diff mbox series

[2/9] libceph: avoid clang out-of-range warning

Message ID 20240328143051.1069575-3-arnd@kernel.org
State New
Headers show
Series None | expand

Commit Message

Arnd Bergmann March 28, 2024, 2:30 p.m. UTC
From: Arnd Bergmann <arnd@arndb.de>

clang-14 points out that on 64-bit architectures, a u32
is never larger than constant based on SIZE_MAX:

net/ceph/osdmap.c:1425:10: error: result of comparison of constant 4611686018427387891 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
            ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/ceph/osdmap.c:1608:10: error: result of comparison of constant 2305843009213693945 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
            ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The code is correct anyway, so just shut up that warning.

Fixes: 6f428df47dae ("libceph: pg_upmap[_items] infrastructure")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/ceph/snap.c    | 2 +-
 net/ceph/osdmap.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Justin Stitt March 28, 2024, 10:53 p.m. UTC | #1
On Thu, Mar 28, 2024 at 7:31 AM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> clang-14 points out that on 64-bit architectures, a u32
> is never larger than constant based on SIZE_MAX:
>
> net/ceph/osdmap.c:1425:10: error: result of comparison of constant 4611686018427387891 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
>         if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
>             ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> net/ceph/osdmap.c:1608:10: error: result of comparison of constant 2305843009213693945 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
>         if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
>             ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The code is correct anyway, so just shut up that warning.

OK.

>
> Fixes: 6f428df47dae ("libceph: pg_upmap[_items] infrastructure")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  fs/ceph/snap.c    | 2 +-
>  net/ceph/osdmap.c | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
> index c65f2b202b2b..521507ea8260 100644
> --- a/fs/ceph/snap.c
> +++ b/fs/ceph/snap.c
> @@ -374,7 +374,7 @@ static int build_snap_context(struct ceph_mds_client *mdsc,
>
>         /* alloc new snap context */
>         err = -ENOMEM;
> -       if (num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
> +       if ((size_t)num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
>                 goto fail;
>         snapc = ceph_create_snap_context(num, GFP_NOFS);
>         if (!snapc)
> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
> index 295098873861..8e7cb2fde6f1 100644
> --- a/net/ceph/osdmap.c
> +++ b/net/ceph/osdmap.c
> @@ -1438,7 +1438,7 @@ static struct ceph_pg_mapping *__decode_pg_temp(void **p, void *end,
>         ceph_decode_32_safe(p, end, len, e_inval);
>         if (len == 0 && incremental)
>                 return NULL;    /* new_pg_temp: [] to remove */
> -       if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
> +       if ((size_t)len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
>                 return ERR_PTR(-EINVAL);
>
>         ceph_decode_need(p, end, len * sizeof(u32), e_inval);
> @@ -1621,7 +1621,7 @@ static struct ceph_pg_mapping *__decode_pg_upmap_items(void **p, void *end,
>         u32 len, i;
>
>         ceph_decode_32_safe(p, end, len, e_inval);
> -       if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
> +       if ((size_t)len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
>                 return ERR_PTR(-EINVAL);
>
>         ceph_decode_need(p, end, 2 * len * sizeof(u32), e_inval);
> --
> 2.39.2
>
Xiubo Li March 29, 2024, 12:06 a.m. UTC | #2
On 3/28/24 22:30, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> clang-14 points out that on 64-bit architectures, a u32
> is never larger than constant based on SIZE_MAX:
>
> net/ceph/osdmap.c:1425:10: error: result of comparison of constant 4611686018427387891 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
>          if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
>              ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> net/ceph/osdmap.c:1608:10: error: result of comparison of constant 2305843009213693945 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
>          if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
>              ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The code is correct anyway, so just shut up that warning.
>
> Fixes: 6f428df47dae ("libceph: pg_upmap[_items] infrastructure")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   fs/ceph/snap.c    | 2 +-
>   net/ceph/osdmap.c | 4 ++--
>   2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
> index c65f2b202b2b..521507ea8260 100644
> --- a/fs/ceph/snap.c
> +++ b/fs/ceph/snap.c
> @@ -374,7 +374,7 @@ static int build_snap_context(struct ceph_mds_client *mdsc,
>   
>   	/* alloc new snap context */
>   	err = -ENOMEM;
> -	if (num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
> +	if ((size_t)num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
>   		goto fail;
>   	snapc = ceph_create_snap_context(num, GFP_NOFS);
>   	if (!snapc)
> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
> index 295098873861..8e7cb2fde6f1 100644
> --- a/net/ceph/osdmap.c
> +++ b/net/ceph/osdmap.c
> @@ -1438,7 +1438,7 @@ static struct ceph_pg_mapping *__decode_pg_temp(void **p, void *end,
>   	ceph_decode_32_safe(p, end, len, e_inval);
>   	if (len == 0 && incremental)
>   		return NULL;	/* new_pg_temp: [] to remove */
> -	if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
> +	if ((size_t)len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
>   		return ERR_PTR(-EINVAL);
>   
>   	ceph_decode_need(p, end, len * sizeof(u32), e_inval);
> @@ -1621,7 +1621,7 @@ static struct ceph_pg_mapping *__decode_pg_upmap_items(void **p, void *end,
>   	u32 len, i;
>   
>   	ceph_decode_32_safe(p, end, len, e_inval);
> -	if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
> +	if ((size_t)len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
>   		return ERR_PTR(-EINVAL);
>   
>   	ceph_decode_need(p, end, 2 * len * sizeof(u32), e_inval);


Reviewed-by: Xiubo Li <xiubli@redhat.com>

Thanks

- Xiubo
diff mbox series

Patch

diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index c65f2b202b2b..521507ea8260 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -374,7 +374,7 @@  static int build_snap_context(struct ceph_mds_client *mdsc,
 
 	/* alloc new snap context */
 	err = -ENOMEM;
-	if (num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
+	if ((size_t)num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
 		goto fail;
 	snapc = ceph_create_snap_context(num, GFP_NOFS);
 	if (!snapc)
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 295098873861..8e7cb2fde6f1 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -1438,7 +1438,7 @@  static struct ceph_pg_mapping *__decode_pg_temp(void **p, void *end,
 	ceph_decode_32_safe(p, end, len, e_inval);
 	if (len == 0 && incremental)
 		return NULL;	/* new_pg_temp: [] to remove */
-	if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
+	if ((size_t)len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
 		return ERR_PTR(-EINVAL);
 
 	ceph_decode_need(p, end, len * sizeof(u32), e_inval);
@@ -1621,7 +1621,7 @@  static struct ceph_pg_mapping *__decode_pg_upmap_items(void **p, void *end,
 	u32 len, i;
 
 	ceph_decode_32_safe(p, end, len, e_inval);
-	if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
+	if ((size_t)len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
 		return ERR_PTR(-EINVAL);
 
 	ceph_decode_need(p, end, 2 * len * sizeof(u32), e_inval);