diff options
| author | Breno Leitao <leitao@debian.org> | 2026-05-08 06:55:03 -0700 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-05-12 09:44:31 +0900 |
| commit | 5a643e4623238e14b03d75ca0d4eda0645720cee (patch) | |
| tree | 7ac920c465cef7d2568331f0486f587d3e46df0f /lib | |
| parent | 5d6919055dec134de3c40167a490f33c74c12581 (diff) | |
| download | ath-5a643e4623238e14b03d75ca0d4eda0645720cee.tar.gz | |
bootconfig: move xbc_snprint_cmdline() to lib/bootconfig.c
Move xbc_snprint_cmdline() from init/main.c to lib/bootconfig.c so the
function (and its xbc_namebuf scratch buffer) becomes part of the shared
parser library. tools/bootconfig already compiles lib/bootconfig.c
directly, which lets a follow-up patch reuse the same renderer in the
userspace tool to convert a bootconfig file into a flat cmdline string
at build time.
No functional change.
Link: https://lore.kernel.org/all/20260508-bootconfig_using_tools-v1-1-1132219aa773@debian.org/
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/bootconfig.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/lib/bootconfig.c b/lib/bootconfig.c index c470b93d5dbc2..f445b7703fdd9 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -408,6 +408,62 @@ const char * __init xbc_node_find_next_key_value(struct xbc_node *root, return ""; /* No value key */ } +static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; + +#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) + +/** + * xbc_snprint_cmdline() - Render bootconfig keys under @root as a cmdline string + * @buf: Destination buffer (may be NULL when @size is 0 to query the length) + * @size: Size of @buf in bytes + * @root: Subtree root whose key=value pairs should be rendered + * + * Walk all key/value pairs under @root and emit them as a space-separated + * cmdline string into @buf. Values containing whitespace are quoted with + * double quotes. Returns the number of bytes that would be written if @buf + * were large enough (matching snprintf semantics), or a negative errno on + * failure. + */ +int __init xbc_snprint_cmdline(char *buf, size_t size, struct xbc_node *root) +{ + struct xbc_node *knode, *vnode; + char *end = buf + size; + const char *val, *q; + int ret; + + xbc_node_for_each_key_value(root, knode, val) { + ret = xbc_node_compose_key_after(root, knode, + xbc_namebuf, XBC_KEYLEN_MAX); + if (ret < 0) + return ret; + + vnode = xbc_node_get_child(knode); + if (!vnode) { + ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); + if (ret < 0) + return ret; + buf += ret; + continue; + } + xbc_array_for_each_value(vnode, 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; + } + } + + return buf - (end - size); +} +#undef rest + /* XBC parse and tree build */ static int __init xbc_init_node(struct xbc_node *node, char *data, uint16_t flag) |