• Stephen Boyd's avatar
    cpufreq: OPP: Avoid sleeping while atomic · 84d172d6
    Stephen Boyd authored
    commit 3c5445ce upstream.
    
    We allocate the cpufreq table after calling rcu_read_lock(),
    which disables preemption. This causes scheduling while atomic
    warnings. Use GFP_ATOMIC instead of GFP_KERNEL and update for
    kcalloc while we're here.
    
    BUG: sleeping function called from invalid context at mm/slub.c:1246
    in_atomic(): 0, irqs_disabled(): 0, pid: 80, name: modprobe
    5 locks held by modprobe/80:
     #0:  (&dev->mutex){......}, at: [<c050d484>] __driver_attach+0x48/0x98
     #1:  (&dev->mutex){......}, at: [<c050d494>] __driver_attach+0x58/0x98
     #2:  (subsys mutex#5){+.+.+.}, at: [<c050c114>] subsys_interface_register+0x38/0xc8
     #3:  (cpufreq_rwsem){.+.+.+}, at: [<c05a9c8c>] __cpufreq_add_dev.isra.22+0x84/0x92c
     #4:  (rcu_read_lock){......}, at: [<c05ab24c>] dev_pm_opp_init_cpufreq_table+0x18/0x10c
    Preemption disabled at:[<  (null)>]   (null)
    
    CPU: 2 PID: 80 Comm: modprobe Not tainted 3.16.0-rc3-next-20140701-00035-g286857f216aa-dirty #217
    [<c0214da8>] (unwind_backtrace) from [<c02123f8>] (show_stack+0x10/0x14)
    [<c02123f8>] (show_stack) from [<c070141c>] (dump_stack+0x70/0xbc)
    [<c070141c>] (dump_stack) from [<c02f4cb0>] (__kmalloc+0x124/0x250)
    [<c02f4cb0>] (__kmalloc) from [<c05ab270>] (dev_pm_opp_init_cpufreq_table+0x3c/0x10c)
    [<c05ab270>] (dev_pm_opp_init_cpufreq_table) from [<bf000508>] (cpufreq_init+0x48/0x378 [cpufreq_generic])
    [<bf000508>] (cpufreq_init [cpufreq_generic]) from [<c05a9e08>] (__cpufreq_add_dev.isra.22+0x200/0x92c)
    [<c05a9e08>] (__cpufreq_add_dev.isra.22) from [<c050c160>] (subsys_interface_register+0x84/0xc8)
    [<c050c160>] (subsys_interface_register) from [<c05a9494>] (cpufreq_register_driver+0x108/0x2d8)
    [<c05a9494>] (cpufreq_register_driver) from [<bf000888>] (generic_cpufreq_probe+0x50/0x74 [cpufreq_generic])
    [<bf000888>] (generic_cpufreq_probe [cpufreq_generic]) from [<c050e994>] (platform_drv_probe+0x18/0x48)
    [<c050e994>] (platform_drv_probe) from [<c050d1f4>] (driver_probe_device+0x128/0x370)
    [<c050d1f4>] (driver_probe_device) from [<c050d4d0>] (__driver_attach+0x94/0x98)
    [<c050d4d0>] (__driver_attach) from [<c050b778>] (bus_for_each_dev+0x54/0x88)
    [<c050b778>] (bus_for_each_dev) from [<c050c894>] (bus_add_driver+0xe8/0x204)
    [<c050c894>] (bus_add_driver) from [<c050dd48>] (driver_register+0x78/0xf4)
    [<c050dd48>] (driver_register) from [<c0208870>] (do_one_initcall+0xac/0x1d8)
    [<c0208870>] (do_one_initcall) from [<c028b6b4>] (load_module+0x190c/0x21e8)
    [<c028b6b4>] (load_module) from [<c028c034>] (SyS_init_module+0xa4/0x110)
    [<c028c034>] (SyS_init_module) from [<c020f0c0>] (ret_fast_syscall+0x0/0x48)
    
    Fixes: a0dd7b79 (PM / OPP: Move cpufreq specific OPP functions out of generic OPP library)
    Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
    Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    84d172d6
cpufreq_opp.c 3.08 KB