[RFC PATCH 21/24] do_mmap: add locked argument

From: Michel Lespinasse <walken@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	 Laurent Dufour <ldufour@linux.ibm.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	 Matthew Wilcox <willy@infradead.org>,
	"Liam R . Howlett" <Liam.Howlett@oracle.com>,
	 Jerome Glisse <jglisse@redhat.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	 David Rientjes <rientjes@google.com>
Cc: linux-mm <linux-mm@kvack.org>, Michel Lespinasse <walken@google.com>
Subject: [RFC PATCH 21/24] do_mmap: add locked argument
Date: Mon, 24 Feb 2020 12:30:54 -0800	[thread overview]
Message-ID: <20200224203057.162467-22-walken@google.com> (raw)
In-Reply-To: <20200224203057.162467-1-walken@google.com>

Change the do_mmap() prototype to add a "locked" boolean argument.
For now all call sites set it to true.

Also remove the do_mmap_pgoff() API, which was just wrapping do_mmap()
with a forced vm_flags == 0 argument.

Signed-off-by: Michel Lespinasse <walken@google.com>
---
 arch/x86/mm/mpx.c  |  3 ++-
 fs/aio.c           |  6 +++---
 include/linux/mm.h | 13 ++-----------
 ipc/shm.c          |  3 ++-
 mm/mmap.c          |  8 ++++----
 mm/nommu.c         |  1 +
 mm/util.c          |  4 ++--
 7 files changed, 16 insertions(+), 22 deletions(-)

diff --git arch/x86/mm/mpx.c arch/x86/mm/mpx.c
index 3835c18020b8..f83cdf80f210 100644
--- arch/x86/mm/mpx.c
+++ arch/x86/mm/mpx.c
@@ -54,7 +54,8 @@ static unsigned long mpx_mmap(unsigned long len)
 
 	mm_write_lock(mm);
 	addr = do_mmap(NULL, 0, len, PROT_READ | PROT_WRITE,
-		       MAP_ANONYMOUS | MAP_PRIVATE, VM_MPX, 0, &populate, NULL);
+			MAP_ANONYMOUS | MAP_PRIVATE, VM_MPX, 0,
+			true, &populate, NULL);
 	mm_write_unlock(mm);
 	if (populate)
 		mm_populate(addr, populate);
diff --git fs/aio.c fs/aio.c
index 704766588df4..018bd24d6204 100644
--- fs/aio.c
+++ fs/aio.c
@@ -525,9 +525,9 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 		return -EINTR;
 	}
 
-	ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size,
-				       PROT_READ | PROT_WRITE,
-				       MAP_SHARED, 0, &unused, NULL);
+	ctx->mmap_base = do_mmap(ctx->aio_ring_file, 0, ctx->mmap_size,
+				PROT_READ | PROT_WRITE,
+				MAP_SHARED, 0, 0, true, &unused, NULL);
 	mm_write_unlock(mm);
 	if (IS_ERR((void *)ctx->mmap_base)) {
 		ctx->mmap_size = 0;
diff --git include/linux/mm.h include/linux/mm.h
index 28b6af200214..8427e1d07b59 100644
--- include/linux/mm.h
+++ include/linux/mm.h
@@ -2361,22 +2361,13 @@ extern unsigned long mmap_region(struct file *file, unsigned long addr,
 	struct list_head *uf);
 extern unsigned long do_mmap(struct file *file, unsigned long addr,
 	unsigned long len, unsigned long prot, unsigned long flags,
-	vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate,
-	struct list_head *uf);
+	vm_flags_t vm_flags, unsigned long pgoff, bool locked,
+	unsigned long *populate, struct list_head *uf);
 extern int __do_munmap(struct mm_struct *, unsigned long, size_t,
 		       struct list_head *uf, bool downgrade);
 extern int do_munmap(struct mm_struct *, unsigned long, size_t,
 		     struct list_head *uf);
 
-static inline unsigned long
-do_mmap_pgoff(struct file *file, unsigned long addr,
-	unsigned long len, unsigned long prot, unsigned long flags,
-	unsigned long pgoff, unsigned long *populate,
-	struct list_head *uf)
-{
-	return do_mmap(file, addr, len, prot, flags, 0, pgoff, populate, uf);
-}
-
 #ifdef CONFIG_MMU
 extern int __mm_populate(unsigned long addr, unsigned long len,
 			 int ignore_errors);
diff --git ipc/shm.c ipc/shm.c
index c04fc21cbe46..90d24c4960b9 100644
--- ipc/shm.c
+++ ipc/shm.c
@@ -1558,7 +1558,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
 			goto invalid;
 	}
 
-	addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate, NULL);
+	addr = do_mmap(file, addr, size, prot, flags, 0, 0,
+			true, &populate, NULL);
 	*raddr = addr;
 	err = 0;
 	if (IS_ERR_VALUE(addr))
diff --git mm/mmap.c mm/mmap.c
index 0f95300c2788..2868e61927a1 100644
--- mm/mmap.c
+++ mm/mmap.c
@@ -1369,8 +1369,8 @@ static inline bool file_mmap_ok(struct file *file, struct inode *inode,
 unsigned long do_mmap(struct file *file, unsigned long addr,
 			unsigned long len, unsigned long prot,
 			unsigned long flags, vm_flags_t vm_flags,
-			unsigned long pgoff, unsigned long *populate,
-			struct list_head *uf)
+			unsigned long pgoff, bool locked,
+			unsigned long *populate, struct list_head *uf)
 {
 	struct mm_struct *mm = current->mm;
 	int pkey = 0;
@@ -2954,8 +2954,8 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 	}
 
 	file = get_file(vma->vm_file);
-	ret = do_mmap_pgoff(vma->vm_file, start, size,
-			prot, flags, pgoff, &populate, NULL);
+	ret = do_mmap(vma->vm_file, start, size,
+			prot, flags, 0, pgoff, true, &populate, NULL);
 	fput(file);
 out:
 	mm_write_unlock(mm);
diff --git mm/nommu.c mm/nommu.c
index c137db1923bd..a2c2bf8d7676 100644
--- mm/nommu.c
+++ mm/nommu.c
@@ -1102,6 +1102,7 @@ unsigned long do_mmap(struct file *file,
 			unsigned long prot,
 			unsigned long flags,
 			vm_flags_t vm_flags,
+			bool locked,
 			unsigned long pgoff,
 			unsigned long *populate,
 			struct list_head *uf)
diff --git mm/util.c mm/util.c
index 511e442e7329..337b006aef6d 100644
--- mm/util.c
+++ mm/util.c
@@ -503,8 +503,8 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
 	if (!ret) {
 		if (mm_write_lock_killable(mm))
 			return -EINTR;
-		ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
-				    &populate, &uf);
+		ret = do_mmap(file, addr, len, prot, flag, 0, pgoff,
+				true, &populate, &uf);
 		mm_write_unlock(mm);
 		userfaultfd_unmap_complete(mm, &uf);
 		if (populate)
-- 
2.25.0.341.g760bfbb309-goog


