xv6

commit 8c59677fe8d560d2a52406294e114dcc0124911f
parent 3121e29fbb5db64ed76b5682d9f99633776de500
Author: Brian Swetland <swetland@frotz.net>
Date:   Sun,  5 Jan 2014 12:46:06 -0800

provide getstackpcs() that takes an ebp to start unwinding from

getcallerpcs() uses a void* to the first argument, but on x64 that
doesn't work (arguments passed in registers), so we just use the
actual rbp and unwind from there.  But for cases where we want to
unwind somebody else's stack (procdump()), we need a way to handle
that sanely.

Diffstat:
M
include/defs.h
 | 
1
+
M
kernel/spinlock.c
 | 
10
++++++++--

2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/include/defs.h b/include/defs.h
@@ -123,6 +123,7 @@ void            swtch(struct context**, struct context*);
 // spinlock.c
 void            acquire(struct spinlock*);
 void            getcallerpcs(void*, uintp*);
+void            getstackpcs(uintp*, uintp*);
 int             holding(struct spinlock*);
 void            initlock(struct spinlock*, char*);
 void            release(struct spinlock*);
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
@@ -74,13 +74,19 @@ void
 getcallerpcs(void *v, uintp pcs[])
 {
   uintp *ebp;
-  int i;
-  
 #if X64
   asm volatile("mov %%rbp, %0" : "=r" (ebp));  
 #else
   ebp = (uintp*)v - 2;
 #endif
+  getstackpcs(ebp, pcs);
+}
+
+void
+getstackpcs(uintp *ebp, uintp pcs[])
+{
+  int i;
+  
   for(i = 0; i < 10; i++){
     if(ebp == 0 || ebp < (uintp*)KERNBASE || ebp == (uintp*)0xffffffff)
       break;