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2019-03-29clean up access to mutex type in pthread_mutex_trylockRich Felker-2/+2
there was no point in masking off the pshared bit when first loading the type, since every subsequent access involves a mask anyway. not masking it may avoid a subsequent load to check the pshared flag, and it's just simpler.
2019-03-21support archs with no renameat syscall, only renameat2Drew DeVault-2/+8
2019-03-21support archs with no mlock syscall, only mlock2Drew DeVault-0/+4
2019-03-21fix data race choosing next key slot in pthread_key_createRich Felker-1/+1
commit 84d061d5a31c9c773e29e1e2b1ffe8cb9557bc58 wrongly moved the access to the global next_key outside of the scope of the lock. the error manifested as spurious failure to find an available key slot under concurrent calls to pthread_key_create, since the stopping condition could be met after only a small number of slots were examined.
2019-03-14fix crash/out-of-bound read in sscanfRich Felker-2/+3
commit d6c855caa88ddb1ab6e24e23a14b1e7baf4ba9c7 caused this "regression", though the behavior was undefined before, overlooking that f->shend=0 was being used as a sentinel for "EOF" status (actual EOF or hitting the scanf field width) of the stream helper (shgetc) functions. obviously the shgetc macro could be adjusted to check for a null pointer in addition to the != comparison, but it's the hot path, and adding extra code/branches to it begins to defeat the purpose. so instead of setting shend to a null pointer to block further reads, which no longer works, set it to the current position (rpos). this makes the shgetc macro work with no change, but it breaks shunget, which can no longer look at the value of shend to determine whether to back up. Szabolcs Nagy suggested a solution which I'm using here: setting shlim to a negative value is inexpensive to test at shunget time, and automatically re-trips the cnt>=shlim stop condition in __shgetc no matter what the original limit was.
2019-03-13fix namespace violation in dependencies of mtx_lockRich Felker-1/+1
commit 2de29bc994029b903a366b8a4a9f8c3c3ee2be90 left behind one reference to pthread_mutex_trylock. fixing this also improves code generation due to the namespace-safe version being hidde.
2019-03-13aarch64: add HWCAP_ definitions from linux v5.0Szabolcs Nagy-0/+3
HWCAP_SB - speculation barrier instruction available added in linux commit bd4fb6d270bc423a9a4098108784f7f9254c4e6d HWCAP_PACA, HWCAP_PACG - pointer authentication instructions available (address and generic) added in linux commit 7503197562567b57ec14feb3a9d5400ebc56812f
2019-03-13sys/prctl.h: add PR_PAC_RESET_KEYS from linux v5.0Szabolcs Nagy-0/+7
aarch64 pointer authentication code related prctl that allows reinitializing the key for the thread, added in linux commit ba830885656414101b2f8ca88786524d4bb5e8c1
2019-03-13elf.h: add NT_ definitions from linux v5.0Szabolcs Nagy-0/+2
NT_MIPS_MSA for ptrace access to mips simd arch reg set, added in linux commit 3cd640832894b85b5929d5bda74505452c800421 NT_ARM_PAC_MASK for ptrace access to pointer auth code mask, added in commit ec6e822d1a22d0eef1d1fa260dff751dba9a4258
2019-03-13elf.h: update with C-SKY definitionsSzabolcs Nagy-1/+57
C-SKY support was added to binutils 2.32 in commit b8891f8d622a31306062065813fc278d8a94fe21 the elf.h change was added to glibc 2.29 in commit 4975f0c3d0131fdf697be0b1631c265e5fd39088
