PM: sleep: annotate RCU list iterations
These iterations require the read lock, otherwise RCU
lockdep will splat:
=============================
WARNING: suspicious RCU usage
6.17.0-rc3-00014-g31419c045d64 #6 Tainted: G O
-----------------------------
drivers/base/power/main.c:1333 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
5 locks held by rtcwake/547:
#0:
00000000643ab418 (sb_writers#6){.+.+}-{0:0}, at: file_start_write+0x2b/0x3a
#1:
0000000067a0ca88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x181/0x24b
#2:
00000000631eac40 (kn->active#3){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x191/0x24b
#3:
00000000609a1308 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0xaf/0x30b
#4:
0000000060c0fdb0 (device_links_srcu){.+.+}-{0:0}, at: device_links_read_lock+0x75/0x98
stack backtrace:
CPU: 0 UID: 0 PID: 547 Comm: rtcwake Tainted: G O
6.17.0-rc3-00014-g31419c045d64 #6 VOLUNTARY
Tainted: [O]=OOT_MODULE
Stack:
223721b3a80 6089eac6 00000001 00000001
ffffff00 6089eac6 00000535 6086e528
721b3ac0 6003c294 00000000 60031fc0
Call Trace:
[<
600407ed>] show_stack+0x10e/0x127
[<
6003c294>] dump_stack_lvl+0x77/0xc6
[<
6003c2fd>] dump_stack+0x1a/0x20
[<
600bc2f8>] lockdep_rcu_suspicious+0x116/0x13e
[<
603d8ea1>] dpm_async_suspend_superior+0x117/0x17e
[<
603d980f>] device_suspend+0x528/0x541
[<
603da24b>] dpm_suspend+0x1a2/0x267
[<
603da837>] dpm_suspend_start+0x5d/0x72
[<
600ca0c9>] suspend_devices_and_enter+0xab/0x736
[...]
Add the fourth argument to the iteration to annotate
this and avoid the splat.
Fixes:
06799631d522 ("PM: sleep: Make async suspend handle suppliers like parents")
Fixes:
ed18738fff02 ("PM: sleep: Make async resume handle consumers like children")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20250826134348.aba79f6e6299.I9ecf55da46ccf33778f2c018a82e1819d815b348@changeid
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>