Commit 4df43095 authored Apr 03, 2019 by Gustavo A. R. Silva Committed by Thomas Gleixner Apr 05, 2019

x86/kexec/crash: Use struct_size() in vzalloc()



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;
    struct boo entry[];
};

instance = vzalloc(sizeof(struct foo) + count * sizeof(struct boo));

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

   instance = vzalloc(struct_size(instance, entry, count));

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20190403184230.GA5295@embeddedor

parent a72a1932

arch/x86/kernel/crash.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -204,8 +204,7 @@ static struct crash_mem *fill_up_crash_elf_data(void)
		* another range split. So add extra two slots here.
		*/
		nr_ranges += 2;
		cmem = vzalloc(sizeof(struct crash_mem) +
		sizeof(struct crash_mem_range) * nr_ranges);
		cmem = vzalloc(struct_size(cmem, ranges, nr_ranges));
		if (!cmem)
		return NULL;

Admin message