diff mbox series

powerpc/spufs: use struct_size() in kmalloc()

Message ID 20190108183720.GA14238@embeddedor (mailing list archive)
State Accepted
Commit 00def7130af8b3fad1bdef98429c94a67dbbd896
Headers show
Series powerpc/spufs: use struct_size() in kmalloc() | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success next/apply_patch Successfully applied
snowpatch_ozlabs/build-ppc64le success build succeeded & removed 0 sparse warning(s)
snowpatch_ozlabs/build-ppc64be success build succeeded & removed 0 sparse warning(s)
snowpatch_ozlabs/build-ppc64e success build succeeded & removed 0 sparse warning(s)
snowpatch_ozlabs/build-pmac32 success build succeeded & removed 0 sparse warning(s)
snowpatch_ozlabs/checkpatch warning total: 0 errors, 1 warnings, 1 checks, 11 lines checked

Commit Message

Gustavo A. R. Silva Jan. 8, 2019, 6:37 p.m. UTC 
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 arch/powerpc/platforms/cell/spufs/file.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index ae8123edddc6..48c2477e7e2a 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -2338,9 +2338,8 @@  static int spufs_switch_log_open(struct inode *inode, struct file *file)
 		goto out;
 	}
 
-	ctx->switch_log = kmalloc(sizeof(struct switch_log) +
-		SWITCH_LOG_BUFSIZE * sizeof(struct switch_log_entry),
-		GFP_KERNEL);
+	ctx->switch_log = kmalloc(struct_size(ctx->switch_log, log,
+				  SWITCH_LOG_BUFSIZE), GFP_KERNEL);
 
 	if (!ctx->switch_log) {
 		rc = -ENOMEM;