tools/bootconfig: Show line and column in parse error

Show line and column when we got a parse error in bootconfig tool.
Current lib/bootconfig shows the parse error with byte offset, but
that is not human readable.
This makes xbc_init() not showing error message itself but able to
pass the error message and position to caller, so that the caller
can decode it and show the error message with line number and columns.

With this patch, bootconfig tool shows an error with line:column as
below.

  $ cat samples/bad-dotword.bconf
  # do not start keyword with .
  key {
    .word = 1
  }
  $ ./bootconfig -a samples/bad-dotword.bconf initrd
  Parse Error: Invalid keyword at 3:3

Link: http://lkml.kernel.org/r/158323469002.10560.4023923847704522760.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 10 insertions, 4 deletions

diff --git a/init/main.c b/init/main.c
index ee4947af823f..e488213857e2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -353,6 +353,8 @@ static int __init bootconfig_params(char *param, char *val,
 static void __init setup_boot_config(const char *cmdline)
 {
 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
+	const char *msg;
+	int pos;
 	u32 size, csum;
 	char *data, *copy;
 	u32 *hdr;
@@ -400,10 +402,14 @@ static void __init setup_boot_config(const char *cmdline)
 	memcpy(copy, data, size);
 	copy[size] = '\0';
 
-	ret = xbc_init(copy);
-	if (ret < 0)
-		pr_err("Failed to parse bootconfig\n");
-	else {
+	ret = xbc_init(copy, &msg, &pos);
+	if (ret < 0) {
+		if (pos < 0)
+			pr_err("Failed to init bootconfig: %s.\n", msg);
+		else
+			pr_err("Failed to parse bootconfig: %s at %d.\n",
+				msg, pos);
+	} else {
 		pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
 		/* keys starting with "kernel." are passed via cmdline */
 		extra_command_line = xbc_make_cmdline("kernel");