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

3 files changed, 32 insertions, 22 deletions

diff --git a/sys/arm/arm/machdep.c b/sys/arm/arm/machdep.c
index 7043a7b..1e9f5b1 100644
--- a/sys/arm/arm/machdep.c
+++ b/sys/arm/arm/machdep.c
@@ -101,11 +101,10 @@ int _min_memcpy_size = 0;
 int _min_bzero_size = 0;
 
 void
-sendsig(catcher, sig, mask, code)
+sendsig(catcher, ksi, mask)
 	sig_t catcher;
-	int sig;
+	ksiginfo_t *ksi;
 	sigset_t *mask;
-	u_long code;
 {
 	struct thread *td = curthread;
 	struct proc *p = td->td_proc;
@@ -113,9 +112,13 @@ sendsig(catcher, sig, mask, code)
 	struct sigframe *fp, frame;
 	struct sigacts *psp = td->td_proc->p_sigacts;
 	int onstack;
+	int sig;
+	int code;
 
 	onstack = sigonstack(td->td_frame->tf_usr_sp);
 
+	sig = ksi->ksi_signo;
+	code = ksi->ksi_code;
 	if ((td->td_flags & TDP_ALTSTACK) &&
 	    !(onstack) &&
 	    SIGISMEMBER(td->td_proc->p_sigacts->ps_sigonstack, sig)) {
@@ -130,8 +133,7 @@ sendsig(catcher, sig, mask, code)
 	/* make the stack aligned */
 	fp = (struct sigframe *)STACKALIGN(fp);
 	/* Populate the siginfo frame. */
-	frame.sf_si.si_signo = sig;
-	frame.sf_si.si_code = code;
+	frame.sf_si = ksi->ksi_info;
 	frame.sf_uc.uc_sigmask = *mask;
 	frame.sf_uc.uc_link = NULL;
 	frame.sf_uc.uc_flags = (td->td_pflags & TDP_ALTSTACK ) 
@@ -436,17 +438,6 @@ exec_setregs(struct thread *td, u_long entry, u_long stack, u_long ps_strings)
 }
 
 /*
- * Build siginfo_t for SA thread
- */
-void
-cpu_thread_siginfo(int sig, u_long code, siginfo_t *si)
-{
-	bzero(si, sizeof(*si));
-	si->si_signo = sig;
-	si->si_code = code;
-}
-
-/*
  * Get machine context.
  */
 int
diff --git a/sys/arm/arm/trap.c b/sys/arm/arm/trap.c
index 8248783..f858af0 100644
--- a/sys/arm/arm/trap.c
+++ b/sys/arm/arm/trap.c
@@ -184,8 +184,12 @@ static const struct data_abort data_aborts[] = {
 static __inline void
 call_trapsignal(struct thread *td, int sig, u_long code)
 {
+	ksiginfo_t ksi;
 
-	trapsignal(td, sig, code);
+	ksiginfo_init_trap(&ksi);
+	ksi.ksi_signo = sig;
+	ksi.ksi_code = (int)code;
+	trapsignal(td, &ksi);
 }
 
 static __inline int
@@ -875,7 +879,7 @@ syscall(struct thread *td, trapframe_t *frame, u_int32_t insn)
 		nap = 4;
 		break;
 	default:
-		trapsignal(td, SIGILL, 0);
+		call_trapsignal(td, SIGILL, 0);
 		userret(td, frame, td->td_sticks);
 		return;
 	}
@@ -993,7 +997,7 @@ swi_handler(trapframe_t *frame)
 	 * don't take an alignment fault trying to read the opcode.
 	 */
 	if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) {
-		trapsignal(td, SIGILL, 0);
+		call_trapsignal(td, SIGILL, 0);
 		userret(td, frame, td->td_sticks);
 		return;
 	}
diff --git a/sys/arm/arm/undefined.c b/sys/arm/arm/undefined.c
index 3d7d3cb..94a3ec1 100644
--- a/sys/arm/arm/undefined.c
+++ b/sys/arm/arm/undefined.c
@@ -134,11 +134,17 @@ static int
 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code)
 {
 	struct thread *td;
+	ksiginfo_t ksi;
+
 	td = (curthread == NULL) ? &thread0 : curthread;
 
 	if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) {
 		if (code == FAULT_USER) {
-			trapsignal(td, SIGTRAP, 0);
+			ksiginfo_init_trap(&ksi);
+			ksi.ksi_signo = SIGTRAP;
+			ksi.ksi_code = TRAP_BRKPT;
+			ksi.ksi_addr = (u_int32_t *)addr;
+			trapsignal(td, &ksi);
 			return 0;
 		}
 #if 0
@@ -179,6 +185,7 @@ undefinedinstruction(trapframe_t *frame)
 #ifdef VERBOSE_ARM32
 	int s;
 #endif
+	ksiginfo_t ksi;
 
 	/* Enable interrupts if they were enabled before the exception. */
 	if (!(frame->tf_spsr & I32_bit))
@@ -200,7 +207,11 @@ undefinedinstruction(trapframe_t *frame)
 	 * don't take an alignment fault trying to read the opcode.
 	 */
 	if (__predict_false((fault_pc & 3) != 0)) {
-		trapsignal(td, SIGILL, 0);
+		ksiginfo_init_trap(&ksi);
+		ksi.ksi_signo = SIGILL;
+		ksi.ksi_code = ILL_ILLADR;
+		ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
+		trapsignal(td, &ksi);
 		userret(td, frame, 0);
 		return;
 	}
@@ -256,7 +267,11 @@ undefinedinstruction(trapframe_t *frame)
 
 	if (uh == NULL && (fault_code & FAULT_USER)) {
 		/* Fault has not been handled */
-		trapsignal(td, SIGILL, 0);
+		ksiginfo_init_trap(&ksi);
+		ksi.ksi_signo = SIGILL;
+		ksi.ksi_code = ILL_ILLOPC;
+		ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
+		trapsignal(td, &ksi);
 	}
 
 	if ((fault_code & FAULT_USER) == 0) {