lkml.org 
[lkml]   [2024]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH 2/9] libceph: avoid clang out-of-range warning
    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
    >

    \
     
     \ /
      Last update: 2024-03-28 23:54    [W:2.089 / U:0.500 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site