initramfs: free initrd memory if opening /initrd.image fails

[ Upstream commit 54c7a8916a887f357088f99e9c3a7720cd57d2c8 ]

Patch series "initramfs tidyups".

I've spent some time chasing down behavior in initramfs and found
plenty of opportunity to improve the code.  A first stab on that is
contained in this series.

This patch (of 7):

We free the initrd memory for all successful or error cases except for the
case where opening /initrd.image fails, which looks like an oversight.

Steven said:

: This also changes the behaviour when CONFIG_INITRAMFS_FORCE is enabled
: - specifically it means that the initrd is freed (previously it was
: ignored and never freed).  But that seems like reasonable behaviour and
: the previous behaviour looks like another oversight.

Link: http://lkml.kernel.org/r/20190213174621.29297-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/init/initramfs.c b/init/initramfs.c
index f6f4a1e..cd5fb00 100644 (file)
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -612,13 +612,12 @@ static int __init populate_rootfs(void)
                printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
                err = unpack_to_rootfs((char *)initrd_start,
                        initrd_end - initrd_start);
-               if (!err) {
-                       free_initrd();
+               if (!err)
                        goto done;
-               } else {
-                       clean_rootfs();
-                       unpack_to_rootfs(__initramfs_start, __initramfs_size);
-               }
+
+               clean_rootfs();
+               unpack_to_rootfs(__initramfs_start, __initramfs_size);
+
                printk(KERN_INFO "rootfs image is not initramfs (%s)"
                                "; looks like an initrd\n", err);
                fd = ksys_open("/initrd.image",
@@ -632,7 +631,6 @@ static int __init populate_rootfs(void)
                                       written, initrd_end - initrd_start);
 
                        ksys_close(fd);
-                       free_initrd();
                }
        done:
                /* empty statement */;
@@ -642,9 +640,9 @@ static int __init populate_rootfs(void)
                        initrd_end - initrd_start);
                if (err)
                        printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
-               free_initrd();
 #endif
        }
+       free_initrd();
        flush_delayed_fput();
        /*
         * Try loading default modules from initramfs.  This gives