On Wed, 2017-10-11 at 08:19 +0300, Matan Barak wrote:
> But what about cases where UVERBS_OPTIMIZE_USING_STACK_SZ is defined but
> is insufficient in size?
Sorry. How about the patch below? The most significant change compared to the
current code is that UVERBS_OPTIMIZE_USING_STACK_SZ has to be defined as 0
instead of not defining that macro to disable the optimization. A new change
is that this version uses gcc's support for zero-length arrays (which is an
extension of the C standard and is already used elsewhere in the kernel).
Subject: [PATCH] RDMA/uverbs: Make the code in ib_uverbs_cmd_verbs() less
confusing
This patch reduces the number of #ifdefs and also avoids that
smatch reports the following:
drivers/infiniband/core/uverbs_ioctl.c:276: ib_uverbs_cmd_verbs() warn: if statement not indented
drivers/infiniband/core/uverbs_ioctl.c:280: ib_uverbs_cmd_verbs() warn: possible memory leak of 'ctx'
drivers/infiniband/core/uverbs_ioctl.c:315: ib_uverbs_cmd_verbs() warn: if statement not indented
References: commit fac9658cabb9 ("IB/core: Add new ioctl interface")
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Matan Barak <matanb@xxxxxxxxxxxx>
Cc: Yishai Hadas <yishaih@xxxxxxxxxxxx>
---
drivers/infiniband/core/uverbs_ioctl.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index 5286ad57d903..71ff2644e053 100644
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -241,9 +241,7 @@ static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
struct uverbs_attr *curr_attr;
unsigned long *curr_bitmap;
size_t ctx_size;
-#ifdef UVERBS_OPTIMIZE_USING_STACK_SZ
uintptr_t data[UVERBS_OPTIMIZE_USING_STACK_SZ / sizeof(uintptr_t)];
-#endif
if (hdr->reserved)
return -EINVAL;
@@ -269,13 +267,10 @@ static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
(method_spec->num_child_attrs / BITS_PER_LONG +
method_spec->num_buckets);
-#ifdef UVERBS_OPTIMIZE_USING_STACK_SZ
if (ctx_size <= UVERBS_OPTIMIZE_USING_STACK_SZ)
ctx = (void *)data;
-
if (!ctx)
-#endif
- ctx = kmalloc(ctx_size, GFP_KERNEL);
+ ctx = kmalloc(ctx_size, GFP_KERNEL);
if (!ctx)
return -ENOMEM;
@@ -311,10 +306,8 @@ static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
err = uverbs_handle_method(buf, ctx->uattrs, hdr->num_attrs, ib_dev,
file, method_spec, ctx->uverbs_attr_bundle);
out:
-#ifdef UVERBS_OPTIMIZE_USING_STACK_SZ
- if (ctx_size > UVERBS_OPTIMIZE_USING_STACK_SZ)
-#endif
- kfree(ctx);
+ if (ctx != (void *)data)
+ kfree(ctx);
return err;
}
--
2.14.2
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