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2014-07-20fix regression that negated some mips syscall error returnsRich Felker-5/+5
due to what was essentially a copy and paste error, the changes made in commit f61be1f875a2758509d6e9e2cf6f1d9603b28b65 caused syscalls with 5 or 6 arguments (and syscalls with 2, 3, or 4 arguments when compiled with clang compatibility) to negate the returned error code a second time, breaking errno reporting.
2014-07-19fix mips struct stat dev_t members for big endianRich Felker-20/+81
the mips version of this structure on the kernel side wrongly has 32-bit type rather than 64-bit type. fortunately there is adjacent padding to bring it up to 64 bits, and on little-endian, this allows us to treat the adjacent kernel st_dev and st_pad0[0] as as single 64-bit dev_t. however, on big endian, such treatment results in the upper and lower 32-bit parts of the dev_t value being swapped. for the purpose of just comparing st_dev values this did not break anything, but it precluded actually processing the device numbers as major/minor values. since the broken kernel behavior that needs to be worked around is isolated to one arch, I put the workarounds in syscall_arch.h rather than adding a stat fixup path in the common code. on little endian mips, the added code optimizes out completely. the changes necessary were incompatible with the way the __asm_syscall macro was factored so I just removed it and flattened the individual __syscallN functions. this arguably makes the code easier to read and understand, anyway.
2014-07-19add issetugid function to check for elevated privilegeBrent Cook-0/+8
this function provides a way for third-party library code to use the same logic that's used internally in libc for suppressing untrusted input/state (e.g. the environment) when the application is running with privleges elevated by the setuid or setgid bit or some other mechanism. its semantics are intended to match the openbsd function by the same name. there was some question as to whether this function is necessary: getauxval(AT_SECURE) was proposed as an alternative. however, this has several drawbacks. the most obvious is that it asks programmers to be aware of an implementation detail of ELF-based systems (the aux vector) rather than simply the semantic predicate to be checked. and trying to write a safe, reliable version of issetugid in terms of getauxval is difficult. for example, early versions of the glibc getauxval did not report ENOENT, which could lead to false negatives if AT_SECURE was not present in the aux vector (this could probably only happen when running on non-linux kernels under linux emulation, since glibc does not support linux versions old enough to lack AT_SECURE). as for musl, getauxval has always properly reported errors, but prior to commit 7bece9c2095ee81f14b1088f6b0ba2f37fecb283, the musl implementation did not emulate AT_SECURE if missing, which would result in a false positive. since musl actually does partially support kernels that lack AT_SECURE, this was problematic. the intent is that library authors will use issetugid if its availability is detected at build time, and only fall back to the unreliable alternatives on systems that lack it. patch by Brent Cook. commit message/rationale by Rich Felker.
2014-07-19fix or1k atomic storeRich Felker-1/+1
at the very least, a compiler barrier is required no matter what, and that was missing. current or1k implementations have strong ordering, but this is not guaranteed as part of the ISA, so some sort of synchronizing operation is necessary. in principle we should use l.msync, but due to misinterpretation of the spec, it was wrongly treated as an optional instruction and is not supported by some implementations. if future kernels trap it and treat it as a nop (rather than illegal instruction) when the hardware/emulator does not support it, we could consider using it. in the absence of l.msync support, the l.lwa/l.swa instructions, which are specified to have a built-in l.msync, need to be used. the easiest way to use them to implement atomic store is to perform an atomic swap and throw away the result. using compare-and-swap would be lighter, and would probably be sufficient for all actual usage cases, but checking this is difficult and error-prone: with store implemented in terms of swap, it's guaranteed that, when another atomic operation is performed at the same time as the store, either the result of the store followed by the other operation, or just the store (clobbering the other operation's result) is seen. if store were implemented in terms of cas, there are cases where this invariant would fail to hold, and we would need detailed rules for the situations in which the store operation is well-defined.
2014-07-19fix missing barriers in powerpc atomic storeRich Felker-1/+5
2014-07-19fix microblaze atomic storeRich Felker-1/+3
as far as I can tell, microblaze is strongly ordered, but this does not seem to be well-documented and the assumption may need revisiting. even with strong ordering, however, a volatile C assignment is not sufficient to implement atomic store, since it does not preclude reordering by the compiler with respect to non-volatile stores and loads. simply flanking a C store with empty volatile asm blocks with memory clobbers would achieve the desired result, but is likely to result in worse code generation, since the address and value for the store may need to be spilled. actually writing the store in asm, so that there's only one asm block, should give optimal code generation while satisfying the requirement for having a compiler barrier.
