On 03/20/18 at 04:56pm, Michal Suchanek wrote:
> Not all architectures implement KEXEC_FILE_LOAD. However, on some
> archiectures KEXEC_FILE_LOAD is required when secure boot is enabled in
> locked-down mode. Previously users had to select the KEXEC_FILE_LOAD
> syscall with undocumented -s option. However, if they did pass the
> option kexec would fail on architectures that do not support it.
>
> So add an -a option that tries KEXEC_FILE_LOAD and when it is not
> supported tries KEXEC_LOAD.
>
> Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
> ---
> v3: instead of changing the deafult add extra option
> v4: actually check -ENOSYS as well
> v5: add missing break
> ---
> kexec/kexec.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++-----
> kexec/kexec.h | 6 +++++-
> 2 files changed, 58 insertions(+), 6 deletions(-)
>
> diff --git a/kexec/kexec.c b/kexec/kexec.c
> index 68ae0594d4a7..44042345a16e 100644
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -1243,6 +1243,7 @@ int main(int argc, char *argv[])
> int do_unload = 0;
> int do_reuse_initrd = 0;
> int do_kexec_file_syscall = 0;
> + int do_kexec_fallback = 0;
> int do_status = 0;
> void *entry = 0;
> char *type = 0;
> @@ -1367,6 +1368,15 @@ int main(int argc, char *argv[])
> break;
> case OPT_KEXEC_FILE_SYSCALL:
> do_kexec_file_syscall = 1;
> + do_kexec_fallback = 0;
> + break;
> + case OPT_KEXEC_SYSCALL:
> + do_kexec_file_syscall = 0;
> + do_kexec_fallback = 0;
> + break;
> + case OPT_KEXEC_SYSCALL_AUTO:
> + do_kexec_file_syscall = 1;
> + do_kexec_fallback = 1;
> break;
> case OPT_STATUS:
> do_status = 1;
> @@ -1433,7 +1443,7 @@ int main(int argc, char *argv[])
> }
> }
> if (do_kexec_file_syscall) {
> - if (do_load_jump_back_helper)
> + if (do_load_jump_back_helper && !do_kexec_fallback)
> die("--load-jump-back-helper not supported with kexec_file_load\n");
> if (kexec_flags & KEXEC_PRESERVE_CONTEXT)
> die("--load-preserve-context not supported with kexec_file_load\n");
> @@ -1447,16 +1457,54 @@ int main(int argc, char *argv[])
> result = k_status(kexec_flags);
> }
> if (do_unload) {
> - if (do_kexec_file_syscall)
> + if (do_kexec_file_syscall) {
> result = kexec_file_unload(kexec_file_flags);
> - else
> + if ((result == -ENOSYS) && do_kexec_fallback)
> + do_kexec_file_syscall = 0;
> + }
> + if (!do_kexec_file_syscall)
> result = k_unload(kexec_flags);
> }
> if (do_load && (result == 0)) {
> - if (do_kexec_file_syscall)
> + if (do_kexec_file_syscall) {
> result = do_kexec_file_load(fileind, argc, argv,
> kexec_file_flags);
> - else
> + if (do_kexec_fallback) switch (result) {
> + /*
> + * Something failed with signature verification.
> + * Reject the image.
> + */
> + case -ELIBBAD:
> + case -EKEYREJECTED:
> + case -ENOPKG:
> + case -ENOKEY:
> + case -EBADMSG:
> + case -EMSGSIZE:
> + /*
> + * By default reject or do nothing if
> + * succeded
> + */
> + default: break;
> + case -ENOSYS: /* not implemented */
> + /*
> + * Parsing image or other options failed
> + * The image may be invalid or image
> + * type may not supported by kernel so
> + * retry parsing in kexec-tools.
> + */
> + case -EINVAL:
> + case -ENOEXEC:
> + /*
> + * ENOTSUPP can be unsupported image
> + * type or unsupported PE signature
> + * wrapper type, duh
> + */
> + case -ENOTSUP:
Hmm, this is still used in latest version. kernel does not return such
error number, I might not say clearly previously. Please check the
kernel code, the only one place I know is because no kdump support in
power kexec_file:
arch/powerpc/kernel/machine_kexec_file_64.c
/* We don't support crash kernels yet. */
if (image->type == KEXEC_TYPE_CRASH)
return -ENOTSUPP;
So I suggest not checking this as well since -ENOTSUPP is not populated
in userspace headers, and -ENOTSUP is not used at all.
Also as I mentioned in another reply -EINVAL and -ENOEXEC is also not
ncessary.
For -ENOTSUP, maybe someone can submit a patch to switch to -ENOTSUPP
so that userspace can check it.
Ccing Thiago and Hari for the -ENOTSUPP errno issue.
> + do_kexec_file_syscall = 0;
> + break;
> + }
> + }
> + if (!do_kexec_file_syscall)
> result = my_load(type, fileind, argc, argv,
> kexec_flags, entry);
> }
> diff --git a/kexec/kexec.h b/kexec/kexec.h
> index 26225d2c002a..d445fbe3e486 100644
> --- a/kexec/kexec.h
> +++ b/kexec/kexec.h
> @@ -219,6 +219,8 @@ extern int file_types;
> #define OPT_TYPE 't'
> #define OPT_PANIC 'p'
> #define OPT_KEXEC_FILE_SYSCALL 's'
> +#define OPT_KEXEC_SYSCALL 'c'
> +#define OPT_KEXEC_SYSCALL_AUTO 'a'
> #define OPT_STATUS 'S'
> #define OPT_MEM_MIN 256
> #define OPT_MEM_MAX 257
> @@ -246,11 +248,13 @@ 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 }, \
> + { "kexec-syscall", 0, 0, OPT_KEXEC_SYSCALL }, \
> + { "kexec-syscall-auto", 0, 0, OPT_KEXEC_SYSCALL_AUTO }, \
> { "debug", 0, 0, OPT_DEBUG }, \
> { "status", 0, 0, OPT_STATUS }, \
> { "print-ckr-size", 0, 0, OPT_PRINT_CKR_SIZE }, \
>
> -#define KEXEC_OPT_STR "h?vdfxyluet:psS"
> +#define KEXEC_OPT_STR "h?vdfxyluet:pscaS"
>
> extern void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr);
> extern void die(const char *fmt, ...)
> --
> 2.13.6
>
>
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> http://lists.infradead.org/mailman/listinfo/kexec
Thanks
Dave
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