[PATCH v2] coresight: trbe: Defer the probe on offline CPUs
Subsystems:
arm/coresight framework and drivers , hardware tracing facilities , the rest
1747d
LANDED: 1 (0M)
1 review trailer; landed in mainline as a08025b3fe56 on 2021-10-27.
3 messages,
3 authors,
2021-10-18
· open the first message on its own page
If a CPU is offline during the driver init, we could end up causing
a kernel crash trying to register the coresight device for the TRBE
instance. The trbe_cpudata for the TRBE instance is initialized only
when it is probed. Otherwise, we could end up dereferencing a NULL
cpudata->drvdata.
e.g:
[ 0.149999] coresight ete0: CPU0: ete v1.1 initialized
[ 0.149999] coresight-etm4x ete_1: ETM arch init failed
[ 0.149999] coresight-etm4x: probe of ete_1 failed with error -22
[ 0.150085] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050
[ 0.150085] Mem abort info:
[ 0.150085] ESR = 0x96000005
[ 0.150085] EC = 0x25: DABT (current EL), IL = 32 bits
[ 0.150085] SET = 0, FnV = 0
[ 0.150085] EA = 0, S1PTW = 0
[ 0.150085] Data abort info:
[ 0.150085] ISV = 0, ISS = 0x00000005
[ 0.150085] CM = 0, WnR = 0
[ 0.150085] [0000000000000050] user address but active_mm is swapper
[ 0.150085] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[ 0.150085] Modules linked in:
[ 0.150085] Hardware name: FVP Base RevC (DT)
[ 0.150085] pstate: 00800009 (nzcv daif -PAN +UAO -TCO BTYPE=--)
[ 0.150155] pc : arm_trbe_register_coresight_cpu+0x74/0x144
[ 0.150155] lr : arm_trbe_register_coresight_cpu+0x48/0x144
...
[ 0.150237] Call trace:
[ 0.150237] arm_trbe_register_coresight_cpu+0x74/0x144
[ 0.150237] arm_trbe_device_probe+0x1c0/0x2d8
[ 0.150259] platform_drv_probe+0x94/0xbc
[ 0.150259] really_probe+0x1bc/0x4a8
[ 0.150266] driver_probe_device+0x7c/0xb8
[ 0.150266] device_driver_attach+0x6c/0xac
[ 0.150266] __driver_attach+0xc4/0x148
[ 0.150266] bus_for_each_dev+0x7c/0xc8
[ 0.150266] driver_attach+0x24/0x30
[ 0.150266] bus_add_driver+0x100/0x1e0
[ 0.150266] driver_register+0x78/0x110
[ 0.150266] __platform_driver_register+0x44/0x50
[ 0.150266] arm_trbe_init+0x28/0x84
[ 0.150266] do_one_initcall+0x94/0x2bc
[ 0.150266] do_initcall_level+0xa4/0x158
[ 0.150266] do_initcalls+0x54/0x94
[ 0.150319] do_basic_setup+0x24/0x30
[ 0.150319] kernel_init_freeable+0xe8/0x14c
[ 0.150319] kernel_init+0x14/0x18c
[ 0.150319] ret_from_fork+0x10/0x30
[ 0.150319] Code: f94012c8 b0004ce2 9134a442 52819801 (f9402917)
[ 0.150319] ---[ end trace d23e0cfe5098535e ]---
[ 0.150346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Fix this by skipping the step, if we are unable to probe the CPU.
Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver")
Reported-by: Bransilav Rankov <redacted>
Cc: Anshuman Khandual <redacted>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <redacted>
Cc: Leo Yan <redacted>
Tested-by: Branislav Rankov <redacted>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since v1:
- Explain why we crash
- Add a WARN_ON to ensure the probe was successful.
---
drivers/hwtracing/coresight/coresight-trbe.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 5d350acef798..27225b88a2fc 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -1182,6 +1182,10 @@ static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cp
if ( WARN_ON ( trbe_csdev ))
return ;
+ /* If the TRBE was not probed on the CPU, we shouldn't be here */ + if ( WARN_ON ( ! cpudata -> drvdata )) + return ; + dev = & cpudata -> drvdata -> pdev -> dev ;
desc . name = devm_kasprintf ( dev , GFP_KERNEL , "trbe%d" , cpu );
if ( ! desc . name ) @@ -1286,7 +1290,9 @@ static int arm_trbe_probe_coresight(struct trbe_drvdata *drvdata)
return - ENOMEM ;
for_each_cpu ( cpu , & drvdata -> supported_cpus ) {
- smp_call_function_single ( cpu , arm_trbe_probe_cpu , drvdata , 1 ); + /* If we fail to probe the CPU, let us defer it to hotplug callbacks */ + if ( smp_call_function_single ( cpu , arm_trbe_probe_cpu , drvdata , 1 )) + continue ; if ( cpumask_test_cpu ( cpu , & drvdata -> supported_cpus ))
arm_trbe_register_coresight_cpu ( drvdata , cpu );
if ( cpumask_test_cpu ( cpu , & drvdata -> supported_cpus )) --
2.25.4
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linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 10/14/21 7:52 PM, Suzuki K Poulose wrote: If a CPU is offline during the driver init, we could end up causing
a kernel crash trying to register the coresight device for the TRBE
instance. The trbe_cpudata for the TRBE instance is initialized only
when it is probed. Otherwise, we could end up dereferencing a NULL
cpudata->drvdata.
