path: root/arch/sh/crt_arch.h
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2015-11-02generalize sh entry point asm not to assume call dests fit in 12 bitsRich Felker-5/+12
this assumption is borderline-unsafe to begin with, and fails badly with -ffunction-sections since the linker can move the callee arbitrarily far away when it lies in a different section.
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.
2015-09-22size-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.
2015-09-22add general fdpic support in dynamic linker and arch support for shRich Felker-0/+3
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.
2015-09-12add fdpic version of entry point code for shRich Felker-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.
2015-05-22add .text section directive to all crt_arch.h files missing itRich Felker-0/+1
i386 and x86_64 versions already had the .text directive; other archs did not. normally, top-level (file scope) __asm__ starts in the .text section anyway, but problems were reported with some versions of clang, and it seems preferable to set it explicitly anyway, at least for the sake of consistency between archs.
2015-04-13dynamic linker bootstrap overhaulRich Felker-9/+19
this overhaul further reduces the amount of arch-specific code needed by the dynamic linker and removes a number of assumptions, including: - that symbolic function references inside libc are bound at link time via the linker option -Bsymbolic-functions. - that libc functions used by the dynamic linker do not require access to data symbols. - that static/internal function calls and data accesses can be made without performing any relocations, or that arch-specific startup code handled any such relocations needed. removing these assumptions paves the way for allowing itself to be built with stack protector (among other things), and is achieved by a three-stage bootstrap process: 1. relative relocations are processed with a flat function. 2. symbolic relocations are processed with no external calls/data. 3. main program and dependency libs are processed with a fully-functional libc/ldso. reduction in arch-specific code is achived through the following: - crt_arch.h, used for generating crt1.o, now provides the entry point for the dynamic linker too. - asm is no longer responsible for skipping the beginning of argv[] when ldso is invoked as a command. - the functionality previously provided by __reloc_self for heavily GOT-dependent RISC archs is now the arch-agnostic stage-1. - arch-specific relocation type codes are mapped directly as macros rather than via an inline translation function/switch statement.
2014-03-16superh: fix dynamic linking of __fpscr_valuesBobby Bingham-0/+3
Applications ended up with copy relocations for this array, which resulted in libc's references to this array pointing to the application's copy. The dynamic linker, however, can require this array before the application is relocated, and therefore before the application's copy of this array is initialized. This resulted in garbage being loaded into FPSCR before executing main, which violated the ABI. We fix this by putting the array in crt1 and making the libc copy private. This prevents libc's reference to the array from pointing to an uninitialized copy in the application.
2014-02-27rename superh port to "sh" for consistencyRich Felker-0/+9
linux, gcc, etc. all use "sh" as the name for the superh arch. there was already some inconsistency internally in musl: the dynamic linker was searching for "ld-musl-sh.path" as its path file despite its own name being "". there was some sentiment in both directions as to how to resolve the inconsistency, but overall "sh" was favored.