um: adjust current_thread_info() for newer gcc versions

In some cases gcc >= 4.5.2 will optimize away current_thread_info().  To
prevent gcc from doing so the stack address has to be obtained via inline
asm.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Richard Weinberger 2011-04-27 15:26:54 -07:00 committed by Linus Torvalds
parent 365a0deae2
commit 534e3adbd2

View file

@ -49,7 +49,10 @@ static inline struct thread_info *current_thread_info(void)
{
struct thread_info *ti;
unsigned long mask = THREAD_SIZE - 1;
ti = (struct thread_info *) (((unsigned long) &ti) & ~mask);
void *p;
asm volatile ("" : "=r" (p) : "0" (&ti));
ti = (struct thread_info *) (((unsigned long)p) & ~mask);
return ti;
}