2020-04-17 02:59:01

by Wei Yongjun

Subject: [PATCH -next] kcsan: Use GFP_ATOMIC under spin lock

A spin lock is taken here so we should use GFP_ATOMIC.

Signed-off-by: Wei Yongjun <[email protected]>
---
kernel/kcsan/debugfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
index 1a08664a7fab..023e49c58d55 100644
--- a/kernel/kcsan/debugfs.c
+++ b/kernel/kcsan/debugfs.c
@@ -230,7 +230,7 @@ static ssize_t insert_report_filterlist(const char *func)
/* initial allocation */
report_filterlist.addrs =
kmalloc_array(report_filterlist.size,
- sizeof(unsigned long), GFP_KERNEL);
+ sizeof(unsigned long), GFP_ATOMIC);
if (report_filterlist.addrs == NULL) {
ret = -ENOMEM;
goto out;
@@ -240,7 +240,7 @@ static ssize_t insert_report_filterlist(const char *func)
size_t new_size = report_filterlist.size * 2;
unsigned long *new_addrs =
krealloc(report_filterlist.addrs,
- new_size * sizeof(unsigned long), GFP_KERNEL);
+ new_size * sizeof(unsigned long), GFP_ATOMIC);

if (new_addrs == NULL) {
/* leave filterlist itself untouched */

2020-04-17 09:26:57

by Marco Elver

Subject: Re: [PATCH -next] kcsan: Use GFP_ATOMIC under spin lock

On Fri, 17 Apr 2020 at 04:56, Wei Yongjun <[email protected]> wrote:
>
> A spin lock is taken here so we should use GFP_ATOMIC.
>
> Signed-off-by: Wei Yongjun <[email protected]>

Good catch, thank you!

Reviewed-by: Marco Elver <[email protected]>


> ---
> kernel/kcsan/debugfs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
> index 1a08664a7fab..023e49c58d55 100644
> --- a/kernel/kcsan/debugfs.c
> +++ b/kernel/kcsan/debugfs.c
> @@ -230,7 +230,7 @@ static ssize_t insert_report_filterlist(const char *func)
> /* initial allocation */
> report_filterlist.addrs =
> kmalloc_array(report_filterlist.size,
> - sizeof(unsigned long), GFP_KERNEL);
> + sizeof(unsigned long), GFP_ATOMIC);
> if (report_filterlist.addrs == NULL) {
> ret = -ENOMEM;
> goto out;
> @@ -240,7 +240,7 @@ static ssize_t insert_report_filterlist(const char *func)
> size_t new_size = report_filterlist.size * 2;
> unsigned long *new_addrs =
> krealloc(report_filterlist.addrs,
> - new_size * sizeof(unsigned long), GFP_KERNEL);
> + new_size * sizeof(unsigned long), GFP_ATOMIC);
>
> if (new_addrs == NULL) {
> /* leave filterlist itself untouched */
>
>
>
>
>

2020-04-17 15:08:01

by Paul E. McKenney

Subject: Re: [PATCH -next] kcsan: Use GFP_ATOMIC under spin lock

On Fri, Apr 17, 2020 at 11:23:05AM +0200, Marco Elver wrote:
> On Fri, 17 Apr 2020 at 04:56, Wei Yongjun <[email protected]> wrote:
> >
> > A spin lock is taken here so we should use GFP_ATOMIC.
> >
> > Signed-off-by: Wei Yongjun <[email protected]>
>
> Good catch, thank you!
>
> Reviewed-by: Marco Elver <[email protected]>

Queued and pushed, thank you both!

Thanx, Paul

> > ---
> > kernel/kcsan/debugfs.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
> > index 1a08664a7fab..023e49c58d55 100644
> > --- a/kernel/kcsan/debugfs.c
> > +++ b/kernel/kcsan/debugfs.c
> > @@ -230,7 +230,7 @@ static ssize_t insert_report_filterlist(const char *func)
> > /* initial allocation */
> > report_filterlist.addrs =
> > kmalloc_array(report_filterlist.size,
> > - sizeof(unsigned long), GFP_KERNEL);
> > + sizeof(unsigned long), GFP_ATOMIC);
> > if (report_filterlist.addrs == NULL) {
> > ret = -ENOMEM;
> > goto out;
> > @@ -240,7 +240,7 @@ static ssize_t insert_report_filterlist(const char *func)
> > size_t new_size = report_filterlist.size * 2;
> > unsigned long *new_addrs =
> > krealloc(report_filterlist.addrs,
> > - new_size * sizeof(unsigned long), GFP_KERNEL);
> > + new_size * sizeof(unsigned long), GFP_ATOMIC);
> >
> > if (new_addrs == NULL) {
> > /* leave filterlist itself untouched */
> >
> >
> >
> >
> >