From: Jamie Iles <jamie@nuviainc.com>
To: linux-acpi@vger.kernel.org
Cc: Jamie Iles <jamie@nuviainc.com>, "Rafael J. Wysocki" <rjw@rjwysocki.net>
Subject: [PATCH] ACPI: debug: don't allow debugging when ACPI is disabled
Date: Fri, 9 Oct 2020 16:21:16 +0100 [thread overview]
Message-ID: <20201009152116.35184-1-jamie@nuviainc.com> (raw)
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
Fail module loading to avoid this and any subsequent problems that might
arise by trying to debug AML when ACPI is disabled.
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
---
drivers/acpi/acpi_dbg.c | 3 +++
1 file changed, 3 insertions(+)
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);
--
2.25.1
next reply other threads:[~2020-10-09 15:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 15:21 Jamie Iles [this message]
2020-10-10 3:27 ` [PATCH] ACPI: debug: don't allow debugging when ACPI is disabled Hanjun Guo
2020-10-12 13:04 ` [PATCHv2] " Jamie Iles
2020-10-14 0:43 ` Hanjun Guo
2020-10-16 16:00 ` Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201009152116.35184-1-jamie@nuviainc.com \
--to=jamie@nuviainc.com \
--cc=linux-acpi@vger.kernel.org \
--cc=rjw@rjwysocki.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).