[PATCH v1 1/5] devres: Fix devm_krealloc() wasting memory
From: Zijun Hu
Date: Tue Jul 02 2024 - 10:53:27 EST
Driver API devm_krealloc() calls alloc_dr() with wrong argument
@total_new_size, so causes more memory to be allocated than required
fix this memory waste by using @new_size as the argument for alloc_dr().
Fixes: f82485722e5d ("devres: provide devm_krealloc()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
Previous discussion link:
https://lore.kernel.org/all/1718531655-29761-1-git-send-email-quic_zijuhu@xxxxxxxxxxx/
Changes since the original one:
- Correct tile and commit message
- Add inline comments and stable tag
drivers/base/devres.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 3df0025d12aa..ff2247eec43c 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -896,9 +896,12 @@ void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
/*
* Otherwise: allocate new, larger chunk. We need to allocate before
* taking the lock as most probably the caller uses GFP_KERNEL.
+ * alloc_dr() will call check_dr_size() to reserve extra memory
+ * for struct devres automatically, so size @new_size user request
+ * is delivered to it directly as devm_kmalloc() does.
*/
new_dr = alloc_dr(devm_kmalloc_release,
- total_new_size, gfp, dev_to_node(dev));
+ new_size, gfp, dev_to_node(dev));
if (!new_dr)
return NULL;
--
2.34.1