lkml.org 
[lkml]   [2015]   [Oct]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH 1/2] dynamic_debug: fix boot parameters parse
On Wed, Oct 28, 2015 at 10:17:59AM -0400, Jason Baron wrote:
> On 10/27/2015 03:40 AM, Peter Chen wrote:
> > The parse_args will delete space between boot parameters, so
> > if we add dyndbg="file drivers/usb/* +p" at bootargs, the parse_args
> > will split it as three parameters, and only "file" is for dyndbg,
> > then below error will occur at ddebug, it causes all non-module
> > ddebug fail during the boot process.
> >
> > ===============================================================
> > dynamic_debug:ddebug_parse_flags: bad flag-op f, at start of file
> > dynamic_debug:ddebug_exec_query: flags parse failed
> > ===============================================================
> >
>
> Hi,
>
> So the spaces there should be preserved if they are in quotes. Looking at
> kernel/params.c:next_arg(), the comment there explicitly says:
>
> /* You can use " around spaces, but can't escape ". */
>
> So this should still be working. And if its not, I suspect other
> command-line parsing would be broken as well. So if it did change,
> what changed in command line parsing?
>
> What's the output of $ cat /proc/cmdline ? Perhaps, the quotes
> were not passed properly from the bootloader to the kernel?
>
> Thanks,
>
> -Jason

Oh, Jason. skip this patch pleaes, the u-boot needs to use "\\" below
double quoting to setenv. eg: dyndbg="\\"file drivers/usb/chipidea/*+p"\\",
then, the cmdline will like: dyndbg="file drivers/usb/chipidea/* +p",
otherwise, there is no double quoting around QUERY.

Peter
>
>
> > As a solution, we can use comma to split parameters for ddebug booting
> > parameter, and replace comma with space at code, in that case, the ddebug
> > core can handle it with the same way we do it for /sys.
> >
> > Signed-off-by: Peter Chen <peter.chen@freescale.com>
> > Cc: <stable@vger.kernel.org>
> > ---
> > lib/dynamic_debug.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
> > index e491e02..da4883b 100644
> > --- a/lib/dynamic_debug.c
> > +++ b/lib/dynamic_debug.c
> > @@ -880,6 +880,8 @@ static int ddebug_dyndbg_param_cb(char *param, char *val,
> > if (strcmp(param, "dyndbg"))
> > return on_err; /* determined by caller */
> >
> > + /* relace comma with space */
> > + strreplace(val, ',', ' ');
> > ddebug_exec_queries((val ? val : "+p"), modname);
> >
> > return 0; /* query failure shouldnt stop module load */
> >
>

--

Best Regards,
Peter Chen


\
 
 \ /
  Last update: 2015-10-29 07:41    [W:1.509 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site