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authorGustavo A. R. Silva <gustavo@embeddedor.com>2019-07-16 16:30:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-16 19:23:25 -0700
commit43e11fa2d1d3b6e35629fa556eb7d571edba2010 (patch)
treee031de3623167cd0fa10f8de744b24627885e4e8 /fs
parent79eb597cba06c435b72f220e9d426ae413fc2579 (diff)
downloadlinux-43e11fa2d1d3b6e35629fa556eb7d571edba2010.tar.bz2
fs/select.c: use struct_size() in kmalloc()
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[]; }; size = sizeof(struct foo) + count * sizeof(struct boo); instance = kmalloc(size, 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); Also, notice that variable size is unnecessary, hence it is removed. This code was detected with the help of Coccinelle. Link: http://lkml.kernel.org/r/20190604164226.GA13823@embeddedor Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/select.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/select.c b/fs/select.c
index 51ceec292f2f..53a0c149f528 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -961,7 +961,7 @@ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
struct timespec64 *end_time)
{
struct poll_wqueues table;
- int err = -EFAULT, fdcount, len, size;
+ int err = -EFAULT, fdcount, len;
/* Allocate small arguments on the stack to save memory and be
faster - use long to make sure the buffer is aligned properly
on 64 bit archs to avoid unaligned access */
@@ -989,8 +989,8 @@ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
break;
len = min(todo, POLLFD_PER_PAGE);
- size = sizeof(struct poll_list) + sizeof(struct pollfd) * len;
- walk = walk->next = kmalloc(size, GFP_KERNEL);
+ walk = walk->next = kmalloc(struct_size(walk, entries, len),
+ GFP_KERNEL);
if (!walk) {
err = -ENOMEM;
goto out_fds;