Hi Andrew, Would you like me to resend the series with the "+ depends on KEXEC_HANDOVER" fix from Mike, or would you apply it into your tree directly?
Thank you, Pasha On Wed, Oct 29, 2025 at 4:48 AM Mike Rapoport <[email protected]> wrote: > > Hi Pasha, > > On Mon, Oct 20, 2025 at 08:08:50PM -0400, Pasha Tatashin wrote: > > It is invalid for KHO metadata or preserved memory regions to be located > > within the KHO scratch area, as this area is overwritten when the next > > kernel is loaded, and used early in boot by the next kernel. This can > > lead to memory corruption. > > > > Adds checks to kho_preserve_* and KHO's internal metadata allocators > > (xa_load_or_alloc, new_chunk) to verify that the physical address of the > > memory does not overlap with any defined scratch region. If an overlap > > is detected, the operation will fail and a WARN_ON is triggered. To > > avoid performance overhead in production kernels, these checks are > > enabled only when CONFIG_KEXEC_HANDOVER_DEBUG is selected. > > > > Signed-off-by: Pasha Tatashin <[email protected]> > > --- > > kernel/Kconfig.kexec | 9 ++++++ > > kernel/Makefile | 1 + > > kernel/kexec_handover.c | 53 ++++++++++++++++++++++---------- > > kernel/kexec_handover_debug.c | 25 +++++++++++++++ > > kernel/kexec_handover_internal.h | 16 ++++++++++ > > 5 files changed, 87 insertions(+), 17 deletions(-) > > create mode 100644 kernel/kexec_handover_debug.c > > create mode 100644 kernel/kexec_handover_internal.h > > > > diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec > > index 422270d64820..c94d36b5fcd9 100644 > > --- a/kernel/Kconfig.kexec > > +++ b/kernel/Kconfig.kexec > > @@ -109,6 +109,15 @@ config KEXEC_HANDOVER > > to keep data or state alive across the kexec. For this to work, > > both source and target kernels need to have this option enabled. > > > > +config KEXEC_HANDOVER_DEBUG > > + bool "Enable Kexec Handover debug checks" > > + depends on KEXEC_HANDOVER_DEBUGFS > > I missed that in the earlier review, should be "depends on KEXEC_HANDOVER" > > @Andrew, can you please fold this into what's now commit 0e0faeffd144 > ("kho: warn and fail on metadata or preserved memory in scratch area") > > diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec > index c94d36b5fcd9..54e581072617 100644 > --- a/kernel/Kconfig.kexec > +++ b/kernel/Kconfig.kexec > @@ -111,7 +111,7 @@ config KEXEC_HANDOVER > > config KEXEC_HANDOVER_DEBUG > bool "Enable Kexec Handover debug checks" > - depends on KEXEC_HANDOVER_DEBUGFS > + depends on KEXEC_HANDOVER > help > This option enables extra sanity checks for the Kexec Handover > subsystem. Since, KHO performance is crucial in live update > > > + help > > + This option enables extra sanity checks for the Kexec Handover > > + subsystem. Since, KHO performance is crucial in live update > > + scenarios and the extra code might be adding overhead it is > > + only optionally enabled. > > + > > config CRASH_DUMP > > bool "kernel crash dumps" > > default ARCH_DEFAULT_CRASH_DUMP > > -- > Sincerely yours, > Mike.