2014-07-19fix missing barrier instructions in powerpc atomic asmRich Felker-1/+4
2014-07-19fix missing barrier instructions in mips atomic asmRich Felker-14/+18
previously I had wrongly assumed the ll/sc instructions also provided memory synchronization; apparently they do not. this commit adds sync instructions before and after each atomic operation and changes the atomic store to simply use sync before and after a plain store, rather than a useless compare-and-swap.
2014-07-19use memory constraints for mips atomic asmRich Felker-24/+24
despite lacking the semantic content that the asm accesses the pointed-to object rather than just using its address as a value, the mips asm was not actually broken. the asm blocks were declared volatile, meaning that the compiler must treat them as having unknown side effects. however changing the asm to use memory constraints is desirable not just from a semantic correctness and consistency standpoint, but also produces better code. the compiler is able to use base/offset addressing expressions for the atomic object's address rather than having to load the address into a single register. this improves access to global locks in static libc, and access to non-zero-offset atomic fields in synchronization primitives, etc.
2014-07-19fix build breakage from ppc asm constraints changeRich Felker-3/+3
due to a mistake in my testing procedure, the changes in the previous commit were not correctly tested and wrongly assumed to be valid. the lwarx and stwcx. instructions do not accept general ppc memory address expressions and thus the argument associated with the memory constraint cannot be used directly. instead, the memory constraint can be left as an argument that the asm does not actually use, and the address can be provided in a separate register constraint.
2014-07-19remove cruft from microblaze atomic.hRich Felker-13/+0
2014-07-19fix broken constraints for powerpc atomic cas asmRich Felker-1/+1
the register constraint for the address to be accessed did not convey that the asm can access the pointed-to object. as far as the compiler could tell, the result of the asm was just a pure function of the address and the values passed in, and thus the asm could be hoisted out of loops or omitted entirely if the result was not used.
2014-07-18fix missing flags arg to fstatat syscall in fstat fallback pathRich Felker-1/+1
this code path is used only on archs without the plain, non-at syscalls, and only when the fstat syscall fails with EBADF on a valid file descriptor. this in turn can happen only for O_PATH file descriptors, and may not happen at all on the newer kernels needed for supporting such archs. with the flags argument omitted, spurious fstat failures may happen when the argument register happens to have the AT_SYMLINK_NOFOLLOW bit set.
2014-07-18fix microblaze definition of struct statRich Felker-3/+2
the erroneous definition was missed because with works with qemu user-level emulation, which also has the wrong definition. the actual kernel uses the asm-generic generic definition.
2014-07-18add or1k (OpenRISC 1000) architecture portStefan Kristiansson-1/+1982
With the exception of a fenv implementation, the port is fully featured. The port has been tested in or1ksim, the golden reference functional simulator for OpenRISC 1000. It passes all libc-test tests (except the math tests that requires a fenv implementation). The port assumes an or1k implementation that has support for atomic instructions (l.lwa/l.swa). Although it passes all the libc-test tests, the port is still in an experimental state, and has yet experienced very little 'real-world' use.
2014-07-17provide getauxval(AT_SECURE) even if it is missing from the aux vectorRich Felker-0/+1
this could happen on 2.4-series linux kernels that predate AT_SECURE and possibly on other kernels that are emulating the linux syscall API but not providing AT_SECURE in the aux vector at startup. in principle applications should be checking errno anyway, but this does not really work. to be secure, the caller would have to treat ENOENT (indeterminate result) as possibly-suid and thereby disable functionality in the typical non-suid usage case. and since glibc only runs on kernels that provide AT_SECURE, applications written to the glibc getauxval API might simply assume it succeeds.
2014-07-17remove useless infinite loop from end of exit functionRich Felker-1/+0
this was originally added as a cheap but portable way to quell warnings about reaching the end of a function that does not return, but since _Exit is marked _Noreturn, it's not needed. removing it makes the call to _Exit into a tail call and shaves off a few bytes of code from minimal static programs.
2014-07-17fix crash in regexec for nonzero nmatch argument with REG_NOSUBRich Felker-0/+1
per POSIX, the nmatch and pmatch arguments are ignored when the regex was compiled with REG_NOSUB.
