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2015-02-21add new masked cancellation modeRich Felker-10/+17
this is a new extension which is presently intended only for experimental and internal libc use. interface and behavior details may change subject to feedback and experience from using it internally. the basic concept for the new PTHREAD_CANCEL_MASKED state is that the first cancellation point to observe the cancellation request fails with an errno value of ECANCELED rather than acting on cancellation, allowing the caller to process the status and choose whether/how to act upon it.
2015-02-20prepare cancellation syscall asm for possibility of __cancel returningRich Felker-11/+32
2015-02-20map interruption of close by signal to success rather than EINPROGRESSRich Felker-1/+1
commit 82dc1e2e783815e00a90cd3f681436a80d54a314 addressed the resolution of Austin Group issue 529, which requires close to leave the fd open when failing with EINTR, by returning the newly defined error code EINPROGRESS. this turns out to be a bad idea, though, since legacy applications not aware of the new specification are likely to interpret any error from close except EINTR as a hard failure.
2015-02-16make pthread_exit responsible for disabling cancellationRich Felker-3/+2
this requirement is tucked away in XSH 2.9.5 Thread Cancellation under the heading Thread Cancellation Cleanup Handlers.
2015-02-14fix type error (arch-dependent) in new aio codeRich Felker-1/+1
a_store is only valid for int, but ssize_t may be defined as long or another type. since there is no valid way for another thread to acess the return value without first checking the error/completion status of the aiocb anyway, an atomic store is not necessary.
2015-02-13refactor group file access codeJosiah Worcester-51/+71
this allows getgrnam and getgrgid to share code with the _r versions in preparation for alternate backend support.
2015-02-13overhaul aio implementation for correctnessRich Felker-193/+440
previously, aio operations were not tracked by file descriptor; each operation was completely independent. this resulted in non-conforming behavior for non-seekable/append-mode writes (which are required to be ordered) and made it impossible to implement aio_cancel, which in turn made closing file descriptors with outstanding aio operations unsafe. the new implementation is significantly heavier (roughly twice the size, and seems to be slightly slower) and presently aims mainly at correctness, not performance. most of the public interfaces have been moved into a single file, aio.c, because there is little benefit to be had from splitting them. whenever any aio functions are used, aio_cancel and the internal queue lifetime management and fd-to-queue mapping code must be linked, and these functions make up the bulk of the code size. the close function's interaction with aio is implemented with weak alias magic, to avoid pulling in heavy aio cancellation code in programs that don't use aio, and the expensive cancellation path (which includes signal blocking) is optimized out when there are no active aio queues.
2015-02-11fix bad character checking in wordexpRich Felker-0/+1
the character sequence '$((' was incorrectly interpreted as the opening of arithmetic even within single-quoted contexts, thereby suppressing the checks for bad characters after the closing quote. presently bad character checking is only performed when the WRDE_NOCMD is used; this patch only corrects checking in that case.
2015-02-10refactor passwd file access codeJosiah Worcester-49/+65
this allows getpwnam and getpwuid to share code with the _r versions in preparation for alternate backend support.
2015-02-10x86_64/memset: avoid performing final store twiceDenys Vlasenko-1/+1
The code does a potentially misaligned 8-byte store to fill the tail of the buffer. Then it fills the initial part of the buffer which is a multiple of 8 bytes. Therefore, if size is divisible by 8, we were storing last word twice. This patch decrements byte count before dividing it by 8, making one less store in "size is divisible by 8" case, and not changing anything in all other cases. All at the cost of replacing one MOV insn with LEA insn. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-02-10x86_64/memset: simple optimizationsDenys Vlasenko-14/+16
"and $0xff,%esi" is a six-byte insn (81 e6 ff 00 00 00), can use 4-byte "movzbl %sil,%esi" (40 0f b6 f6) instead. 64-bit imul is slow, move it as far up as possible so that the result (rax) has more time to be ready by the time we start using it in mem stores. There is no need to shuffle registers in preparation to "rep movs" if we are not going to take that code path. Thus, patch moves "jump if len < 16" instructions up, and changes alternate code path to use rdx and rdi instead of rcx and r8. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-02-10make protocol table zero byte separated and add ipv6 protocolsTimo Teräs-22/+26
2015-02-09add syscall numbers for the new execveat syscallSzabolcs Nagy-4/+19
this syscall allows fexecve to be implemented without /proc, it is new in linux v3.19, added in commit 51f39a1f0cea1cacf8c787f652f26dfee9611874 (sh and microblaze do not have allocated syscall numbers yet) added a x32 fix as well: the io_setup and io_submit syscalls are no longer common with x86_64, so use the x32 specific numbers.
