Messages in this thread Patch in this message | | | Date | Tue, 25 Jun 2019 15:15:12 -0400 | From | Steven Rostedt <> | Subject | [for-next][PATCH 02/12] tracepoint: Use struct_size() in kmalloc() |
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From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
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 tp_probes { ... struct tracepoint_func probes[0]; };
instance = kmalloc(sizeof(sizeof(struct tp_probes) + sizeof(struct tracepoint_func) * 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, probes, count) GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> --- kernel/tracepoint.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 46f2ab1e08a9..fb9353ed901b 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -68,8 +68,8 @@ struct tp_probes { static inline void *allocate_probes(int count) { - struct tp_probes *p = kmalloc(count * sizeof(struct tracepoint_func) - + sizeof(struct tp_probes), GFP_KERNEL); + struct tp_probes *p = kmalloc(struct_size(p, probes, count), + GFP_KERNEL); return p == NULL ? NULL : p->probes; } -- 2.20.1
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