Differential D33704 Diff 101487 lib/libthr/thread/thr_stack.c

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lib/libthr/thread/thr_stack.c

Show First 20 Lines • Show All 143 Lines • ▼ Show 20 Lines	mprotect((char *)thrd->attr.stackaddr_attr +
_rtld_get_stack_prot());		_rtld_get_stack_prot());
}		}

static void		static void
singlethread_map_stacks_exec(void)		singlethread_map_stacks_exec(void)
{		{
int mib[2];		int mib[2];
struct rlimit rlim;		struct rlimit rlim;
u_long stacktop;		u_long usrstack;
size_t len;		size_t len;

mib[0] = CTL_KERN;		mib[0] = CTL_KERN;
mib[1] = KERN_STACKTOP;
len = sizeof(stacktop);
if (sysctl(mib, nitems(mib), &stacktop, &len, NULL, 0) == -1) {
mib[1] = KERN_USRSTACK;		mib[1] = KERN_USRSTACK;
if (sysctl(mib, nitems(mib), &stacktop, &len, NULL, 0) == -1)		len = sizeof(usrstack);
		if (sysctl(mib, nitems(mib), &usrstack, &len, NULL, 0) == -1)
return;		return;
}
if (getrlimit(RLIMIT_STACK, &rlim) == -1)		if (getrlimit(RLIMIT_STACK, &rlim) == -1)
return;		return;
mprotect((void *)(uintptr_t)(stacktop - rlim.rlim_cur),		mprotect((void *)(uintptr_t)(usrstack - rlim.rlim_cur),
rlim.rlim_cur, _rtld_get_stack_prot());		rlim.rlim_cur, _rtld_get_stack_prot());
}		}

void		void
__thr_map_stacks_exec(void)		__thr_map_stacks_exec(void)
{		{
struct pthread curthread, thrd;		struct pthread curthread, thrd;
struct stack *st;		struct stack *st;
Show All 36 Lines	_thr_stack_alloc(struct pthread_attr *attr)
stacksize = round_up(attr->stacksize_attr);		stacksize = round_up(attr->stacksize_attr);
guardsize = round_up(attr->guardsize_attr);		guardsize = round_up(attr->guardsize_attr);

attr->stackaddr_attr = NULL;		attr->stackaddr_attr = NULL;
attr->flags &= ~THR_STACK_USER;		attr->flags &= ~THR_STACK_USER;

/*		/*
* Use the garbage collector lock for synchronization of the		* Use the garbage collector lock for synchronization of the
* spare stack lists and allocations from stacktop.		* spare stack lists and allocations from usrstack.
*/		*/
THREAD_LIST_WRLOCK(curthread);		THREAD_LIST_WRLOCK(curthread);
/*		/*
* If the stack and guard sizes are default, try to allocate a stack		* If the stack and guard sizes are default, try to allocate a stack
* from the default-size stack cache:		* from the default-size stack cache:
*/		*/
if ((stacksize == THR_STACK_DEFAULT) &&		if ((stacksize == THR_STACK_DEFAULT) &&
(guardsize == _thr_guard_default)) {		(guardsize == _thr_guard_default)) {
Show All 19 Lines	else {
}		}
}		}
if (attr->stackaddr_attr != NULL) {		if (attr->stackaddr_attr != NULL) {
/* A cached stack was found. Release the lock. */		/* A cached stack was found. Release the lock. */
THREAD_LIST_UNLOCK(curthread);		THREAD_LIST_UNLOCK(curthread);
}		}
else {		else {
/*		/*
* Allocate a stack from or below stacktop, depending		* Allocate a stack from or below usrstack, depending
* on the LIBPTHREAD_BIGSTACK_MAIN env variable.		* on the LIBPTHREAD_BIGSTACK_MAIN env variable.
*/		*/
if (last_stack == NULL)		if (last_stack == NULL)
last_stack = _stacktop - _thr_stack_initial -		last_stack = _usrstack - _thr_stack_initial -
_thr_guard_default;		_thr_guard_default;

/* Allocate a new stack. */		/* Allocate a new stack. */
stackaddr = last_stack - stacksize - guardsize;		stackaddr = last_stack - stacksize - guardsize;

/*		/*
* Even if stack allocation fails, we don't want to try to		* Even if stack allocation fails, we don't want to try to
* use this location again, so unconditionally decrement		* use this location again, so unconditionally decrement
▲ Show 20 Lines • Show All 56 Lines • Show Last 20 Lines