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The setjmp() function doesn't specify whether signal masks are saved and restored; on Linux they are not, but on BSD (including MacOSX) they are. We want to have consistent behaviour across platforms, so we should always use "don't save/restore signal mask" (this is also generally going to be faster). This also works around a bug in MacOSX where the signal-restoration on longjmp() affects the signal mask for a completely different thread, not just the mask for the thread which did the longjmp. The most visible effect of this was that ctrl-C was ignored on MacOSX because the CPU thread did a longjmp which resulted in its signal mask being applied to every thread, so that all threads had SIGINT and SIGTERM blocked. The POSIX-sanctioned portable way to do a jump without affecting signal masks is to siglongjmp() to a sigjmp_buf which was created by calling sigsetjmp() with a zero savemask parameter, so change all uses of setjmp()/longjmp() accordingly. [Technically POSIX allows sigsetjmp(buf, 0) to save the signal mask; however the following siglongjmp() must not restore the signal mask, so the pair can be effectively considered as "sigjmp/longjmp which don't touch the mask".] For Windows we provide a trivial sigsetjmp/siglongjmp in terms of setjmp/longjmp -- this is OK because no user will ever pass a non-zero savemask. The setjmp() uses in tests/tcg/test-i386.c and tests/tcg/linux-test.c are left untouched because these are self-contained singlethreaded test programs intended to be run under QEMU's Linux emulation, so they have neither the portability nor the multithreading issues to deal with. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Tested-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com> |
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| arch_init.h | ||
| balloon.h | ||
| blockdev.h | ||
| cpus.h | ||
| device_tree.h | ||
| dma.h | ||
| dump.h | ||
| kvm.h | ||
| memory_mapping.h | ||
| os-posix.h | ||
| os-win32.h | ||
| qtest.h | ||
| seccomp.h | ||
| sysemu.h | ||
| xen-mapcache.h | ||