2019-03-13aarch64, or1k: add kexec_file_load syscall number from linux v5.0Szabolcs Nagy-0/+2
added in linux commit 4e21565b7fd4d9045765f697887e74a704135fe2
2019-03-13netinet/tcp.h: add TCP_NLA_SRTT from linux v5.0Szabolcs Nagy-0/+1
smoothed RTT for SCM_TIMESTAMPING_OPT_STATS control messages. added in linux commit e8bd8fca6773ef49390269bd467bf940a0841ccf
2019-03-13netinet/udp.h: add UDP_GRO from linux v5.0Szabolcs Nagy-0/+1
sockopt to enable gro for udp. added in linux commit e20cf8d3f1f763ad28a9cb3b41305b8a8a42653e
2019-03-13powerpc: add PTRACE_SYSEMU from linux v4.20Szabolcs Nagy-0/+4
added in linux commit 5521eb4bca2db733952f068c37bdf3cd656ad23c
2019-03-13aarch64: add HWCAP_SSBS from linux v4.20Szabolcs Nagy-0/+1
for armv8.5 speculative store bypass PSTATE bit support, added in linux commit d71be2b6c0e19180b5f80a6d42039cc074a693a2
2019-03-13bits/ioctl.h: add TIOC{G,S}ISO7816 from linux v4.20Szabolcs Nagy-0/+2
ISO7816 smart cards ioctls. linux commit ad8c0eaa0a418ae8ef3f9217638bb86439399eac the actual kernel definitions are #define TIOCGISO7816 _IOR('T', 0x42, struct serial_iso7816) #define TIOCSISO7816 _IOWR('T', 0x43, struct serial_iso7816) where struct serial_iso7816 is defined in linux/serial.h as struct serial_iso7816 { __u32 flags; __u32 tg; __u32 sc_fi; __u32 sc_di; __u32 clk; __u32 reserved[5]; };
2019-03-13sys/prctl.h: add PR_SPEC_INDIRECT_BRANCH from linux v4.20Szabolcs Nagy-0/+1
prctls to allow per task control of indirect branch speculation on x86. added in linux commit 9137bb27e60e554dab694eafa4cca241fa3a694f
2019-03-13netinet/in.h add IPV6_MULTICAST_ALL from linux v4.20Szabolcs Nagy-0/+1
ipv6 analogue of IP_MULTICAST_ALL sockopt. added in linux commit 15033f0457dca569b284bef0c8d3ad55fb37eacb
2019-03-13add PACKET_IGNORE_OUTGOING sockopt from linux v4.20Szabolcs Nagy-0/+1
new in linux commit fa788d986a3aac5069378ed04697bd06f83d3488
2019-03-13sys/mman.h: add new hugetlb mmap flags from linux v4.19Szabolcs Nagy-0/+4
aarch64 supports 32MB and 512MB hugetlb page sizes too. added in linux commit 20916d4636a9b3c1bf562b305f91d126771edaf9
2019-03-13arm: add io_pgetevents syscall number from v4.19Szabolcs Nagy-0/+1
wired up in linux commit 73aeb2cbcdc9be391b3d32a55319a59ce425426f
2019-03-13aarch64, or1k: define rseq syscall number following linux v4.19Szabolcs Nagy-0/+2
added in linux commit db7a2d1809a5b6b08d138ff68837f805fc073351
2019-03-13elf.h: add new mips core dump note values from linux v4.19Szabolcs Nagy-0/+2
NT_MIPS_FP_MODE is new in linux commit 1ae22a0e35636efceab83728ba30b013df761592 NT_MIPS_DSP is new in linux commit 44109c60176ae73924a42a6bef64ef151aba9095
2019-03-13netinet/udp.h: add UDP_ENCAP_RXRPC from linux v4.19Szabolcs Nagy-0/+1
used for optimizing the rxrpc protocol added in linux commit 5271953cad31b97dea80f848c16e96ad66401199
2019-03-13netinet/tcp.h: add tcp_info fields from linux v4.19Szabolcs Nagy-0/+8
new fields for RFC 4898 tcp stats in linux tcpi_bytes_sent added in commit ba113c3aa79a7f941ac162d05a3620bdc985c58d tcpi_bytes_retrans added in commit fb31c9b9f6c85b1bad569ecedbde78d9e37cd87b tcpi_dsack_dups added in commit 7e10b6554ff2ce7f86d5d3eec3af5db8db482caa tcpi_reord_seen added in commit 7ec65372ca534217b53fd208500cf7aac223a383 The new fields change the size of a public struct and thus an ABI break, but this is how the getsockopt TCP_INFO api is designed: the tcp_info type must only be used with a length parameter in extern interfaces.