2014-07-16work around constant folding bug 61144 in gcc 4.9.0 and 4.9.1Rich Felker-30/+9
previously we detected this bug in configure and issued advice for a workaround, but this turned out not to work. since then gcc 4.9.0 has appeared in several distributions, and now 4.9.1 has been released without a fix despite this being a wrong code generation bug which is supposed to be a release-blocker, per gcc policy. since the scope of the bug seems to affect only data objects (rather than functions) whose definitions are overridable, and there are only a very small number of these in musl, I am just changing them from const to volatile for the time being. simply removing the const would be sufficient to make gcc 4.9.1 work (the non-const case was inadvertently fixed as part of another change in gcc), and this would also be sufficient with 4.9.0 if we forced -O0 on the affected files or on the whole build. however it's cleaner to just remove all the broken compiler detection and use volatile, which will ensure that they are never constant-folded. the quality of a non-broken compiler's output should not be affected except for the fact that these objects are no longer const and thus possibly add a few bytes to data/bss. this change can be reconsidered and possibly reverted at some point in the future when the broken gcc versions are no longer relevant.
2014-07-16simplify __stdio_exit static linking logicRich Felker-16/+12
the purpose of this logic is to avoid linking __stdio_exit unless any stdio reads (which might require repositioning the file offset at exit time) or writes (which might require flushing at exit time) could have been performed. previously, exit called two wrapper functions for __stdio_exit named __flush_on_exit and __seek_on_exit. both of these functions actually performed both tasks (seek and flushing) by calling the underlying __stdio_exit. in order to avoid doing this twice, an overridable data object __towrite_used was used to cause __seek_on_exit to act as a nop when __towrite was linked. now, exit only makes one call, directly to __stdio_exit. this is satisfiable by a weak dummy definition in exit.c, but the real definition is pulled in by either __toread.c or __towrite.c through their referencing a symbol which is defined only in __stdio_exit.c.
2014-07-11implement the LOG_CONS option in syslogRich Felker-1/+9
this was previously a no-op, somewhat intentionally, because I failed to understand that it only has an effect when sending to the logging facility fails and thus is not the nuisance that it would be if always sent output to the console.
2014-07-11suppress early syslog return when log socket cannot be openedRich Felker-4/+1
this behavior is no longer valid in general, and was never necessary. if the LOG_PERROR option is set, output to stderr could still succeed. also, when the LOG_CONS option is added, it will need syslog to proceed even if opening the log socket fails.
2014-07-11implement the LOG_PERROR option in syslogRich Felker-2/+4
this is a nonstandard feature, but easy and inexpensive to add. since the corresponding macro has always been defined in our syslog.h, it makes sense to actually support it. applications may reasonably be using the presence of the macro to assume that the feature is supported. the behavior of omitting the 'header' part of the log message does not seem to be well-documented, but matches other implementations (at least glibc) which have this option. based on a patch by Clément Vasseur, but simplified using %n.
2014-07-11fix the %m specifier in syslogClément Vasseur-0/+3
errno must be saved upon vsyslog entry, otherwise its value could be changed by some libc function before reaching the %m handler in vsnprintf.
2014-07-11explicitly reject empty names in dynamic linker load_library functionRich Felker-0/+5
previously passing an empty string for name resulted in failure, as expected, but only after spurious syscalls, and it produced confusing errno values (and thus dlerror strings). in addition to dlopen calls, this issue affected use of LD_PRELOAD with trailing whitespace or colon characters.
2014-07-11make dynamic linker accept colon as a separator for LD_PRELOADRich Felker-2/+2
2014-07-08fix typo in microblaze setjmp asmRich Felker-1/+1
r24 was wrongly being saved at a misaligned offset of 30 rather than the correct offset of 40 in the jmp_buf. the exact effects of this error have not been studied, but it's clear that the value of r24 was lost across setjmp/longjmp and the saved values of r21 and/or r22 may also have been corrupted.
2014-07-06rename file containing pthread_cleanup_push and pop for consistencyRich Felker-0/+0
2014-07-06rework cancellation weak alias logic not to depend on archive orderRich Felker-6/+12
if the order of object files in the static archive libc.a was not respected by the linker, the old logic could wrongly cause POSIX symbols outside of the ISO C namespace to be pulled into pure C programs. this should not happen with well-behaved linkers, but relying on the link order was a bad idea anyway. files are renamed to better reflect their contents now that they don't need names to control their order as members in the archive file.
