[PATCH v1 1/1] kcsan: debugfs: Use krealloc_array() to replace krealloc()

[PATCH v1 1/1] kcsan: debugfs: Use krealloc_array() to replace krealloc()

[Andy Shevchenko]

Use krealloc_array() to replace krealloc() with multiplication.
krealloc_array() has multiply overflow check, which will be safer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 kernel/kcsan/debugfs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
index 53b21ae30e00..be7051d0e7f4 100644
--- a/kernel/kcsan/debugfs.c
+++ b/kernel/kcsan/debugfs.c
@@ -166,10 +166,10 @@ static ssize_t insert_report_filterlist(const char *func)
 	} else if (report_filterlist.used == report_filterlist.size) {
 		/* resize filterlist */
 		size_t new_size = report_filterlist.size * 2;
-		unsigned long *new_addrs =
-			krealloc(report_filterlist.addrs,
-				 new_size * sizeof(unsigned long), GFP_ATOMIC);
+		unsigned long *new_addrs;
 
+		new_addrs = krealloc_array(report_filterlist.addrs,
+					   new_size, sizeof(*new_addrs), GFP_ATOMIC);
 		if (new_addrs == NULL) {
 			/* leave filterlist itself untouched */
 			ret = -ENOMEM;
-- 
2.43.0.rc1.1336.g36b5255a03ac

Re: [PATCH v1 1/1] kcsan: debugfs: Use krealloc_array() to replace krealloc()

[Marco Elver]

On Thu, 21 Nov 2024 at 14:58, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> Use krealloc_array() to replace krealloc() with multiplication.
> krealloc_array() has multiply overflow check, which will be safer.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Reviewed-by: Marco Elver <elver@google.com>

Do you have a tree to take this through? Otherwise I'll take it.

> ---
>  kernel/kcsan/debugfs.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
> index 53b21ae30e00..be7051d0e7f4 100644
> --- a/kernel/kcsan/debugfs.c
> +++ b/kernel/kcsan/debugfs.c
> @@ -166,10 +166,10 @@ static ssize_t insert_report_filterlist(const char *func)
>         } else if (report_filterlist.used == report_filterlist.size) {
>                 /* resize filterlist */
>                 size_t new_size = report_filterlist.size * 2;
> -               unsigned long *new_addrs =
> -                       krealloc(report_filterlist.addrs,
> -                                new_size * sizeof(unsigned long), GFP_ATOMIC);
> +               unsigned long *new_addrs;
>
> +               new_addrs = krealloc_array(report_filterlist.addrs,
> +                                          new_size, sizeof(*new_addrs), GFP_ATOMIC);
>                 if (new_addrs == NULL) {
>                         /* leave filterlist itself untouched */
>                         ret = -ENOMEM;
> --
> 2.43.0.rc1.1336.g36b5255a03ac
>

Re: [PATCH v1 1/1] kcsan: debugfs: Use krealloc_array() to replace krealloc()

[Marco Elver]

On Thu, 21 Nov 2024 at 15:04, Marco Elver <elver@google.com> wrote:
>
> On Thu, 21 Nov 2024 at 14:58, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > Use krealloc_array() to replace krealloc() with multiplication.
> > krealloc_array() has multiply overflow check, which will be safer.
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>
> Reviewed-by: Marco Elver <elver@google.com>

Unreview.

> Do you have a tree to take this through? Otherwise I'll take it.

Whoops. We got rid of that krealloc() in 59458fa4ddb4 ("kcsan: Turn
report_filterlist_lock into a raw_spinlock"). And the replacement
kmalloc() is already a kmalloc_array(). I suppose this patch is
therefore obsolete.

Re: [PATCH v1 1/1] kcsan: debugfs: Use krealloc_array() to replace krealloc()

[Andy Shevchenko]

On Thu, Nov 21, 2024 at 03:11:41PM +0100, Marco Elver wrote:
> On Thu, 21 Nov 2024 at 15:04, Marco Elver <elver@google.com> wrote:
> > On Thu, 21 Nov 2024 at 14:58, Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > >
> > > Use krealloc_array() to replace krealloc() with multiplication.
> > > krealloc_array() has multiply overflow check, which will be safer.
> > >
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> >
> > Reviewed-by: Marco Elver <elver@google.com>
> 
> Unreview.
> 
> > Do you have a tree to take this through? Otherwise I'll take it.
> 
> Whoops. We got rid of that krealloc() in 59458fa4ddb4 ("kcsan: Turn
> report_filterlist_lock into a raw_spinlock"). And the replacement
> kmalloc() is already a kmalloc_array(). I suppose this patch is
> therefore obsolete.

Ah, I made this on top of v6.12 + something most likely unrelated.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] kcsan: debugfs: Use krealloc_array() to replace krealloc()

[Andy Shevchenko]

On Thu, Nov 21, 2024 at 03:04:04PM +0100, Marco Elver wrote:
> On Thu, 21 Nov 2024 at 14:58, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > Use krealloc_array() to replace krealloc() with multiplication.
> > krealloc_array() has multiply overflow check, which will be safer.
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> Reviewed-by: Marco Elver <elver@google.com>

Thank you!

> Do you have a tree to take this through? Otherwise I'll take it.

No, but please, wait a bit, I have a sequential dependent patch.
I'll send a v2 soon.

-- 
With Best Regards,
Andy Shevchenko