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2014-06-19add tlsdesc support for i386Rich Felker-0/+29
2014-06-19optimize i386 ___tls_get_addr asmRich Felker-1/+8
2014-06-19change dynamic TLS installation strategy to optimize accessRich Felker-8/+14
previously, accesses to dynamic TLS had to check two conditions before being able to use a dtv slot: (1) that the module index was within the bounds of the current dtv size, and (2) that the dynamic tls for the requested module index was already installed in the dtv. this commit changes the installation strategy so that, whenever an attempt is made to access dynamic TLS that's not yet installed in the dtv, the dynamic TLS for all lower-index modules is also installed. thus it provides a new invariant: if a given module index is within the bounds of the current dtv size, we automatically know that its TLS is installed and directly available. the requirement that the second condition (above) be checked is eliminated.
2014-06-19add arch-generic support for tlsdesc relocations to dynamic linkerRich Felker-0/+54
this code is non-functional without further changes to link up the arch-specific reloc types for tlsdesc and add asm implementations of __tlsdesc_static and __tlsdesc_dynamic.
2014-06-19fix incorrect comparison loop condition in memmemRich Felker-2/+2
the logic for this loop was copied from null-terminated-string logic in strstr without properly adapting it to work with explicit lengths. presumably this error could result in false negatives (wrongly comparing past the end of the needle/haystack), false positives (stopping comparison early when the needle contains null bytes), and crashes (from runaway reads past the end of mapped memory).
2014-06-18reduce code duplication in dynamic linker error pathsRich Felker-16/+16
eventually this should help making dlerror thread-safe too.
2014-06-18refactor to remove arch-specific relocation code from dynamic linkerRich Felker-208/+187
this was one of the main instances of ugly code duplication: all archs use basically the same types of relocations, but roughly equivalent logic was duplicated for each arch to account for the different naming and numbering of relocation types and variation in whether REL or RELA records are used. as an added bonus, both REL and RELA are now supported on all archs, regardless of which is used by the standard toolchain.
2014-06-17fix powerpc dynamic linker thread-pointer-relative relocationsRich Felker-3/+3
processing of R_PPC_TPREL32 was ignoring the addend provided by the RELA-style relocation and instead using the inline value as the addend. this presumably broke dynamic-linked access to initial TLS in cases where the addend was nonzero.
2014-06-17multiple fixes to sh (superh) dynamic linker relocationsRich Felker-10/+8
the following issues are fixed: - R_SH_REL32 was adding the load address of the module being relocated to the result. this seems to have been a mistake in the original port, since it does not match other dynamic linker implementations and since adding a difference between two addresses (the symbol value and the relocation address) to a load address does not make sense. - R_SH_TLS_DTPMOD32 was wrongly accepting an inline addend (i.e. using += rather than = on *reloc_addr) which makes no sense; addition is not an operation that's defined on module ids. - R_SH_TLS_DTPOFF32 and R_SH_TLS_TPOFF32 were wrongly using inline addends rather than the RELA-provided addends. in addition, handling of R_SH_GLOB_DAT, R_SH_JMP_SLOT, and R_SH_DIR32 are merged to all honor the addend. the first two should not need it for correct usage generated by toolchains, but other dynamic linkers allow addends here, and it simplifies the code anyway. these issues were spotted while reviewing the code for the purpose of refactoring this part of the dynamic linker. no testing was performed.
2014-06-16dynamic linker: permit error returns from arch-specific reloc functionRich Felker-8/+16
the immediate motivation is supporting TLSDESC relocations which require allocation and thus may fail (unless we pre-allocate), but this mechanism should also be used for throwing an error on unsupported or invalid relocation types, and perhaps in certain cases, for reporting when a relocation is not satisfiable.
2014-06-14fix missing argument to syscall in fanotify_markClément Vasseur-1/+1
2014-06-11support optional-argument extension to getopt via double-colonRich Felker-2/+5
this extension is not incompatible with the standard behavior of the function, not expensive, and avoids requiring a replacement getopt with full GNU extensions for a few important apps including busybox's sed with the -i option.
2014-06-10fail configure on --enable-shared if -Bsymbolic-functions doesn't workRich Felker-1/+4
previously, a warning was issued in this case no matter what, even if --disable-shared was used. now, the default for --enable-shared is changed from "yes" to "auto", and the warning is issued by default, but becomes an error if --enable-shared is used, and the test is suppressed completely if --disable-shared is used.