2014-07-06fix multiple issues in legacy function getpassRich Felker-5/+6
1. failure to output a newline after the password is read 2. fd leaks via missing FD_CLOEXEC 3. fd leaks via failure-to-close when any of the standard streams are closed at the time of the call 4. wrongful fallback to use of stdin when opening /dev/tty fails 5. wrongful use of stderr rather than /dev/tty for prompt 6. failure to report error reading password
2014-07-05eliminate use of cached pid from thread structureRich Felker-12/+9
the main motivation for this change is to remove the assumption that the tid of the main thread is also the pid of the process. (the value returned by the set_tid_address syscall was used to fill both fields despite it semantically being the tid.) this is historically and presently true on linux and unlikely to change, but it conceivably could be false on other systems that otherwise reproduce the linux syscall api/abi. only a few parts of the code were actually still using the cached pid. in a couple places (aio and synccall) it was a minor optimization to avoid a syscall. caching could be reintroduced, but lazily as part of the public getpid function rather than at program startup, if it's deemed important for performance later. in other places (cancellation and pthread_kill) the pid was completely unnecessary; the tkill syscall can be used instead of tgkill. this is actually a rather subtle issue, since tgkill is supposedly a solution to race conditions that can affect use of tkill. however, as documented in the commit message for commit 7779dbd2663269b465951189b4f43e70839bc073, tgkill does not actually solve this race; it just limits it to happening within one process rather than between processes. we use a lock that avoids the race in pthread_kill, and the use in the cancellation signal handler is self-targeted and thus not subject to tid reuse races, so both are safe regardless of which syscall (tgkill or tkill) is used.
2014-07-02properly pass current locale to *_l functions when used internallyRich Felker-8/+16
this change is presently non-functional since the callees do not yet use their locale argument for anything.
2014-07-02consolidate str[n]casecmp_l into str[n]casecmp source filesRich Felker-13/+16
this is mainly done for consistency with the ctype functions and to declutter the src/locale directory.
2014-07-02consolidate *_l ctype/wctype functions into their non-_l source filesRich Felker-213/+256
the main practical purposes of this commit are to remove a huge amount of clutter from the src/locale directory, to cut down on the length of the $(AR) and $(LD) command lines, and to reduce the amount of space wasted by object file headers in the static libc.a. build time may also be reduced, though this has not been measured. as an additional justification, if there ever were a need for the behavior of these functions to vary by locale, it would be necessary for the non-_l versions to call the _l versions, so that linking the former without the latter would not be possible anyway.
2014-07-02add locale frameworkRich Felker-22/+186
this commit adds non-stub implementations of setlocale, duplocale, newlocale, and uselocale, along with the data structures and minimal code needed for representing the active locale on a per-thread basis and optimizing the common case where thread-local locale settings are not in use. at this point, the data structures only contain what is necessary to represent LC_CTYPE (a single flag) and LC_MESSAGES (a name for use in finding message translation files). representation for the other categories will be added later; the expectation is that a single pointer will suffice for each. for LC_CTYPE, the strings "C" and "POSIX" are treated as special; any other string is accepted and treated as "C.UTF-8". for other categories, any string is accepted after being truncated to a maximum supported length (currently 15 bytes). for LC_MESSAGES, the name is kept regardless of whether libc itself can use such a message translation locale, since applications using catgets or gettext should be able to use message locales libc is not aware of. for other categories, names which are not successfully loaded as locales (which, at present, means all names) are treated as aliases for "C". setlocale never fails. locale settings are not yet used anywhere, so this commit should have no visible effects except for the contents of the string returned by setlocale.
2014-07-02fix failure of wide printf/scanf functions to set wide orientationRich Felker-0/+3
in some cases, these functions internally call a byte-based input or output function before calling getwc/putwc, so they cannot rely on the latter to set the orientation.
2014-07-01fix typo in a comment in __libc_start_mainRich Felker-1/+1
2014-07-01fix incorrect return value for fwide functionRich Felker-1/+2
when the orientation of the stream was already set, fwide was incorrectly returning its argument (the requested orientation) rather than the actual orientation of the stream.
