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* factor common awk functions for CFI generation scripts into new fileAlex Dowad2015-10-083-28/+27
| | | | | | There is a lot which could be common between i386 and x86_64, but none of it will be useful for any other arch. These should be useful for all archs, however.
* make nl_langinfo(CODESET) always return "ASCII" in byte-based C localeRich Felker2015-10-011-1/+1
| | | | | | | | | | | | | | | | | | | | | commit 844212d94f582c4e3c5055e0a1524931e89ebe76, which did not make it into any releases, changed nl_langinfo(CODESET) to always return "UTF-8", even in the byte-based C locale. this was problematic because application software was found to use the string match for "UTF-8" to activate its own UTF-8 processing. this both undermines the byte-based functionality of the C locale, and if mixed with with calls to the standard multibyte functions, which happened in practice, could result in severe mis-handling of input. the motive for the previous change was that, to avoid widespread compatibility problems, the string returned by nl_langinfo(CODESET) needs to be accepted by iconv and by third-party character conversion code. thus, the only remaining choice is "ASCII". this choice accurately represents the intent that high bytes do not have individual meaning in the C locale, but it does mean that iconv, when passed nl_langinfo(CODESET) in the C locale, will produce errors in cases where mbrtowc would have succeeded. for reference, glibc behaves similarly in this regard, so I don't think it will be a problem.
* fix mips fesetround failure to write back resulting modeRich Felker2015-10-011-0/+1
| | | | patch by Anand Takale.
* eliminate protected-visibility data in libc.so with vis.h preincludeRich Felker2015-09-292-3/+14
| | | | | | | | | | | | | | | some newer binutils versions print scary warnings about protected data because most gcc versions fail to produce the right address references/relocations for such data that might be subject to copy relocations. originally vis.h explicitly assigned default visibility to all public data symbols to avoid this issue, but commit b8dda24fe1caa901a99580f7a52defb95aedb67c removed this treatment for stdin/out/err to work around a gcc 3.x bug, and since they don't actually need it (because taking their addresses is not valid C). instead, a check for the gcc 3.x bug is added to the configure check for vis.h preinclude support; this feature will simply be disabled when using a buggy version of gcc.
* avoid attempting to lookup IP literals as hostnamesRich Felker2015-09-251-27/+32
| | | | | | | | | | | | | | | | previously, __lookup_ipliteral only checked its argument against the requested address family, so IPv4 literals passed through to __lookup_name if the caller asked for only IPv6 results, and likewise for IPv6 literals when the caller asked for only IPv4. this resulted in spurious DNS lookups that reportedly even succeeded with some nameservers. now, __lookup_ipliteral attempts to parse its argument as both IPv4 and IPv6, and returns an error (to stop further search) rather than 0 (no results yet) if the form of the argument mismatches the requested address family. based on patch by Julien Ramseier.
* make getaddrinfo return error if both host and service name are nullRich Felker2015-09-251-0/+2
| | | | | | this case is specified as a mandatory ("shall fail") error. based on patch by Julien Ramseier.
* fix localeconv field value for unavailable valuesRich Felker2015-09-241-14/+15
| | | | | | | per ISO C, CHAR_MAX, not -1, is the value used to indicate that a char field in struct lconv is unavailable. patch by Julien Ramseier.
* avoid reading uninitialized memory in __map_fileSzabolcs Nagy2015-09-241-2/+3
| | | | | | | The value of *size is not relevant in case of failure, but it's better not to copy garbage from the stack into it. (The compiler cannot see through the syscall, so optimization was not affected by the unspecified value).
* regcomp: propagate allocation failuresSzabolcs Nagy2015-09-241-1/+2
| | | | The error code of an allocating function was not checked in tre_add_tag.
* fix signal return for sh/fdpicRich Felker2015-09-235-4/+12
| | | | | | | | | | | | | | | | the restorer function pointer provided in the kernel sigaction structure is interpreted by the kernel as a raw code address, not a function descriptor. this commit moves the declarations of the __restore and __restore_rt symbols to ksigaction.h so that arch versions of the file can override them, and introduces a version for sh which declares them as objects rather than functions. an alternate solution would have been defining SA_RESTORER to 0 so that the functions are not used, but this both requires executable stack (since the sh kernel does not have a vdso page with permanent restorer functions) and crashes on qemu user-level emulation.