2015-02-09add new socket options SO_INCOMING_CPU, SO_ATTACH_BPF, SO_DETACH_BPFSzabolcs Nagy-0/+4
these socket options are new in linux v3.19, introduced in commit 2c8c56e15df3d4c2af3d656e44feb18789f75837 and commit 89aa075832b0da4402acebd698d0411dcc82d03e with SO_INCOMING_CPU the cpu can be queried on which a socket is managed inside the kernel and optimize polling of large number of sockets accordingly. SO_ATTACH_BPF lets eBPF programs (created by the bpf syscall) to be attached to sockets.
2015-02-09use the internal macro name FUTEX_PRIVATE in __waitSzabolcs Nagy-1/+1
the name was recently added for the setxid/synccall rework, so use the name now that we have it.
2015-02-09add IEEE binary128 long double support to floatscanSzabolcs Nagy-1/+9
just defining the necessary constants: LD_B1B_MAX is 2^113 - 1 in base 10^9 KMAX is 2048 so the x array can hold up to 18432 decimal digits (the worst case is converting 2^-16495 = 5^16495 * 10^-16495 to binary, it requires the processing of int(log10(5)*16495)+1 = 11530 decimal digits after discarding the leading zeros, the conversion requires some headroom in x, but KMAX is more than enough for that) However this code is not optimal on archs with IEEE binary128 long double because the arithmetics is software emulated (on all such platforms as far as i know) which means big and slow strtod.
2015-02-09math: fix fmodl for IEEE binary128Szabolcs Nagy-1/+1
This trivial copy-paste bug went unnoticed due to lack of testing. No currently supported target archs are affected.
2015-02-08simplify armhf fesetenvSzabolcs Nagy-1/+0
armhf fesetenv implementation did a useless read of the fpscr.
2015-02-08fix fesetenv(FE_DFL_ENV) on mipsSzabolcs Nagy-1/+3
mips fesetenv did not handle FE_DFL_ENV, now fcsr is cleared in that case.
2015-02-08math: fix __fpclassifyl(-0.0) for IEEE binary128Szabolcs Nagy-3/+2
The sign bit was not cleared before checking for 0 so -0.0 was misclassified as FP_SUBNORMAL instead of FP_ZERO.
2015-02-08add parenthesis in fma.c to clarify intent and silence warningsSzabolcs Nagy-1/+1
2015-02-07make getaddrinfo support SOCK_RAW and other socket typesRich Felker-34/+42
all socket types are accepted at this point, but that may be changed at a later time if the behavior is not meaningful for other types. as before, omitting type (a value of 0) gives both UDP and TCP results, and SOCK_DGRAM or SOCK_STREAM restricts to UDP or TCP, respectively. for other socket types, the service name argument is required to be a null pointer, and the protocol number provided by the caller is used.
2015-02-07remove cruft from x86_64 syscall.hSzabolcs Nagy-23/+3
x86_64 syscall.h defined some musl internal syscall names and made them public. These defines were already moved to src/internal/syscall.h (except for SYS_fadvise which is added now) so the cruft in x86_64 syscall.h is not needed.
2015-02-05fix failure of fchmodat to report EOPNOTSUPP in the race pathRich Felker-2/+4
in the case where a non-symlink file was replaced by a symlink during the fchmodat operation with AT_SYMLINK_NOFOLLOW, mode change on the new symlink target was successfully suppressed, but the error was not reported. instead, fchmodat simply returned 0.
2015-02-04fix fd leak race (missing O_CLOEXEC) in fchmodatRich Felker-1/+1
2015-02-03make execvp continue PATH search on EACCES rather than issuing an errrorRich Felker-1/+4
the specification for execvp itself is unclear as to whether encountering a file that cannot be executed due to EACCES during the PATH search is a mandatory error condition; however, XBD 8.3's specification of the PATH environment variable clarifies that the search continues until a file with "appropriate execution permissions" is found. since it seems undesirable/erroneous to report ENOENT rather than EACCES when an early path element has a non-executable file and all later path elements lack any file by the requested name, the new code stores a flag indicating that EACCES was seen and sets errno back to EACCES in this case.
