From: Werner Almesberger <werner@almesberger.net>
If setting the printk log buffer (with the boot command line option
"log_buf_len") to a value that's not a power of two, the index calculations
go wrong and yield confusing results.
This patch rounds the size to the next higher power of two. It'll yield
garbage for sizes > INT_MAX bytes.
Signed-off-by: Werner Almesberger <werner@almesberger.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/kernel/printk.c | 2 ++
1 files changed, 2 insertions(+)
diff -puN kernel/printk.c~round-log-buffer-size-to-power-of-two kernel/printk.c
--- 25/kernel/printk.c~round-log-buffer-size-to-power-of-two 2004-09-21 03:29:51.000000000 -0700
+++ 25-akpm/kernel/printk.c 2004-09-21 03:29:51.000000000 -0700
@@ -193,6 +193,8 @@ static int __init log_buf_len_setup(char
unsigned long size = memparse(str, &str);
unsigned long flags;
+ if (size)
+ size = roundup_pow_of_two(size);
if (size > log_buf_len) {
unsigned long start, dest_idx, offset;
char * new_log_buf;
_