| Message ID | 1581398649-125989-1-git-send-email-yang.shi@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] mm: vmpressure: don't need call kfree if kstrndup fails | expand |
On Tue, 11 Feb 2020, Yang Shi wrote: > When kstrndup fails (returns NULL) there is no memory is allocated by > kmalloc, so no need to call kfree(). > > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Acked-by: David Rientjes <rientjes@google.com>
On 11.02.20 06:24, Yang Shi wrote: > When kstrndup fails (returns NULL) there is no memory is allocated by > kmalloc, so no need to call kfree(). "When kstrndup fails, no memory was allocated and we can exit directly." Reviewed-by: David Hildenbrand <david@redhat.com> > > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> > --- > mm/vmpressure.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/mm/vmpressure.c b/mm/vmpressure.c > index 4bac22f..0590f00 100644 > --- a/mm/vmpressure.c > +++ b/mm/vmpressure.c > @@ -371,10 +371,8 @@ int vmpressure_register_event(struct mem_cgroup *memcg, > int ret = 0; > > spec_orig = spec = kstrndup(args, MAX_VMPRESSURE_ARGS_LEN, GFP_KERNEL); > - if (!spec) { > - ret = -ENOMEM; > - goto out; > - } > + if (!spec) > + return -ENOMEM; > > /* Find required level */ > token = strsep(&spec, ","); >
On 2/12/20 3:21 AM, David Hildenbrand wrote: > On 11.02.20 06:24, Yang Shi wrote: >> When kstrndup fails (returns NULL) there is no memory is allocated by >> kmalloc, so no need to call kfree(). > "When kstrndup fails, no memory was allocated and we can exit directly." Thanks for correcting the commit log. Andrew, do you prefer I send an updated version or you would just update the patch in -mm tree? > > Reviewed-by: David Hildenbrand <david@redhat.com> > >> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> >> --- >> mm/vmpressure.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/mm/vmpressure.c b/mm/vmpressure.c >> index 4bac22f..0590f00 100644 >> --- a/mm/vmpressure.c >> +++ b/mm/vmpressure.c >> @@ -371,10 +371,8 @@ int vmpressure_register_event(struct mem_cgroup *memcg, >> int ret = 0; >> >> spec_orig = spec = kstrndup(args, MAX_VMPRESSURE_ARGS_LEN, GFP_KERNEL); >> - if (!spec) { >> - ret = -ENOMEM; >> - goto out; >> - } >> + if (!spec) >> + return -ENOMEM; >> >> /* Find required level */ >> token = strsep(&spec, ","); >> >
On Wed, 12 Feb 2020 19:14:27 -0800 Yang Shi <yang.shi@linux.alibaba.com> wrote: > On 2/12/20 3:21 AM, David Hildenbrand wrote: > > On 11.02.20 06:24, Yang Shi wrote: > >> When kstrndup fails (returns NULL) there is no memory is allocated by > >> kmalloc, so no need to call kfree(). > > "When kstrndup fails, no memory was allocated and we can exit directly." > > Thanks for correcting the commit log. > > Andrew, do you prefer I send an updated version or you would just update > the patch in -mm tree? I have already done this. From: Yang Shi <yang.shi@linux.alibaba.com> Subject: mm: vmpressure: don't need call kfree if kstrndup fails When kstrndup fails, no memory was allocated and we can exit directly. [david@redhat.com: reword changelog] Link: http://lkml.kernel.org/r/1581398649-125989-1-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/vmpressure.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/mm/vmpressure.c~mm-vmpressure-dont-need-call-kfree-if-kstrndup-fails +++ a/mm/vmpressure.c @@ -371,10 +371,8 @@ int vmpressure_register_event(struct mem int ret = 0; spec_orig = spec = kstrndup(args, MAX_VMPRESSURE_ARGS_LEN, GFP_KERNEL); - if (!spec) { - ret = -ENOMEM; - goto out; - } + if (!spec) + return -ENOMEM; /* Find required level */ token = strsep(&spec, ",");
On 2/12/20 8:48 PM, Andrew Morton wrote: > On Wed, 12 Feb 2020 19:14:27 -0800 Yang Shi <yang.shi@linux.alibaba.com> wrote: > >> On 2/12/20 3:21 AM, David Hildenbrand wrote: >>> On 11.02.20 06:24, Yang Shi wrote: >>>> When kstrndup fails (returns NULL) there is no memory is allocated by >>>> kmalloc, so no need to call kfree(). >>> "When kstrndup fails, no memory was allocated and we can exit directly." >> Thanks for correcting the commit log. >> >> Andrew, do you prefer I send an updated version or you would just update >> the patch in -mm tree? > I have already done this. Thanks! > > From: Yang Shi <yang.shi@linux.alibaba.com> > Subject: mm: vmpressure: don't need call kfree if kstrndup fails > > When kstrndup fails, no memory was allocated and we can exit directly. > > [david@redhat.com: reword changelog] > Link: http://lkml.kernel.org/r/1581398649-125989-1-git-send-email-yang.shi@linux.alibaba.com > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> > Reviewed-by: Andrew Morton <akpm@linux-foundation.org> > Reviewed-by: David Hildenbrand <david@redhat.com> > Acked-by: David Rientjes <rientjes@google.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > --- > > mm/vmpressure.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > --- a/mm/vmpressure.c~mm-vmpressure-dont-need-call-kfree-if-kstrndup-fails > +++ a/mm/vmpressure.c > @@ -371,10 +371,8 @@ int vmpressure_register_event(struct mem > int ret = 0; > > spec_orig = spec = kstrndup(args, MAX_VMPRESSURE_ARGS_LEN, GFP_KERNEL); > - if (!spec) { > - ret = -ENOMEM; > - goto out; > - } > + if (!spec) > + return -ENOMEM; > > /* Find required level */ > token = strsep(&spec, ","); > _
diff --git a/mm/vmpressure.c b/mm/vmpressure.c index 4bac22f..0590f00 100644 --- a/mm/vmpressure.c +++ b/mm/vmpressure.c @@ -371,10 +371,8 @@ int vmpressure_register_event(struct mem_cgroup *memcg, int ret = 0; spec_orig = spec = kstrndup(args, MAX_VMPRESSURE_ARGS_LEN, GFP_KERNEL); - if (!spec) { - ret = -ENOMEM; - goto out; - } + if (!spec) + return -ENOMEM; /* Find required level */ token = strsep(&spec, ",");
When kstrndup fails (returns NULL) there is no memory is allocated by kmalloc, so no need to call kfree(). Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> --- mm/vmpressure.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)