lkml.org 
[lkml]   [2020]   [May]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip: locking/kcsan] netfilter: Avoid assigning 'const' pointer to non-const pointer
The following commit has been merged into the locking/kcsan branch of tip:

Commit-ID: f64554152014597a40403ea1a291c80785a2dfe9
Gitweb: https://git.kernel.org/tip/f64554152014597a40403ea1a291c80785a2dfe9
Author: Will Deacon <will@kernel.org>
AuthorDate: Mon, 11 May 2020 21:41:38 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 12 May 2020 11:04:11 +02:00

netfilter: Avoid assigning 'const' pointer to non-const pointer

nf_remove_net_hook() uses WRITE_ONCE() to assign a 'const' pointer to a
'non-const' pointer. Cleanups to the implementation of WRITE_ONCE() mean
that this will give rise to a compiler warning, just like a plain old
assignment would do:

| In file included from ./include/linux/export.h:43,
| from ./include/linux/linkage.h:7,
| from ./include/linux/kernel.h:8,
| from net/netfilter/core.c:9:
| net/netfilter/core.c: In function ‘nf_remove_net_hook’:
| ./include/linux/compiler.h:216:30: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
| *(volatile typeof(x) *)&(x) = (val); \
| ^
| net/netfilter/core.c:379:3: note: in expansion of macro ‘WRITE_ONCE’
| WRITE_ONCE(orig_ops[i], &dummy_ops);
| ^~~~~~~~~~

Follow the pattern used elsewhere in this file and add a cast to 'void *'
to squash the warning.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Link: https://lkml.kernel.org/r/20200511204150.27858-7-will@kernel.org

---
net/netfilter/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index 78f046e..3ac7c8c 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -376,7 +376,7 @@ static bool nf_remove_net_hook(struct nf_hook_entries *old,
if (orig_ops[i] != unreg)
continue;
WRITE_ONCE(old->hooks[i].hook, accept_all);
- WRITE_ONCE(orig_ops[i], &dummy_ops);
+ WRITE_ONCE(orig_ops[i], (void *)&dummy_ops);
return true;
}

\
 
 \ /
  Last update: 2020-05-12 16:38    [W:0.448 / U:0.688 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site