Skip to content

Q
qemu

openeuler / qemu

通知 10
Star 0
Fork 0
Q
qemu

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 24 2月, 2013 1 次提交
    • P
      Replace all setjmp()/longjmp() with sigsetjmp()/siglongjmp() · 6ab7e546
      由 Peter Maydell 提交于 
      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: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Tested-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NLaszlo Ersek <lersek@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>
      6ab7e546
  3. 23 2月, 2013 1 次提交
  5. 19 12月, 2012 1 次提交
  7. 18 4月, 2010 1 次提交
  9. 07 3月, 2010 1 次提交
  11. 17 7月, 2009 1 次提交
  13. 08 3月, 2009 2 次提交
  15. 05 1月, 2009 1 次提交
  17. 03 10月, 2008 1 次提交
  19. 27 8月, 2008 1 次提交
  21. 26 8月, 2008 1 次提交
  23. 22 8月, 2008 1 次提交
  25. 21 7月, 2008 1 次提交
  27. 18 11月, 2007 1 次提交
  29. 13 10月, 2004 1 次提交
  31. 18 3月, 2004 1 次提交
  33. 09 6月, 2003 1 次提交
  35. 10 4月, 2003 1 次提交
  37. 19 3月, 2003 1 次提交