From: Mimi Zohar <zohar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: initramfs <initramfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Cc: Taras Kondratiuk
<takondra-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>,
Victor Kamensky
<kamensky-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>,
Rob Landley <rob-VoJi6FS/r0vR7s880joybQ@public.gmane.org>,
linux-security-module
<linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Al Viro <viro-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>,
linux-kernel
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: [RFC PATCH] rootfs: force mounting rootfs as tmpfs
Date: Tue, 30 Jan 2018 16:46:17 -0500 [thread overview]
Message-ID: <1517348777.3469.5.camel@linux.vnet.ibm.com> (raw)
Commit 16203a7a9422 ("initmpfs: make rootfs use tmpfs when CONFIG_TMPFS
enabled") introduced using tmpfs as the rootfs filesystem. The use of
tmpfs is limited to systems that do not specify "root=" on the boot
command line.
Without the check "!saved_root_name[0]", rootfs uses tmpfs. As there
must be a valid reason for this check, this patch introduces a new boot
command line option named "noramfs" to force rootfs to use tmpfs.
Signed-off-by: Mimi Zohar <zohar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
---
Documentation/admin-guide/kernel-parameters.txt | 2 ++
init/do_mounts.c | 15 +++++++++++++--
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 6571fbfdb2a1..fd82df2ff150 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2733,6 +2733,8 @@
nopcid [X86-64] Disable the PCID cpu feature.
+ noramfs Don't use ramfs for rootfs, use tmpfs.
+
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 7cf4f6dafd5f..74d8bfcd1294 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -315,6 +315,16 @@ static int __init root_data_setup(char *str)
return 1;
}
+static bool force_tmpfs;
+static int __init force_tmpfs_setup(char *str)
+{
+ if (*str)
+ return 0;
+ force_tmpfs = true;
+ return 1;
+
+}
+
static char * __initdata root_fs_names;
static int __init fs_names_setup(char *str)
{
@@ -332,6 +342,7 @@ static int __init root_delay_setup(char *str)
__setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);
+__setup("noramfs", force_tmpfs_setup);
static void __init get_fs_names(char *page)
{
@@ -632,8 +643,8 @@ int __init init_rootfs(void)
if (err)
return err;
- if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
- (!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
+ if (IS_ENABLED(CONFIG_TMPFS) && (force_tmpfs || (!saved_root_name[0] &&
+ (!root_fs_names || strstr(root_fs_names, "tmpfs"))))) {
err = shmem_init();
is_tmpfs = true;
} else {
--
2.7.5
next reply other threads:[~2018-01-30 21:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-30 21:46 Mimi Zohar [this message]
2018-01-31 19:32 ` [RFC PATCH] rootfs: force mounting rootfs as tmpfs Rob Landley
[not found] ` <1814af5c-170d-39c0-58fd-02eb7216e008-VoJi6FS/r0vR7s880joybQ@public.gmane.org>
2018-01-31 22:07 ` Mimi Zohar
2018-01-31 23:48 ` Rob Landley
[not found] ` <a538e55c-81ca-6d59-20cf-21b47387c3e2-VoJi6FS/r0vR7s880joybQ@public.gmane.org>
2018-02-01 2:03 ` Arvind Sankar
2018-02-01 4:22 ` Mimi Zohar
[not found] ` <1517458921.3329.2.camel-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-02-01 15:20 ` Rob Landley
2018-02-01 15:55 ` Mimi Zohar
[not found] ` <1517500500.3974.45.camel-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-02-01 17:09 ` Rob Landley
[not found] ` <875e5d2d-9ffe-14ab-090a-4a9632af0f35-VoJi6FS/r0vR7s880joybQ@public.gmane.org>
2018-02-01 21:51 ` Mimi Zohar
[not found] ` <1517521912.3619.0.camel-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-02-01 22:41 ` Taras Kondratiuk
2018-02-01 23:34 ` Rob Landley
2018-04-16 15:46 ` Mimi Zohar
2018-02-01 22:46 ` Rob Landley
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