[Devel] [PATCH 4/6] net/sock: teach sock_kmalloc() to call kvmalloc() when possible

[Alexander Mikhalitsyn]

From: Konstantin Khorenko <khorenko at virtuozzo.com>

sock_setsockopt()
 sk_attach_filter()
  sock_kmalloc()

Memory size to be allocated depends on the number of rules provided by
userspace, but not more than net.core.optmem_max (20480 by default),
which still allows to allocate 3rd order pages via kmalloc() =>
it's better to substitute it with kvmalloc().

But sock_kmalloc() can be called with GFP_ATOMIC from some places,
so we cannot unconditionally call kvmalloc() instead of kmalloc().

Hopefully sk_attach_filter() calls sock_kmalloc() with GFP_KERNEL,
so kvmalloc() can be used there.

=> use kvmalloc_check() which calls kvmalloc() if it's allowed
by provided flags.

https://jira.sw.ru/browse/PSBM-82593

Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>

Ughh, but ok.
Reviewed-by: Andrey Ryabinin <aryabinin at virtuozzo.com>

(cherry picked from commit 29b736c18d060941df7fc08dda6d07ddf386d0c1)

VZ 8 rebase part https://jira.sw.ru/browse/PSBM-127798

Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn at virtuozzo.com>
---
 net/core/sock.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 18b8908d200a..03ad9fbb2906 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2107,7 +2107,7 @@ void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
 		 * might sleep.
 		 */
 		atomic_add(size, &sk->sk_omem_alloc);
-		mem = kmalloc(size, priority);
+		mem = kvmalloc_check(size, priority);
 		if (mem)
 			return mem;
 		atomic_sub(size, &sk->sk_omem_alloc);
@@ -2126,9 +2126,9 @@ static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
 	if (WARN_ON_ONCE(!mem))
 		return;
 	if (nullify)
-		kzfree(mem);
-	else
-		kfree(mem);
+		memset(mem, 0, size);
+
+	kvfree(mem);
 	atomic_sub(size, &sk->sk_omem_alloc);
 }
 
-- 
2.28.0