From: Rob Landley
> Sent: 12 November 2020 12:46
>
> On 11/12/20 1:11 AM, kernel test robot wrote:
> >
> > Greeting,
> >
> > FYI, we noticed the following commit (built with gcc-9):
>
> Blah, switched from strlcpy to sprintf due to the lack of spaces and didn't
> adjust the size.
>
> (And yes, the compiler's lifetime analysis should free the stack space before
> the tail call, and I'd assume exec restarts the stack anyway.)
>
> Second-attempt-by: Rob Landley <r...@landley.net>
> ---
>
> init/main.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/init/main.c b/init/main.c
> index 130376ec10ba..e92320816ef8 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -1328,15 +1328,16 @@ static void __init do_pre_smp_initcalls(void)
> static int run_init_process(const char *init_filename)
> {
> const char *const *p;
> + char buf[512], *s = buf;
>
> argv_init[0] = init_filename;
> - pr_info("Run %s as init process\n", init_filename);
> - pr_debug(" with arguments:\n");
> - for (p = argv_init; *p; p++)
> - pr_debug(" %s\n", *p);
> - pr_debug(" with environment:\n");
> - for (p = envp_init; *p; p++)
> - pr_debug(" %s\n", *p);
> +
> + for (p = (void *)envp_init; *p; p++)
> + s += sprintf(s, "%.*s ", (int)(sizeof(buf)-(s-buf)-2), *p);
> + for (p = (void *)argv_init; *p; p++)
> + s += sprintf(s, "%.*s ", (int)(sizeof(buf)-(s-buf)-2), *p);
> + pr_info("Run init: %s\n", buf);
> +
Why not use scnprintf() as:
len += scnprintf(buf + len, 256 - len, " %s", *p);
or even:
s = buf + sizeof buf;
len = sizeof buf;
...
len -= scnprintf(s - len, len, " %s", *p);
and remove the " " before the %s in the final pr_info().
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT,
UK
Registration No: 1397386 (Wales)
