@@ -47,12 +47,12 @@
#include <rdma/ib_umem.h>
#include <rdma/ib_user_verbs.h>
-#define INIT_UDATA(udata, ibuf, obuf, ilen, olen) \
- do { \
- (udata)->inbuf = (const void __user *) (ibuf); \
- (udata)->outbuf = (void __user *) (obuf); \
- (udata)->inlen = (ilen); \
- (udata)->outlen = (olen); \
+#define INIT_UDATA(udata, ibuf, obuf, ilen, olen) \
+ do { \
+ (udata)->inbuf = (ibuf); \
+ (udata)->outbuf = (obuf); \
+ (udata)->inlen = (ilen); \
+ (udata)->outlen = (olen); \
} while (0)
/*
@@ -635,6 +635,7 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
__u32 command;
struct ib_uverbs_ex_cmd_hdr ex_hdr;
+ char __user *response;
struct ib_udata ucore;
struct ib_udata uhw;
int err;
@@ -668,7 +669,9 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count)
return -EINVAL;
- if (ex_hdr.response) {
+ response = (char __user *)(unsigned long)ex_hdr.response;
+
+ if (response) {
if (!hdr.out_words && !ex_hdr.provider_out_words)
return -EINVAL;
} else {
@@ -677,14 +680,14 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
}
INIT_UDATA(&ucore,
- (hdr.in_words) ? buf : 0,
- (unsigned long)ex_hdr.response,
+ (hdr.in_words) ? buf : NULL,
+ 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) ? buf + ucore.inlen : NULL,
+ (ex_hdr.provider_out_words) ? response + ucore.outlen : NULL,
ex_hdr.provider_in_words * 8,
ex_hdr.provider_out_words * 8);
Currently, INIT_UDATA() does an implicit cast to a pointer, so that 'response' address, eg. output buffer, can be used as is to initialize a struct ib_udata: do { \ (udata)->inbuf = (void __user *) (ibuf); \ (udata)->outbuf = (void __user *) (obuf); \ (udata)->inlen = (ilen); \ (udata)->outlen = (olen); \ } while (0) ... INIT_UDATA(&udata, buf + sizeof cmd, (unsigned long) cmd.response + sizeof resp, in_len - sizeof cmd, out_len - sizeof resp); ... Unfortunately, sparse reports an error if literal 0 is used to initialize inbuf or outbuf, for example in: INIT_UDATA(&ucore, (hdr.in_words) ? buf : 0, (unsigned long)ex_hdr.response, hdr.in_words * 8, hdr.out_words * 8); It was reported by kbuild test robot in message[1]: From: kbuild test robot <fengguang.wu@intel.com> Subject: "drivers/infiniband/core/uverbs_main.c:683:17: sparse: Using plain integer as NULL pointer", Message-Id: <528b3984.SVGs20ZWpcuR/Jls%fengguang.wu@intel.com> Replacing 0 by NULL in ib_uverbs_write() might turn off sparse warning, but it trigger a GCC warning: drivers/infiniband/core/uverbs_main.c: In function 'ib_uverbs_write': drivers/infiniband/core/uverbs_main.c:685:200: warning: pointer/integer type mismatch in conditional expression [enabled by default] So fixing the sparse warning require broad changes in uverbs. By removing the implicit cast INIT_UDATA(), this patch fixes the warnings reported by sparse and allows the compiler to report a warning in case a plain integer get used to initialize an udata pointer. This patch requires - calls to INIT_UDATA() to be modified to pass a pointer instead of an unsigned long, - struct ib_udata to be modified to have a const void __user *inbuf field[2], otherwise compiler will report warnings regarding const to non const conversion: drivers/infiniband/core/uverbs_main.c: In function ‘ib_uverbs_write’: drivers/infiniband/core/uverbs_main.c:682:24: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] drivers/infiniband/core/uverbs_main.c:688:22: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] drivers/infiniband/core/uverbs_cmd.c: In function ‘ib_uverbs_get_context’: drivers/infiniband/core/uverbs_cmd.c:307:23: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] drivers/infiniband/core/uverbs_cmd.c: In function ‘ib_uverbs_alloc_pd’: drivers/infiniband/core/uverbs_cmd.c:516:23: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] ... [1] https://lists.01.org/pipermail/kbuild-all/2013-November/002120.html [2] https://patchwork.kernel.org/patch/2846202/ http://marc.info/?i=3050a98379b4342ea59d59aeaf1ce162171df928.1376847403.git.ydroneaud@opteya.com Link: http://marc.info/?i=cover.1387273677.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> --- drivers/infiniband/core/uverbs.h | 12 ++++++------ drivers/infiniband/core/uverbs_main.c | 13 ++++++++----- 2 files changed, 14 insertions(+), 11 deletions(-)