linux-kernel - [PATCH 2/8] mm: remove unused GUP flags

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Message-ID: <Pine.LNX.4.64.0909072230010.15430@sister.anvils>
Date:	Mon, 7 Sep 2009 22:31:09 +0100 (BST)
From:	Hugh Dickins <hugh.dickins@...cali.co.uk>
To:	Andrew Morton <akpm@...ux-foundation.org>
cc:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Nick Piggin <npiggin@...e.de>, Rik van Riel <riel@...hat.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: [PATCH 2/8] mm: remove unused GUP flags

GUP_FLAGS_IGNORE_VMA_PERMISSIONS and GUP_FLAGS_IGNORE_SIGKILL were
flags added solely to prevent __get_user_pages() from doing some of
what it usually does, in the munlock case: we can now remove them.

Signed-off-by: Hugh Dickins <hugh.dickins@...cali.co.uk>
---

 mm/internal.h |    6 ++----
 mm/memory.c   |   14 ++++----------
 mm/nommu.c    |    6 ++----
 3 files changed, 8 insertions(+), 18 deletions(-)

--- mm1/mm/internal.h	2009-06-25 05:18:10.000000000 +0100
+++ mm2/mm/internal.h	2009-09-07 13:16:22.000000000 +0100
@@ -250,10 +250,8 @@ static inline void mminit_validate_memmo
 }
 #endif /* CONFIG_SPARSEMEM */
 
-#define GUP_FLAGS_WRITE                  0x1
-#define GUP_FLAGS_FORCE                  0x2
-#define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
-#define GUP_FLAGS_IGNORE_SIGKILL         0x8
+#define GUP_FLAGS_WRITE		0x01
+#define GUP_FLAGS_FORCE		0x02
 
 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 		     unsigned long start, int len, int flags,
--- mm1/mm/memory.c	2009-09-05 14:40:16.000000000 +0100
+++ mm2/mm/memory.c	2009-09-07 13:16:22.000000000 +0100
@@ -1217,8 +1217,6 @@ int __get_user_pages(struct task_struct
 	unsigned int vm_flags = 0;
 	int write = !!(flags & GUP_FLAGS_WRITE);
 	int force = !!(flags & GUP_FLAGS_FORCE);
-	int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
-	int ignore_sigkill = !!(flags & GUP_FLAGS_IGNORE_SIGKILL);
 
 	if (nr_pages <= 0)
 		return 0;
@@ -1244,7 +1242,7 @@ int __get_user_pages(struct task_struct
 			pte_t *pte;
 
 			/* user gate pages are read-only */
-			if (!ignore && write)
+			if (write)
 				return i ? : -EFAULT;
 			if (pg > TASK_SIZE)
 				pgd = pgd_offset_k(pg);
@@ -1278,7 +1276,7 @@ int __get_user_pages(struct task_struct
 
 		if (!vma ||
 		    (vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
-		    (!ignore && !(vm_flags & vma->vm_flags)))
+		    !(vm_flags & vma->vm_flags))
 			return i ? : -EFAULT;
 
 		if (is_vm_hugetlb_page(vma)) {
@@ -1298,13 +1296,9 @@ int __get_user_pages(struct task_struct
 
 			/*
 			 * If we have a pending SIGKILL, don't keep faulting
-			 * pages and potentially allocating memory, unless
-			 * current is handling munlock--e.g., on exit. In
-			 * that case, we are not allocating memory.  Rather,
-			 * we're only unlocking already resident/mapped pages.
+			 * pages and potentially allocating memory.
 			 */
-			if (unlikely(!ignore_sigkill &&
-					fatal_signal_pending(current)))
+			if (unlikely(fatal_signal_pending(current)))
 				return i ? i : -ERESTARTSYS;
 
 			if (write)
--- mm1/mm/nommu.c	2009-09-05 14:40:16.000000000 +0100
+++ mm2/mm/nommu.c	2009-09-07 13:16:22.000000000 +0100
@@ -136,7 +136,6 @@ int __get_user_pages(struct task_struct
 	int i;
 	int write = !!(flags & GUP_FLAGS_WRITE);
 	int force = !!(flags & GUP_FLAGS_FORCE);
-	int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
 
 	/* calculate required read or write permissions.
 	 * - if 'force' is set, we only require the "MAY" flags.
@@ -150,8 +149,8 @@ int __get_user_pages(struct task_struct
 			goto finish_or_fault;
 
 		/* protect what we can, including chardevs */
-		if (vma->vm_flags & (VM_IO | VM_PFNMAP) ||
-		    (!ignore && !(vm_flags & vma->vm_flags)))
+		if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+		    !(vm_flags & vma->vm_flags))
 			goto finish_or_fault;
 
 		if (pages) {
@@ -170,7 +169,6 @@ finish_or_fault:
 	return i ? : -EFAULT;
 }
 
-
 /*
  * get a list of pages in an address range belonging to the specified process
  * and indicate the VMA that covers each page
--
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