On Thu, Jul 14, 2016 at 04:45:11PM +0800, Lee, Chun-Yi wrote:
> This patch adds a new "--fallback-kexec" option to give a chance to
> fallback to old kexec syscall when file based kexec syscall operation
> failed.
I think caller should switch to using different interface if need be. But
I don't see much point in providing an option for this in kexec-tools.
Vivek
>
> This option works with --kexec-file-syscall to provide more flexible
> way to adapt to different kernels that those kernels built with
> different kexec syscall config or have different verification policy.
>
> Cc: Simon Horman <horms at verge.net.au>
> Cc: Petr Tesarik <ptesarik at suse.com>
> Cc: Vivek Goyal <vgoyal at redhat.com>
> Signed-off-by: Lee, Chun-Yi <jlee at suse.com>
> ---
> kexec/kexec.c | 13 +++++++++++++
> kexec/kexec.h | 4 +++-
> 2 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/kexec/kexec.c b/kexec/kexec.c
> index 500e5a9..e05b43f 100644
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -969,6 +969,7 @@ void usage(void)
> " preserve context)\n"
> " to original kernel.\n"
> " -s, --kexec-file-syscall Use file based syscall for kexec operation\n"
> + " --fallback-kexec Fallback to old kexec when file based syscall failed\n"
> " -d, --debug Enable debugging to help spot a failure.\n"
> "\n"
> "Supported kernel file types and options: \n");
> @@ -1204,6 +1205,7 @@ int main(int argc, char *argv[])
> int do_unload = 0;
> int do_reuse_initrd = 0;
> int do_kexec_file_syscall = 0;
> + int do_fallback_kexec_syscall = 0;
> void *entry = 0;
> char *type = 0;
> char *endptr;
> @@ -1226,9 +1228,13 @@ int main(int argc, char *argv[])
> case OPT_KEXEC_FILE_SYSCALL:
> do_kexec_file_syscall = 1;
> break;
> + case OPT_FALLBACK_KEXEC:
> + do_fallback_kexec_syscall = 1;
> + break;
> }
> }
>
> +fallback:
> /* Reset getopt for the next pass. */
> opterr = 1;
> optind = 1;
> @@ -1407,6 +1413,13 @@ int main(int argc, char *argv[])
> result = my_load(type, fileind, argc, argv,
> kexec_flags, entry);
> }
> + /* fallback to old kexec syscall */
> + if (do_kexec_file_syscall && result != 0 && do_fallback_kexec_syscall) {
> + fprintf(stderr, "Fallback to kexec syscall\n");
> + do_kexec_file_syscall = 0;
> + do_fallback_kexec_syscall = 0;
> + goto fallback;
> + }
> /* Don't shutdown unless there is something to reboot to! */
> if ((result == 0) && (do_shutdown || do_exec) && !kexec_loaded()) {
> die("Nothing has been loaded!\n");
> diff --git a/kexec/kexec.h b/kexec/kexec.h
> index 9194f1c..65dbd56 100644
> --- a/kexec/kexec.h
> +++ b/kexec/kexec.h
> @@ -225,7 +225,8 @@ extern int file_types;
> #define OPT_LOAD_PRESERVE_CONTEXT 259
> #define OPT_LOAD_JUMP_BACK_HELPER 260
> #define OPT_ENTRY 261
> -#define OPT_MAX 262
> +#define OPT_FALLBACK_KEXEC 262
> +#define OPT_MAX 263
> #define KEXEC_OPTIONS \
> { "help", 0, 0, OPT_HELP }, \
> { "version", 0, 0, OPT_VERSION }, \
> @@ -244,6 +245,7 @@ extern int file_types;
> { "mem-max", 1, 0, OPT_MEM_MAX }, \
> { "reuseinitrd", 0, 0, OPT_REUSE_INITRD }, \
> { "kexec-file-syscall", 0, 0, OPT_KEXEC_FILE_SYSCALL }, \
> + { "fallback-kexec", 0, 0, OPT_FALLBACK_KEXEC }, \
> { "debug", 0, 0, OPT_DEBUG }, \
>
> #define KEXEC_OPT_STR "h?vdfxyluet:ps"
> --
> 2.6.6
