Pass array length to getcallerpcs

b0ecf098 · Silas Boyd-Wickizer · 96068001 · b0ecf098 · b0ecf098 · b0ecf098
--- a/console.c
+++ b/console.c
@@ -182,7 +182,7 @@ kerneltrap(struct trapframe *tf)
          tf->trapno, mycpu()->id, 
          tf->rip, tf->rsp, rcr2(),
          name, pid, kstack);
-  getcallerpcs((void*)tf->rbp, pc);
+  getcallerpcs((void*)tf->rbp, pc, NELEM(pc));
  for (i = 0; i < NELEM(pc) && pc[i] != 0; i++)
    __cprintf("  %p\n", pc[i]);


--- a/kernel.h
+++ b/kernel.h
@@ -299,7 +299,7 @@ void            swtch(struct context**, struct context*);
 extern struct segdesc bootgdt[NSEGS];
 void            pushcli(void);
 void            popcli(void);
-void            getcallerpcs(void*, uptr*);
+void            getcallerpcs(void*, uptr*, int);

 // uart.c
 void            uartputc(char c);

--- a/proc.c
+++ b/proc.c
@@ -507,6 +507,7 @@ void *procdump(void *vk, void *v, void *arg)
  struct proc *p = (struct proc *) v;
  const char *name = "(no name)";
  const char *state;
+  uptr pc[10];

  if(p->state >= 0 && p->state < NELEM(states) && states[p->state])
    state = states[p->state];
@@ -518,9 +519,8 @@ void *procdump(void *vk, void *v, void *arg)

  cprintf("\n%-3d %-10s %8s %2u  %lu\n", p->pid, name, state, p->cpuid, p->tsc);

-  uptr pc[10];
  if(p->state == SLEEPING){
-    getcallerpcs((void*)p->context->rbp, pc);
+    getcallerpcs((void*)p->context->rbp, pc, NELEM(pc));
    for(int i=0; i<10 && pc[i] != 0; i++)
      cprintf(" %lx\n", pc[i]);
  }

--- a/spinlock.c
+++ b/spinlock.c
@@ -40,7 +40,7 @@ tryacquire(struct spinlock *lk)
 #if SPINLOCK_DEBUG
  // Record info about lock acquisition for debugging.
  lk->cpu = mycpu();
-  getcallerpcs(&lk, lk->pcs);
+  getcallerpcs(&lk, lk->pcs, NELEM(lk->pcs));
 #endif
  return 1;
 }
@@ -72,7 +72,7 @@ acquire(struct spinlock *lk)
 #if SPINLOCK_DEBUG
  // Record info about lock acquisition for debugging.
  lk->cpu = mycpu();
-  getcallerpcs(&lk, lk->pcs);
+  getcallerpcs(&lk, lk->pcs, NELEM(lk->pcs));
 #endif
 }


--- a/trap.c
+++ b/trap.c
@@ -234,18 +234,18 @@ popcli(void)

 // Record the current call stack in pcs[] by following the %rbp chain.
 void
-getcallerpcs(void *v, uptr pcs[])
+getcallerpcs(void *v, uptr pcs[], int n)
 {
  uptr *rbp;
  int i;

  rbp = (uptr*)v;
-  for(i = 0; i < 10; i++){
+  for(i = 0; i < n; i++){
    if(rbp == 0 || rbp < (uptr*)KBASE || rbp == (uptr*)(~0UL))
      break;
    pcs[i] = rbp[1];     // saved %rip
    rbp = (uptr*)rbp[0]; // saved %rbp
  }
-  for(; i < 10; i++)
+  for(; i < n; i++)
    pcs[i] = 0;
 }