on the negative side, I have to add the mmap back or else it segfaults on the...

on the negative side, I have to add the mmap back or else it segfaults on the positive side, with ds's fix for stack_...

Original commit message from CVS:
on the negative side, I have to add the mmap back or else it segfaults
on the positive side, with ds's fix for stack_top, I haven't had a
segfault in any of the thread tests since ;)
Let's cross fingers here
parent 5fa7e059
......@@ -176,6 +176,8 @@ cothread_create (cothread_context *ctx)
cothread_state *cothread;
void *sp;
unsigned long stack_top;
void *mmaped = 0;
gint slot = 0;
g_return_val_if_fail (ctx != NULL, NULL);
......@@ -203,20 +205,42 @@ cothread_create (cothread_context *ctx)
* could use casts to uintptr_t from inttypes.h
* if only all platforms had inttypes.h
*/
/* stack_top is the address of th first byte past our stack segment. */
/* stack_top is the address of the first byte past our stack segment. */
/* FIXME: an assumption is made that the stack segment is STACK_SIZE
* aligned. */
stack_top = ((gulong) sp | (STACK_SIZE - 1)) + 1;
GST_DEBUG(GST_CAT_COTHREADS, "stack top is %lu", stack_top);
GST_DEBUG (GST_CAT_COTHREADS, "stack top is %lu", stack_top);
/* cothread stack space of the thread is mapped in reverse, with cothread 0
* stack space at the top */
cothread = (cothread_state *) (stack_top - (slot + 1) * COTHREAD_STACKSIZE);
GST_DEBUG(GST_CAT_COTHREADS, "cothread pointer is %p", cothread);
cothread->magic_number = COTHREAD_MAGIC_NUMBER;
GST_DEBUG (GST_CAT_COTHREADS,
"mmap cothread slot stack from %p to 0x%lx (size 0x%lx)",
cothread, (unsigned long) cothread + COTHREAD_STACKSIZE,
(long) COTHREAD_STACKSIZE);
GST_DEBUG (GST_CAT_COTHREADS, "going into mmap");
/* the mmap is used to reserve part of the stack
* ie. we state explicitly that we are going to use it */
/* FIXME: maybe we should map slightly less than COTHREAD_STACKSIZE,
* so that stack overruns possibly could segfault ? */
mmaped = mmap ((void *) cothread, COTHREAD_STACKSIZE,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
GST_DEBUG (GST_CAT_COTHREADS, "coming out of mmap");
if (mmaped == MAP_FAILED) {
perror ("mmap'ing cothread stack space");
return NULL;
}
if (mmaped != cothread) {
g_warning ("could not mmap requested memory for cothread");
return NULL;
}
GST_DEBUG (GST_CAT_COTHREADS, "create cothread %d with magic number 0x%x",
slot, cothread->magic_number);
cothread->magic_number = COTHREAD_MAGIC_NUMBER;
cothread->ctx = ctx;
cothread->cothreadnum = slot;
cothread->flags = 0;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment