sysinfo symbolsRich Felker-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.
2015-04-22remove additional libc struct accessor cruftRich Felker-12/+0
commit f9cccfc16e58b39ee381fbdfb8688db3bb8e3555 left behind the part in libc.c; remove it too.
2015-04-22remove useless visibility application from static-linking-only codeRich Felker-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'.
2015-04-22remove libc.h dependency from otherwise-independent multibyte codeRich Felker-2/+4
2015-04-22remove cruft for libc struct accessor function and broken visibilityRich Felker-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.
2015-04-21fix duplocale clobbering of new locale struct with memcpy of oldRich Felker-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.
2015-04-21remove dead case for F_SETLKW in fcntlRich Felker-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.
2015-04-21fix mmap leak in sem_open failure path for link callRich Felker-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.
2015-04-21remove always-true conditional in dynamic linker TLSDESC processingRich Felker-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.
2015-04-21remove redundant code in do_dlsym functionRich Felker-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.
2015-04-19add optional global visibility overrideRich Felker-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.
2015-04-19remove invalid PLT calls from or1k asmRich Felker-3/+7
analogous to commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 for sh.
2015-04-19remove possible-textrels from powerpc asmRich Felker-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.
2015-04-19remove invalid PLT calls from microblaze asmRich Felker-2/+6
analogous to commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 for sh.
2015-04-19remove invalid PLT calls from sh asmRich Felker-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.
2015-04-18remove potentially PIC-incompatible relocations from x86_64 and x32 asmRich Felker-7/+11
analogous to commit 8ed66ecbcba1dd0f899f22b534aac92a282f42d5 for i386.
2015-04-18remove the last of possible-textrels from i386 asmRich Felker-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.
2015-04-18make dlerror state and message thread-local and dynamically-allocatedRich Felker-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.
2015-04-18add missing 'void' in prototypes of internal pthread functionsAlexander Monakov-6/+6
2015-04-18math: fix pow(+-0,-inf) not to raise divbyzero flagSzabolcs Nagy-3/+3
this reverts the commit f29fea00b5bc72d4b8abccba2bb1e312684d1fce which was based on a bug in C99 and POSIX and did not match IEEE-754 http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1515.pdf
2015-04-17apply hidden visibility to tlsdesc accessor functionsRich Felker-0/+10
these functions are never called directly; only their addresses are used, so PLT indirections should never happen unless a broken application tries to redefine them, but it's still best to make them hidden.
2015-04-17comment fixes in aarch64 tlsdesc asmSzabolcs Nagy-4/+4
2015-04-17ensure debugger hook for dynamic linker does not point to a PLT slotRich Felker-2/+4
this change is made in preparation to support linking without -Bsymbolic-functions.
2015-04-17fix mips fesetenv(FE_DFL_ENV) againRich Felker-0/+1
commit 5fc1487832e16aa2119e735a388d5f36c8c139e2 attempted to fix it, but neglected the fact that mips has branch delay slots.
2015-04-17fix PLT call offset in sh dlsym asmRich Felker-3/+3
the braf instruction's destination register is an offset from the address of the braf instruction plus 4 (or equivalently, the address of the next instruction after the delay slot). the code for dlsym was incorrectly computing the offset to pass using the address of the delay slot itself. in other places, a label was placed after the delay slot, but I find this confusing. putting the label on the branch instruction itself, and manually adding 4, makes it more clear which branch the offset in the constant pool goes with.
2015-04-17fix sh build regressions in asmRich Felker-2/+2
even hidden functions need @PLT symbol references; otherwise an absolute address is produced instead of a PC-relative one.
2015-04-17fix sh __set_thread_area uninitialized return valueRich Felker-1/+2
this caused the dynamic linker/startup code to abort when r0 happened to contain a negative value.
2015-04-17redesign sigsetjmp so that signal mask is restored after longjmpRich Felker-133/+177
the conventional way to implement sigsetjmp is to save the signal mask then tail-call to setjmp; siglongjmp then restores the signal mask and calls longjmp. the problem with this approach is that a signal already pending, or arriving between unmasking of signals and restoration of the saved stack pointer, will have its signal handler run on the stack that was active before siglongjmp was called. this can lead to unbounded stack usage when siglongjmp is used to leave a signal handler. in the new design, sigsetjmp saves its own return address inside the extended part of the sigjmp_buf (outside the __jmp_buf part used by setjmp) then calls setjmp to save a jmp_buf inside its own execution. it then tail-calls to __sigsetjmp_tail, which uses the return value of setjmp to determine whether to save the current signal mask or restore a previously-saved mask. as an added bonus, this design makes it so that siglongjmp and longjmp are identical. this is useful because the __longjmp_chk function we need to add for ABI-compatibility assumes siglongjmp and longjmp are the same, but for different reasons -- it was designed assuming either can access a flag just past the __jmp_buf indicating whether the signal masked was saved, and act on that flag. however, early versions of musl did not have space past the __jmp_buf for the non-sigjmp_buf version of jmp_buf, so our setjmp cannot store such a flag without risking clobbering memory on (very) old binaries.
2015-04-14use hidden __tls_get_new for tls/tlsdesc lookup fallback casesRich Felker-5/+13
previously, the dynamic tlsdesc lookup functions and the i386 special-ABI ___tls_get_addr (3 underscores) function called __tls_get_addr when the slot they wanted was not already setup; __tls_get_addr would then in turn also see that it's not setup and call __tls_get_new. calling __tls_get_new directly is both more efficient and avoids the issue of calling a non-hidden (public API/ABI) function from asm. for the special i386 function, a weak reference to __tls_get_new is used since this function is not defined when static linking (the code path that needs it is unreachable in static-linked programs).
2015-04-14cleanup use of visibility attributes in pthread_cancel.cRich Felker-8/+9
applying the attribute to a weak_alias macro was a hack. instead use a separate declaration to apply the visibility, and consolidate declarations together to avoid having visibility mess all over the file.
2015-04-14fix inconsistent visibility for internal syscall symbolsRich Felker-1/+16
2015-04-14use hidden visibility for call from dlsym to internal __dlsymRich Felker-3/+14
2015-04-14consistently use hidden visibility for cancellable syscall internalsRich Felker-30/+96
in a few places, non-hidden symbols were referenced from asm in ways that assumed ld-time binding. while these is no semantic reason these symbols need to be hidden, fixing the references without making them hidden was going to be ugly, and hidden reduces some bloat anyway. in the asm files, .global/.hidden directives have been moved to the top to unclutter the actual code.
2015-04-14fix inconsistent visibility for internal __tls_get_new functionRich Felker-3/+3
at the point of call it was declared hidden, but the definition was not hidden. for some toolchains this inconsistency produced textrels without ld-time binding.