From c7142aead87aa5026e4b57671c7dbb1706b02606 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 12 Dec 2016 16:43:09 -0800 Subject: [PATCH] mm/pkeys: generate pkey system call code only if ARCH_HAS_PKEYS is selected Having code for the pkey_mprotect, pkey_alloc and pkey_free system calls makes only sense if ARCH_HAS_PKEYS is selected. If not selected these system calls will always return -ENOSPC or -EINVAL. To simplify things and have less code generate the pkey system call code only if ARCH_HAS_PKEYS is selected. For architectures which have already wired up the system calls, but do not select ARCH_HAS_PKEYS this will result in less generated code and a different return code: the three system calls will now always return -ENOSYS, using the cond_syscall mechanism. For architectures which have not wired up the system calls less unreachable code will be generated. Link: http://lkml.kernel.org/r/20161114111251.70084-1-heiko.carstens@de.ibm.com Signed-off-by: Heiko Carstens Acked-by: Dave Hansen Cc: Mark Rutland Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mprotect.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/mprotect.c b/mm/mprotect.c index c5ba2aae0f54..cc2459c57f60 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -497,6 +497,8 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, return do_mprotect_pkey(start, len, prot, -1); } +#ifdef CONFIG_ARCH_HAS_PKEYS + SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, unsigned long, prot, int, pkey) { @@ -547,3 +549,5 @@ SYSCALL_DEFINE1(pkey_free, int, pkey) */ return ret; } + +#endif /* CONFIG_ARCH_HAS_PKEYS */ -- 2.20.1