• Guenter Roeck's avatar
    regmap: maple: Use alloc_flags for memory allocations · b0393e1f
    Guenter Roeck authored
    REGCACHE_MAPLE needs to allocate memory for regmap operations.
    This results in lockdep splats if used with fast_io since fast_io uses
    spinlocks for locking.
    
    BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
    in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 167, name: kunit_try_catch
    preempt_count: 1, expected: 0
    1 lock held by kunit_try_catch/167:
     #0: 838e9c10 (regmap_kunit:86:(config)->lock){....}-{2:2}, at: regmap_lock_spinlock+0x14/0x1c
    irq event stamp: 146
    hardirqs last  enabled at (145): [<8078bfa8>] crng_make_state+0x1a0/0x294
    hardirqs last disabled at (146): [<80c5f62c>] _raw_spin_lock_irqsave+0x7c/0x80
    softirqs last  enabled at (0): [<80110cc4>] copy_process+0x810/0x216c
    softirqs last disabled at (0): [<00000000>] 0x0
    CPU: 0 PID: 167 Comm: kunit_try_catch Tainted: G                 N 6.5.0-rc1-00028-gc4be22597a36-dirty #6
    Hardware name: Generic DT based system
     unwind_backtrace from show_stack+0x18/0x1c
     show_stack from dump_stack_lvl+0x38/0x5c
     dump_stack_lvl from __might_resched+0x188/0x2d0
     __might_resched from __kmem_cache_alloc_node+0x1f4/0x258
     __kmem_cache_alloc_node from __kmalloc+0x48/0x170
     __kmalloc from regcache_maple_write+0x194/0x248
     regcache_maple_write from _regmap_write+0x88/0x140
     _regmap_write from regmap_write+0x44/0x68
     regmap_write from basic_read_write+0x8c/0x27c
     basic_read_write from kunit_generic_run_threadfn_adapter+0x1c/0x28
     kunit_generic_run_threadfn_adapter from kthread+0xf8/0x120
     kthread from ret_from_fork+0x14/0x3c
    Exception stack(0x881a5fb0 to 0x881a5ff8)
    5fa0:                                     00000000 00000000 00000000 00000000
    5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
    5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
    
    Use map->alloc_flags instead of GFP_KERNEL for memory allocations to fix
    the problem.
    
    Fixes: f033c26d ("regmap: Add maple tree based register cache")
    Cc: Dan Carpenter <dan.carpenter@linaro.org>
    Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Link: https://lore.kernel.org/r/20230720172021.2617326-1-linux@roeck-us.netSigned-off-by: default avatarMark Brown <broonie@kernel.org>
    b0393e1f
regcache-maple.c 7.64 KB