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From: Greg KH <gregkh@linuxfoundation.org>
To: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 22/28] coresight: tmc-etf: Do not call smp_processor_id from preemptible
Date: Thu, 20 Jun 2019 08:03:53 +0200	[thread overview]
Message-ID: <20190620060353.GC26319@kroah.com> (raw)
In-Reply-To: <20190619195318.19254-23-mathieu.poirier@linaro.org>

On Wed, Jun 19, 2019 at 01:53:12PM -0600, Mathieu Poirier wrote:
> From: Suzuki K Poulose <suzuki.poulose@arm.com>
> 
> During a perf session we try to allocate buffers on the "node" associated
> with the CPU the event is bound to. If it is not bound to a CPU, we
> use the current CPU node, using smp_processor_id(). However this is unsafe
> in a pre-emptible context and could generate the splats as below :
> 
>  BUG: using smp_processor_id() in preemptible [00000000] code: perf/2544
>  caller is tmc_alloc_etf_buffer+0x5c/0x60
>  CPU: 2 PID: 2544 Comm: perf Not tainted 5.1.0-rc6-147786-g116841e #344
>  Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb  1 2019
>  Call trace:
>   dump_backtrace+0x0/0x150
>   show_stack+0x14/0x20
>   dump_stack+0x9c/0xc4
>   debug_smp_processor_id+0x10c/0x110
>   tmc_alloc_etf_buffer+0x5c/0x60
>   etm_setup_aux+0x1c4/0x230
>   rb_alloc_aux+0x1b8/0x2b8
>   perf_mmap+0x35c/0x478
>   mmap_region+0x34c/0x4f0
>   do_mmap+0x2d8/0x418
>   vm_mmap_pgoff+0xd0/0xf8
>   ksys_mmap_pgoff+0x88/0xf8
>   __arm64_sys_mmap+0x28/0x38
>   el0_svc_handler+0xd8/0x138
>   el0_svc+0x8/0xc
> 
> Use NUMA_NO_NODE hint instead of using the current node for events
> not bound to CPUs.
> 
> Fixes: 2e499bbc1a929ac ("coresight: tmc: implementing TMC-ETF AUX space API")
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---
>  drivers/hwtracing/coresight/coresight-tmc-etf.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)

And again, should go into 5.2-final and stable.

thanks,

greg k-h

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  reply	other threads:[~2019-06-20  6:04 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-19 19:52 [PATCH 00/28] coresight: next v5.2-rc5 (V2) Mathieu Poirier
2019-06-19 19:52 ` [PATCH 01/28] coresight: Rename of_coresight to coresight-platform Mathieu Poirier
2019-06-19 19:52 ` [PATCH 02/28] coresight: platform: Make memory allocation helper generic Mathieu Poirier
2019-06-19 19:52 ` [PATCH 03/28] coresight: Make sure device uses DT for obsolete compatible check Mathieu Poirier
2019-06-19 19:52 ` [PATCH 04/28] coresight: Introduce generic platform data helper Mathieu Poirier
2019-06-19 19:52 ` [PATCH 05/28] coresight: Make device to CPU mapping generic Mathieu Poirier
2019-06-19 19:52 ` [PATCH 06/28] coresight: Remove cpu field from platform data Mathieu Poirier
2019-06-19 19:52 ` [PATCH 07/28] coresight: Remove name from platform description Mathieu Poirier
2019-06-19 19:52 ` [PATCH 08/28] coresight: Cleanup coresight_remove_conns Mathieu Poirier
2019-06-19 19:52 ` [PATCH 09/28] coresight: Reuse platform data structure for connection tracking Mathieu Poirier
2019-06-19 19:53 ` [PATCH 10/28] coresight: Rearrange platform data probing Mathieu Poirier
2019-06-19 19:53 ` [PATCH 11/28] coresight: Add support for releasing platform specific data Mathieu Poirier
2019-06-19 19:53 ` [PATCH 12/28] coresight: platform: Use fwnode handle for device search Mathieu Poirier
2019-06-19 19:53 ` [PATCH 13/28] coresight: Use fwnode handle instead of device names Mathieu Poirier
2019-06-19 19:53 ` [PATCH 14/28] coresight: Use platform agnostic names Mathieu Poirier
2019-06-19 19:53 ` [PATCH 15/28] coresight: stm: ACPI support for parsing stimulus base Mathieu Poirier
2019-06-19 19:53 ` [PATCH 16/28] coresight: Support for ACPI bindings Mathieu Poirier
2019-06-19 19:53 ` [PATCH 17/28] coresight: acpi: Support for AMBA components Mathieu Poirier
2019-06-19 19:53 ` [PATCH 18/28] coresight: acpi: Support for platform devices Mathieu Poirier
2019-06-19 19:53 ` [PATCH 19/28] coresight: Add dummy definition for of_coresight_get_cpu() Mathieu Poirier
2019-06-19 19:53 ` [PATCH 20/28] coresight: tmc-etr: Do not call smp_processor_id() from preemptible Mathieu Poirier
2019-06-20  6:02   ` Greg KH
2019-06-19 19:53 ` [PATCH 21/28] coresight: tmc-etr: alloc_perf_buf: Do not call smp_processor_id " Mathieu Poirier
2019-06-20  6:03   ` Greg KH
2019-06-19 19:53 ` [PATCH 22/28] coresight: tmc-etf: " Mathieu Poirier
2019-06-20  6:03   ` Greg KH [this message]
2019-06-19 19:53 ` [PATCH 23/28] coresight: etb10: " Mathieu Poirier
2019-06-20  6:04   ` Greg KH
2019-06-19 19:53 ` [PATCH 24/28] coresight: Potential uninitialized variable in probe() Mathieu Poirier
2019-06-20  6:04   ` Greg KH
2019-06-19 19:53 ` [PATCH 25/28] coresight: etm3x: Smatch: Fix potential NULL pointer dereference Mathieu Poirier
2019-06-20  6:04   ` Greg KH
2019-06-20 21:38     ` Mathieu Poirier
2019-06-21  6:59       ` Greg KH
2019-06-19 19:53 ` [PATCH 26/28] coresight: tmc: " Mathieu Poirier
2019-06-20  6:05   ` Greg KH
2019-06-20 21:42     ` Mathieu Poirier
2019-06-21  6:59       ` Greg KH
2019-06-19 19:53 ` [PATCH 27/28] coresight: platform: add OF/APCI dependency Mathieu Poirier
2019-06-19 19:53 ` [PATCH 28/28] coresight: replicator: Add terminate entry for acpi_device_id tables Mathieu Poirier
2019-06-20  6:08 ` [PATCH 00/28] coresight: next v5.2-rc5 (V2) Greg KH

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