[PATCH 6.1 163/303] bootconfig: do not put quotes on cmdline items unless necessary

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Rasmus Villemoes <[email protected]>

[ Upstream commit 212f863fa8811c780abacc1d0404c573fdc0a2de ]

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  So do not
quote the value unless it contains whitespace.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/[email protected]
Signed-off-by: Rasmus Villemoes <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Stable-dep-of: dec4d8118c17 ("bootconfig: fix NULL-pointer arithmetic in xbc_snprint_cmdline()")
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 init/main.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/init/main.c
+++ b/init/main.c
@@ -332,7 +332,7 @@ 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) {
@@ -350,8 +350,14 @@ 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;