* fix dlsym RTLD_NEXT behavior for fdpicRich Felker2015-09-221-4/+28
| | | | | | | | | | | | | | lookup the dso an address falls in based on the loadmap and not just a base/length. fix the main app's fake loadmap used when loaded by a non-fdpic-aware loader so that it does not cover the whole memory space. function descriptor addresses are also matched for future use by dladdr, but reverse lookups of function descriptors via dladdr have not been implemented yet. some revisions may be needed in the future once reclaim_gaps supports fdpic, so that function descriptors allocated in reclaimed heap space do not get detected as belonging to the module whose gaps they were allocated in.
* fix dlsym lookup of function symbols on fdpicRich Felker2015-09-221-0/+6
| | | | | | | | | | | | | | previously these resolved to the code address rather than the address of the function descriptor. the conditions for accepting or rejecting symbols are quite inconsistent between the different points in the dynamic linker code where such decisions are made. this commit attempts to be at least as correct as anything already there, but does not improve consistency. it has been tested to correctly avoid symbols that are merely references to functions defined in other modules, at least in simple usage, but at some point all symbol lookup logic should be reviewed and refactored/unified.
* have sh/fdpic entry point set fdpic personality if neededRich Felker2015-09-221-0/+12
| | | | | | | | | | | | | | | | | the entry point code supports being loaded by a loader which is not fdpic-aware (in practice, either kernel with mmu or qemu without fdpic support). this mostly just works, but signal handling will wrongly use a function descriptor address as a code address if the personality is not adjusted to fdpic. ideally this code could be placed with sigaction so that it's not needed except if/when a signal handler is installed. however, personality is incorrectly maintained per-thread by the kernel, rather than per-process, so it's necessary to correct the personality before any threads are started. also, in order to skip the personality syscall when an fdpic-aware loader is used, we need to be able to detect how the program was loaded, and this information is only readily available at the entry point.
* move calls to application init functions after crt1 entry pointRich Felker2015-09-222-1/+8
| | | | | | | | | | | | | | this change is needed to be compatible with fdpic, where some of the main application's relocations may be performed as part of the crt1 entry point. if we call init functions before passing control, these relocations will not yet have been performed, and the init code will potentially make use of invalid pointers. conceptually, no code provided by the application or third-party libraries should run before the application entry point. the difference is not observable to programs using the crt1 we provide, but it could come into play if custom entry point code is used, so it's better to be doing this right anyway.
* fix breakage in non-fdpic dynamic linker init/fini processingRich Felker2015-09-221-1/+1
| | | | | a mistaken #ifdef instead of #if caused conversion of code addresses to function descriptors to be performed even on non-fdpic.
* fix resolving interp string address on fdpic ldd commandRich Felker2015-09-221-2/+1
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* add real fdpic loading of shared librariesRich Felker2015-09-223-9/+59
| | | | | | previously, the normal ELF library loading code was used even for fdpic, so only the kernel-loaded dynamic linker and main app could benefit from separate placement of segments and shared text.
* try to suppress linking libc.so if there are undefined symbolsRich Felker2015-09-221-0/+6
| | | | | | | | | | this is always an error and usually results from failure to find/link the compiler runtime library, but it could also result from implementation errors in libc, using functions that don't (yet) exist. either way the resulting libc.so will crash mysteriously at runtime. the crash happens too early to produce a meaningful error, so these crashes are very confusing to users and waste a lot of debugging time. this commit should ensure that they do not happen.
* remove configure's suppression of enable sh/fdpic shared library buildRich Felker2015-09-221-1/+0
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* size-optimize sh/fdpic dynamic entry pointRich Felker2015-09-221-0/+4
| | | | | | the __fdpic_fixup code is not needed for ET_DYN executables, which instead use reloctions, so we can omit it from the dynamic linker and static-pie entry point and save some code size.
* work around breakage in sh/fdpic __unmapself functionRich Felker2015-09-221-0/+5
| | | | | | | | | | | | the C implementation of __unmapself used for potentially-nommu sh assumed CRTJMP takes a function descriptor rather than a code address; however, the actual dynamic linker needs a code address, and so commit 7a9669e977e5f750cf72ccbd2614f8b72ce02c4c changed the definition of the macro in reloc.h. this commit puts the old macro back in a place where it only affects __unmapself. this is an ugly workaround and should be cleaned up at some point, but at least it's well isolated.
* add general fdpic support in dynamic linker and arch support for shRich Felker2015-09-225-17/+214
| | | | | | | | | | | | | | | | | | at this point not all functionality is complete. the dynamic linker itself, and main app if it is also loaded by the kernel, take advantage of fdpic and do not need constant displacement between segments, but additional libraries loaded by the dynamic linker follow normal ELF semantics for mapping still. this fully works, but does not admit shared text on nommu. in terms of actual functional correctness, dlsym's results are presently incorrect for function symbols, RTLD_NEXT fails to identify the caller correctly, and dladdr fails almost entirely. with the dynamic linker entry point working, support for static pie is automatically included, but linking the main application as ET_DYN (pie) probably does not make sense for fdpic anyway. ET_EXEC is equally relocatable but more efficient at representing relocations.
