* [patch] dma-debug: debugfs_create_bool() takes a u32 pointer
@ 2012-03-02 6:58 Dan Carpenter
2012-03-02 11:22 ` Neil Horman
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2012-03-02 6:58 UTC (permalink / raw)
To: Joerg Roedel
Cc: Stanislaw Gruszka, Paul Gortmaker, Neil Horman, Alan Stern,
linux-kernel, kernel-janitors
Even though it has "bool" in the name, you have pass a u32 pointer to
debugfs_create_bool(). Otherwise you get memory corruption in
write_file_bool(). Fortunately in this case the corruption happens in
an alignment hole between variables so it doesn't cause any problems.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 13ef233..08cd5a6 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -78,7 +78,7 @@ static LIST_HEAD(free_entries);
static DEFINE_SPINLOCK(free_entries_lock);
/* Global disable flag - will be set in case of an error */
-static bool global_disable __read_mostly;
+static u32 global_disable __read_mostly;
/* Global error count */
static u32 error_count;
@@ -657,7 +657,7 @@ static int dma_debug_fs_init(void)
global_disable_dent = debugfs_create_bool("disabled", 0444,
dma_debug_dent,
- (u32 *)&global_disable);
+ &global_disable);
if (!global_disable_dent)
goto out_err;
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [patch] dma-debug: debugfs_create_bool() takes a u32 pointer
2012-03-02 6:58 [patch] dma-debug: debugfs_create_bool() takes a u32 pointer Dan Carpenter
@ 2012-03-02 11:22 ` Neil Horman
2012-03-02 12:55 ` Dan Carpenter
0 siblings, 1 reply; 3+ messages in thread
From: Neil Horman @ 2012-03-02 11:22 UTC (permalink / raw)
To: Dan Carpenter
Cc: Joerg Roedel, Stanislaw Gruszka, Paul Gortmaker, Alan Stern,
linux-kernel, kernel-janitors
On Fri, Mar 02, 2012 at 09:58:32AM +0300, Dan Carpenter wrote:
> Even though it has "bool" in the name, you have pass a u32 pointer to
> debugfs_create_bool(). Otherwise you get memory corruption in
> write_file_bool(). Fortunately in this case the corruption happens in
> an alignment hole between variables so it doesn't cause any problems.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> diff --git a/lib/dma-debug.c b/lib/dma-debug.c
> index 13ef233..08cd5a6 100644
> --- a/lib/dma-debug.c
> +++ b/lib/dma-debug.c
> @@ -78,7 +78,7 @@ static LIST_HEAD(free_entries);
> static DEFINE_SPINLOCK(free_entries_lock);
>
> /* Global disable flag - will be set in case of an error */
> -static bool global_disable __read_mostly;
> +static u32 global_disable __read_mostly;
>
> /* Global error count */
> static u32 error_count;
> @@ -657,7 +657,7 @@ static int dma_debug_fs_init(void)
>
> global_disable_dent = debugfs_create_bool("disabled", 0444,
> dma_debug_dent,
> - (u32 *)&global_disable);
> + &global_disable);
> if (!global_disable_dent)
> goto out_err;
>
>
This certainly works, but a quick search of call sites shows this isn't the only
place someone passes a bool to debugfs_create_bool. I think the better solution
would be to change debugfs_create_bool and its corresponding read/write methods
to actually work with a bool type, and then clean all the call sites to pass in
a bool properly, instead of a u32.
Thanks
Neil
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [patch] dma-debug: debugfs_create_bool() takes a u32 pointer
2012-03-02 11:22 ` Neil Horman
@ 2012-03-02 12:55 ` Dan Carpenter
0 siblings, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2012-03-02 12:55 UTC (permalink / raw)
To: Neil Horman
Cc: Joerg Roedel, Stanislaw Gruszka, Paul Gortmaker, Alan Stern,
linux-kernel, kernel-janitors
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On Fri, Mar 02, 2012 at 06:22:03AM -0500, Neil Horman wrote:
> This certainly works, but a quick search of call sites shows this isn't the only
> place someone passes a bool to debugfs_create_bool. I think the better solution
> would be to change debugfs_create_bool and its corresponding read/write methods
> to actually work with a bool type, and then clean all the call sites to pass in
> a bool properly, instead of a u32.
There is only one other call site which gets this wrong, and I sent
a fix for that today as well. But yes, you're probably right that
would be cleaner.
regards,
dan carpenter
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2012-03-02 6:58 [patch] dma-debug: debugfs_create_bool() takes a u32 pointer Dan Carpenter
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