2010-04-06 10:45:54

by Dan Carpenter

Subject: [patch] proc: copy_to_user() returns unsigned

copy_to_user() returns the number of bytes left to be copied.

This was a typo from: d82ef020cf31504c816803b1def94eb5ff173363
"proc: pagemap: Hold mmap_sem during page walk".

Signed-off-by: Dan Carpenter <[email protected]>

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 0962739..bfb2773 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -799,7 +799,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
start_vaddr = end;

len = min(count, PM_ENTRY_BYTES * pm.pos);
- if (copy_to_user(buf, pm.buffer, len) < 0) {
+ if (copy_to_user(buf, pm.buffer, len)) {
ret = -EFAULT;
goto out_free;
}

2010-04-06 11:04:13

by Minchan Kim

Subject: Re: [patch] proc: copy_to_user() returns unsigned

I got confused when I see the title of patch.
That's because I understood copy_to_user returns unsigned.
Please, change title to describe your patch.

[PATCH] proc : fix wrong usage of copy_to_user's return value.

Maybe you could name it well than me who is a not native English.

On Tue, Apr 6, 2010 at 7:45 PM, Dan Carpenter <[email protected]> wrote:
> copy_to_user() returns the number of bytes left to be copied.
>
> This was a typo from: d82ef020cf31504c816803b1def94eb5ff173363
> "proc: pagemap: Hold mmap_sem during page walk".
>
> Signed-off-by: Dan Carpenter <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>



--
Kind regards,
Minchan Kim

2010-04-06 11:32:46

by KOSAKI Motohiro

Subject: Re: [patch] proc: copy_to_user() returns unsigned

> copy_to_user() returns the number of bytes left to be copied.
>
> This was a typo from: d82ef020cf31504c816803b1def94eb5ff173363
> "proc: pagemap: Hold mmap_sem during page walk".
>
> Signed-off-by: Dan Carpenter <[email protected]>
>
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 0962739..bfb2773 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -799,7 +799,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
> start_vaddr = end;
>
> len = min(count, PM_ENTRY_BYTES * pm.pos);
> - if (copy_to_user(buf, pm.buffer, len) < 0) {
> + if (copy_to_user(buf, pm.buffer, len)) {
> ret = -EFAULT;
> goto out_free;
> }

Reviewed-by: KOSAKI Motohiro <[email protected]>


However I don't think this patch is kernel-janitors material. it should
be just merged mainline soon.

2010-04-06 15:18:11

by Matt Mackall

Subject: Re: [patch] proc: copy_to_user() returns unsigned

On Tue, 2010-04-06 at 13:45 +0300, Dan Carpenter wrote:
> copy_to_user() returns the number of bytes left to be copied.
>
> This was a typo from: d82ef020cf31504c816803b1def94eb5ff173363
> "proc: pagemap: Hold mmap_sem during page walk".
>
> Signed-off-by: Dan Carpenter <[email protected]>
>
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 0962739..bfb2773 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -799,7 +799,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
> start_vaddr = end;
>
> len = min(count, PM_ENTRY_BYTES * pm.pos);
> - if (copy_to_user(buf, pm.buffer, len) < 0) {
> + if (copy_to_user(buf, pm.buffer, len)) {
> ret = -EFAULT;
> goto out_free;
> }

Acked-by: Matt Mackall <[email protected]>

Linus, please take this one too.

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