| Message ID | 20210727225650.726875-1-nathan@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [4.9,1/2] iommu/amd: Fix backport of 140456f994195b568ecd7fc2287a34eadffef3ca | expand |
On Tue, Jul 27, 2021 at 03:56:49PM -0700, Nathan Chancellor wrote: > Clang warns: > > drivers/iommu/amd_iommu.c:1335:6: warning: variable 'flags' is used > uninitialized whenever 'if' condition is true > [-Wsometimes-uninitialized] > if (!pte) > ^~~~ > drivers/iommu/amd_iommu.c:1352:40: note: uninitialized use occurs here > spin_unlock_irqrestore(&domain->lock, flags); > ^~~~~ > drivers/iommu/amd_iommu.c:1335:2: note: remove the 'if' if its condition > is always false > if (!pte) > ^~~~~~~~~ > drivers/iommu/amd_iommu.c:1331:21: note: initialize the variable 'flags' > to silence this warning > unsigned long flags; > ^ > = 0 > 1 warning generated. > > The backport of commit 140456f99419 ("iommu/amd: Fix sleeping in atomic > in increase_address_space()") to 4.9 as commit 1d648460d7c5 ("iommu/amd: > Fix sleeping in atomic in increase_address_space()") failed to keep the > "return false", which in 4.9 needs to be a regular "return" due to a > lack of commit f15d9a992f90 ("iommu/amd: Remove domain->updated"). > > This resolves the warning and matches the 4.14-4.19 backport. > > Cc: Andrey Ryabinin <arbn@yandex-team.com> > Cc: Joerg Roedel <joro@8bytes.org> > Cc: Will Deacon <will@kernel.org> > Fixes: 1d648460d7c5 ("iommu/amd: Fix sleeping in atomic in increase_address_space()") > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Joerg Roedel <jroedel@suse.de>
On Tue, Jul 27, 2021 at 03:56:50PM -0700, Nathan Chancellor wrote: > Clang warns: > > net/tipc/link.c:896:23: warning: variable 'hdr' is uninitialized when > used here [-Wuninitialized] > imp = msg_importance(hdr); > ^~~ > net/tipc/link.c:890:22: note: initialize the variable 'hdr' to silence > this warning > struct tipc_msg *hdr; > ^ > = NULL > 1 warning generated. > > The backport of commit b77413446408 ("tipc: fix NULL deref in > tipc_link_xmit()") to 4.9 as commit 310014f572a5 ("tipc: fix NULL deref > in tipc_link_xmit()") added the hdr initialization above the > > if (unlikely(msg_size(hdr) > mtu)) { > > like in the upstream commit; however, in 4.9, that check is below imp's > first use because commit 365ad353c256 ("tipc: reduce risk of user > starvation during link congestion") is not present. This results in hdr > being used uninitialized. > > Fix this by moving hdr's initialization before imp and after the if > check like the original backport did. > > Cc: Hoang Le <hoang.h.le@dektech.com.au> > Cc: Jon Maloy <jon.maloy@ericsson.com> > Cc: Ying Xue <ying.xue@windriver.com> > Fixes: 310014f572a5 ("tipc: fix NULL deref in tipc_link_xmit()") > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > --- > net/tipc/link.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/tipc/link.c b/net/tipc/link.c > index 06327f78f203..6fc2fa75503d 100644 > --- a/net/tipc/link.c > +++ b/net/tipc/link.c > @@ -893,6 +893,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, > if (pkt_cnt <= 0) > return 0; > > + hdr = buf_msg(skb_peek(list)); > imp = msg_importance(hdr); > /* Match msg importance against this and all higher backlog limits: */ > if (!skb_queue_empty(backlogq)) { > @@ -902,7 +903,6 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, > } > } > > - hdr = buf_msg(skb_peek(list)); > if (unlikely(msg_size(hdr) > mtu)) { > skb_queue_purge(list); > return -EMSGSIZE; > -- > 2.32.0.264.g75ae10bc75 > Thanks for these, now both queued up. greg k-h
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 8377bd388d67..14e9b06829d5 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1333,7 +1333,7 @@ static void increase_address_space(struct protection_domain *domain, pte = (void *)get_zeroed_page(gfp); if (!pte) - goto out; + return; spin_lock_irqsave(&domain->lock, flags);
Clang warns: drivers/iommu/amd_iommu.c:1335:6: warning: variable 'flags' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!pte) ^~~~ drivers/iommu/amd_iommu.c:1352:40: note: uninitialized use occurs here spin_unlock_irqrestore(&domain->lock, flags); ^~~~~ drivers/iommu/amd_iommu.c:1335:2: note: remove the 'if' if its condition is always false if (!pte) ^~~~~~~~~ drivers/iommu/amd_iommu.c:1331:21: note: initialize the variable 'flags' to silence this warning unsigned long flags; ^ = 0 1 warning generated. The backport of commit 140456f99419 ("iommu/amd: Fix sleeping in atomic in increase_address_space()") to 4.9 as commit 1d648460d7c5 ("iommu/amd: Fix sleeping in atomic in increase_address_space()") failed to keep the "return false", which in 4.9 needs to be a regular "return" due to a lack of commit f15d9a992f90 ("iommu/amd: Remove domain->updated"). This resolves the warning and matches the 4.14-4.19 backport. Cc: Andrey Ryabinin <arbn@yandex-team.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Will Deacon <will@kernel.org> Fixes: 1d648460d7c5 ("iommu/amd: Fix sleeping in atomic in increase_address_space()") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- drivers/iommu/amd_iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: 0db822f6dee813f746ed196fc561945eee4cd4b9