* [PATCH] mm/slab: One function call less in verify_redzone_free()
@ 2019-07-05 14:50 Markus Elfring
2019-07-05 18:13 ` Christopher Lameter
0 siblings, 1 reply; 4+ messages in thread
From: Markus Elfring @ 2019-07-05 14:50 UTC (permalink / raw)
To: linux-mm, Andrew Morton, Christoph Lameter, David Rientjes,
Joonsoo Kim, Pekka Enberg
Cc: LKML, kernel-janitors
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Fri, 5 Jul 2019 16:40:09 +0200
Avoid an extra function call by using a ternary operator instead of
a conditional statement for a string literal selection.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
mm/slab.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c
index 9df370558e5d..849b5c276588 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2701,10 +2701,10 @@ static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
return;
- if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
- slab_error(cache, "double free detected");
- else
- slab_error(cache, "memory outside object was overwritten");
+ slab_error(cache,
+ redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE
+ ? "double free detected"
+ : "memory outside object was overwritten");
pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n",
obj, redzone1, redzone2);
--
2.22.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/slab: One function call less in verify_redzone_free()
2019-07-05 14:50 [PATCH] mm/slab: One function call less in verify_redzone_free() Markus Elfring
@ 2019-07-05 18:13 ` Christopher Lameter
2019-07-06 22:45 ` David Rientjes
0 siblings, 1 reply; 4+ messages in thread
From: Christopher Lameter @ 2019-07-05 18:13 UTC (permalink / raw)
To: Markus Elfring
Cc: linux-mm, Andrew Morton, David Rientjes, Joonsoo Kim,
Pekka Enberg, LKML, kernel-janitors
On Fri, 5 Jul 2019, Markus Elfring wrote:
> Avoid an extra function call by using a ternary operator instead of
> a conditional statement for a string literal selection.
Well. I thought the compiler does that on its own? And the tenary operator
makes the code difficult to read.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/slab: One function call less in verify_redzone_free()
2019-07-05 18:13 ` Christopher Lameter
@ 2019-07-06 22:45 ` David Rientjes
0 siblings, 0 replies; 4+ messages in thread
From: David Rientjes @ 2019-07-06 22:45 UTC (permalink / raw)
To: Christopher Lameter
Cc: Markus Elfring, linux-mm, Andrew Morton, Joonsoo Kim,
Pekka Enberg, LKML, kernel-janitors
On Fri, 5 Jul 2019, Christopher Lameter wrote:
> On Fri, 5 Jul 2019, Markus Elfring wrote:
>
> > Avoid an extra function call by using a ternary operator instead of
> > a conditional statement for a string literal selection.
>
> Well. I thought the compiler does that on its own? And the tenary operator
> makes the code difficult to read.
>
Right, and I don't understand the changelog: yes, there's one less
function call in the source but functionally there's still a conditional;
this isn't even optimizing DEBUG builds.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] mm/slab: One function call less in verify_redzone_free()
@ 2019-07-05 14:50 Markus Elfring
0 siblings, 0 replies; 4+ messages in thread
From: Markus Elfring @ 2019-07-05 14:50 UTC (permalink / raw)
To: linux-mm, Andrew Morton, Christoph Lameter, David Rientjes,
Joonsoo Kim, Pekka Enberg
Cc: LKML, kernel-janitors
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Fri, 5 Jul 2019 16:40:09 +0200
Avoid an extra function call by using a ternary operator instead of
a conditional statement for a string literal selection.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
mm/slab.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c
index 9df370558e5d..849b5c276588 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2701,10 +2701,10 @@ static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
return;
- if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
- slab_error(cache, "double free detected");
- else
- slab_error(cache, "memory outside object was overwritten");
+ slab_error(cache,
+ redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE
+ ? "double free detected"
+ : "memory outside object was overwritten");
pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n",
obj, redzone1, redzone2);
--
2.22.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-07-06 22:45 UTC | newest]
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2019-07-05 14:50 [PATCH] mm/slab: One function call less in verify_redzone_free() Markus Elfring
2019-07-05 18:13 ` Christopher Lameter
2019-07-06 22:45 ` David Rientjes
2019-07-05 14:50 Markus Elfring
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