IB/uverbs: New macro to set pointers to NULL if length is 0 in INIT_UDATA()
Trying to have a ternary operator to choose between NULL (or 0) and the
real pointer value in invocations leads to an impossible choice between
a sparse error about a literal 0 used as a NULL pointer, and a gcc
warning about "pointer/integer type mismatch in conditional expression."
Rather than clutter the source with more casts, move the ternary
operator into a new INIT_UDATA_BUF_OR_NULL() macro, which makes it
easier to use and simplifies its callers.
Reported-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index 9879568..a283274 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -55,6 +55,14 @@
(udata)->outlen = (olen); \
} while (0)
+#define INIT_UDATA_BUF_OR_NULL(udata, ibuf, obuf, ilen, olen) \
+ do { \
+ (udata)->inbuf = (ilen) ? (const void __user *) (ibuf) : NULL; \
+ (udata)->outbuf = (olen) ? (void __user *) (obuf) : NULL; \
+ (udata)->inlen = (ilen); \
+ (udata)->outlen = (olen); \
+ } while (0)
+
/*
* Our lifetime rules for these structs are the following:
*
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 3438694..699463b 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -676,17 +676,14 @@
return -EINVAL;
}
- INIT_UDATA(&ucore,
- (hdr.in_words) ? buf : 0,
- (unsigned long)ex_hdr.response,
- hdr.in_words * 8,
- hdr.out_words * 8);
+ INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
+ hdr.in_words * 8, hdr.out_words * 8);
- INIT_UDATA(&uhw,
- (ex_hdr.provider_in_words) ? buf + ucore.inlen : 0,
- (ex_hdr.provider_out_words) ? (unsigned long)ex_hdr.response + ucore.outlen : 0,
- ex_hdr.provider_in_words * 8,
- ex_hdr.provider_out_words * 8);
+ INIT_UDATA_BUF_OR_NULL(&uhw,
+ buf + ucore.inlen,
+ (unsigned long) ex_hdr.response + ucore.outlen,
+ ex_hdr.provider_in_words * 8,
+ ex_hdr.provider_out_words * 8);
err = uverbs_ex_cmd_table[command](file,
&ucore,