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path: root/src/signal/microblaze/sigsetjmp.s
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2015-04-19remove invalid PLT calls from microblaze asmRich Felker1-2/+3
analogous to commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 for sh.
2015-04-17redesign sigsetjmp so that signal mask is restored after longjmpRich Felker1-13/+13
the conventional way to implement sigsetjmp is to save the signal mask then tail-call to setjmp; siglongjmp then restores the signal mask and calls longjmp. the problem with this approach is that a signal already pending, or arriving between unmasking of signals and restoration of the saved stack pointer, will have its signal handler run on the stack that was active before siglongjmp was called. this can lead to unbounded stack usage when siglongjmp is used to leave a signal handler. in the new design, sigsetjmp saves its own return address inside the extended part of the sigjmp_buf (outside the __jmp_buf part used by setjmp) then calls setjmp to save a jmp_buf inside its own execution. it then tail-calls to __sigsetjmp_tail, which uses the return value of setjmp to determine whether to save the current signal mask or restore a previously-saved mask. as an added bonus, this design makes it so that siglongjmp and longjmp are identical. this is useful because the __longjmp_chk function we need to add for ABI-compatibility assumes siglongjmp and longjmp are the same, but for different reasons -- it was designed assuming either can access a flag just past the __jmp_buf indicating whether the signal masked was saved, and act on that flag. however, early versions of musl did not have space past the __jmp_buf for the non-sigjmp_buf version of jmp_buf, so our setjmp cannot store such a flag without risking clobbering memory on (very) old binaries.
2014-04-02add __sigsetjmp ABI-compat alias for sigsetjmpRich Felker1-0/+3
2012-10-18fix (hopefully; untested) completely broken/incomplete microblaze sigsetjmpRich Felker1-3/+12
2012-10-17fix microblaze asm relocations for shared libcRich Felker1-2/+2
only @PLT relocations are considered functions for purposes of -Bsymbolic-functions, so always use @PLT. it should not hurt in the static-linked case.
2012-09-29microblaze portRich Felker1-0/+9
based on initial work by rdp, with heavy modifications. some features including threads are untested because qemu app-level emulation seems to be broken and I do not have a proper system image for testing.