platform/x86/intel: power-domains: Handle failed init in tpmi_get_linux_die_id()

tpmi_init() returns early with -ENODEV on CPU models that are not in
tpmi_cpu_ids, before domain_die_map is allocated. When the driver is
built in, tpmi_get_linux_die_id() remains callable after the failed
init and dereferences the NULL domain_die_map.

This is reachable from user space: uncore-frequency-tpmi calls
tpmi_get_linux_die_id() from the show function of the world-readable
die_id sysfs attribute. The attribute is created on multi-die packages
for clusters with the core agent type, so reading it on such a CPU
that is missing from tpmi_cpu_ids oopses.

Likewise, if cpuhp_setup_state() fails, the error path frees
domain_die_map but leaves the pointer set, so a later call would read
freed memory.

Return -ENODEV when the map was not allocated, and clear the pointer
wherever it is freed.

tpmi_get_linux_cpu_number(), tpmi_get_punit_core_number() and
tpmi_get_power_domain_id() read only the static per-CPU data and hash
table, so they are safe after a failed init. tpmi_get_power_domain_mask()
has the same problem as this helper but no callers, so it is handled
separately.

Fixes: e37be5d85c60 ("platform/x86/intel: power-domains: Add interface to get Linux die ID")
Assisted-by: LLM
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://patch.msgid.link/20260924193625.1830526-2-kristen.c.accardi@intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

0 files changed, 0 insertions, 0 deletions