save process name for debugging

proc.h

@@ -40,6 +40,7 @@ struct proc {
   struct inode *cwd;        // Current directory
   struct jmpbuf jmpbuf;     // Jump here to run process
   struct trapframe *tf;     // Trap frame for current interrupt
+  char name[16];            // Process name (debugging)
 };
 
 // Process memory is laid out contiguously:

sysfile.c

@@ -322,7 +322,7 @@ sys_exec(void)
   struct elfhdr elf;
   struct proghdr ph;
   char *mem = 0;
-  char *path, *s;
+  char *path, *s, *last;
   uint argv;
   
   if(argstr(0, &path) < 0 || argint(1, (int*)&argv) < 0)
@@ -399,6 +399,12 @@ sys_exec(void)
   }
   *(uint*)(mem + p1) = 0;
 
+  // Save name for debugging.
+  for(last=s=path; *s; s++)
+    if(*s == '/')
+      last = s+1;
+  safestrcpy(cp->name, last, sizeof cp->name);
+
   // commit to the new image.
   kfree(cp->mem, cp->sz);
   cp->sz = sz;
@@ -419,7 +425,7 @@ sys_exec(void)
   }
 
   iput(ip);
-
+  
   cp->tf->eip = elf.entry;
   cp->tf->esp = sp;
   setupsegs(cp);

trap.c

@@ -80,10 +80,10 @@ trap(struct trapframe *tf)
     break;
     
   default:
-    if(curproc[cpu()]) {
+    if(cp) {
       // Assume process divided by zero or dereferenced null, etc.
-      cprintf("pid %d: unhandled trap %d on cpu %d eip %x -- kill proc\n",
-              curproc[cpu()]->pid, v, cpu(), tf->eip);
+      cprintf("pid %d %s: unhandled trap %d on cpu %d eip %x -- kill proc\n",
+              cp->pid, cp->name, v, cpu(), tf->eip);
       proc_exit();
     }