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Commit a96e4e2f authored by Roland Dreier's avatar Roland Dreier
Browse files

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: default avatarYann Droneaud <ydroneaud@opteya.com>
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent 309243ec

drivers/infiniband/core/uverbs.h

+8 −0
Original line number Diff line number Diff line
@@ -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:

 *

drivers/infiniband/core/uverbs_main.c

+8 −11
Original line number Diff line number Diff line
@@ -676,15 +676,12 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf, 
				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(&uhw,

			   (ex_hdr.provider_in_words) ? buf + ucore.inlen : 0,

			   (ex_hdr.provider_out_words) ? (unsigned long)ex_hdr.response + ucore.outlen : 0,

		INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,

				       hdr.in_words * 8, hdr.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);