* factor symbol counting out of dladdr as its own functionRich Felker2015-09-211-19/+20
| | | | | | | | | | | | | the fdpic code will need to count symbols, and it may be useful elsewhere in the future too. counting is trivial as long as sysv hash is present, but for gnu-hash-only libraries it's complex. the behavior of the count is changed slightly: we now include symbols that are not accessible by the gnu hash table in the count. this may make dladdr slightly slower. if this is a problem, dladdr can subtract out the part that should not be accessible. unlike in the old code, subtracting this out is easy even in the fast path where sysv hash is available too.
* simplify dlstart code by using integer type for base addressRich Felker2015-09-211-8/+7
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* refactor some more dynamic linker load address computationsRich Felker2015-09-171-7/+7
| | | | these were just missed in the previous commits.
* remove some useless casts in dynamic linkerRich Felker2015-09-171-2/+2
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* add fdpic structs and reloc types for dynamic linkingRich Felker2015-09-171-0/+16
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* further refactoring of dynamic linker load address computationsRich Felker2015-09-171-2/+2
| | | | | | | these are in do_relocs. the first one was omitted in commit 301335a80b85f12c018e4acf1a2c28615e119f8d because it slightly changes code (using dso->base rather than cached local var base) and would have prevented easy verification. the other was an oversight.
* begin refactoring load address computations in dynamic linkerRich Felker2015-09-171-19/+22
| | | | | | | | | | | | | for ordinary ELF with fixed segment displacements, load address computation is simply adding the base load address. but for FDPIC, each segment has its own load address, and virtual addresses need to be adjusted according to the segment they fall in. abstracting this computation is the first step to making the dynamic linker ready for FDPIC. for this first commit, a macro is used rather than a function in order to facilitate correctness checking. I have verified that the generated code does not change on my i386 build.
* remove old dlstart stage-2 symbolic lookup code; add new genericRich Felker2015-09-171-14/+8
| | | | | | | | | | | | | | this new generic version of the stage-2 function lookup should work for any arch where static data is accessible via got-relative or pc-relative addressing, using approximately the technique described in the log message for commit 2907afb8dbd4c1d34825c3c9bd2b41564baca210. since all the mips-like archs that need got slots fo access static data have already transitioned to the new stage chaining scheme, the old dynamic symbol lookup code is now removed. aarch64, arm, and sh have not yet transitioned; with this commit, they are now using the new generic code.
* new dlstart stage-2 chaining for x86_64 and x32Rich Felker2015-09-172-0/+10
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* new dlstart stage-2 chaining for powerpcRich Felker2015-09-171-0/+9
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* new dlstart stage-2 chaining for or1kRich Felker2015-09-171-0/+9
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* new dlstart stage-2 chaining for mipsRich Felker2015-09-171-0/+15
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* new dlstart stage-2 chaining for microblazeRich Felker2015-09-171-0/+7
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* introduce new symbol-lookup-free rcrt1/dlstart stage chainingRich Felker2015-09-172-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | previously, the call into stage 2 was made by looking up the symbol name "__dls2" (which was chosen short to be easy to look up) from the dynamic symbol table. this was no problem for the dynamic linker, since it always exports all its symbols. in the case of the static pie entry point, however, the dynamic symbol table does not contain the necessary symbol unless -rdynamic/-E was used when linking. this linking requirement is a major obstacle both to practical use of static-pie as a nommu binary format (since it greatly enlarges the file) and to upstream toolchain support for static-pie (adding -E to default linking specs is not reasonable). this patch replaces the runtime symbolic lookup with a link-time lookup via an inline asm fragment, which reloc.h is responsible for providing. in this initial commit, the asm is provided only for i386, and the old lookup code is left in place as a fallback for archs that have not yet transitioned. modifying crt_arch.h to pass the stage-2 function pointer as an argument was considered as an alternative, but such an approach would not be compatible with fdpic, where it's impossible to compute function pointers without already having performed relocations. it was also deemed desirable to keep crt_arch.h as simple/minimal as possible. in principle, archs with pc-relative or got-relative addressing of static variables could instead load the stage-2 function pointer from a static volatile object. that does not work for fdpic, and is not safe against reordering on mips-like archs that use got slots even for static functions, but it's a valid on i386 and many others, and could provide a reasonable default implementation in the future.
* remove attribute((const)) from pthread_self and errno location declsRich Felker2015-09-173-9/+0
| | | | | | | | | | | | | | | | | | | | | | this attribute was applied to pthread_self and the functions providing the locations for errno and h_errno as an optimization; however, it is subtly incorrect. as specified, it means the return value will always be the same, which is not true; it varies per-thread. this attribute also implies that the function does not depend on any state, and that calls to it can safely be reordered across any other code. however such reordering is unsafe for these functions: they break when reordered before initialization of the thread pointer. such breakage was actually observed when compiled by libfirm/cparser. to some extent the reordering problem could be solved with strong compiler barriers between the stages of early startup code, but the specified meaning of of attribute((const)) is sufficiently strong that a compiler would theoretically be justified inserting gratuitous calls to attribute((const)) const functions at random locations (e.g. to save the value in static storage for later use). this reverts commit cbf35978a9870fb1f5c73a852c986d4fcca6c2d4.
* add format argument attributes to gettext function prototypesKhem Raj2015-09-151-6/+14
| | | | | | | | | | their absence completely breaks format string warnings in programs with gettext message translations: -Wformat gives no results, and -Wformat-nonliteral produces spurious warnings. with gcc, the problem manifests only in standards-conforming profiles; otherwise gcc sets these attributes by default for the gettext family. with clang, the problem always manifests; clang has no such defaults.
* reindent powerpc's bits/termios.h to be consistent with other archsFelix Janda2015-09-151-140/+138
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* fix namespace violations in aarch64/bits/termios.hFelix Janda2015-09-151-7/+7
| | | | in analogy with commit a627eb35864d5c29a3c3300dfe83745ab1e7a00f
* add sh fdpic subarch variantsRich Felker2015-09-122-1/+20
| | | | | | | | | with this commit it should be possible to produce a working static-linked fdpic libc and application binaries for sh. the changes in reloc.h are largely unused at this point since dynamic linking is not supported, but the CRTJMP macro is used one place outside of dynamic linking, in __unmapself.
* add fdpic version of entry point code for shRich Felker2015-09-121-0/+29
| | | | | | | this version of the entry point is only suitable for static linking in ET_EXEC form. neither dynamic linking nor pie is supported yet. at some point in the future the fdpic and non-fdpic versions of this code may be unified but for now it's easiest to work with them separately.
* provide arch-generic fdpic self-relocation code for crt1 to useRich Felker2015-09-121-0/+28
| | | | | this file is intended to be included by crt_arch.h on fdpic-based targets and needs to be called from the entry point asm.
* make sh clone asm fdpic-compatibleRich Felker2015-09-122-3/+14
| | | | | | | | | | | clone calls back to a function pointer provided by the caller, which will actually be a pointer to a function descriptor on fdpic. the obvious solution is to have a separate version of clone for fdpic, but I have taken a simpler approach to go around the problem. instead of calling the pointed-to function from asm, a direct call is made to an internal C function which then calls the pointed-to function. this lets the C compiler generate the appropriate calling convention for an indirect call with no need for ABI-specific assembly.
* make sh crti/crtn init/fini fragments setup proper stack frameRich Felker2015-09-122-2/+14
| | | | | | for fdpic support is is essential that the got pointer be saved at a known, ABI-dictated offset from the frame pointer, since there is no way to recover it once it's lost.
* add sh relocation types needed for fdpic to elf.hRich Felker2015-09-121-0/+8
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* fix uninitialized scopeid in lookups from hosts file and ip literalsTimo Teräs2015-09-111-2/+2
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* fix missing earlyclobber flag in i386 a_ctz_64 asmRich Felker2015-09-091-1/+1
| | | | | | | | | this error was only found by reading the code, but it seems to have been causing gcc to produce wrong code in malloc: the same register was used for the output and the high word of the input. in principle this could have caused an infinite loop searching for an available bin, but in practice most x86 models seem to implement the "undefined" result of the bsf instruction as "unchanged".
* remove unused (and invalid) C version of sigsetjmpRich Felker2015-09-091-17/+0
| | | | | | | | | originally, the comment in this code was correct and it would likely work if the compiler generated a tail call to setjmp. however, commit 583e55122e767b1586286a0d9c35e2a4027998ab redesigned sigsetjmp and siglongjmp such that the old C implementation (which was not intended to be used) is not even conceptually correct. remove it in the interest of avoiding confusion when porting to new archs.
* fix breakage in nl_langinfo from previous commitRich Felker2015-09-091-1/+1
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