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| author | Jamie Iles <jamie@nuviainc.com> | 2020-10-12 16:04:46 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-10-16 18:58:52 +0300 |
| commit | 0fada277147ffc6d694aa32162f51198d4f10d94 (patch) | |
| tree | a671995d5627030cd5362a2cbf2e24e4d38f3a78 | |
| parent | cf1d2b44f6c701ffff58606b5b8a8996190d6e7d (diff) | |
| download | linux-0fada277147ffc6d694aa32162f51198d4f10d94.tar.xz | |
ACPI: debug: don't allow debugging when ACPI is disabled
If ACPI is disabled then loading the acpi_dbg module will result in the
following splat when lock debugging is enabled.
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 0 PID: 1 at kernel/locking/mutex.c:938 __mutex_lock+0xa10/0x1290
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc8+ #103
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x4d8
show_stack+0x34/0x48
dump_stack+0x174/0x1f8
panic+0x360/0x7a0
__warn+0x244/0x2ec
report_bug+0x240/0x398
bug_handler+0x50/0xc0
call_break_hook+0x160/0x1d8
brk_handler+0x30/0xc0
do_debug_exception+0x184/0x340
el1_dbg+0x48/0xb0
el1_sync_handler+0x170/0x1c8
el1_sync+0x80/0x100
__mutex_lock+0xa10/0x1290
mutex_lock_nested+0x6c/0xc0
acpi_register_debugger+0x40/0x88
acpi_aml_init+0xc4/0x114
do_one_initcall+0x24c/0xb10
kernel_init_freeable+0x690/0x728
kernel_init+0x20/0x1e8
ret_from_fork+0x10/0x18
This is because acpi_debugger.lock has not been initialized as
acpi_debugger_init() is not called when ACPI is disabled. Fail module
loading to avoid this and any subsequent problems that might arise by
trying to debug AML when ACPI is disabled.
Fixes: 8cfb0cdf07e2 ("ACPI / debugger: Add IO interface to access debugger functionalities")
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/acpi_dbg.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_dbg.c b/drivers/acpi/acpi_dbg.c index 6041974c7627..fb7290338593 100644 --- a/drivers/acpi/acpi_dbg.c +++ b/drivers/acpi/acpi_dbg.c @@ -749,6 +749,9 @@ static int __init acpi_aml_init(void) { int ret; + if (acpi_disabled) + return -ENODEV; + /* Initialize AML IO interface */ mutex_init(&acpi_aml_io.lock); init_waitqueue_head(&acpi_aml_io.wait); |