e.g:
[ 0.149999] coresight ete0: CPU0: ete v1.1 initialized
[ 0.149999] coresight-etm4x ete_1: ETM arch init failed
[ 0.149999] coresight-etm4x: probe of ete_1 failed with error -22
[ 0.150085] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050
[ 0.150085] Mem abort info:
[ 0.150085] ESR = 0x96000005
[ 0.150085] EC = 0x25: DABT (current EL), IL = 32 bits
[ 0.150085] SET = 0, FnV = 0
[ 0.150085] EA = 0, S1PTW = 0
[ 0.150085] Data abort info:
[ 0.150085] ISV = 0, ISS = 0x00000005
[ 0.150085] CM = 0, WnR = 0
[ 0.150085] [0000000000000050] user address but active_mm is swapper
[ 0.150085] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[ 0.150085] Modules linked in:
[ 0.150085] Hardware name: FVP Base RevC (DT)
[ 0.150085] pstate: 00800009 (nzcv daif -PAN +UAO -TCO BTYPE=--)
[ 0.150155] pc : arm_trbe_register_coresight_cpu+0x74/0x144
[ 0.150155] lr : arm_trbe_register_coresight_cpu+0x48/0x144
...
[ 0.150237] Call trace:
[ 0.150237] arm_trbe_register_coresight_cpu+0x74/0x144
[ 0.150237] arm_trbe_device_probe+0x1c0/0x2d8
[ 0.150259] platform_drv_probe+0x94/0xbc
[ 0.150259] really_probe+0x1bc/0x4a8
[ 0.150266] driver_probe_device+0x7c/0xb8
[ 0.150266] device_driver_attach+0x6c/0xac
[ 0.150266] __driver_attach+0xc4/0x148
[ 0.150266] bus_for_each_dev+0x7c/0xc8
[ 0.150266] driver_attach+0x24/0x30
[ 0.150266] bus_add_driver+0x100/0x1e0
[ 0.150266] driver_register+0x78/0x110
[ 0.150266] __platform_driver_register+0x44/0x50
[ 0.150266] arm_trbe_init+0x28/0x84
[ 0.150266] do_one_initcall+0x94/0x2bc
[ 0.150266] do_initcall_level+0xa4/0x158
[ 0.150266] do_initcalls+0x54/0x94
[ 0.150319] do_basic_setup+0x24/0x30
[ 0.150319] kernel_init_freeable+0xe8/0x14c
[ 0.150319] kernel_init+0x14/0x18c
[ 0.150319] ret_from_fork+0x10/0x30
[ 0.150319] Code: f94012c8 b0004ce2 9134a442 52819801 (f9402917)
[ 0.150319] ---[ end trace d23e0cfe5098535e ]---
[ 0.150346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Fix this by skipping the step, if we are unable to probe the CPU.
Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver")
Reported-by: Bransilav Rankov <redacted>
Cc: Anshuman Khandual <redacted>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <redacted>
Cc: Leo Yan <redacted>
Tested-by: Branislav Rankov <redacted>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Anshuman Khandual <redacted>
quoted hunk ---
Changes since v1:
- Explain why we crash
- Add a WARN_ON to ensure the probe was successful.
---
drivers/hwtracing/coresight/coresight-trbe.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 5d350acef798..27225b88a2fc 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -1182,6 +1182,10 @@ static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cp
if ( WARN_ON ( trbe_csdev ))
return ;
+ /* If the TRBE was not probed on the CPU, we shouldn't be here */ + if ( WARN_ON ( ! cpudata -> drvdata )) + return ; + dev = & cpudata -> drvdata -> pdev -> dev ;
desc . name = devm_kasprintf ( dev , GFP_KERNEL , "trbe%d" , cpu );
if ( ! desc . name ) @@ -1286,7 +1290,9 @@ static int arm_trbe_probe_coresight(struct trbe_drvdata *drvdata)
return - ENOMEM ;
for_each_cpu ( cpu , & drvdata -> supported_cpus ) {
- smp_call_function_single ( cpu , arm_trbe_probe_cpu , drvdata , 1 ); + /* If we fail to probe the CPU, let us defer it to hotplug callbacks */ + if ( smp_call_function_single ( cpu , arm_trbe_probe_cpu , drvdata , 1 )) + continue ; if ( cpumask_test_cpu ( cpu , & drvdata -> supported_cpus ))
arm_trbe_register_coresight_cpu ( drvdata , cpu );
if ( cpumask_test_cpu ( cpu , & drvdata -> supported_cpus ))
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Thu, Oct 14, 2021 at 03:22:38PM +0100, Suzuki K Poulose wrote: If a CPU is offline during the driver init, we could end up causing
a kernel crash trying to register the coresight device for the TRBE
instance. The trbe_cpudata for the TRBE instance is initialized only
when it is probed. Otherwise, we could end up dereferencing a NULL
cpudata->drvdata.