2014-06-10simplify errno implementationRich Felker-4/+2
the motivation for the errno_ptr field in the thread structure, which this commit removes, was to allow the main thread's errno to keep its address when lazy thread pointer initialization was used. &errno was evaluated prior to setting up the thread pointer and stored in errno_ptr for the main thread; subsequently created threads would have errno_ptr pointing to their own errno_val in the thread structure. since lazy initialization was removed, there is no need for this extra level of indirection; __errno_location can simply return the address of the thread's errno_val directly. this does cause &errno to change, but the change happens before entry to application code, and thus is not observable.
2014-06-10replace all remaining internal uses of pthread_self with __pthread_selfRich Felker-12/+12
prior to version 1.1.0, the difference between pthread_self (the public function) and __pthread_self (the internal macro or inline function) was that the former would lazily initialize the thread pointer if it was not already initialized, whereas the latter would crash in this case. since lazy initialization is no longer supported, use of pthread_self no longer makes sense; it simply generates larger, slower code.
2014-06-10add thread-pointer support for pre-2.6 kernels on i386Rich Felker-13/+22
such kernels cannot support threads, but the thread pointer is also important for other purposes, most notably stack protector. without a valid thread pointer, all code compiled with stack protector will crash. the same applies to any use of thread-local storage by applications or libraries. the concept of this patch is to fall back to using the modify_ldt syscall, which has been around since linux 1.0, to setup the gs segment register. since the kernel does not have a way to automatically assign ldt entries, use of slot zero is hard-coded. if this fallback path is used, __set_thread_area returns a positive value (rather than the usual zero for success, or negative for error) indicating to the caller that the thread pointer was successfully set, but only for the main thread, and that thread creation will not work properly. the code in __init_tp has been changed accordingly to record this result for later use by pthread_create.
2014-06-07avoid spurious lookup failures from badly-behaved nameserversRich Felker-5/+22
the results of a dns query, whether it's performed as part of one of the standard name-resolving functions or directly by res_send, should be a function of the query, not of the particular nameserver that responds to it. thus, all responses which indicate a failure or refusal by the nameserver, as opposed to a positive or negative result for the query, should be ignored. the strategy used is to re-issue the query immediately (but with a limit on the number of retries, in case the server is really broken) when a response code of 2 (server failure, typically transient) is seen, and otherwise take no action on bad responses (which generally indicate a misconfigured nameserver or one which the client does not have permission to use), allowing the normal retry interval to apply and of course accepting responses from other nameservers queried in parallel. empirically this matches the traditional resolver behavior for nameservers that respond with a code of 2 in the case where there is just a single nameserver configured. the behavior diverges when multiple nameservers are available, since musl is querying them in parallel. in this case we are mildly more aggressive at retrying.
2014-06-06use default timezone from /etc/localtime if $TZ is unset/blankRich Felker-2/+3
the way this is implemented, it also allows explicit setting of TZ=/etc/localtime even for suid programs. this is not a problem because /etc/localtime is a trusted path, much like the trusted zoneinfo search path.
2014-06-06release 1.1.2v1.1.2Rich Felker-1/+32
2014-06-06implement %y and %C specifiers in strptimeTimo Teräs-4/+10
2014-06-06avoid invalid use of va_arg in openRich Felker-5/+8
reading the variadic mode argument is only valid when the O_CREAT flag is present. this probably does not matter, but is needed for formal correctness, and could affect LTO or other full-program analysis.
2014-06-06add O_CLOEXEC fallback for open and related functionsRich Felker-1/+9
since there is no easy way to detect whether open honored or ignored the O_CLOEXEC flag, the optimal solution to providing a fallback is simply to make the fcntl syscall to set the close-on-exec flag immediately after open returns.
2014-06-06optimize SOCK_CLOEXEC fallback for socket functionRich Felker-2/+2
the fcntl function is heavy, so make the syscall directly instead. also, avoid the code size and runtime overhead of querying the old flags, since it's reasonable to assume nothing will be set on a newly-created socket. this code is only used on old kernels which lack proper atomic close-on-exec support, so future changes that might invalidate such an assumption do not need to be considered.
2014-06-06add SOCK_CLOEXEC fallback for socketpair on old kernelsRich Felker-1/+19
as usual, this is non-atomic, but better than producing an error or failing to set the close-on-exec flag at all.
2014-06-06implement dn_comp RFC 1035 domain name compressionSzabolcs Nagy-1/+102
the input name is validated, the other parameters are assumed to be valid (the list of already compressed names are not checked for infinite reference loops or out-of-bound offsets). names are handled case-sensitively for now.
