The patch titled
Subject: bootconfig: do not put quotes on cmdline items unless necessary
has been added to the -mm mm-nonmm-unstable branch. Its filename is
bootconfig-do-not-put-quotes-on-cmdline-items-unless-necessary.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/bootconfig-do-not-put-quotes-on-cmdline-items-unless-necessary.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Subject: bootconfig: do not put quotes on cmdline items unless necessary
Date: Wed, 20 Mar 2024 11:19:52 +0100
When trying to migrate to using bootconfig to embed the kernel's and
PID1's command line with the kernel image itself, and so allowing changing
that without modifying the bootloader, I noticed that /proc/cmdline
changed from e.g.
console=ttymxc0,115200n8 cma=128M quiet -- --log-level=notice
to
console="ttymxc0,115200n8" cma="128M" quiet -- --log-level="notice"
The kernel parameters are parsed just fine, and the quotes are indeed
stripped from the actual argv[] given to PID1. However, the quoting
doesn't really serve any purpose and looks excessive, and might confuse
some (naive) userspace tool trying to parse /proc/cmdline. So do not
quote the value unless it contains whitespace.
Link: https://lkml.kernel.org/r/20240320101952.62135-1-linux@xxxxxxxxxxxxxxxxxx
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
init/main.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
--- a/init/main.c~bootconfig-do-not-put-quotes-on-cmdline-items-unless-necessary
+++ a/init/main.c
@@ -327,7 +327,7 @@ static int __init xbc_snprint_cmdline(ch
{
struct xbc_node *knode, *vnode;
char *end = buf + size;
- const char *val;
+ const char *val, *q;
int ret;
xbc_node_for_each_key_value(root, knode, val) {
@@ -345,8 +345,14 @@ static int __init xbc_snprint_cmdline(ch
continue;
}
xbc_array_for_each_value(vnode, val) {
- ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
- xbc_namebuf, val);
+ /*
+ * For prettier and more readable /proc/cmdline, only
+ * quote the value when necessary, i.e. when it contains
+ * whitespace.
+ */
+ q = strpbrk(val, " \t\r\n") ? "\"" : "";
+ ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ",
+ xbc_namebuf, q, val, q);
if (ret < 0)
return ret;
buf += ret;
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are
bootconfig-do-not-put-quotes-on-cmdline-items-unless-necessary.patch
