From: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Date: Fri, 20 Mar 2026 22:39:40 +0000 (+0000)
Subject: mtdchar: replace deprecated mmap hook with mmap_prepare, clean up
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0858653748eec59c1133fafc37b2bb7f6b20b6b4;p=thirdparty%2Fkernel%2Flinux.git

mtdchar: replace deprecated mmap hook with mmap_prepare, clean up

Replace the deprecated mmap callback with mmap_prepare.

Commit f5cf8f07423b ("mtd: Disable mtdchar mmap on MMU systems") commented
out the CONFIG_MMU part of this function back in 2012, so after ~14 years
it's probably reasonable to remove this altogether rather than updating
dead code.

Link: https://lkml.kernel.org/r/d036855c21962c58ace0eb24ecd6d973d77424fe.1774045440.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Richard Weinberger <richard@nod.at>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bodo Stroesser <bostroesser@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Long Li <longli@microsoft.com>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 55a43682c567e..bf01e6ac72931 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -1376,27 +1376,12 @@ static unsigned mtdchar_mmap_capabilities(struct file *file)
 /*
  * set up a mapping for shared memory segments
  */
-static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
+static int mtdchar_mmap_prepare(struct vm_area_desc *desc)
 {
 #ifdef CONFIG_MMU
-	struct mtd_file_info *mfi = file->private_data;
-	struct mtd_info *mtd = mfi->mtd;
-	struct map_info *map = mtd->priv;
-
-        /* This is broken because it assumes the MTD device is map-based
-	   and that mtd->priv is a valid struct map_info.  It should be
-	   replaced with something that uses the mtd_get_unmapped_area()
-	   operation properly. */
-	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
-#ifdef pgprot_noncached
-		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
-			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-#endif
-		return vm_iomap_memory(vma, map->phys, map->size);
-	}
 	return -ENODEV;
 #else
-	return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
+	return vma_desc_test(desc, VMA_SHARED_BIT) ? 0 : -EACCES;
 #endif
 }
 
@@ -1411,7 +1396,7 @@ static const struct file_operations mtd_fops = {
 #endif
 	.open		= mtdchar_open,
 	.release	= mtdchar_close,
-	.mmap		= mtdchar_mmap,
+	.mmap_prepare	= mtdchar_mmap_prepare,
 #ifndef CONFIG_MMU
 	.get_unmapped_area = mtdchar_get_unmapped_area,
 	.mmap_capabilities = mtdchar_mmap_capabilities,