Re: [PATCH] coresight: tmc: Fix bad register address for CLAIM

From: Mathieu Poirier
Date: Fri Oct 19 2018 - 11:47:45 EST


On Thu, 18 Oct 2018 at 22:56, Leo Yan <leo.yan@xxxxxxxxxx> wrote:
>
> Commit 4d3ebd3658d8 ("coreisght: tmc: Claim device before use") uses
> CLAIM tag to validate if the device is available, it needs to pass
> the device base address to access related registers.
>
> In the function tmc_etb_disable_hw() it wrongly passes the driver data
> pointer as register base address, thus it's easily to produce the kernel
> warning info like below:
>
> [ 83.579898] WARNING: CPU: 4 PID: 2970 at drivers/hwtracing/coresight/coresight.c:207 coresight_disclaim_device_unlocked+0x44/0x80
> [ 83.591448] Modules linked in:
> [ 83.594485] CPU: 4 PID: 2970 Comm: uname Not tainted 4.19.0-rc6-00417-g721b509 #110
> [ 83.602067] Hardware name: ARM Juno development board (r2) (DT)
> [ 83.607932] pstate: 80000085 (Nzcv daIf -PAN -UAO)
> [ 83.612681] pc : coresight_disclaim_device_unlocked+0x44/0x80
> [ 83.618375] lr : coresight_disclaim_device_unlocked+0x44/0x80
> [ 83.624064] sp : ffff00000fe3ba20
> [ 83.627347] x29: ffff00000fe3ba20 x28: ffff80002d430dc0
> [ 83.632618] x27: ffff800033177c00 x26: ffff80002eb44480
> [ 83.637889] x25: 0000000000000001 x24: ffff800033c72600
> [ 83.643160] x23: ffff0000099b11f8 x22: ffff0000099b11c8
> [ 83.648430] x21: 0000000000000002 x20: ffff800033a90418
> [ 83.653701] x19: ffff0000099b11c8 x18: 0000000000000000
> [ 83.658971] x17: 0000000000000000 x16: 0000000000000000
> [ 83.664241] x15: 0000000000000000 x14: 0000000000000000
> [ 83.669511] x13: 0000000000000000 x12: 0000000000000000
> [ 83.674782] x11: 0000000000000000 x10: 0000000000000000
> [ 83.680052] x9 : 0000000000000000 x8 : 0000000000000001
> [ 83.685322] x7 : 0000000000010000 x6 : ffff800033ebab18
> [ 83.690593] x5 : ffff800033ebab18 x4 : ffff800033e6c698
> [ 83.695862] x3 : 0000000000000001 x2 : 0000000000000000
> [ 83.701133] x1 : 0000000000000000 x0 : 0000000000000001
> [ 83.706404] Call trace:
> [ 83.708830] coresight_disclaim_device_unlocked+0x44/0x80
> [ 83.714180] coresight_disclaim_device+0x34/0x48
> [ 83.718756] tmc_disable_etf_sink+0xc4/0xf0
> [ 83.722902] coresight_disable_path_from+0xc8/0x240
> [ 83.727735] coresight_disable_path+0x24/0x30
> [ 83.732053] etm_event_stop+0x130/0x170
> [ 83.735854] etm_event_del+0x24/0x30
> [ 83.739399] event_sched_out.isra.51+0xcc/0x1e8
> [ 83.743887] group_sched_out.part.53+0x44/0xb0
> [ 83.748291] ctx_sched_out+0x298/0x2b8
> [ 83.752005] task_ctx_sched_out+0x74/0xa8
> [ 83.755980] perf_event_exit_task+0x140/0x418
> [ 83.760298] do_exit+0x3f4/0xcf0
> [ 83.763497] do_group_exit+0x5c/0xc0
> [ 83.767041] __arm64_sys_exit_group+0x24/0x28
> [ 83.771359] el0_svc_common+0x110/0x178
> [ 83.775160] el0_svc_handler+0x94/0xe8
> [ 83.778875] el0_svc+0x8/0xc
> [ 83.781728] ---[ end trace 02d8d8eac46db9e5 ]---
>
> This patch is to fix this bug by using 'drvdata->base' as the
> register base address for CLAIM related operation.
>
> Fixes: 4d3ebd3658d8 ("coreisght: tmc: Claim device before use")
> Cc: Suzuki Poulose <suzuki.poulose@xxxxxxx>
> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Cc: Mike Leach <mike.leach@xxxxxxxxxx>
> Cc: Robert Walker <robert.walker@xxxxxxx>
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> ---
> drivers/hwtracing/coresight/coresight-tmc-etf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index 53fc83b..5864ac5 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -86,7 +86,7 @@ static void __tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
>
> static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
> {
> - coresight_disclaim_device(drvdata);
> + coresight_disclaim_device(drvdata->base);
> __tmc_etb_disable_hw(drvdata);
> }
>

Applied - thanks.
Mathieu

> --
> 2.7.4
>