[PATCH v4 2/5] kexec: do not special-case the -s option

[Simon Horman]

On Tue, Mar 06, 2018 at 02:15:53PM +0100, Michal Suchanek wrote:
> It is parsed separately to save a few CPU cycles when setting up other
> options but it just complicates the code. So fold it back and set up all
> flags both for KEXEC_LOAD and KEXEC_FILE_LOAD
> 
> Signed-off-by: Michal Suchanek <msuchanek at suse.de>
> ---
>  kexec/kexec.c | 25 ++++---------------------
>  1 file changed, 4 insertions(+), 21 deletions(-)
> 
> diff --git a/kexec/kexec.c b/kexec/kexec.c
> index ab8cff7fe083..9ea102e1565a 100644
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -1256,19 +1256,6 @@ int main(int argc, char *argv[])
>  	};
>  	static const char short_options[] = KEXEC_ALL_OPT_STR;
>  
> -	/*
> -	 * First check if --use-kexec-file-syscall is set. That changes lot of
> -	 * things
> -	 */
> -	while ((opt = getopt_long(argc, argv, short_options,
> -				  options, 0)) != -1) {
> -		switch(opt) {
> -		case OPT_KEXEC_FILE_SYSCALL:
> -			do_kexec_file_syscall = 1;
> -			break;
> -		}
> -	}
> -
>  	/* Reset getopt for the next pass. */
>  	opterr = 1;
>  	optind = 1;
> @@ -1310,8 +1297,7 @@ int main(int argc, char *argv[])
>  			do_shutdown = 0;
>  			do_sync = 0;
>  			do_unload = 1;
> -			if (do_kexec_file_syscall)
> -				kexec_file_flags |= KEXEC_FILE_UNLOAD;
> +			kexec_file_flags |= KEXEC_FILE_UNLOAD;
>  			break;
>  		case OPT_EXEC:
>  			do_load = 0;
 @@ -1354,11 +1340,8 @@ int main(int argc, char *argv[])

 The existing code has the following above the context shown in the patch:

			do_load = 1;


>  			do_exec = 0;
>  			do_shutdown = 0;
>  			do_sync = 0;
> -			if (do_kexec_file_syscall)
> -				kexec_file_flags |= KEXEC_FILE_ON_CRASH;
> -			else
> -				kexec_flags = KEXEC_ON_CRASH;
> -			break;
> +			kexec_file_flags |= KEXEC_FILE_ON_CRASH;
> +			kexec_flags = KEXEC_ON_CRASH;

kexec_flags is now set regardless of the value of do_kexec_file_syscall,
which was not the case prior to this patch. That seems to affect the
following which appears later in the function. Is that ok?


        if (do_load && (kexec_flags & KEXEC_ON_CRASH) &&
            !is_crashkernel_mem_reserved()) {
                die("Memory for crashkernel is not reserved\n"
                    "Please reserve memory by passing"
                    "\"crashkernel=X at Y\" parameter to kernel\n"
                    "Then try to loading kdump kernel\n");
        }

	...

        if ((result == 0) && do_load_jump_back_helper) {
                result = my_load_jump_back_helper(kexec_flags, entry);
        }

>  		case OPT_MEM_MIN:
>  			mem_min = strtoul(optarg, &endptr, 0);
>  			if (*endptr) {
> @@ -1383,7 +1366,7 @@ int main(int argc, char *argv[])
>  			do_reuse_initrd = 1;
>  			break;
>  		case OPT_KEXEC_FILE_SYSCALL:
> -			/* We already parsed it. Nothing to do. */
> +			do_kexec_file_syscall = 1;
>  			break;
>  		case OPT_STATUS:
>  			do_status = 1;
> -- 
> 2.13.6
>