2019-03-13sys/inotify.h: add IN_MASK_CREATE from linux v4.19Szabolcs Nagy-0/+1
inotify_add_watch flag to prevent modifying existing watch descriptors, when used on an already watched inode it fails with EEXIST. added in linux commit 4d97f7d53da7dc830dbf416a3d2a6778d267ae68
2019-03-13sys/socket.h: add SO_TXTIME from linux v4.19Szabolcs Nagy-0/+2
added in linux commit 80b14dee2bea128928537d61c333f24cb8cbb62f
2019-03-13handle labels with 8-bit byte values in dn_skipnameRyan Fairfax-2/+5
The original logic considered each byte until it either found a 0 value or a value >= 192. This means if a string segment contained any byte >= 192 it was interepretted as a compressed segment marker even if it wasn't in a position where it should be interpretted as such. The fix is to adjust dn_skipname to increment by each segments size rather than look at each character. This avoids misinterpretting string segment characters by not considering those bytes.
2019-03-13fix POSIX_FADV_DONTNEED/_NOREUSE on s390xJonathan Neuschäfer-0/+5
On s390x, POSIX_FADV_DONTNEED and POSIX_FADV_NOREUSE have different values than on all other architectures that Linux supports. Handle this difference by wrapping their definitions in include/fcntl.h in #ifdef, so that arch/s390x/bits/fcntl.h can override them.
2019-03-13expose TSVTX unconditionally in tar.hRich Felker-4/+0
as noted in Austin Group issue #1236, the XSI shading for TSVTX is misplaced in the html version of the standard; it was only supposed to be on the description text. the intent was that the definition always be visible, which is reflected in the pdf version of the standard. this reverts commits d93c0740d86aaf7043e79b942a6c0b3f576af4c8 and 729fef0a9358e2f6f1cd8c75a1a0f7ee48b08c95.
2019-03-12setvbuf: return failure if mode is invalidA. Wilcox-1/+3
POSIX requires setvbuf to return non-zero if `mode` is not one of _IONBF, _IOLBF, or _IOFBF.
2019-03-12make FILE a complete type for pre-C11 standard profilesRich Felker-0/+20
C11 removed the requirement that FILE be a complete type, which was deemed erroneous, as part of the changes introduced by N1439 regarding completeness of types (see footnote 6 for specific mention of FILE). however the current version of POSIX is still based on C99 and incorporates the old requirement that FILE be a complete type. expose an arbitrary, useless complete type definition because the actual object used to represent FILE streams cannot be public/ABI. thanks to commit 13d1afa46f8098df290008c681816c9eb89ffbdb, we now have a framework for suppressing the public complete-type definition of FILE when stdio.h is included internally, so that a different internal definition can be provided. this is perfectly well-defined, since the same struct tag can refer to different types in different translation units. it would be a problem if the implementation were accessing the application's FILE objects or vice versa, but either would be undefined behavior.
2019-03-10fix invalid-/double-/use-after-free in new dlopen ctor executionRich Felker-1/+2
this affected the error path where dlopen successfully found and loaded the requested dso and all its dependencies, but failed to resolve one or more relocations, causing the operation to fail after storage for the ctor queue was allocated. commit 188759bbee057aa94db2bbb7cf7f5855f3b9ab53 wrongly put the free for the ctor_queue array in the error path inside a loop over each loaded dso that needed to be backed-out, rather than just doing it once. in addition, the exit path also observed the ctor_queue pointer still being nonzero, and would attempt to call ctors on the backed-out dsos unless the double-free crashed the process first.
2019-03-05don't reject unknown/future flags in sigaltstack, allow SS_AUTODISARMRich Felker-1/+1
historically, and likely accidentally, sigaltstack was specified to fail with EINVAL if any flag bit other than SS_DISABLE was set. the resolution of Austin Group issue 1187 fixes this so that the requirement is only to fail for SS_ONSTACK (which cannot be set) or "invalid" flags. Linux fails on the kernel side for invalid flags, but historically accepts SS_ONSTACK as a no-op, so it needs to be rejected in userspace still. with this change, the Linux-specific SS_AUTODISARM, provided since commit 9680e1d03a794b0e0d5815c749478228ed40a36d but unusable due to rejection at runtime, is now usable.
