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do not quote the value unless it contains whitespace.
Signed-off-by: Rasmus Villemoes <[email protected]>
---
v3: Add comment explaining why the quoting is conditional.
v2: use strpbrk(, " \t\r\n") instead of a loop doing isspace().
init/main.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/init/main.c b/init/main.c
index e24b0780fdff..7a5efe363938 100644
--- a/init/main.c
+++ b/init/main.c
@@ -324,7 +324,7 @@ static int __init xbc_snprint_cmdline(char *buf, size_t size,
{
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) {
@@ -342,8 +342,14 @@ static int __init xbc_snprint_cmdline(char *buf, size_t size,
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;
--
2.40.1.1.g1c60b9335d