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authorKees Cook <keescook@chromium.org>2020-02-19 22:23:04 -0800
committerDavid S. Miller <davem@davemloft.net>2020-02-20 10:00:19 -0800
commit161d179261f95ac56f61f94f89304e0620534230 (patch)
tree37da619c59ec1ea196fd0f17e529c587ff904bad /net
parent41f57cfde186dba6e357f9db25eafbed017e4487 (diff)
downloadlinux-161d179261f95ac56f61f94f89304e0620534230.tar.bz2
net: core: Distribute switch variables for initialization
Variables declared in a switch statement before any case statements cannot be automatically initialized with compiler instrumentation (as they are not part of any execution flow). With GCC's proposed automatic stack variable initialization feature, this triggers a warning (and they don't get initialized). Clang's automatic stack variable initialization (via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also doesn't initialize such variables[1]. Note that these warnings (or silent skipping) happen before the dead-store elimination optimization phase, so even when the automatic initializations are later elided in favor of direct initializations, the warnings remain. To avoid these problems, move such variables into the "case" where they're used or lift them up into the main function body. net/core/skbuff.c: In function ‘skb_checksum_setup_ip’: net/core/skbuff.c:4809:7: warning: statement will never be executed [-Wswitch-unreachable] 4809 | int err; | ^~~ [1] https://bugs.llvm.org/show_bug.cgi?id=44916 Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/skbuff.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 1365a556152c..e1101a4f90a6 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4803,9 +4803,9 @@ static __sum16 *skb_checksum_setup_ip(struct sk_buff *skb,
typeof(IPPROTO_IP) proto,
unsigned int off)
{
- switch (proto) {
- int err;
+ int err;
+ switch (proto) {
case IPPROTO_TCP:
err = skb_maybe_pull_tail(skb, off + sizeof(struct tcphdr),
off + MAX_TCP_HDR_LEN);