On 10/21/15 at 04:12pm, Geoff Levand wrote: > Add a new option --lite to kexec that allows for a fast reboot > by avoiding the purgatory integrity checks. This option is > intended for use by kexec based bootloaders that load a new > image and then immediately transfer control to it.
I think Vivek was rejecting this --lite since kdump need the purgatory integrity checks. Ccing him. > > Signed-off-by: Geoff Levand <[email protected]> > --- > Hi Simon, > > It was reported that on some systems where purgatory is running > without caches enabled the sha256 calculations would take several > minutes. For bootloaders that just load a new image and > immediately jump into it the loss of the integrity check is worth > the increase in boot speed. Please consider. Pratyush reported the arm64 issue, he sent a patch to fix it with enabling cache for purgatory. I think the patch can fix the problem. Why not fix it? The fix is simple enough and it does not introduce complicate logic. > > -Geoff > > kexec/kexec.8 | 3 +++ > kexec/kexec.c | 19 +++++++++++++++++-- > kexec/kexec.h | 4 ++++ > purgatory/purgatory.c | 3 ++- > 4 files changed, 26 insertions(+), 3 deletions(-) > > diff --git a/kexec/kexec.8 b/kexec/kexec.8 > index 4d0c1d1..93ed588 100644 > --- a/kexec/kexec.8 > +++ b/kexec/kexec.8 > @@ -126,6 +126,9 @@ in one call. > Open a help file for > .BR kexec . > .TP > +.B \-i\ (\-\-lite) > +Fast reboot, no memory integrity checks. > +.TP > .BI \-l\ (\-\-load) \ kernel > Load the specified > .I kernel > diff --git a/kexec/kexec.c b/kexec/kexec.c > index ff024f3..ebb1310 100644 > --- a/kexec/kexec.c > +++ b/kexec/kexec.c > @@ -613,6 +613,15 @@ static void update_purgatory(struct kexec_info *info) > return; > } > arch_update_purgatory(info); > + > + if (info->kexec_lite) { > + unsigned int tmp = 1; > + > + elf_rel_set_symbol(&info->rhdr, "kexec_lite", &tmp, > + sizeof(tmp)); > + return; > + } > + > memset(region, 0, sizeof(region)); > sha256_starts(&ctx); > /* Compute a hash of the loaded kernel */ > @@ -652,7 +661,7 @@ static void update_purgatory(struct kexec_info *info) > * Load the new kernel > */ > static int my_load(const char *type, int fileind, int argc, char **argv, > - unsigned long kexec_flags, void *entry) > + unsigned long kexec_flags, int kexec_lite, void *entry) > { > char *kernel; > char *kernel_buf; > @@ -665,6 +674,7 @@ static int my_load(const char *type, int fileind, int > argc, char **argv, > > memset(&info, 0, sizeof(info)); > info.kexec_flags = kexec_flags; > + info.kexec_lite = kexec_lite; > > result = 0; > if (argc - fileind <= 0) { > @@ -914,6 +924,7 @@ void usage(void) > " -v, --version Print the version of kexec.\n" > " -f, --force Force an immediate kexec,\n" > " don't call shutdown.\n" > + " -i, --lite Fast reboot, no memory integrity > checks.\n" > " -x, --no-ifdown Don't bring down network interfaces.\n" > " -y, --no-sync Don't sync filesystems before kexec.\n" > " -l, --load Load the new kernel into the\n" > @@ -1173,6 +1184,7 @@ int main(int argc, char *argv[]) > int do_unload = 0; > int do_reuse_initrd = 0; > int do_kexec_file_syscall = 0; > + int do_lite = 0; > void *entry = 0; > char *type = 0; > char *endptr; > @@ -1314,6 +1326,9 @@ int main(int argc, char *argv[]) > case OPT_KEXEC_FILE_SYSCALL: > /* We already parsed it. Nothing to do. */ > break; > + case OPT_LITE: > + do_lite = 1; > + break; > default: > break; > } > @@ -1374,7 +1389,7 @@ int main(int argc, char *argv[]) > kexec_file_flags); > else > result = my_load(type, fileind, argc, argv, > - kexec_flags, entry); > + kexec_flags, do_lite, entry); > } > /* Don't shutdown unless there is something to reboot to! */ > if ((result == 0) && (do_shutdown || do_exec) && !kexec_loaded()) { > diff --git a/kexec/kexec.h b/kexec/kexec.h > index 7c97b25..06e08f4 100644 > --- a/kexec/kexec.h > +++ b/kexec/kexec.h > @@ -165,6 +165,8 @@ struct kexec_info { > int initrd_fd; > char *command_line; > int command_line_len; > + > + int kexec_lite; > }; > > struct arch_map_entry { > @@ -218,6 +220,7 @@ extern int file_types; > #define OPT_TYPE 't' > #define OPT_PANIC 'p' > #define OPT_KEXEC_FILE_SYSCALL 's' > +#define OPT_LITE 'i' > #define OPT_MEM_MIN 256 > #define OPT_MEM_MAX 257 > #define OPT_REUSE_INITRD 258 > @@ -243,6 +246,7 @@ 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 }, \ > + { "lite", 0, 0, OPT_LITE }, \ > { "debug", 0, 0, OPT_DEBUG }, \ > > #define KEXEC_OPT_STR "h?vdfxyluet:ps" > diff --git a/purgatory/purgatory.c b/purgatory/purgatory.c > index 3bbcc09..7e99b92 100644 > --- a/purgatory/purgatory.c > +++ b/purgatory/purgatory.c > @@ -8,6 +8,7 @@ > > struct sha256_region sha256_regions[SHA256_REGIONS] = {}; > sha256_digest_t sha256_digest = { }; > +int kexec_lite = 0; > > int verify_sha256_digest(void) > { > @@ -43,7 +44,7 @@ void purgatory(void) > { > printf("I'm in purgatory\n"); > setup_arch(); > - if (verify_sha256_digest()) { > + if (!kexec_lite && verify_sha256_digest()) { > for(;;) { > /* loop forever */ > } > -- > 2.5.0 > > > _______________________________________________ > kexec mailing list > [email protected] > http://lists.infradead.org/mailman/listinfo/kexec > > _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