2015-02-03fix missing memory barrier in cancellation signal handlerRich Felker-0/+1
in practice this was probably a non-issue, because the necessary barrier almost certainly exists in kernel space -- implementing signal delivery without such a barrier seems impossible -- but for the sake of correctness, it should be done here too. in principle, without a barrier, it is possible that the thread to be cancelled does not see the store of its cancellation flag performed by another thread. this affects both the case where the signal arrives before entering the critical program counter range from __cp_begin to __cp_end (in which case both the signal handler and the inline check fail to see the value which was already stored) and the case where the signal arrives during the critical range (in which case the signal handler should be responsible for cancellation, but when it does not see the cancellation flag, it assumes the signal is spurious and refuses to act on it). in the fix, the barrier is placed only in the signal handler, not in the inline check at the beginning of the critical program counter range. if the signal handler runs before the critical range is entered, it will of course take no action, but its barrier will ensure that the inline check subsequently sees the store. if on the other hand the inline check runs first, it may miss seeing the store, but the subsequent signal handler in the critical range will act upon the cancellation request. this strategy avoids adding a memory barrier in the common, non-cancellation code path.
2015-02-01fix typo in x86_64/x32 user_fpregs_structFelix Janda-2/+2
mxcs_mask should be mxcr_mask
2015-01-30make fsync, fdatasync, and msync cancellation pointsTrutz Behn-3/+3
these are mandatory cancellation points per POSIX, so their omission was a conformance bug.
2015-01-30move MREMAP_MAYMOVE and MREMAP_FIXED out of bitsTrutz Behn-27/+2
the definitions are generic for all kernel archs. exposure of these macros now only occurs on the same feature test as for the function accepting them, which is believed to be more correct.
2015-01-30fix missing comma in sh setjmp asmTrutz Behn-1/+1
this typo did not result in an erroneous setjmp with at least binutils 2.22 but fix it for clarity and compatibility with potentially stricter sh assemblers.
2015-01-30remove mips-only EINIT and EREMDEV errnosTrutz Behn-2/+0
the errno values are unused by the kernel and the macro definitions were never exposed by glibc.
2015-01-30fix failure of configure to detect gcc due to message translationsRich Felker-1/+1
based on patch by Vadim Ushakov. in general overriding LC_ALL rather than specific categories (here, LC_MESSAGES) is undesirable, but LC_ALL is easier and in this case there is nothing else that depends on the locale in this invocation of the compiler.
2015-01-21fix erroneous return of partial username matches by getspnam[_r]Rich Felker-1/+1
when using /etc/shadow (rather than tcb) as its backend, getspnam_r matched any username starting with the caller-provided string rather than requiring an exact match. in practice this seems to have affected only systems where one valid username is a prefix for another valid username, and where the longer username appears first in the shadow file.
2015-01-21simplify part of getopt_longRich Felker-13/+11
as a result of commit e8e4e56a8ce1f3d7e4a027ff5478f2f8ea70c46b, the later code path for setting optarg to a null pointer is no longer necessary, and removing it eliminates an indention level and arguably makes the code more readable.
2015-01-21always set optarg in getopt_longRich Felker-1/+1
the standard getopt does not touch optarg unless processing an option with an argument. however, programs using the GNU getopt API, which we attempt to provide in getopt_long, expect optarg to be a null pointer after processing an option without an argument. before argument permutation support was added, such programs typically detected its absence and used their own replacement getopt_long, masking the discrepency in behavior.
2015-01-15overhaul __synccall and fix AS-safety and other issues in set*idRich Felker-45/+138
multi-threaded set*id and setrlimit use the internal __synccall function to work around the kernel's wrongful treatment of these process properties as thread-local. the old implementation of __synccall failed to be AS-safe, despite POSIX requiring setuid and setgid to be AS-safe, and was not rigorous in assuring that all threads were caught. in a worst case, threads late in the process of exiting could retain permissions after setuid reported success, in which case attacks to regain dropped permissions may have been possible under the right conditions. the new implementation of __synccall depends on the presence of /proc/self/task and will fail if it can't be opened, but is able to determine that it has caught all threads, and does not use any locks except its own. it thereby achieves AS-safety simply by blocking signals to preclude re-entry in the same thread. with this commit, all known conformance and safety issues in set*id functions should be fixed.
2015-01-15add FUTEX_PRIVATE macro to internal futex.hRich Felker-0/+2
2015-01-15suppress EINTR in sem_wait and sem_timedwaitRich Felker-1/+1
per POSIX, the EINTR condition is an optional error for these functions, not a mandatory one. since old kernels (pre-2.6.22) failed to honor SA_RESTART for the futex syscall, it's dangerous to trust EINTR from the kernel. thankfully POSIX offers an easy way out.
