diff options
| author | Christopher Faylor <me@cgf.cx> | 2001-01-27 05:23:46 +0300 |
|---|---|---|
| committer | Christopher Faylor <me@cgf.cx> | 2001-01-27 05:23:46 +0300 |
| commit | 206a8d884b0386bb0b88872f8a044835897074f4 (patch) | |
| tree | a6c144ea202e9580cb934124897a20af1f8a0f8c /winsup/cygwin/exceptions.cc | |
| parent | 7646d1a111e689ba2f25fcc26de9a1668547de8a (diff) | |
* exceptions.cc (sigreturn): Call any pending signals prior to resetting the
signal mask so that stacked signals behave correctly.
(sigdelayed): Avoid a race where a signal could end up calling an incorrect
signal handler if two signals come in close together.
Diffstat (limited to 'winsup/cygwin/exceptions.cc')
| -rw-r--r-- | winsup/cygwin/exceptions.cc | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc index 9a51f49f1..f3135843b 100644 --- a/winsup/cygwin/exceptions.cc +++ b/winsup/cygwin/exceptions.cc @@ -653,7 +653,6 @@ interrupt_setup (int sig, void *handler, DWORD retaddr, DWORD *retaddr_on_stack, { sigsave.retaddr = retaddr; sigsave.retaddr_on_stack = retaddr_on_stack; - sigsave.oldmask = myself->getsigmask (); // Remember for restoration /* FIXME: Not multi-thread aware */ sigsave.newmask = myself->getsigmask () | siga.sa_mask | SIGTOMASK (sig); sigsave.sa_flags = siga.sa_flags; @@ -738,9 +737,9 @@ set_sig_errno (int e) // sigproc_printf ("errno %d", e); } -static int call_handler (int, void *, struct sigaction&) __attribute__((regparm(3))); +static int setup_handler (int, void *, struct sigaction&) __attribute__((regparm(3))); static int -call_handler (int sig, void *handler, struct sigaction& siga) +setup_handler (int sig, void *handler, struct sigaction& siga) { CONTEXT cx; bool interrupted = 0; @@ -860,7 +859,7 @@ set_pending: #endif /* i386 */ #ifndef HAVE_CALL_HANDLER -#error "Need to supply machine dependent call_handler" +#error "Need to supply machine dependent setup_handler" #endif /* Keyboard interrupt handler. */ @@ -1000,7 +999,7 @@ stop: dosig: /* Dispatch to the appropriate function. */ sigproc_printf ("signal %d, about to call %p", sig, handler); - rc = call_handler (sig, handler, thissig); + rc = setup_handler (sig, handler, thissig); done: sigproc_printf ("returning %d", rc); @@ -1123,13 +1122,23 @@ _sigreturn: addl $4,%%esp # Remove argument movl %%esp,%%ebp addl $36,%%ebp - call _set_process_mask@4 + + cmpl $0,%4 # Did a signal come in? + jz 1f # No, if zero + call _call_signal_handler@0 # yes handle the signal + +# FIXME: There is a race here. The signal handler could set up +# the sigsave structure between _call_signal_handler and the +# end of _set_process_mask. This would make cygwin detect an +# incorrect signal mask. + +1: call _set_process_mask@4 popl %%eax # saved errno testl %%eax,%%eax # Is it < 0 - jl 1f # yup. ignore it + jl 2f # yup. ignore it movl %1,%%ebx movl %%eax,(%%ebx) -1: popl %%eax +2: popl %%eax popl %%ebx popl %%ecx popl %%edx @@ -1158,11 +1167,13 @@ _sigdelayed0: pushl $_sigreturn call _reset_signal_arrived@0 + pushl %5 movl $0,%0 pushl %8 call _set_process_mask@4 - jmp *%5 + popl %%eax + jmp *%%eax __no_sig_end: " : "=m" (sigsave.sig) : "m" (&_impure_ptr->_errno), |