[PATCH v2 0/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[PATCH v2 0/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Uros Bizjak]

Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
and percpu address spaces and add __percpu annotation to *stats pointer
to fix percpu address space issues.

NOTE: The patch depends on a patch that introduces *_PCPU() macros [1]
that is on the way to mainline through the mm tree. For convience, the
patch is included in this patch series, so CI tester is able to test
the second patch without compile failures.

[1] https://lore.kernel.org/lkml/20240818210235.33481-1-ubizjak@gmail.com/

The netfilter patch obsoletes patch [2].

[2] https://patchwork.ozlabs.org/project/netfilter-devel/patch/20240806102808.804619-1-ubizjak@gmail.com/

Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>

Uros Bizjak (2):
  err.h: Add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() macros
  netfilter: nf_tables: Fix percpu address space issues in
    nf_tables_api.c

 include/linux/err.h           |  9 +++++++++
 net/netfilter/nf_tables_api.c | 16 ++++++++--------
 2 files changed, 17 insertions(+), 8 deletions(-)

-- 
2.42.0

[PATCH v2 1/2] err.h: Add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() macros

[Uros Bizjak]

Add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() macros that
operate on pointers in the percpu address space.

These macros remove the need for (__force void *) function
argument casts (to avoid sparse -Wcast-from-as warnings).

The patch will also avoid future build errors due to pointer address
space mismatch with enabled strict percpu address space checks.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
---
 include/linux/err.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/err.h b/include/linux/err.h
index b5d9bb2a2349..a4dacd745fcf 100644
--- a/include/linux/err.h
+++ b/include/linux/err.h
@@ -41,6 +41,9 @@ static inline void * __must_check ERR_PTR(long error)
 	return (void *) error;
 }
 
+/* Return the pointer in the percpu address space. */
+#define ERR_PTR_PCPU(error) ((void __percpu *)(unsigned long)ERR_PTR(error))
+
 /**
  * PTR_ERR - Extract the error code from an error pointer.
  * @ptr: An error pointer.
@@ -51,6 +54,9 @@ static inline long __must_check PTR_ERR(__force const void *ptr)
 	return (long) ptr;
 }
 
+/* Read an error pointer from the percpu address space. */
+#define PTR_ERR_PCPU(ptr) (PTR_ERR((const void *)(__force const unsigned long)(ptr)))
+
 /**
  * IS_ERR - Detect an error pointer.
  * @ptr: The pointer to check.
@@ -61,6 +67,9 @@ static inline bool __must_check IS_ERR(__force const void *ptr)
 	return IS_ERR_VALUE((unsigned long)ptr);
 }
 
+/* Read an error pointer from the percpu address space. */
+#define IS_ERR_PCPU(ptr) (IS_ERR((const void *)(__force const unsigned long)(ptr)))
+
 /**
  * IS_ERR_OR_NULL - Detect an error pointer or a null pointer.
  * @ptr: The pointer to check.
-- 
2.42.0

[PATCH v2 2/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Uros Bizjak]

Compiling nf_tables_api.c results in several sparse warnings:

nf_tables_api.c:2077:31: warning: incorrect type in return expression (different address spaces)
nf_tables_api.c:2080:31: warning: incorrect type in return expression (different address spaces)
nf_tables_api.c:2084:31: warning: incorrect type in return expression (different address spaces)

nf_tables_api.c:2740:23: warning: incorrect type in assignment (different address spaces)
nf_tables_api.c:2752:38: warning: incorrect type in assignment (different address spaces)
nf_tables_api.c:2798:21: warning: incorrect type in argument 1 (different address spaces)

Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
and percpu address spaces and add __percpu annotation to *stats pointer
to fix these warnings.

Found by GCC's named address space checks.

