[IA64] sys_mmap doesn't follow posix.1 when parameter len=0

In IA64 kernel, sys_mmap calls do_mmap2 and do_mmap2 returns addr if
len=0, which means the mmap sys call succeeds.

Posix.1 says:
The mmap() function shall fail if:
[EINVAL] The value of len is zero.

Here is a patch to fix it.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Acked-by: David Mosberger <davidm@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/kernel/sys_ia64.c b/arch/ia64/kernel/sys_ia64.c
index a8cf6d8..770fab3 100644 (file)
--- a/arch/ia64/kernel/sys_ia64.c
+++ b/arch/ia64/kernel/sys_ia64.c
@@ -182,13 +182,6 @@ do_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, un
                }
        }
 
-       /*
-        * A zero mmap always succeeds in Linux, independent of whether or not the
-        * remaining arguments are valid.
-        */
-       if (len == 0)
-               goto out;
-
        /* Careful about overflows.. */
        len = PAGE_ALIGN(len);
        if (!len || len > TASK_SIZE) {