From 08a408161749d2406f94f4e3d47cfdbc826ad1cc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 14 Sep 2009 09:31:35 -0400 Subject: [PATCH] ring-buffer: typecast cmpxchg to fix PowerPC warning The cmpxchg used by PowerPC does the following: ({ \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ (unsigned long)_n_, sizeof(*(ptr))); \ }) This does a type check of *ptr to both o and n. Unfortunately, the code in ring-buffer.c assigns longs to pointers and pointers to longs and causes a warning on PowerPC: ring_buffer.c: In function 'rb_head_page_set': ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c: In function 'rb_head_page_replace': ring_buffer.c:797: warning: initialization makes integer from pointer without a cast This patch adds the typecasts inside cmpxchg to annotate that a long is being cast to a pointer and a pointer is being casted to a long and this removes the PowerPC warnings. Reported-by: Stephen Rothwell Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 8786c350b4ca..6eef38923b07 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -701,8 +701,8 @@ static int rb_head_page_set(struct ring_buffer_per_cpu *cpu_buffer, val &= ~RB_FLAG_MASK; - ret = (unsigned long)cmpxchg(&list->next, - val | old_flag, val | new_flag); + ret = cmpxchg((unsigned long *)&list->next, + val | old_flag, val | new_flag); /* check if the reader took the page */ if ((ret & ~RB_FLAG_MASK) != val) @@ -794,7 +794,7 @@ static int rb_head_page_replace(struct buffer_page *old, val = *ptr & ~RB_FLAG_MASK; val |= RB_PAGE_HEAD; - ret = cmpxchg(ptr, val, &new->list); + ret = cmpxchg(ptr, val, (unsigned long)&new->list); return ret == val; } -- 2.11.0