There were no changes in the resulting object files.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
---
v2: Also use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros.
---
 net/netfilter/nf_tables_api.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0a2f79346958..46f362d4859d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2074,14 +2074,14 @@ static struct nft_stats __percpu *nft_stats_alloc(const struct nlattr *attr)
 	err = nla_parse_nested_deprecated(tb, NFTA_COUNTER_MAX, attr,
 					  nft_counter_policy, NULL);
 	if (err < 0)
-		return ERR_PTR(err);
+		return ERR_PTR_PCPU(err);
 
 	if (!tb[NFTA_COUNTER_BYTES] || !tb[NFTA_COUNTER_PACKETS])
-		return ERR_PTR(-EINVAL);
+		return ERR_PTR_PCPU(-EINVAL);
 
 	newstats = netdev_alloc_pcpu_stats(struct nft_stats);
 	if (newstats == NULL)
-		return ERR_PTR(-ENOMEM);
+		return ERR_PTR_PCPU(-ENOMEM);
 
 	/* Restore old counters on this cpu, no problem. Per-cpu statistics
 	 * are not exposed to userspace.
@@ -2525,10 +2525,10 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
 
 		if (nla[NFTA_CHAIN_COUNTERS]) {
 			stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);
-			if (IS_ERR(stats)) {
+			if (IS_ERR_PCPU(stats)) {
 				nft_chain_release_hook(&hook);
 				kfree(basechain);
-				return PTR_ERR(stats);
+				return PTR_ERR_PCPU(stats);
 			}
 			rcu_assign_pointer(basechain->stats, stats);
 		}
@@ -2642,7 +2642,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
 	struct nft_table *table = ctx->table;
 	struct nft_chain *chain = ctx->chain;
 	struct nft_chain_hook hook = {};
-	struct nft_stats *stats = NULL;
+	struct nft_stats __percpu *stats = NULL;
 	struct nft_hook *h, *next;
 	struct nf_hook_ops *ops;
 	struct nft_trans *trans;
@@ -2738,8 +2738,8 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
 		}
 
 		stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);
-		if (IS_ERR(stats)) {
-			err = PTR_ERR(stats);
+		if (IS_ERR_PCPU(stats)) {
+			err = PTR_ERR_PCPU(stats);
 			goto err_hooks;
 		}
 	}
-- 
2.42.0

Re: [PATCH v2 2/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Simon Horman]

On Thu, Aug 29, 2024 at 05:29:32PM +0200, Uros Bizjak wrote:
> Compiling nf_tables_api.c results in several sparse warnings:
> 
> nf_tables_api.c:2077:31: warning: incorrect type in return expression (different address spaces)
> nf_tables_api.c:2080:31: warning: incorrect type in return expression (different address spaces)
> nf_tables_api.c:2084:31: warning: incorrect type in return expression (different address spaces)
> 
> nf_tables_api.c:2740:23: warning: incorrect type in assignment (different address spaces)
> nf_tables_api.c:2752:38: warning: incorrect type in assignment (different address spaces)
> nf_tables_api.c:2798:21: warning: incorrect type in argument 1 (different address spaces)
> 
> Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
> and percpu address spaces and add __percpu annotation to *stats pointer
> to fix these warnings.
> 
> Found by GCC's named address space checks.
> 
> There were no changes in the resulting object files.
> 
> Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
> Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> ---
> v2: Also use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH v2 2/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Pablo Neira Ayuso]

On Thu, Aug 29, 2024 at 05:29:32PM +0200, Uros Bizjak wrote:
> Compiling nf_tables_api.c results in several sparse warnings:
> 
> nf_tables_api.c:2077:31: warning: incorrect type in return expression (different address spaces)
> nf_tables_api.c:2080:31: warning: incorrect type in return expression (different address spaces)
> nf_tables_api.c:2084:31: warning: incorrect type in return expression (different address spaces)
> 
> nf_tables_api.c:2740:23: warning: incorrect type in assignment (different address spaces)
> nf_tables_api.c:2752:38: warning: incorrect type in assignment (different address spaces)
> nf_tables_api.c:2798:21: warning: incorrect type in argument 1 (different address spaces)
> 
> Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
> and percpu address spaces and add __percpu annotation to *stats pointer
> to fix these warnings.
> 
> Found by GCC's named address space checks.
> 
> There were no changes in the resulting object files.