2014-06-06accept trailing . and empty domain namesSzabolcs Nagy-12/+16
trailing . should be accepted in domain name strings by convention (RFC 1034), host name lookup accepts "." but rejects empty "", res_* interfaces also accept empty name following existing practice.
2014-06-06add vdso clock_gettime acceleration support to i386Rich Felker-0/+4
2014-06-06fix fd leak in tmpfile when the fdopen operation failsRich Felker-1/+2
this condition could only happen due to malloc failure. the fdopen operation is also moved to take place after the unlink to minimize the window during which a link to the file exists in the directory table.
2014-06-05fix the domain name length limit checksSzabolcs Nagy-8/+8
A domain name is at most 255 bytes long (RFC 1035), but the string representation is two bytes smaller so the strlen maximum is 253.
2014-06-05fix multiple validation issues in dns response label parsingSzabolcs Nagy-4/+6
Due to an error introduced in commit fcc522c92335783293ac19df318415cd97fbf66b, checking of the remaining output buffer space was not performed correctly, allowing malformed input to write past the end of the buffer. In addition, the loop detection logic failed to account for the possibility of infinite loops with no output, which would hang the function. The output size is now limited more strictly so only names with valid length are accepted.
2014-06-05fix missing function declarations in refactored ip literal parsing codeRich Felker-0/+1
2014-06-04add support for reverse port lookups from services file to getnameinfoRich Felker-4/+35
this also affects the legacy getservbyport family, which uses getnameinfo as its backend.
2014-06-04add support for reverse name lookups from hosts file to getnameinfoRich Felker-50/+122
this also affects the legacy gethostbyaddr family, which uses getnameinfo as its backend. some other minor changes associated with the refactoring of source files are also made; in particular, the resolv.conf parser now uses the same code that's used elsewhere to handle ip literals, so as a side effect it can now accept a scope id for nameserver addressed with link-local scope.
2014-06-04remove some dummy "ent" function aliases that duplicated real onesRich Felker-8/+0
the service and protocol functions are defined also in other files, and the protocol ones are actually non-nops elsewhere, so the weak definitions in ent.c could have prevented the strong definitions from getting pulled in and used in some static programs.
2014-06-04simplify vasprintf implementationRich Felker-14/+1
the old implementation preallocated a buffer in order to try to avoid calling vsnprintf more than once. not only did this potentially lead to memory fragmentation from trimming with realloc; it also pulled in realloc/free, which otherwise might not be needed in a static linked program.
2014-06-04add support for ipv6 scope_id to getaddrinfo and getnameinfoRich Felker-9/+57
for all address types, a scope_id specified as a decimal value is accepted. for addresses with link-local scope, a string containing the interface name is also accepted. some changes are made to error handling to avoid unwanted fallbacks in the case where the scope_id is invalid: if an earlier name lookup backend fails with an error rather than simply "0 results", this failure now suppresses any later attempts with other backends. in getnameinfo, a light "itoa" type function is added for generating decimal scope_id results, and decimal port strings for services are also generated using this function now so as not to pull in the dependency on snprintf. in netdb.h, a definition for the NI_NUMERICSCOPE flag is added. this is required by POSIX (it was previously missing) and needed to allow callers to suppress interface-name lookups.
2014-06-03fix if_nametoindex return value when interface does not existRich Felker-1/+1
the return value is unsigned, so negative results for "errors" do not make sense; 0 is the value reserved for when the interface name does not exist.
2014-06-03fix negative response and non-response handling for dns queriesRich Felker-1/+4
previously, all failures to obtain at least one address were treated as nonexistant names (EAI_NONAME). this failed to account for the possibility of transient failures (no response at all, or a response with rcode of 2, server failure) or permanent failures that do not indicate the nonexistence of the requested name. only an rcode of 3 should be treated as an indication of nonexistence.
2014-06-03fix some validation checks in dns response parsing codeRich Felker-2/+3
since the buffer passed always has an actual size of 512 bytes, the maximum possible response packet size, no out-of-bounds access was possible; however, reading past the end of the valid portion of the packet could cause the parser to attempt to process junk as answer content.
