| Message ID | 20240930162345.3938790-2-matttbe@kernel.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Delegated to: | Matthieu Baerts |
| Headers | show |
| Series | [5.10.y] mptcp: fix sometimes-uninitialized warning | expand |
| Context | Check | Description |
|---|---|---|
| matttbe/build | success | Build and static analysis OK |
| matttbe/checkpatch | warning | total: 0 errors, 2 warnings, 0 checks, 8 lines checked |
| matttbe/shellcheck | success | MPTCP selftests files have not been modified |
| matttbe/KVM_Validation__normal | success | Success! ✅ |
| matttbe/KVM_Validation__debug | success | Success! ✅ |
| matttbe/KVM_Validation__btf__only_bpftest_all_ | success | Success! ✅ |
Hi Matthieu,
Thank you for your modifications, that's great!
Our CI did some validations and here is its report:
- KVM Validation: normal: Success! ✅
- KVM Validation: debug: Success! ✅
- KVM Validation: btf (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/11110355350
Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/56a5e603a7b6
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=894151
If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:
$ cd [kernel source code]
$ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
--pull always mptcp/mptcp-upstream-virtme-docker:latest \
auto-normal
For more details:
https://github.com/multipath-tcp/mptcp-upstream-virtme-docker
Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)
Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)
On Mon, Sep 30, 2024 at 06:23:46PM +0200, Matthieu Baerts (NGI0) wrote: > Nathan reported this issue: > > $ make -skj"$(nproc)" ARCH=x86_64 LLVM=1 LLVM_IAS=1 mrproper allmodconfig net/mptcp/subflow.o > net/mptcp/subflow.c:877:6: warning: variable 'incr' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > 877 | if (WARN_ON_ONCE(offset > skb->len)) > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > include/asm-generic/bug.h:101:33: note: expanded from macro 'WARN_ON_ONCE' > 101 | #define WARN_ON_ONCE(condition) ({ \ > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 102 | int __ret_warn_on = !!(condition); \ > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 103 | if (unlikely(__ret_warn_on)) \ > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 104 | __WARN_FLAGS(BUGFLAG_ONCE | \ > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 105 | BUGFLAG_TAINT(TAINT_WARN)); \ > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 106 | unlikely(__ret_warn_on); \ > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 107 | }) > | ~~ > net/mptcp/subflow.c:893:6: note: uninitialized use occurs here > 893 | if (incr) > | ^~~~ > net/mptcp/subflow.c:877:2: note: remove the 'if' if its condition is always false > 877 | if (WARN_ON_ONCE(offset > skb->len)) > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 878 | goto out; > | ~~~~~~~~ > net/mptcp/subflow.c:874:18: note: initialize the variable 'incr' to silence this warning > 874 | u32 offset, incr, avail_len; > | ^ > | = 0 > 1 warning generated. > > As mentioned by Nathan, this issue is present because 5.10 does not > include commit ea4ca586b16f ("mptcp: refine MPTCP-level ack scheduling"), > which removed the use of 'incr' in the error path added by this change. > This other commit does not really look suitable for stable, hence this > dedicated patch for 5.10. > > Fixes: e93fa44f0714 ("mptcp: fix duplicate data handling") > Reported-by: Nathan Chancellor <nathan@kernel.org> > Closes: https://lore.kernel.org/20240928175524.GA1713144@thelio-3990X > Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> > --- > net/mptcp/subflow.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Now applied, thanks! greg k-h
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 8a0ef50c307c..843c61ebd421 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -871,7 +871,7 @@ static void mptcp_subflow_discard_data(struct sock *ssk, struct sk_buff *skb, struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); bool fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; struct tcp_sock *tp = tcp_sk(ssk); - u32 offset, incr, avail_len; + u32 offset, incr = 0, avail_len; offset = tp->copied_seq - TCP_SKB_CB(skb)->seq; if (WARN_ON_ONCE(offset > skb->len))
Nathan reported this issue: $ make -skj"$(nproc)" ARCH=x86_64 LLVM=1 LLVM_IAS=1 mrproper allmodconfig net/mptcp/subflow.o net/mptcp/subflow.c:877:6: warning: variable 'incr' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] 877 | if (WARN_ON_ONCE(offset > skb->len)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/asm-generic/bug.h:101:33: note: expanded from macro 'WARN_ON_ONCE' 101 | #define WARN_ON_ONCE(condition) ({ \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 102 | int __ret_warn_on = !!(condition); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 103 | if (unlikely(__ret_warn_on)) \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 104 | __WARN_FLAGS(BUGFLAG_ONCE | \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 105 | BUGFLAG_TAINT(TAINT_WARN)); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 106 | unlikely(__ret_warn_on); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 107 | }) | ~~ net/mptcp/subflow.c:893:6: note: uninitialized use occurs here 893 | if (incr) | ^~~~ net/mptcp/subflow.c:877:2: note: remove the 'if' if its condition is always false 877 | if (WARN_ON_ONCE(offset > skb->len)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 878 | goto out; | ~~~~~~~~ net/mptcp/subflow.c:874:18: note: initialize the variable 'incr' to silence this warning 874 | u32 offset, incr, avail_len; | ^ | = 0 1 warning generated. As mentioned by Nathan, this issue is present because 5.10 does not include commit ea4ca586b16f ("mptcp: refine MPTCP-level ack scheduling"), which removed the use of 'incr' in the error path added by this change. This other commit does not really look suitable for stable, hence this dedicated patch for 5.10. Fixes: e93fa44f0714 ("mptcp: fix duplicate data handling") Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/20240928175524.GA1713144@thelio-3990X Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> --- net/mptcp/subflow.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)