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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2019-07-16 16:30:58 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-16 19:23:25 -0700 |
| commit | 43e11fa2d1d3b6e35629fa556eb7d571edba2010 (patch) | |
| tree | e031de3623167cd0fa10f8de744b24627885e4e8 /fs | |
| parent | 79eb597cba06c435b72f220e9d426ae413fc2579 (diff) | |
| download | linux-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.c | 6 |
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; |