From: Roland Dreier Date: Thu, 19 Dec 2013 16:37:03 +0000 (-0800) Subject: IB/uverbs: New macro to set pointers to NULL if length is 0 in INIT_UDATA() X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=a96e4e2ffe439e45732d820fac6fee486b6412bf;p=openwrt%2Fstaging%2Fblogic.git 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 Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index 9879568aed8c..a283274a5a09 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 34386943ebcf..699463bbfd2d 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -676,17 +676,14 @@ 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, - ex_hdr.provider_in_words * 8, - ex_hdr.provider_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_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,