2014-06-02fix incorrect end pointer in some cases when wcsrtombs stops earlyRich Felker-7/+15
when wcsrtombs stopped due to hitting zero remaining space in the output buffer, it was wrongly clearing the position pointer as if it had completed the conversion successfully. this commit rearranges the code somewhat to make a clear separation between the cases of ending due to running out of output buffer space, and ending due to reaching the end of input or an illegal sequence in the input. the new branches have been arranged with the hope of optimizing more common cases, too.
2014-06-02remove cruft from old resolver and numeric ip parsingRich Felker-79/+49
the old resolver code used a function __ipparse which contained the logic for inet_addr and inet_aton, which is needed in getaddrinfo. this was phased out in the resolver overhaul in favor of directly using inet_aton and inet_pton as appropriate. this commit cleans up some stuff that was left behind.
2014-06-02switch standard resolver functions to use the new dns backendRich Felker-309/+145
this is the third phase of the "resolver overhaul" project. this commit removes all of the old dns code, and switches the __lookup_name backend (used by getaddrinfo, etc.) and the getnameinfo function to use the newly implemented __res_mkquery and __res_msend interfaces. for parsing the results, a new callback-based __dns_parse function, based on __dns_get_rr from the old dns code, is used.
2014-06-02fix uninitialized variable in new __res_msend dns functionRich Felker-0/+1
2014-06-02implement new dns backend, res_send and other legacy resolver functionsRich Felker-18/+263
this is the second phase of the "resolver overhaul" project. the key additions in this commit are the __res_msend and __res_mkquery functions, which have been factored so as to provide a backend for both the legacy res_* functions and the standard getaddrinfo and getnameinfo functions. the latter however are still using the old backend code; there is code duplication which still needs to be removed, and this will be the next phase of the resolver overhaul. __res_msend is derived from the old __dns_doqueries function, but generalized to send arbitrary caller-provided packets in parallel rather than producing the parallel queries itself. this allows it to be used (completely trivially) as a backend for res_send. the factored-out query generation code, with slightly more generality, is now part of __res_mkquery.
2014-06-02add ipsec and tunneling protocols to getprotoent-family functionsTimo Teräs-0/+4
iptables and ipsec-tools among others require these to function properly.
2014-06-02fix off-by-one in checking hostname length in new resolver backendRich Felker-2/+2
this bug was introduced in the recent resolver overhaul commits. it likely had visible symptoms. these were probably limited to wrongly accepting truncated versions of over-long names (vs rejecting them), as opposed to stack-based overflows or anything more severe, but no extensive checks were made. there have been no releases where this bug was present.
2014-06-01improve getservbyname_r using new resolver backendRich Felker-22/+16
now that host and service lookup have been separated in the backend, there's no need for service lookup functions to pull in the host lookup code. moreover, dynamic allocation is no longer needed, so this function should now be async-signal-safe. it's also significantly smaller. one change in getservbyname is also made: knowing that getservbyname_r needs only two character pointers in the caller-provided buffer, some wasted bss can be avoided.
2014-06-01improve gethostbyname2_r using new resolver backendRich Felker-35/+22
these changes reduce the size of the function somewhat and remove many of its dependencies, including free. in principle it should now be async-signal-safe, but this has not been verified in detail. minor changes to error handling are also made.
2014-05-31refactor getaddrinfo and add support for most remaining featuresRich Felker-228/+360
this is the first phase of the "resolver overhaul" project. conceptually, the results of getaddrinfo are a direct product of a list of address results and a list of service results. the new code makes this explicit by computing these lists separately and combining the results. this adds support for services that have both tcp and udp versions, where the caller has not specified which it wants, and eliminates a number of duplicate code paths which were all producing the final output addrinfo structures, but in subtly different ways, making it difficult to implement any of the features which were missing. in addition to the above benefits, the refactoring allows for legacy functions like gethostbyname to be implemented without using the getaddrinfo function itself. such changes to the legacy functions have not yet been made, however. further improvements include matching of service alias names from /etc/services (previously only the primary name was supported), returning multiple results from /etc/hosts (previously only the first matching line was honored), and support for the AI_V4MAPPED and AI_ALL flags. features which remain unimplemented are IDN translations (encoding non-ASCII hostnames for DNS lookup) and the AI_ADDRCONFIG flag. at this point, the DNS-based name resolving code is still based on the old interfaces in __dns.c, albeit somewhat simpler in its use of them. there may be some dead code which could already be removed, but changes to this layer will be a later phase of the resolver overhaul.
2014-05-30fix POSIX namespace pollution in sys/types.hSzabolcs Nagy-10/+6
int8_t, u_int8_t, etc types are moved under _BSD_SOURCE