# HG changeset patch
# User Noah Evans <noah.evans@gmail.com>
# Date 1316446916 -7200
# Node ID b8d65a4850098db4f3d4cacb115e2116f3dae52c
# Parent  9adfd913d396d815b6dda8309eb907ec4e60321d
syscall.c: reenable ratrace.

R=rminnich, nix-dev, nemo
CC=john, nemo.mbox, nix-dev
http://codereview.appspot.com/5049044

diff -r 9adfd913d396 -r b8d65a485009 sys/src/nix/k10/syscall.c
--- a/sys/src/nix/k10/syscall.c	Mon Sep 19 17:39:00 2011 +0200
+++ b/sys/src/nix/k10/syscall.c	Mon Sep 19 17:41:56 2011 +0200
@@ -234,6 +234,7 @@
 	char *e;
 	uintptr	sp;
 	int s;
+	vlong startns, stopns;
 	Ar0 ar0;
 	static Ar0 zar0;
 
@@ -260,10 +261,27 @@
 	up->insyscall = 1;
 	up->pc = ureg->ip;
 	up->dbgreg = ureg;
+	sp = ureg->sp;
+	startns = 0;
 
 	if(up->procctl == Proc_tracesyscall){
+		/*
+		 * Redundant validaddr.  Do we care?
+		 * Tracing syscalls is not exactly a fast path...
+		 * Beware, validaddr currently does a pexit rather
+		 * than an error if there's a problem; that might
+		 * change in the future.
+		 */
+		if(sp < (USTKTOP-BIGPGSZ) || sp > (USTKTOP-sizeof(up->arg)-BY2SE))
+			validaddr(UINT2PTR(sp), sizeof(up->arg)+BY2SE, 0);
+
+		syscallfmt(scallnr, (va_list)(sp+BY2SE));	
 		up->procctl = Proc_stopme;
 		procctl(up);
+		if(up->syscalltrace)
+			free(up->syscalltrace);
+		up->syscalltrace = nil;
+		startns = todget(nil);		
 	}
 
 	up->scallnr = scallnr;
@@ -329,10 +347,15 @@
 	ureg->ax = ar0.p;
 
 	if(up->procctl == Proc_tracesyscall){
+		stopns = todget(nil);
 		up->procctl = Proc_stopme;
+		sysretfmt(scallnr, (va_list)(sp+BY2SE), &ar0, startns, stopns);
 		s = splhi();
 		procctl(up);
 		splx(s);
+		if(up->syscalltrace)
+			free(up->syscalltrace);
+		up->syscalltrace = nil;		
 	}else if(up->procctl == Proc_totc || up->procctl == Proc_toac)
 		procctl(up);