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path: root/arch/sh/pthread_arch.h
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2018-10-16make thread-pointer-loading asm non-volatileRich Felker1-1/+1
this will allow the compiler to cache and reuse the result, meaning we no longer have to take care not to load it more than once for the sake of archs where the load may be expensive. depends on commit 1c84c99913bf1cd47b866ed31e665848a0da84a2 for correctness, since otherwise the compiler could hoist loads during stage 3 of dynamic linking before the initial thread-pointer setup.
2018-08-29fix async thread cancellation on sh-fdpicRich Felker1-0/+5
if __cp_cancel was reached via __syscall_cp, r12 will necessarily still contain a GOT pointer (for libc.so or for the static-linked main program) valid for entering __cancel. however, in the case of async cancellation, r12 may contain any scratch value; it's not necessarily even a valid GOT pointer for the code that was interrupted. unlike in commit 0ec49dab6794166d67fae4764ce7fdea42ea6103 where the corresponding issue was fixed for powerpc64, there is fundamentally no way for fdpic code to recompute its GOT pointer. so a new mechanism is introduced for cancel_handler to write a GOT register value into the interrupted context on archs where it is needed.
2018-06-02fix TLS layout of TLS variant I when there is a gap above TPSzabolcs Nagy1-2/+3
In TLS variant I the TLS is above TP (or above a fixed offset from TP) but on some targets there is a reserved gap above TP before TLS starts. This matters for the local-exec tls access model when the offsets of TLS variables from the TP are hard coded by the linker into the executable, so the libc must compute these offsets the same way as the linker. The tls offset of the main module has to be alignup(GAP_ABOVE_TP, main_tls_align). If there is no TLS in the main module then the gap can be ignored since musl does not use it and the tls access models of shared libraries are not affected. The previous setup only worked if (tls_align & -GAP_ABOVE_TP) == 0 (i.e. TLS did not require large alignment) because the gap was treated as a fixed offset from TP. Now the TP points at the end of the pthread struct (which is aligned) and there is a gap above it (which may also need alignment). The fix required changing TP_ADJ and __pthread_self on affected targets (aarch64, arm and sh) and in the tlsdesc asm the offset to access the dtv changed too.
2015-11-02properly access mcontext_t program counter in cancellation handlerRich Felker1-1/+1
using the actual mcontext_t definition rather than an overlaid pointer array both improves correctness/readability and eliminates some ugly hacks for archs with 64-bit registers bit 32-bit program counter. also fix UB due to comparison of pointers not in a common array object.
2014-02-27rename superh port to "sh" for consistencyRich Felker1-0/+11
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 "ld-musl-superh.so.1". there was some sentiment in both directions as to how to resolve the inconsistency, but overall "sh" was favored.