2019-03-03avoid malloc of ctor queue for programs with no external depsRich Felker-2/+9
together with the previous two commits, this completes restoration of the property that dynamic-linked apps with no external deps and no tls have no failure paths before entry.
2019-03-03avoid malloc of deps arrays for ldso and vdsoRich Felker-0/+3
neither has or can have any dependencies, but since commit 403555690775f7c8806372644f543518e6664e3b, gratuitous zero-length deps arrays were being allocated for them. use a dummy array instead.
2019-03-03avoid malloc of deps array for programs with no external depsRich Felker-3/+10
traditionally, we've provided a guarantee that dynamic-linked applications with no external dependencies (nothing but libc) and no thread-local storage have no failure paths before the entry point. normally, thanks to reclaim_gaps, such a malloc will not require a syscall anyway, but if segment alignment is unlucky, it might. use a builtin array for this common special case.
2019-03-03fix malloc misuse for startup ctor queue, breakage on fdpic archsRich Felker-5/+9
in the case where malloc is being replaced, it's not valid to call malloc between final relocations and main app's crt1 entry point; on fdpic archs the main app's entry point will not yet have performed the self-fixups necessary to call its code. to fix, reorder queue_ctors before final relocations. an alternative solution would be doing the allocation from __libc_start_init, after the entry point but before any ctors run. this is less desirable, since it would leave a call to malloc that might be provided by the application happening at startup when doing so can be easily avoided.
2019-03-03synchronize shared library dtor exec against concurrent loads/ctorsRich Felker-1/+17
previously, going way back, there was simply no synchronization here. a call to exit concurrent with ctor execution from dlopen could cause a dtor to execute concurrently with its corresponding ctor, or could cause dtors for newly-constructed libraries to be skipped. introduce a shutting_down state that blocks further ctor execution, producing the quiescence the dtor execution loop needs to ensure any kind of consistency, and that blocks further calls to dlopen so that a call into dlopen from a dtor cannot deadlock. better approaches to some of this may be possible, but the changes here at least make things safe.
2019-03-03overhaul shared library ctor execution for dependency order, concurrencyRich Felker-17/+101
previously, shared library constructors at program start and dlopen time were executed in reverse load order. some libraries, however, rely on a depth-first dependency order, which most other dynamic linker implementations provide. this is a much more reasonable, less arbitrary order, and it turns out to have much better properties with regard to how slow-running ctors affect multi-threaded programs, and how recursive dlopen behaves. this commit builds on previous work tracking direct dependencies of each dso (commit 403555690775f7c8806372644f543518e6664e3b), and performs a topological sort on the dependency graph at load time while the main ldso lock is held and before success is committed, producing a queue of constructors needed by the newly-loaded dso (or main application). in the case of circular dependencies, the dependency chain is simply broken at points where it becomes circular. when the ctor queue is run, the init_fini_lock is held only for iteration purposes; it's released during execution of each ctor, so that arbitrarily-long-running application code no longer runs with a lock held in the caller. this prevents a dlopen with slow ctors in one thread from arbitrarily delaying other threads that call dlopen. fully-independent ctors can run concurrently; when multiple threads call dlopen with a shared dependency, one will end up executing the ctor while the other waits on a condvar for it to finish. another corner case improved by these changes is recursive dlopen (call from a ctor). previously, recursive calls to dlopen could cause a ctor for a library to be executed before the ctor for its dependency, even when there was no relation between the calling library and the library it was loading, simply due to the naive reverse-load-order traversal. now, we can guarantee that recursive dlopen in non-circular-dependency usage preserves the desired ctor execution order properties, and that even in circular usage, at worst the libraries whose ctors call dlopen will fail to have completed construction when ctors that depend on them run. init_fini_lock is changed to a normal, non-recursive mutex, since it is no longer held while calling back into application code.
2019-03-02record preloaded libraries as direct pseudo-dependencies of main appRich Felker-4/+11
this makes calling dlsym on the main app more consistent with the global symbol table (load order), and is a prerequisite for dependency-order ctor execution to work correctly with LD_PRELOAD.
