1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most

   changes in MD code are trivial, before this change, trapsignal and
   sendsig use discrete parameters, now they uses member fields of
   ksiginfo_t structure. For sendsig, this change allows us to pass
   POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
   generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
   blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
   thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
   be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
   an extra siginfo list holds additional siginfo_t data for signals.
   kernel code uses psignal() still behavior as before, it won't be failed
   even under memory pressure, only exception is when deleting a signal,
   we should call sigqueue_delete to remove signal from sigqueue but
   not SIGDELSET. Current there is no kernel code will deliver a signal
   with additional data, so kernel should be as stable as before,
   a ksiginfo can carry more information, for example, allow signal to
   be delivered but throw away siginfo data if memory is not enough.
   SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
   not be caught or masked.
   The sigqueue() syscall allows user code to queue a signal to target
   process, if resource is unavailable, EAGAIN will be returned as
   specification said.
   Just before thread exits, signal queue memory will be freed by
   sigqueue_flush.
   Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64

1 files changed, 5 insertions, 1 deletions

diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index 4574aad..c305dc0 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -155,6 +155,7 @@ ast(struct trapframe *framep)
 	int sig;
 #if defined(DEV_NPX) && !defined(SMP)
 	int ucode;
+	ksiginfo_t ksi;
 #endif
 
 	td = curthread;
@@ -217,7 +218,10 @@ ast(struct trapframe *framep)
 		    PCB_NPXTRAP);
 		ucode = npxtrap();
 		if (ucode != -1) {
-			trapsignal(td, SIGFPE, ucode);
+			ksiginfo_init_trap(&ksi);
+			ksi.ksi_signo = SIGFPE;
+			ksi.ksi_code = ucode;
+			trapsignal(td, &ksi);
 		}
 	}
 #endif