From: Armin Wolf W_Armin@gmx.de
[ Upstream commit 94a370fc8def6038dbc02199db9584b0b3690f1a ]
The ACPI sysfs code will fail to initialize if acpi_kobj is NULL, together with some ACPI drivers.
Follow the other firmware subsystems and bail out if the kobject cannot be registered.
Signed-off-by: Armin Wolf W_Armin@gmx.de Link: https://patch.msgid.link/20250518185111.3560-2-W_Armin@gmx.de Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---
**YES** This commit should be backported to stable kernel trees. Here's the detailed analysis: **Bug Fix Nature**: The commit fixes a real bug where ACPI initialization continues silently even when `acpi_kobj` registration fails. This creates an inconsistent system state where ACPI sysfs functionality and some drivers that depend on `acpi_kobj` will fail later without clear indication of the root cause. **Code Change Analysis**: - Changes `pr_debug()` to `pr_err()` for better visibility of the failure - Returns `-ENOMEM` immediately when `kobject_create_and_add()` fails instead of continuing - The existing `kobject_put(acpi_kobj)` cleanup in the error path after `acpi_bus_init()` is already present **Comparison with Similar Commits**: This follows the exact pattern of Similar Commit #1 (Status: YES) which added `kobject_put()` cleanup. Both commits address resource management issues in the same function (`acpi_init`) and represent important bugfixes with minimal risk. **Risk Assessment**: - Very low risk - only affects the error path when kobject creation fails - Early failure is better than silent failure leading to confusing symptoms later - Change is contained to a single function with clear error handling - Consistent with how other firmware subsystems handle kobject registration failures **Stable Tree Criteria Met**: - Fixes important bug affecting system reliability - Minimal and contained change - No architectural modifications - Clear improvement in error handling and debugging The commit addresses a legitimate reliability issue where ACPI would continue initialization with a NULL `acpi_kobj`, leading to failures in dependent subsystems that would be harder to diagnose than an early, clear failure.
drivers/acpi/bus.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index a4aa53b7e2bb3..645464f02363f 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -1396,8 +1396,10 @@ static int __init acpi_init(void) }
acpi_kobj = kobject_create_and_add("acpi", firmware_kobj); - if (!acpi_kobj) - pr_debug("%s: kset create error\n", __func__); + if (!acpi_kobj) { + pr_err("Failed to register kobject\n"); + return -ENOMEM; + }
init_prmt(); acpi_init_pcc();