2014-07-01fix ungrammatical comment in posix_spawn codeRich Felker-3/+3
2014-07-01fix aliasing violations in mbtowc and mbrtowcRich Felker-2/+4
these functions were setting wc to point to wchar_t aliasing itself as a "cheap" way to support null wc arguments. doing so was anything but cheap, since even without the aliasing violation, it would limit the compiler's ability to optimize. making wc point to a dummy object is equally easy and does not suffer from the above problems.
2014-06-30fix regression in mips dynamic linkerRich Felker-1/+7
this issue caused the address of functions in shared libraries to resolve to their PLT thunks in the main program rather than their correct addresses. it was observed causing crashes, though the mechanism of the crash was not thoroughly investigated. since the issue is very subtle, it calls for some explanation: on all well-behaved archs, GOT entries that belong to the PLT use a special relocation type, typically called JMP_SLOT, so that the dynamic linker can avoid having the jump destinations for the PLT resolve to PLT thunks themselves (they also provide a definition for the symbol, which must be used whenever the address of the function is taken so that all DSOs see the same address). however, the traditional mips PIC ABI lacked such a JMP_SLOT relocation type, presumably because, due to the way PIC works, the address of the PLT thunk was never needed and could always be ignored. prior to commit adf94c19666e687a728bbf398f9a88ea4ea19996, the mips version of reloc.h contained a hack that caused all symbol lookups to be treated like JMP_SLOT, inhibiting undefined symbols from ever being used to resolve symbolic relocations. this hack goes all the way back to commit babf820180368f00742ec65b2050a82380d7c542, when the mips dynamic linker was first made usable. during the recent refactoring to eliminate arch-specific relocation processing (commit adf94c19666e687a728bbf398f9a88ea4ea19996), this hack was overlooked and no equivalent functionality was provided in the new code. fixing the problem is not as simple as adding back an equivalent hack, since there is now also a "non-PIC ABI" that can be used for the main executable, which actually does use a PLT. the closest thing to official documentation I could find for this ABI is nonpic.txt, attached to Message-ID:, which can be found in the gcc mailing list archives and elsewhere. per this document, undefined symbols corresponding to PLT thunks have the STO_MIPS_PLT bit set in the symbol's st_other field. thus, I have added an arch-specific rule for mips, applied at the find_sym level rather than the relocation level, to reject undefined symbols with the STO_MIPS_PLT bit clear. the previous hack of treating all mips relocations as JMP_SLOT-like, rather than rejecting the unwanted symbols in find_sym, probably also caused dlsym to wrongly return PLT thunks in place of the correct address of a function under at least some conditions. this should now be fixed, at least for global-scope symbol lookups.
2014-06-29fix regression in dynamic linker error reportingRich Felker-9/+5
due to a mistake when refactoring the error printing for the dynamic linker (commit 7c73cacd09a51a87484db5689864743e4984a84d), all messages were suppressed and replaced by blank lines.
2014-06-25release 1.1.3v1.1.3Rich Felker-1/+27
2014-06-25add tarball-producing targets to Makefile for ease of releaseRich Felker-0/+4
my old, out-of-tree release script that performed a clone rather than using git archive checked the VERSION file to make sure that it matched before doing a release. I believe there should be a way to do the same with git commands (without resorting to checking out the desired tag) but I have not yet found a way, so care should be taken when using these targets that the correctness of the VERSION file is not overlooked.
2014-06-25update version reference in the README fileRich Felker-1/+1
2014-06-25add note to INSTALL file about gcc 4.9.0 not being supportedRich Felker-1/+2
2014-06-24add routing protocols to getprotoent-family functionsTimo Teräs-0/+2
iptables and quagga need them to work.
2014-06-23rename dynamic linker _start to _dlstart in the stub versionRich Felker-1/+1
the renaming was previously applied to all real versions of the function in commit 3fa2eb2aba8d6b54dec53e7ad4c37e17392b166f.
2014-06-22add __sysv_signal abi-compat alias for the signal functionRich Felker-0/+1
it should be noted that the "real" __sysv_signal, which we do not implement, is semantically different from signal. references to __sysv_signal arise in code built against glibc under certain combinations of feature test macros, and are almost surely unintentional since the legacy sysv signal behavior has fundamental race conditions that cannot be worked around and which make it impossible to use safely.
2014-06-22add __xmknod and __xmknodat abi-compat functionsRich Felker-0/+10
these are put alongside the similar functions for __xstat, etc. in __xstat.c to avoid bloating the number of source files.