[PATCH 7/9] infiniband: uverbs: avoid out-of-range warnings

Arnd Bergmann
2024-03-28T14:32:07Z

From: Arnd Bergmann <arnd@arndb.de>

clang warns for comparisons that are always true, which is the case
for these two page size checks on architectures with 64KB pages:

drivers/infiniband/core/uverbs_ioctl.c:90:39: error: result of comparison of constant 65536 with expression of type 'u16' (aka 'unsigned short') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
WARN_ON_ONCE(method_elm->bundle_size > PAGE_SIZE);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
include/asm-generic/bug.h:104:25: note: expanded from macro 'WARN_ON_ONCE'
int __ret_warn_on = !!(condition); \
^~~~~~~~~
drivers/infiniband/core/uverbs_ioctl.c:621:17: error: result of comparison of constant 65536 with expression of type '__u16' (aka 'unsigned short') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (hdr.length > PAGE_SIZE ||
~~~~~~~~~~ ^ ~~~~~~~~~

Add a cast to u32 in both cases, so it never warns about this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/infiniband/core/uverbs_ioctl.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index f80da6a67e24..e0cc3ddae71b 100644
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -90,7 +90,7 @@ void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm,
ALIGN(bundle_size + 256, sizeof(*pbundle->internal_buffer));

/* Do not want order-2 allocations for this. */
- WARN_ON_ONCE(method_elm->bundle_size > PAGE_SIZE);
+ WARN_ON_ONCE((u32)method_elm->bundle_size > PAGE_SIZE);
}

/**
@@ -636,7 +636,7 @@ long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (err)
return -EFAULT;

- if (hdr.length > PAGE_SIZE ||
+ if ((u32)hdr.length > PAGE_SIZE ||
hdr.length != struct_size(&hdr, attrs, hdr.num_attrs))
return -EINVAL;

--
2.39.2