Qais Yousef
cd65f53a58
ANDROID: sched/uclamp: Don't enable uclamp_is_used static key by in-kernel requests
We do have now in-kernel users of uclamp to implement inheritance. The
static_branch_enable() path unconditionally holds the cpus_read_lock()
which might_sleep(). The path in binder that implements inheritance
happens from in_atomic() context which leads to a splat like this one:
[ 147.529960] BUG: sleeping function called from invalid context at include/linux/percpu-rwsem.h:56
[ 147.530196] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2586, name: RenderThread
[ 147.530410] INFO: lockdep is turned off.
[ 147.530518] Preemption disabled at:
[ 147.530521] [<ffffffc008ca2cec>] binder_proc_transaction+0x78/0x41c
[ 147.530793] CPU: 8 PID: 2586 Comm: RenderThread Tainted: G S W O 5.15.76-android14-5-00086-gc01afe5d262f #1
[ 147.531214] Call trace:
[ 147.531288] dump_backtrace+0xe8/0x134
[ 147.531444] show_stack+0x1c/0x4c
[ 147.531598] dump_stack_lvl+0x74/0x94
[ 147.531766] dump_stack+0x14/0x3c
[ 147.531920] ___might_sleep+0x210/0x230
[ 147.532094] __might_sleep+0x54/0x84
[ 147.532259] cpus_read_lock+0x2c/0x160
[ 147.532429] static_key_enable+0x1c/0x34
[ 147.532608] __sched_setscheduler+0x2a8/0x99c
[ 147.532802] sched_setattr_nocheck+0x1c/0x24
[ 147.532994] binder_do_set_priority+0x31c/0x4a4
[ 147.533195] binder_transaction_priority+0x200/0x3f4
[ 147.533413] binder_proc_transaction+0x220/0x41c
[ 147.533618] binder_transaction+0x1df0/0x234c
[ 147.533812] binder_thread_write+0xd84/0x2398
[ 147.534007] binder_ioctl_write_read+0x19c/0xb28
[ 147.534212] binder_ioctl+0x344/0x1a3c
[ 147.534382] __arm64_sys_ioctl+0x94/0xc8
[ 147.534561] invoke_syscall+0x44/0xf8
[ 147.534729] el0_svc_common+0xc8/0x10c
[ 147.534900] do_el0_svc+0x20/0x28
[ 147.535053] el0_svc+0x58/0xe0
[ 147.535198] el0t_64_sync_handler+0x7c/0xe4
[ 147.535386] el0t_64_sync+0x188/0x18c
Prevent enabling the lock for !user initiated sched_setattr()
operations. Generally we don't expect in-kernel uclamp users.
Bug: 259145692
Signed-off-by: Qais Yousef <qyousef@google.com>
Change-Id: Iac5be139b5ffd39f5e1c0431ce253133d81b98cf
2022-12-05 20:29:35 +00:00
..
2022-12-05 20:29:35 +00:00
2022-09-21 17:30:12 +02:00
2022-09-24 14:12:45 +02:00
2022-09-21 17:30:12 +02:00
2022-09-20 12:39:42 +02:00
2022-09-08 23:24:37 +00:00
2022-10-07 20:22:29 +00:00
2022-09-21 17:30:12 +02:00
2022-11-15 12:48:44 +00:00
2022-09-08 23:24:37 +00:00