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2015-10-23prevent user CFLAGS overrides from exposing executable stackRich Felker-7/+7
the option to suppress executable stack tagging was placed in CFLAGS, which is treated as optional and overridable by the build system. if a user replaces CFLAGS after configure has run, it could get lost, resulting in a libc.so that's flagged as needing executable stack, which would cause the kernel to map the initial stack as executable. move -Wa,--noexecstack to CFLAGS_C99FSE, the make variable used for mandatory compiler options.
2015-10-22fix breakage when user overrides CFLAGS on the make command lineRich Felker-4/+4
these per-target CFLAGS adjustments are mandatory additions to the command line for building the affected targets, not part of the user-provided CFLAGS for tuning. my intent was always that the variable append operations would take place after user settings, but when a variable is set on the command line, it overrides all definitions in the makefile, including target-specific ones. based on patch by Szabolcs Nagy.
2015-10-19release 1.1.12v1.1.12Rich Felker-1/+36
2015-10-19declare fpu usage to the assembler in arm hard-float asm filesSzabolcs Nagy-0/+6
Some armhf gcc toolchains (built with --with-float=hard but without --with-fpu=vfp*) do not pass -mfpu=vfp to the assembler and then binutils rejects the UAL mnemonics for VFP unless there is an .fpu vfp directive in the asm source.
2015-10-15add missing memory barrier to pthread_joinBobby Bingham-0/+1
POSIX requires pthread_join to synchronize memory on success. The futex wait inside __timedwait_cp cannot handle this because it's not called in all cases. Also, in the case of a spurious wake, tid can become zero between the wake and when the joining thread checks it.
2015-10-15fix dladdr treatment of function descriptors for fdpicRich Felker-9/+22
when determining which module an address belongs to, all function descriptor ranges must be checked first, in case the allocated memory falls inside another module's memory range. dladdr itself must also check addresses against function descriptors before doing a best-match search against the symbol table. even when doing the latter (e.g. for code addresses obtained from mcontext_t), also check whether the best-match was a function, and if so, replace the result with a function descriptor address. which is the nominal "base address" of the function and which the caller needs if it intends to subsequently call the matching function.
2015-10-15fix visibility mismatch in dynamic linker stage 2 function definitionRich Felker-0/+2
since commits 2907afb8dbd4c1d34825c3c9bd2b41564baca210 and 6fc30c2493fcfedec89e45088bea87766a1e3286, __dls2 is no longer called via symbol lookup, but instead uses relative addressing that needs to be resolved at link time. on some linker versions, and/or if -Bsymbolic-functions is not used, the linker may leave behind a dynamic relocation, which is not suitable for bootstrapping the dynamic linker, if the reference to __dls2 is marked hidden but the definition is not actually hidden. correcting the definition to use hidden visibility fixes the problem. the static-PIE entry point rcrt1 was likewise affected and is also fixed by this patch.
2015-10-15suppress sh assembler rejection of instructions based on isa levelRich Felker-0/+1
we need access to all instructions in order for runtime selection of atomic model to work correctly. without this patch, some versions of gcc instruct gas to reject instructions outside the target isa level.
2015-10-15prevent reordering of or1k and powerpc thread pointer loadsRich Felker-0/+2
other archs use asm for the thread pointer load, so making that asm volatile is sufficient to inform the compiler that it has a "side effect" (crashing or giving the wrong result if the thread pointer was not yet initialized) that prevents reordering. however, powerpc and or1k have dedicated general purpose registers for the thread pointer and did not need to use any asm to access it; instead, "local register variables with a specified register" were used. however, there is no specification for ordering constraints on this type of usage, and presumably use of the thread pointer could be reordered across its initialization. to impose an ordering, I have added empty volatile asm blocks that produce the "local register variable with a specified register" as an output constraint.
2015-10-15mark arm thread-pointer-loading inline asm as volatileRich Felker-3/+3
this builds on commits a603a75a72bb469c6be4963ed1b55fabe675fe15 and 0ba35d69c0e77b225ec640d2bd112ff6d9d3b2af to ensure that a compiler cannot conclude that it's valid to reorder the asm to a point before the thread pointer is set up, or to treat the inline function as if it were declared with attribute((const)). other archs already use volatile asm for thread pointer loading.
2015-10-15add comment documenting hard-coded opcode for reading mips thread pointerRich Felker-0/+1
2015-10-15remove attribute((const)) from arm __pthread_self inline functionRich Felker-2/+2
commit a603a75a72bb469c6be4963ed1b55fabe675fe15 did this for the public pthread_self function but not the internal inline one.
2015-10-14fix strftime handling of out-of-range struct tm fieldsRich Felker-8/+12
strftime results are unspecified in this case, but should not invoke undefined behaviour. tm_wday, tm_yday, tm_mon and tm_year fields were used in signed int arithmetic that could overflow. based on patch by Szabolcs Nagy.