2019-03-02fix unsafety of new ldso dep tracking in presence of malloc replacementRich Felker-1/+13
commit 403555690775f7c8806372644f543518e6664e3b introduced runtime realloc of an array that may have been allocated before symbols were resolved outside of libc, which is invalid if the allocator has been replaced. track this condition and manually copy if needed.
2019-02-27fix and overhaul dlsym depedency order, always record direct depsRich Felker-34/+79
dlsym with an explicit handle is specified to use "dependency order", a breadth-first search rooted at the argument. this has always been implemented by iterating a flattened dependency list built at dlopen time. however, the logic for building this list was completely wrong except in trivial cases; it simply used the list of libraries loaded since a given library, and their direct dependencies, as that library's dependencies, which could result in misordering, wrongful omission of deep dependencies from the search, and wrongful inclusion of unrelated libraries in the search. further, libraries did not have any recorded list of resolved dependencies until they were explicitly dlopened, meaning that DT_NEEDED entries had to be resolved again whenever a library participated as a dependency of more than one dlopened library. with this overhaul, the resolved direct dependency list of each library is always recorded when it is first loaded, and can be extended to a full flattened breadth-first search list if dlopen is called on the library. the extension is performed using the direct dependency list as a queue and appending copies of the direct dependency list of each dependency in the queue, excluding duplicates, until the end of the queue is reached. the direct deps remain available for future use as the initial subarray of the full deps array. first-load logic in dlopen is updated to match these changes, and clarified.
2019-02-27fix crash/misbehavior from oob read in new dynamic tls installationRich Felker-1/+1
code introduced in commit 9d44b6460ab603487dab4d916342d9ba4467e6b9 wrongly attempted to read past the end of the currently-installed dtv to determine if a dso provides new, not-already-installed tls. this logic was probably leftover from an earlier draft of the code that wrongly installed the new dtv before populating it. it would work if we instead queried the new, not-yet-installed dtv, but instead, replace the incorrect check with a simple range check against old_cnt. this also catches modules that have no tls at all with a single condition.
2019-02-25fix crash in new dynamic tls installation when last dep lacks tlsRich Felker-1/+4
code introduced in commit 9d44b6460ab603487dab4d916342d9ba4467e6b9 wrongly assumed the dso list tail was the right place to find new dtv storage. however, this is only true if the last-loaded dependency has tls. the correct place to get it is the dso corresponding to the tls module list tail. introduce a container_of macro to get it, and use it. ultimately, dynamic tls allocation should be refactored so that this is not an issue. there is no reason to be allocating new dtv space at each load_library; instead it could happen after all new libraries have been loaded but before they are committed. such changes may be made later, but this commit fixes the present regression.
2019-02-22add membarrier syscall wrapper, refactor dynamic tls install to use itRich Felker-35/+111
the motivation for this change is twofold. first, it gets the fallback logic out of the dynamic linker, improving code readability and organization. second, it provides application code that wants to use the membarrier syscall, which depends on preregistration of intent before the process becomes multithreaded unless unbounded latency is acceptable, with a symbol that, when linked, ensures that this registration happens.
2019-02-22make thread list lock a recursive lockRich Felker-11/+21
this is a prerequisite for factoring the membarrier fallback code into a function that can be called from a context with the thread list already locked or independently.
2019-02-22fix loop logic cruft in dynamic tls installationRich Felker-1/+1
commit 9d44b6460ab603487dab4d916342d9ba4467e6b9 inadvertently contained leftover logic from a previous approach to the fallback signaling loop. it had no adverse effect, since j was always nonzero if the loop body was reachable, but it makes no sense to be there with the current approach to avoid signaling self.
2019-02-20fix spurious undefined behavior in getaddrinfoRich Felker-3/+2
addressing &out[k].sa was arguably undefined, despite &out[k] being defined the slot one past the end of an array, since the member access .sa is intervening between the [] operator and the & operator.
2019-02-20fix invalid free of partial addrinfo list with multiple servicesRich Felker-1/+1
the backindex stored by getaddrinfo to allow freeaddrinfo to perform partial-free wrongly used the address result index, rather than the output slot index, and thus was only valid when they were equal (nservs==1). patch based on report with proposed fix by Markus Wichmann.
generated by cgit v1.2.1 (git 2.18.0) at 2024-04-23 18:33:35 +0000