On Sat, 1 Aug 2020 22:33:18 -0400
Arvind Sankar <nived...@alum.mit.edu> wrote:

> On Fri, Feb 07, 2020 at 02:46:03PM -0500, Steven Rostedt wrote:
> > 
> > diff --git a/init/main.c b/init/main.c
> > index 491f1cdb3105..113c8244e5f0 100644
> > --- a/init/main.c
> > +++ b/init/main.c
> > @@ -142,6 +142,15 @@ static char *extra_command_line;
> >  /* Extra init arguments */
> >  static char *extra_init_args;
> >  
> > +#ifdef CONFIG_BOOT_CONFIG
> > +/* Is bootconfig on command line? */
> > +static bool bootconfig_found;
> > +static bool initargs_found;
> > +#else
> > +# define bootconfig_found false
> > +# define initargs_found false
> > +#endif
> > +
> >  static char *execute_command;
> >  static char *ramdisk_execute_command;
> >  
> > @@ -336,17 +345,32 @@ u32 boot_config_checksum(unsigned char *p, u32 size)
> >     return ret;
> >  }
> >  
> > +static int __init bootconfig_params(char *param, char *val,
> > +                               const char *unused, void *arg)
> > +{
> > +   if (strcmp(param, "bootconfig") == 0) {
> > +           bootconfig_found = true;
> > +   } else if (strcmp(param, "--") == 0) {
> > +           initargs_found = true;
> > +   }
> > +   return 0;
> > +}
> > +
> 
> I came across this as I was poking around some of the command line
> parsing. AFAICT, initargs_found will never be set to true here, because
> parse_args handles "--" itself by immediately returning: it doesn't
> invoke the callback for it. So you'd instead have to check the return of
> parse_args("bootconfig"...) to detect the initargs_found case.

Oops, good catch!
Does this fixes the problem?

>From b078e8b02ad54aea74f8c3645fc11dd3a1cdc1e7 Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhira...@kernel.org>
Date: Mon, 3 Aug 2020 23:57:29 +0900
Subject: [PATCH] bootconfig: Fix to find the initargs correctly

Since the parse_args() stops parsing at '--', bootconfig_params()
will never get the '--' as param and initargs_found never be true.
In the result, if we pass some init arguments via the bootconfig,
those are always appended to the kernel command line with '--'
and user will see double '--'.

To fix this correctly, check the return value of parse_args()
and set initargs_found true if the return value is not an error
but a valid address.

Fixes: f61872bb58a1 ("bootconfig: Use parse_args() to find bootconfig and '--'")
Cc: sta...@vger.kernel.org
Reported-by: Arvind Sankar <nived...@alum.mit.edu>
Suggested-by: Arvind Sankar <nived...@alum.mit.edu>
Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
---
 init/main.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/init/main.c b/init/main.c
index 0ead83e86b5a..627f9230dbe8 100644
--- a/init/main.c
+++ b/init/main.c
@@ -387,8 +387,6 @@ static int __init bootconfig_params(char *param, char *val,
 {
        if (strcmp(param, "bootconfig") == 0) {
                bootconfig_found = true;
-       } else if (strcmp(param, "--") == 0) {
-               initargs_found = true;
        }
        return 0;
 }
@@ -399,19 +397,23 @@ static void __init setup_boot_config(const char *cmdline)
        const char *msg;
        int pos;
        u32 size, csum;
-       char *data, *copy;
+       char *data, *copy, *err;
        int ret;
 
        /* Cut out the bootconfig data even if we have no bootconfig option */
        data = get_boot_config_from_initrd(&size, &csum);
 
        strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
-       parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
-                  bootconfig_params);
+       err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
+                        bootconfig_params);
 
-       if (!bootconfig_found)
+       if (IS_ERR(err) || !bootconfig_found)
                return;
 
+       /* parse_args() stops at '--' and returns an address */
+       if (!IS_ERR(err) && err)
+               initargs_found = true;
+
        if (!data) {
                pr_err("'bootconfig' found on command line, but no bootconfig 
found\n");
                return;
-- 
2.25.1

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