memfd_secret: use unsigned int rather than long as syscall flags type

Yuri Norov says:

  If parameter size is the same for native and compat ABIs, we may
  wire a syscall made by compat client to native handler. This is
  true for unsigned int, but not true for unsigned long or pointer.

  That's why I suggest using unsigned int and so avoid creating compat
  entry point.

Use unsigned int as the type of the flags parameter in memfd_secret()
system call.

Link: https://lkml.kernel.org/r/20210331142345.27532-1-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 49c93c906893d4de52637462a85d6c2a4127a2d9..1a1b5d7244978daba7ec8afd162907ee5ae9467c 100644 (file)
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1050,7 +1050,7 @@ asmlinkage long sys_landlock_create_ruleset(const struct landlock_ruleset_attr _
 asmlinkage long sys_landlock_add_rule(int ruleset_fd, enum landlock_rule_type rule_type,
                const void __user *rule_attr, __u32 flags);
 asmlinkage long sys_landlock_restrict_self(int ruleset_fd, __u32 flags);
-asmlinkage long sys_memfd_secret(unsigned long flags);
+asmlinkage long sys_memfd_secret(unsigned int flags);
 
 /*
  * Architecture-specific system calls