linux/drivers/hwtracing
Junhao He c0a232f1e1 coresight: trbe: Fix TRBE potential sleep in atomic context
smp_call_function_single() will allocate an IPI interrupt vector to
the target processor and send a function call request to the interrupt
vector. After the target processor receives the IPI interrupt, it will
execute arm_trbe_remove_coresight_cpu() call request in the interrupt
handler.

According to the device_unregister() stack information, if other process
is useing the device, the down_write() may sleep, and trigger deadlocks
or unexpected errors.

  arm_trbe_remove_coresight_cpu
    coresight_unregister
      device_unregister
        device_del
          kobject_del
            __kobject_del
              sysfs_remove_dir
                kernfs_remove
                  down_write ---------> it may sleep

Add a helper arm_trbe_disable_cpu() to disable TRBE precpu irq and reset
per TRBE.
Simply call arm_trbe_remove_coresight_cpu() directly without useing the
smp_call_function_single(), which is the same as registering the TRBE
coresight device.

Fixes: 3fbf7f011f ("coresight: sink: Add TRBE driver")
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Link: https://lore.kernel.org/r/20230814093813.19152-2-hejunhao3@huawei.com
[ Remove duplicate cpumask checks during removal ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[ v3 - Remove the operation of assigning NULL to cpudata->drvdata ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230818084052.10116-1-hejunhao3@huawei.com
2023-08-18 16:42:26 +01:00
..
coresight coresight: trbe: Fix TRBE potential sleep in atomic context 2023-08-18 16:42:26 +01:00
intel_th Driver core changes for 6.3-rc1 2023-02-24 12:58:55 -08:00
ptt hwtracing: hisi_ptt: Use pci_dev_id() to simplify the code 2023-08-15 00:45:56 +01:00
stm - Daniel Verkamp has contributed a memfd series ("mm/memfd: add 2023-02-23 17:09:35 -08:00
Kconfig hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device 2022-09-08 16:26:17 -06:00