| Message ID | 20210610210913.536081-3-tyhicks@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tee: Improve support for kexec and kdump | expand |
On Thu, Jun 10, 2021 at 11:09 PM Tyler Hicks <tyhicks@linux.microsoft.com> wrote: > > Fix a hung task issue, seen when booting the kdump kernel, that is > caused by all of the secure world threads being in a permanent suspended > state: > > INFO: task swapper/0:1 blocked for more than 120 seconds. > Not tainted 5.4.83 #1 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > swapper/0 D 0 1 0 0x00000028 > Call trace: > __switch_to+0xc8/0x118 > __schedule+0x2e0/0x700 > schedule+0x38/0xb8 > schedule_timeout+0x258/0x388 > wait_for_completion+0x16c/0x4b8 > optee_cq_wait_for_completion+0x28/0xa8 > optee_disable_shm_cache+0xb8/0xf8 > optee_probe+0x560/0x61c > platform_drv_probe+0x58/0xa8 > really_probe+0xe0/0x338 > driver_probe_device+0x5c/0xf0 > device_driver_attach+0x74/0x80 > __driver_attach+0x64/0xe0 > bus_for_each_dev+0x84/0xd8 > driver_attach+0x30/0x40 > bus_add_driver+0x188/0x1e8 > driver_register+0x64/0x110 > __platform_driver_register+0x54/0x60 > optee_driver_init+0x20/0x28 > do_one_initcall+0x54/0x24c > kernel_init_freeable+0x1e8/0x2c0 > kernel_init+0x18/0x118 > ret_from_fork+0x10/0x18 > > The invoke_fn hook returned OPTEE_SMC_RETURN_ETHREAD_LIMIT, indicating > that the secure world threads were all in a suspended state at the time > of the kernel crash. This intermittently prevented the kdump kernel from > booting, resulting in a failure to collect the kernel dump. > > Make kernel dump collection more reliable on systems utilizing OP-TEE by > refusing to load the driver under the kdump kernel. > > Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> > --- > drivers/tee/optee/core.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) Looks good Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index ddb8f9ecf307..5288cd767d82 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -6,6 +6,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/arm-smccc.h> +#include <linux/crash_dump.h> #include <linux/errno.h> #include <linux/io.h> #include <linux/module.h> @@ -612,6 +613,16 @@ static int optee_probe(struct platform_device *pdev) u32 sec_caps; int rc; + /* + * The kernel may have crashed at the same time that all available + * secure world threads were suspended and we cannot reschedule the + * suspended threads without access to the crashed kernel's wait_queue. + * Therefore, we cannot reliably initialize the OP-TEE driver in the + * kdump kernel. + */ + if (is_kdump_kernel()) + return -ENODEV; + invoke_fn = get_invoke_func(&pdev->dev); if (IS_ERR(invoke_fn)) return PTR_ERR(invoke_fn);
Fix a hung task issue, seen when booting the kdump kernel, that is caused by all of the secure world threads being in a permanent suspended state: INFO: task swapper/0:1 blocked for more than 120 seconds. Not tainted 5.4.83 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. swapper/0 D 0 1 0 0x00000028 Call trace: __switch_to+0xc8/0x118 __schedule+0x2e0/0x700 schedule+0x38/0xb8 schedule_timeout+0x258/0x388 wait_for_completion+0x16c/0x4b8 optee_cq_wait_for_completion+0x28/0xa8 optee_disable_shm_cache+0xb8/0xf8 optee_probe+0x560/0x61c platform_drv_probe+0x58/0xa8 really_probe+0xe0/0x338 driver_probe_device+0x5c/0xf0 device_driver_attach+0x74/0x80 __driver_attach+0x64/0xe0 bus_for_each_dev+0x84/0xd8 driver_attach+0x30/0x40 bus_add_driver+0x188/0x1e8 driver_register+0x64/0x110 __platform_driver_register+0x54/0x60 optee_driver_init+0x20/0x28 do_one_initcall+0x54/0x24c kernel_init_freeable+0x1e8/0x2c0 kernel_init+0x18/0x118 ret_from_fork+0x10/0x18 The invoke_fn hook returned OPTEE_SMC_RETURN_ETHREAD_LIMIT, indicating that the secure world threads were all in a suspended state at the time of the kernel crash. This intermittently prevented the kdump kernel from booting, resulting in a failure to collect the kernel dump. Make kernel dump collection more reliable on systems utilizing OP-TEE by refusing to load the driver under the kdump kernel. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> --- drivers/tee/optee/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+)