ERR_PTR,IS_ERR,PTR_ERR}_PCPU() dependency is now in nf-next.git.

Applied, thanks

Re: [PATCH v2 0/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Pablo Neira Ayuso]

Hi,

On Thu, Aug 29, 2024 at 05:29:30PM +0200, Uros Bizjak wrote:
> Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
> and percpu address spaces and add __percpu annotation to *stats pointer
> to fix percpu address space issues.

IIRC, you submitted patch 1/2 in this series to the mm tree.

Let us know if this patch gets upstreamed via MM tree (if mm
maintainers are fine with it) or maybe MM maintainers prefer an
alternative path for this.

Thanks.

> NOTE: The patch depends on a patch that introduces *_PCPU() macros [1]
> that is on the way to mainline through the mm tree. For convience, the
> patch is included in this patch series, so CI tester is able to test
> the second patch without compile failures.
> 
> [1] https://lore.kernel.org/lkml/20240818210235.33481-1-ubizjak@gmail.com/
> 
> The netfilter patch obsoletes patch [2].
> 
> [2] https://patchwork.ozlabs.org/project/netfilter-devel/patch/20240806102808.804619-1-ubizjak@gmail.com/
> 
> Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> 
> Uros Bizjak (2):
>   err.h: Add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() macros
>   netfilter: nf_tables: Fix percpu address space issues in
>     nf_tables_api.c
> 
>  include/linux/err.h           |  9 +++++++++
>  net/netfilter/nf_tables_api.c | 16 ++++++++--------
>  2 files changed, 17 insertions(+), 8 deletions(-)
> 
> -- 
> 2.42.0
> 

Re: [PATCH v2 0/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Uros Bizjak]

On Tue, Sep 3, 2024 at 6:14 PM Pablo Neira Ayuso <pablo@netfilter.org> wrote:
>
> Hi,
>
> On Thu, Aug 29, 2024 at 05:29:30PM +0200, Uros Bizjak wrote:
> > Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
> > and percpu address spaces and add __percpu annotation to *stats pointer
> > to fix percpu address space issues.
>
> IIRC, you submitted patch 1/2 in this series to the mm tree.

Yes, patch 1/2 is in this series just for convenience.

> Let us know if this patch gets upstreamed via MM tree (if mm
> maintainers are fine with it) or maybe MM maintainers prefer an
> alternative path for this.

The patch is accepted into the MM tree [1].

[1] https://lore.kernel.org/mm-commits/20240820052852.CB380C4AF0B@smtp.kernel.org/

Thanks,
Uros.

>
> Thanks.
>
> > NOTE: The patch depends on a patch that introduces *_PCPU() macros [1]
> > that is on the way to mainline through the mm tree. For convience, the
> > patch is included in this patch series, so CI tester is able to test
> > the second patch without compile failures.
> >
> > [1] https://lore.kernel.org/lkml/20240818210235.33481-1-ubizjak@gmail.com/
> >
> > The netfilter patch obsoletes patch [2].
> >
> > [2] https://patchwork.ozlabs.org/project/netfilter-devel/patch/20240806102808.804619-1-ubizjak@gmail.com/
> >
> > Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> > Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Eric Dumazet <edumazet@google.com>
> > Cc: Jakub Kicinski <kuba@kernel.org>
> > Cc: Paolo Abeni <pabeni@redhat.com>
> >
> > Uros Bizjak (2):
> >   err.h: Add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() macros
> >   netfilter: nf_tables: Fix percpu address space issues in
> >     nf_tables_api.c
> >
> >  include/linux/err.h           |  9 +++++++++
> >  net/netfilter/nf_tables_api.c | 16 ++++++++--------
> >  2 files changed, 17 insertions(+), 8 deletions(-)
> >
> > --
> > 2.42.0
> >

Re: [PATCH v2 0/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Pablo Neira Ayuso]

