Re: [PATCH v10 08/24] firmware: arm_scmi: Add Telemetry configuration operations

[Fayssal Benmlih]

Hi Cristian,

The group-versus-instance cached-state handling is improved in V10, but one
part of the original issue remains.

For a group operation, current_state and current_mode now refer to the
group, but collection_configure() still assigns:

        ti->info.notif_enabled =
                *current_mode == SCMI_TLM_NOTIFICATION;

A group operation can therefore overwrite the instance-wide notification
state. For example, configuring one group for on-demand collection can clear
the global flag while another group is still using notifications.

Please either maintain notification state per group or derive the
instance-wide state from all configured groups.

The SHMTI offset validation is also still incomplete. The checked addition
in scmi_telemetry_de_payld_safe_calc() verifies the line against
shmti->info.len, but a DE line must end before the TDCF epilogue, not merely
before the end of the allocation.

The returned block-timestamp offset is checked through
scmi_telemetry_shmti_overflow(), which uses the same end-of-allocation
boundary. Please validate both complete lines against:

        shmti->info.len - TDCF_EPLG_SZ

using checked arithmetic.

Thanks,
Fayçal