2015-10-14remove hand-written crt1.s and Scrt1.s files for all archsRich Felker-192/+0
since commit c5e34dabbb47d8e97a4deccbb421e0cd93c0094b, crt1.c has provided a "mostly-C" implementation of the crt1 start file that avoids the need for arch-specific symbol referencing, PIC/PIE-specific code variants, etc. but for archs that had existing hand-written versions, the new code was initially unused, and later only used as the dynamic linker entry point. this commit switches all archs to using the new code. the code being removed was a recurring source of subtle errors, and was still broken at least on arm, where it failed to properly align the stack pointer before calling into C code.
2015-10-13add CFI generation script for x86_64Alex Dowad-0/+196
2015-10-13recognize partial register operands in i386 CFI generationAlex Dowad-10/+19
2015-10-13fix misinterpretation of indexed memory operand in i386 CFI generationAlex Dowad-1/+1
a register used as an index in the memory destination of a mov instruction was wrongly interpreted as the destination of the mov.
2015-10-13fix misinterpretation of operand order in i386 CFI generationAlex Dowad-5/+5
binary ops like ADD, AND, etc. modify the 2nd operand, not 1st.
2015-10-08fix integer overflows in time_t/struct tm conversion codeRich Felker-3/+3
as found and reported by Brian Mastenbrook, the expressions 400*qc_cycles and years+100 in __secs_to_tm were both subject to integer overflow for extreme values of the input t. this patch by Szabolcs Nagy fixes the code by switching to larger types, and matches the original intent I had in mind when writing this code.
2015-10-08fix open_[w]memstream behavior when no writes take placeRich Felker-4/+18
the specification for these functions requires that the buffer/size exposed to the caller be valid after any successful call to fflush or fclose on the stream. the implementation's approach is to update them only at flush time, but that misses the case where fflush or fclose is called without any writes having taken place, in which case the write flushing callback will not be called. to fix both the observable bug and the desired invariant, setup empty buffers at open time and fail the open operation if no memory is available.
2015-10-08fix instruction matching errors in i386 CFI generationAlex Dowad-3/+3
fdiv and fmul instructions were wrongly matched by the rules for integer div and mul instructions, leading to incorrect conclusions about register values being clobbered.
2015-10-08factor common awk functions for CFI generation scripts into new fileAlex Dowad-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.
2015-10-01make nl_langinfo(CODESET) always return "ASCII" in byte-based C localeRich Felker-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.
2015-10-01fix mips fesetround failure to write back resulting modeRich Felker-0/+1
patch by Anand Takale.
2015-09-29eliminate protected-visibility data in libc.so with vis.h preincludeRich Felker-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.
2015-09-25avoid attempting to lookup IP literals as hostnamesRich Felker-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.
2015-09-25make getaddrinfo return error if both host and service name are nullRich Felker-0/+2
this case is specified as a mandatory ("shall fail") error. based on patch by Julien Ramseier.
2015-09-24fix localeconv field value for unavailable valuesRich Felker-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.
2015-09-24avoid reading uninitialized memory in __map_fileSzabolcs Nagy-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).
2015-09-24regcomp: propagate allocation failuresSzabolcs Nagy-1/+2
The error code of an allocating function was not checked in tre_add_tag.
2015-09-23fix signal return for sh/fdpicRich Felker-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.
2015-09-22fix dlsym RTLD_NEXT behavior for fdpicRich Felker-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.
2015-09-22fix dlsym lookup of function symbols on fdpicRich Felker-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.
2015-09-22have sh/fdpic entry point set fdpic personality if neededRich Felker-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.
2015-09-22move calls to application init functions after crt1 entry pointRich Felker-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.
2015-09-22fix breakage in non-fdpic dynamic linker init/fini processingRich Felker-1/+1
a mistaken #ifdef instead of #if caused conversion of code addresses to function descriptors to be performed even on non-fdpic.
2015-09-22fix resolving interp string address on fdpic ldd commandRich Felker-2/+1
2015-09-22add real fdpic loading of shared librariesRich Felker-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.
2015-09-22try to suppress linking libc.so if there are undefined symbolsRich Felker-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.
2015-09-22remove configure's suppression of enable sh/fdpic shared library buildRich Felker-1/+0
2015-09-22size-optimize sh/fdpic dynamic entry pointRich Felker-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.
2015-09-22work around breakage in sh/fdpic __unmapself functionRich Felker-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.
2015-09-22add general fdpic support in dynamic linker and arch support for shRich Felker-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.
2015-09-21factor symbol counting out of dladdr as its own functionRich Felker-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.
2015-09-21simplify dlstart code by using integer type for base addressRich Felker-8/+7
2015-09-17refactor some more dynamic linker load address computationsRich Felker-7/+7
these were just missed in the previous commits.
2015-09-17remove some useless casts in dynamic linkerRich Felker-2/+2
2015-09-17add fdpic structs and reloc types for dynamic linkingRich Felker-0/+16
2015-09-17further refactoring of dynamic linker load address computationsRich Felker-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.
2015-09-17begin refactoring load address computations in dynamic linkerRich Felker-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.