On Tue, Sep 03, 2024 at 06:19:57PM +0200, Uros Bizjak wrote:
> On Tue, Sep 3, 2024 at 6:14 PM Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> >
> > Hi,
> >
> > On Thu, Aug 29, 2024 at 05:29:30PM +0200, Uros Bizjak wrote:
> > > Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
> > > and percpu address spaces and add __percpu annotation to *stats pointer
> > > to fix percpu address space issues.
> >
> > IIRC, you submitted patch 1/2 in this series to the mm tree.
> 
> Yes, patch 1/2 is in this series just for convenience.
> 
> > Let us know if this patch gets upstreamed via MM tree (if mm
> > maintainers are fine with it) or maybe MM maintainers prefer an
> > alternative path for this.
> 
> The patch is accepted into the MM tree [1].
> 
> [1] https://lore.kernel.org/mm-commits/20240820052852.CB380C4AF0B@smtp.kernel.org/

Thanks, I will wait for it to propagate to the netdev tree.

Re: [PATCH v2 0/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Uros Bizjak]

On Tue, Sep 3, 2024 at 6:14 PM Pablo Neira Ayuso <pablo@netfilter.org> wrote:
>
> Hi,
>
> On Thu, Aug 29, 2024 at 05:29:30PM +0200, Uros Bizjak wrote:
> > Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
> > and percpu address spaces and add __percpu annotation to *stats pointer
> > to fix percpu address space issues.
>
> IIRC, you submitted patch 1/2 in this series to the mm tree.
>
> Let us know if this patch gets upstreamed via MM tree (if mm
> maintainers are fine with it) or maybe MM maintainers prefer an
> alternative path for this.

Dear maintainers,

I would just like to inform you that patch 1/2 got mainlined [1] as
commit a759e37fb467.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a759e37fb46708029c9c3c56c3b62e6f24d85cf5

Best regards,
Uros.

> Thanks.
>
> > NOTE: The patch depends on a patch that introduces *_PCPU() macros [1]
> > that is on the way to mainline through the mm tree. For convience, the
> > patch is included in this patch series, so CI tester is able to test
> > the second patch without compile failures.
> >
> > [1] https://lore.kernel.org/lkml/20240818210235.33481-1-ubizjak@gmail.com/
> >
> > The netfilter patch obsoletes patch [2].
> >
> > [2] https://patchwork.ozlabs.org/project/netfilter-devel/patch/20240806102808.804619-1-ubizjak@gmail.com/
> >
> > Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> > Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Eric Dumazet <edumazet@google.com>
> > Cc: Jakub Kicinski <kuba@kernel.org>
> > Cc: Paolo Abeni <pabeni@redhat.com>
> >
> > Uros Bizjak (2):
> >   err.h: Add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() macros
> >   netfilter: nf_tables: Fix percpu address space issues in
> >     nf_tables_api.c
> >
> >  include/linux/err.h           |  9 +++++++++
> >  net/netfilter/nf_tables_api.c | 16 ++++++++--------
> >  2 files changed, 17 insertions(+), 8 deletions(-)
> >
> > --
> > 2.42.0
> >

Re: [PATCH v2 0/2] netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c

[Pablo Neira Ayuso]

On Sun, Sep 22, 2024 at 11:04:56AM +0200, Uros Bizjak wrote:
> On Tue, Sep 3, 2024 at 6:14 PM Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> >
> > Hi,
> >
> > On Thu, Aug 29, 2024 at 05:29:30PM +0200, Uros Bizjak wrote:
> > > Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic
> > > and percpu address spaces and add __percpu annotation to *stats pointer
> > > to fix percpu address space issues.
> >
> > IIRC, you submitted patch 1/2 in this series to the mm tree.
> >
> > Let us know if this patch gets upstreamed via MM tree (if mm
> > maintainers are fine with it) or maybe MM maintainers prefer an
> > alternative path for this.
> 
> Dear maintainers,
> 
> I would just like to inform you that patch 1/2 got mainlined [1] as
> commit a759e37fb467.

Thanks for your follow up to notify this, I will place this in
nf-next.

> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a759e37fb46708029c9c3c56c3b62e6f24d85cf5
> 
> Best regards,
> Uros.