Re: [PATCH] parisc: Increase the usage check of kmalloc allocated object a

From: Helge Deller
Date: Wed Sep 14 2022 - 02:18:51 EST


On 9/14/22 08:04, Li zeming wrote:
In the case of memory allocation failure, no alignment operation is
required.

Signed-off-by: Li zeming <zeming@xxxxxxxxxxxx>
---
drivers/parisc/iosapic.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/parisc/iosapic.c b/drivers/parisc/iosapic.c
index 3a8c98615634..33de438916d3 100644
--- a/drivers/parisc/iosapic.c
+++ b/drivers/parisc/iosapic.c
@@ -229,7 +229,9 @@ static struct irt_entry *iosapic_alloc_irt(int num_entries)
* 4-byte alignment on 32-bit kernels
*/
a = (unsigned long)kmalloc(sizeof(struct irt_entry) * num_entries + 8, GFP_KERNEL);
- a = (a + 7UL) & ~7UL;
+ if (a)
+ a = (a + 7UL) & ~7UL;
+

As you said, the adjustment isn't required, but it's still ok.
So I think the additional "if" isn't necessary and so I'm not
applying your patch.

Anyway, thanks for your help to try to improve the code!

Helge


return (struct irt_entry *)a;
}