2015-01-15for multithreaded set*id/setrlimit, handle case where callback does not runRich Felker-4/+4
in the current version of __synccall, the callback is always run, so failure to handle this case did not matter. however, the upcoming overhaul of __synccall will have failure cases, in which case the callback does not run and errno is already set. the changes being committed now are in preparation for that.
2015-01-13release 1.1.6v1.1.6Rich Felker-1/+43
2015-01-13increase syslog message limit from 256 to 1024Rich Felker-1/+1
this addresses alpine linux issue #3692 and brings the syslog message length limit in alignment with uclibc's implementation.
2015-01-12remove rlimit hacks from multi-threaded set*id() codeRich Felker-23/+15
the code being removed was introduced to work around "partial failure" of multi-threaded set*id() operations, where some threads would succeed in changing their ids but an RLIMIT_NPROC setting would prevent the rest from succeeding, leaving the process in an inconsistent and dangerous state. however, the workaround code did not handle important usage cases like swapping real and effective uids then restoring their original values, and the wrongful kernel enforcement of RLIMIT_NPROC at setuid time was removed in Linux 3.1, making the workaround obsolete. since the partial failure still is dangerous on old kernels, and could in principle happen on post-fix kernels as well if set*id() syscalls fail for another spurious reason such as resource-related failures, new code is added to detect and forcibly kill the process if/when such a situation arises. future documentation releases should be updated to reflect that setting RLIMIT_NPROC to RLIM_INFINITY is necessary to avoid this forced-kill on old kernels. ideally, at some point the kernel will get proper multi-threaded set*id() syscalls capable of performing their actions atomically, and all of the userspace code to emulate them can be treated as a fallback for outdated kernels.
2015-01-12simplify ctermidRich Felker-14/+2
opening /dev/tty then using ttyname_r on it does not produce a canonical terminal name; it simply yields "/dev/tty". it would be possible to make ctermid determine the actual controlling terminal device via field 7 of /proc/self/stat, but doing so would introduce a buffer overflow into applications built with L_ctermid==9, which glibc defines, adversely affecting the quality of ABI compat.
2015-01-11fix regression in getopt_long support for non-option argumentsRich Felker-7/+6
commit b72cd07f176b876aa51864d93aa8101477b1d732 added support for a this feature in getopt, but it was later broken in the case where getopt_long is used as a side effect of the changes made in commit 91184c4f16b143107fa9935edebe5d2b20bd70d8, which prevented the underlying getopt call from seeing the leading '-' or '+' character in optstring. this commit changes the logic in the getopt_long core to check for a leading colon, possibly after the leading '-' or '+', without depending on the latter having been skipped by the caller. a minor incorrectness in the return value for one error condition in getopt_long is also fixed when opterr has been set to zero but optstring has no leading ':'.
2015-01-09check for connect failure in syslog log openingRich Felker-2/+6
based on patch by Dima Krasner, with minor improvements for code size. connect can fail if there is no listening syslogd, in which case a useless socket was kept open, preventing subsequent syslog call from attempting to connect again.
2014-12-23add new prctl command PR_SET_MM_MAP to sys/prctl.hSzabolcs Nagy-0/+21
PR_SET_MM_MAP was introduced as a subcommand for PR_SET_MM in linux v3.18 commit f606b77f1a9e362451aca8f81d8f36a3a112139e the associated struct type is replicated in sys/prctl.h using libc types. example usage: struct prctl_mm_map *p; ... prctl(PR_SET_MM, PR_SET_MM_MAP, p, sizeof *p); the kernel side supported struct size may be queried with the PR_SET_MM_MAP_SIZE subcommand.
2014-12-23add new syscall numbers for bpf and kexec_file_loadSzabolcs Nagy-0/+20
these syscalls are new in linux v3.18, bpf is present on all supported archs except sh, kexec_file_load is only allocted for x86_64 and x32 yet. bpf was added in linux commit 99c55f7d47c0dc6fc64729f37bf435abf43f4c60 kexec_file_load syscall number was allocated in commit f0895685c7fd8c938c91a9d8a6f7c11f22df58d2
2014-12-21move wint_t definition to the shared part of alltypes.h.inRich Felker-9/+1
2014-12-21fix signedness of UINT32_MAX and UINT64_MAX at the preprocessor levelRich Felker-2/+2
per the rules for hexadecimal integer constants, the previous definitions were correctly treated as having unsigned type except possibly when used in preprocessor conditionals, where all artithmetic takes place as intmax_t or uintmax_t. the explicit 'u' suffix ensures that they are treated as unsigned in all contexts.