e.g:
[ 0.149999] coresight ete0: CPU0: ete v1.1 initialized
[ 0.149999] coresight-etm4x ete_1: ETM arch init failed
[ 0.149999] coresight-etm4x: probe of ete_1 failed with error -22
[ 0.150085] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050
[ 0.150085] Mem abort info:
[ 0.150085] ESR = 0x96000005
[ 0.150085] EC = 0x25: DABT (current EL), IL = 32 bits
[ 0.150085] SET = 0, FnV = 0
[ 0.150085] EA = 0, S1PTW = 0
[ 0.150085] Data abort info:
[ 0.150085] ISV = 0, ISS = 0x00000005
[ 0.150085] CM = 0, WnR = 0
[ 0.150085] [0000000000000050] user address but active_mm is swapper
[ 0.150085] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[ 0.150085] Modules linked in:
[ 0.150085] Hardware name: FVP Base RevC (DT)
[ 0.150085] pstate: 00800009 (nzcv daif -PAN +UAO -TCO BTYPE=--)
[ 0.150155] pc : arm_trbe_register_coresight_cpu+0x74/0x144
[ 0.150155] lr : arm_trbe_register_coresight_cpu+0x48/0x144
...
[ 0.150237] Call trace:
[ 0.150237] arm_trbe_register_coresight_cpu+0x74/0x144
[ 0.150237] arm_trbe_device_probe+0x1c0/0x2d8
[ 0.150259] platform_drv_probe+0x94/0xbc
[ 0.150259] really_probe+0x1bc/0x4a8
[ 0.150266] driver_probe_device+0x7c/0xb8
[ 0.150266] device_driver_attach+0x6c/0xac
[ 0.150266] __driver_attach+0xc4/0x148
[ 0.150266] bus_for_each_dev+0x7c/0xc8
[ 0.150266] driver_attach+0x24/0x30
[ 0.150266] bus_add_driver+0x100/0x1e0
[ 0.150266] driver_register+0x78/0x110
[ 0.150266] __platform_driver_register+0x44/0x50
[ 0.150266] arm_trbe_init+0x28/0x84
[ 0.150266] do_one_initcall+0x94/0x2bc
[ 0.150266] do_initcall_level+0xa4/0x158
[ 0.150266] do_initcalls+0x54/0x94
[ 0.150319] do_basic_setup+0x24/0x30
[ 0.150319] kernel_init_freeable+0xe8/0x14c
[ 0.150319] kernel_init+0x14/0x18c
[ 0.150319] ret_from_fork+0x10/0x30
[ 0.150319] Code: f94012c8 b0004ce2 9134a442 52819801 (f9402917)
[ 0.150319] ---[ end trace d23e0cfe5098535e ]---
[ 0.150346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Fix this by skipping the step, if we are unable to probe the CPU.
Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver")
Reported-by: Bransilav Rankov <redacted>
Cc: Anshuman Khandual <redacted>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <redacted>
Cc: Leo Yan <redacted>
Tested-by: Branislav Rankov <redacted>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
I have applied this patch.
Thanks,
Mathieu
quoted hunk ---
Changes since v1:
- Explain why we crash
- Add a WARN_ON to ensure the probe was successful.
---
drivers/hwtracing/coresight/coresight-trbe.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 5d350acef798..27225b88a2fc 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -1182,6 +1182,10 @@ static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cp
if ( WARN_ON ( trbe_csdev ))
return ;
+ /* If the TRBE was not probed on the CPU, we shouldn't be here */ + if ( WARN_ON ( ! cpudata -> drvdata )) + return ; + dev = & cpudata -> drvdata -> pdev -> dev ;
desc . name = devm_kasprintf ( dev , GFP_KERNEL , "trbe%d" , cpu );
if ( ! desc . name ) @@ -1286,7 +1290,9 @@ static int arm_trbe_probe_coresight(struct trbe_drvdata *drvdata)
return - ENOMEM ;
for_each_cpu ( cpu , & drvdata -> supported_cpus ) {
- smp_call_function_single ( cpu , arm_trbe_probe_cpu , drvdata , 1 ); + /* If we fail to probe the CPU, let us defer it to hotplug callbacks */ + if ( smp_call_function_single ( cpu , arm_trbe_probe_cpu , drvdata , 1 )) + continue ; if ( cpumask_test_cpu ( cpu , & drvdata -> supported_cpus ))
arm_trbe_register_coresight_cpu ( drvdata , cpu );
if ( cpumask_test_cpu ( cpu , & drvdata -> supported_cpus )) --
2.25.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel