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High speed UART configuration not working? #105

Closed
Stonie opened this issue Sep 6, 2012 · 19 comments
Closed

High speed UART configuration not working? #105

Stonie opened this issue Sep 6, 2012 · 19 comments

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@Stonie
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Stonie commented Sep 6, 2012

Hello,

I am trying to use configuration options in config.txt to enable high speed UART.
(as listed here: http://elinux.org/RPi_config.txt)

My /boot/config.txt

init_uart_baud=1000000
init_uart_clock=16000000

With these settings I am hoping to achieve 1Mbps Uart? but I cant seem to get this working?

Note I have disabled the serial console in boot.txt and /etc/inittab

Testing with stty, yields the following (is there a better way?)

root@raspberrypi:~# stty -F /dev/ttyAMA0 115200
root@raspberrypi:~# stty -F /dev/ttyAMA0 1000000
stty: /dev/ttyAMA0: unable to perform all requested operations

Am I missing something? Do I need to recompile the kernel?

System spec:

Base image is the current Raspbian (2012-08-16-wheezy-raspbian)

# uname -a
Linux raspberrypi 3.2.27+ #102 PREEMPT Sat Sep 1 01:00:50 BST 2012 armv6l GNU/Linux

root@raspberrypi:~# /opt/vc/bin/vcgencmd version
Aug 25 2012 01:12:00 
Copyright (c) 2012 Broadcom
version 333349 (release)

System fully upgraded today using apt-get update and dist-upgrade.

Thanks in advance.
Stonie.

@Stonie
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Stonie commented Sep 6, 2012

I just noticed this closed issue: #78

Given the above issue is "closed" what is the "init_uart_baud" setting for? ... "bug" or "feature"? ;)

@Stonie
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Stonie commented Sep 6, 2012

Hi, I would really appreciate some advice... I am using a serial touch screen and 115200K is too slow... I don't really want end users to have to recompile the kernel for higher UART speeds...

Please advise on what is the best course of action. (happy to do the work and provide a patch if that is what is needed?)

Regards,
Stonie.

@popcornmix
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init_uart_baud just sets the baud rate through GPU before ARM code starts running. This is useful for bare metal/debug from very early on in linux. Once linux has booted then the UART will have been reconfigured and init_uart_baud will have been overwritten.

Currently you have to change
#define UART0_CLOCK 3000000
(to match init_uart_clock=) in arch/arm/mach-bcm2708/include/mach/platform.h
and rebuild kernel if you want a higher UART clock.

As a hack you can just increase init_uart_clock without telling linux. That means if init_uart_clock=6000000, and linux thinks it is 3000000, and you ask linux for 115200, you will actually get 230400 baud.

I did try reading the value from GPU (using mailbox interface), but the uart clock is given to kernel before the mailbox driver is initialised so it didn't prove simple.

@Stonie
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Stonie commented Sep 9, 2012

Thanks for the update.

I had spotted the value in platform.h but was hoping I had missed something, alas no.

I should be able to get away with fudging it for now, but clearly this is not a good long term solution?
How do you plan on implementing "init_uart_baud" from config?

Cheers,
Stonie.

@popcornmix
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init_uart_baud is implemented from config.txt. if you have bare metal OS, or use Linux before it has initialised the uart itself, you can write to the UART and it will output at the expected baud rate.

@Stonie
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Stonie commented Sep 9, 2012

Yeah I greped the entire source tree looking for the use of config.txt... this where I am confused...

What code consumes/owns config.txt?

Can config.txt's values be set in arch_decomp_setup(void) in arch/arm/mach-bcm2708/include/mach/uncompress.h ?

@popcornmix
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@Stonie
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Stonie commented Sep 9, 2012

OK it is clear to me now that config.txt belongs to the GPU boot sequence...

You mention above that "uart clock is given to kernel" if that’s the case why is it not "given" the value specified in config.txt? or is it? and then consequently overwritten by the value in platform.h?

@popcornmix
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bcm2708_init tells the kernel what the UART clock rate is. This is before mailbox driver is initialised so I can't ask the GPU what the actual UART frequency is at this point.
I need someone who knows the kernel init code better than me to say where this should be done.

@Stonie
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Stonie commented Sep 9, 2012

Ok, thanks for the update.

@Stonie
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Stonie commented Aug 22, 2013

@ghollingworth why is this marked as closed? I don't see a resolution? commit? or otherwise?

@ghollingworth
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No problem if you're still working on it, just going through tidying up issues that are dead

@ghollingworth ghollingworth reopened this Aug 22, 2013
@Stonie
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Stonie commented Aug 22, 2013

"Dead" --> pardon? If it's not fixed it's not fixed. So why on earth would you close it without a resolution?

** I spent days digging this one out **

I suspect that the stalling on the fix exists perhaps because GPU code is closed? and therefore not well understood?, Maybe It needs to wait till someone with the knowledge comes along... or Broardcom, actually embraces Open Source for the RPI and opens the GPU code... Or I could be completely wrong, either way its still an "Issue" until its fixed.

So please don't sweep this one under the carpet just yet.

@ghollingworth
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In general my method of handling issues is if they are very old with no progress I close them asking them to retest with the latest kernel. Then we can kick people to look into the issues again, it's nothing personal.

Dom has provided a uart_clock kernel parameter, does this fix the problem?

@ghollingworth
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Sorry pressed wrong button!!!

@mrshifo
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mrshifo commented Feb 24, 2014

Please,
i am a beginner with linux and rpi, can you help me step by step for set high speed baud rate ?

mrshifo at libero.it

uname -a
Linux raspberry 3.6.11+ #538 PREEMPT Fri Aug 30 20:42:08 BST 2013 armv6l GNU/Linux

popcornmix pushed a commit that referenced this issue Jun 8, 2014
…anges

Sasha reported the following bug using trinity

  kernel BUG at mm/mprotect.c:149!
  invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in:
  CPU: 20 PID: 26219 Comm: trinity-c216 Tainted: G        W    3.14.0-rc5-next-20140305-sasha-00011-ge06f5f3-dirty #105
  task: ffff8800b6c80000 ti: ffff880228436000 task.ti: ffff880228436000
  RIP: change_protection_range+0x3b3/0x500
  Call Trace:
    change_protection+0x25/0x30
    change_prot_numa+0x1b/0x30
    task_numa_work+0x279/0x360
    task_work_run+0xae/0xf0
    do_notify_resume+0x8e/0xe0
    retint_signal+0x4d/0x92

The VM_BUG_ON was added in -mm by the patch "mm,numa: reorganize
change_pmd_range".  The race existed without the patch but was just
harder to hit.

The problem is that a transhuge check is made without holding the PTL.
It's possible at the time of the check that a parallel fault clears the
pmd and inserts a new one which then triggers the VM_BUG_ON check.  This
patch removes the VM_BUG_ON but fixes the race by rechecking transhuge
under the PTL when marking page tables for NUMA hinting and bailing if a
race occurred.  It is not a problem for calls to mprotect() as they hold
mmap_sem for write.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
@Ruffio
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Ruffio commented Jul 28, 2016

@Stonie has this issue been resolved? If yes, then please close this issue.

@Ruffio
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Ruffio commented Aug 29, 2016

@popcornmix please consider closing this issue, as there haven't been any real activity since 2014 and I pinged for response a month ago...

@popcornmix
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We have increased the UART clock source which allows higher baud rates. See:
#1601
raspberrypi/firmware#643

popcornmix pushed a commit that referenced this issue Mar 23, 2020
On a system configured to trigger a crash_kexec() reboot, when only one CPU
is online and another CPU panics while starting-up, crash_smp_send_stop()
will fail to send any STOP message to the other already online core,
resulting in fail to freeze and registers not properly saved.

Moreover even if the proper messages are sent (case CPUs > 2)
it will similarly fail to account for the booting CPU when executing
the final stop wait-loop, so potentially resulting in some CPU not
been waited for shutdown before rebooting.

A tangible effect of this behaviour can be observed when, after a panic
with kexec enabled and loaded, on the following reboot triggered by kexec,
the cpu that could not be successfully stopped fails to come back online:

[  362.291022] ------------[ cut here ]------------
[  362.291525] kernel BUG at arch/arm64/kernel/cpufeature.c:886!
[  362.292023] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[  362.292400] Modules linked in:
[  362.292970] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Not tainted 5.6.0-rc4-00003-gc780b890948a #105
[  362.293136] Hardware name: Foundation-v8A (DT)
[  362.293382] pstate: 200001c5 (nzCv dAIF -PAN -UAO)
[  362.294063] pc : has_cpuid_feature+0xf0/0x348
[  362.294177] lr : verify_local_elf_hwcaps+0x84/0xe8
[  362.294280] sp : ffff800011b1bf60
[  362.294362] x29: ffff800011b1bf60 x28: 0000000000000000
[  362.294534] x27: 0000000000000000 x26: 0000000000000000
[  362.294631] x25: 0000000000000000 x24: ffff80001189a25c
[  362.294718] x23: 0000000000000000 x22: 0000000000000000
[  362.294803] x21: ffff8000114aa018 x20: ffff800011156a00
[  362.294897] x19: ffff800010c944a0 x18: 0000000000000004
[  362.294987] x17: 0000000000000000 x16: 0000000000000000
[  362.295073] x15: 00004e53b831ae3c x14: 00004e53b831ae3c
[  362.295165] x13: 0000000000000384 x12: 0000000000000000
[  362.295251] x11: 0000000000000000 x10: 00400032b5503510
[  362.295334] x9 : 0000000000000000 x8 : ffff800010c7e204
[  362.295426] x7 : 00000000410fd0f0 x6 : 0000000000000001
[  362.295508] x5 : 00000000410fd0f0 x4 : 0000000000000000
[  362.295592] x3 : 0000000000000000 x2 : ffff8000100939d8
[  362.295683] x1 : 0000000000180420 x0 : 0000000000180480
[  362.296011] Call trace:
[  362.296257]  has_cpuid_feature+0xf0/0x348
[  362.296350]  verify_local_elf_hwcaps+0x84/0xe8
[  362.296424]  check_local_cpu_capabilities+0x44/0x128
[  362.296497]  secondary_start_kernel+0xf4/0x188
[  362.296998] Code: 52805001 72a00301 6b01001f 54000ec0 (d4210000)
[  362.298652] SMP: stopping secondary CPUs
[  362.300615] Starting crashdump kernel...
[  362.301168] Bye!
[    0.000000] Booting Linux on physical CPU 0x0000000003 [0x410fd0f0]
[    0.000000] Linux version 5.6.0-rc4-00003-gc780b890948a (crimar01@e120937-lin) (gcc version 8.3.0 (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36))) #105 SMP PREEMPT Fri Mar 6 17:00:42 GMT 2020
[    0.000000] Machine model: Foundation-v8A
[    0.000000] earlycon: pl11 at MMIO 0x000000001c090000 (options '')
[    0.000000] printk: bootconsole [pl11] enabled
.....
[    0.138024] rcu: Hierarchical SRCU implementation.
[    0.153472] its@2f020000: unable to locate ITS domain
[    0.154078] its@2f020000: Unable to locate ITS domain
[    0.157541] EFI services will not be available.
[    0.175395] smp: Bringing up secondary CPUs ...
[    0.209182] psci: failed to boot CPU1 (-22)
[    0.209377] CPU1: failed to boot: -22
[    0.274598] Detected PIPT I-cache on CPU2
[    0.278707] GICv3: CPU2: found redistributor 1 region 0:0x000000002f120000
[    0.285212] CPU2: Booted secondary processor 0x0000000001 [0x410fd0f0]
[    0.369053] Detected PIPT I-cache on CPU3
[    0.372947] GICv3: CPU3: found redistributor 2 region 0:0x000000002f140000
[    0.378664] CPU3: Booted secondary processor 0x0000000002 [0x410fd0f0]
[    0.401707] smp: Brought up 1 node, 3 CPUs
[    0.404057] SMP: Total of 3 processors activated.

Make crash_smp_send_stop() account also for the online status of the
calling CPU while evaluating how many CPUs are effectively online: this way
the right number of STOPs is sent and all other stopped-cores's registers
are properly saved.

Fixes: 78fd584 ("arm64: kdump: implement machine_crash_shutdown()")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
popcornmix pushed a commit that referenced this issue Mar 26, 2020
commit f50b7da upstream.

On a system configured to trigger a crash_kexec() reboot, when only one CPU
is online and another CPU panics while starting-up, crash_smp_send_stop()
will fail to send any STOP message to the other already online core,
resulting in fail to freeze and registers not properly saved.

Moreover even if the proper messages are sent (case CPUs > 2)
it will similarly fail to account for the booting CPU when executing
the final stop wait-loop, so potentially resulting in some CPU not
been waited for shutdown before rebooting.

A tangible effect of this behaviour can be observed when, after a panic
with kexec enabled and loaded, on the following reboot triggered by kexec,
the cpu that could not be successfully stopped fails to come back online:

[  362.291022] ------------[ cut here ]------------
[  362.291525] kernel BUG at arch/arm64/kernel/cpufeature.c:886!
[  362.292023] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[  362.292400] Modules linked in:
[  362.292970] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Not tainted 5.6.0-rc4-00003-gc780b890948a #105
[  362.293136] Hardware name: Foundation-v8A (DT)
[  362.293382] pstate: 200001c5 (nzCv dAIF -PAN -UAO)
[  362.294063] pc : has_cpuid_feature+0xf0/0x348
[  362.294177] lr : verify_local_elf_hwcaps+0x84/0xe8
[  362.294280] sp : ffff800011b1bf60
[  362.294362] x29: ffff800011b1bf60 x28: 0000000000000000
[  362.294534] x27: 0000000000000000 x26: 0000000000000000
[  362.294631] x25: 0000000000000000 x24: ffff80001189a25c
[  362.294718] x23: 0000000000000000 x22: 0000000000000000
[  362.294803] x21: ffff8000114aa018 x20: ffff800011156a00
[  362.294897] x19: ffff800010c944a0 x18: 0000000000000004
[  362.294987] x17: 0000000000000000 x16: 0000000000000000
[  362.295073] x15: 00004e53b831ae3c x14: 00004e53b831ae3c
[  362.295165] x13: 0000000000000384 x12: 0000000000000000
[  362.295251] x11: 0000000000000000 x10: 00400032b5503510
[  362.295334] x9 : 0000000000000000 x8 : ffff800010c7e204
[  362.295426] x7 : 00000000410fd0f0 x6 : 0000000000000001
[  362.295508] x5 : 00000000410fd0f0 x4 : 0000000000000000
[  362.295592] x3 : 0000000000000000 x2 : ffff8000100939d8
[  362.295683] x1 : 0000000000180420 x0 : 0000000000180480
[  362.296011] Call trace:
[  362.296257]  has_cpuid_feature+0xf0/0x348
[  362.296350]  verify_local_elf_hwcaps+0x84/0xe8
[  362.296424]  check_local_cpu_capabilities+0x44/0x128
[  362.296497]  secondary_start_kernel+0xf4/0x188
[  362.296998] Code: 52805001 72a00301 6b01001f 54000ec0 (d4210000)
[  362.298652] SMP: stopping secondary CPUs
[  362.300615] Starting crashdump kernel...
[  362.301168] Bye!
[    0.000000] Booting Linux on physical CPU 0x0000000003 [0x410fd0f0]
[    0.000000] Linux version 5.6.0-rc4-00003-gc780b890948a (crimar01@e120937-lin) (gcc version 8.3.0 (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36))) #105 SMP PREEMPT Fri Mar 6 17:00:42 GMT 2020
[    0.000000] Machine model: Foundation-v8A
[    0.000000] earlycon: pl11 at MMIO 0x000000001c090000 (options '')
[    0.000000] printk: bootconsole [pl11] enabled
.....
[    0.138024] rcu: Hierarchical SRCU implementation.
[    0.153472] its@2f020000: unable to locate ITS domain
[    0.154078] its@2f020000: Unable to locate ITS domain
[    0.157541] EFI services will not be available.
[    0.175395] smp: Bringing up secondary CPUs ...
[    0.209182] psci: failed to boot CPU1 (-22)
[    0.209377] CPU1: failed to boot: -22
[    0.274598] Detected PIPT I-cache on CPU2
[    0.278707] GICv3: CPU2: found redistributor 1 region 0:0x000000002f120000
[    0.285212] CPU2: Booted secondary processor 0x0000000001 [0x410fd0f0]
[    0.369053] Detected PIPT I-cache on CPU3
[    0.372947] GICv3: CPU3: found redistributor 2 region 0:0x000000002f140000
[    0.378664] CPU3: Booted secondary processor 0x0000000002 [0x410fd0f0]
[    0.401707] smp: Brought up 1 node, 3 CPUs
[    0.404057] SMP: Total of 3 processors activated.

Make crash_smp_send_stop() account also for the online status of the
calling CPU while evaluating how many CPUs are effectively online: this way
the right number of STOPs is sent and all other stopped-cores's registers
are properly saved.

Fixes: 78fd584 ("arm64: kdump: implement machine_crash_shutdown()")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Mar 27, 2020
commit f50b7da upstream.

On a system configured to trigger a crash_kexec() reboot, when only one CPU
is online and another CPU panics while starting-up, crash_smp_send_stop()
will fail to send any STOP message to the other already online core,
resulting in fail to freeze and registers not properly saved.

Moreover even if the proper messages are sent (case CPUs > 2)
it will similarly fail to account for the booting CPU when executing
the final stop wait-loop, so potentially resulting in some CPU not
been waited for shutdown before rebooting.

A tangible effect of this behaviour can be observed when, after a panic
with kexec enabled and loaded, on the following reboot triggered by kexec,
the cpu that could not be successfully stopped fails to come back online:

[  362.291022] ------------[ cut here ]------------
[  362.291525] kernel BUG at arch/arm64/kernel/cpufeature.c:886!
[  362.292023] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[  362.292400] Modules linked in:
[  362.292970] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Not tainted 5.6.0-rc4-00003-gc780b890948a #105
[  362.293136] Hardware name: Foundation-v8A (DT)
[  362.293382] pstate: 200001c5 (nzCv dAIF -PAN -UAO)
[  362.294063] pc : has_cpuid_feature+0xf0/0x348
[  362.294177] lr : verify_local_elf_hwcaps+0x84/0xe8
[  362.294280] sp : ffff800011b1bf60
[  362.294362] x29: ffff800011b1bf60 x28: 0000000000000000
[  362.294534] x27: 0000000000000000 x26: 0000000000000000
[  362.294631] x25: 0000000000000000 x24: ffff80001189a25c
[  362.294718] x23: 0000000000000000 x22: 0000000000000000
[  362.294803] x21: ffff8000114aa018 x20: ffff800011156a00
[  362.294897] x19: ffff800010c944a0 x18: 0000000000000004
[  362.294987] x17: 0000000000000000 x16: 0000000000000000
[  362.295073] x15: 00004e53b831ae3c x14: 00004e53b831ae3c
[  362.295165] x13: 0000000000000384 x12: 0000000000000000
[  362.295251] x11: 0000000000000000 x10: 00400032b5503510
[  362.295334] x9 : 0000000000000000 x8 : ffff800010c7e204
[  362.295426] x7 : 00000000410fd0f0 x6 : 0000000000000001
[  362.295508] x5 : 00000000410fd0f0 x4 : 0000000000000000
[  362.295592] x3 : 0000000000000000 x2 : ffff8000100939d8
[  362.295683] x1 : 0000000000180420 x0 : 0000000000180480
[  362.296011] Call trace:
[  362.296257]  has_cpuid_feature+0xf0/0x348
[  362.296350]  verify_local_elf_hwcaps+0x84/0xe8
[  362.296424]  check_local_cpu_capabilities+0x44/0x128
[  362.296497]  secondary_start_kernel+0xf4/0x188
[  362.296998] Code: 52805001 72a00301 6b01001f 54000ec0 (d4210000)
[  362.298652] SMP: stopping secondary CPUs
[  362.300615] Starting crashdump kernel...
[  362.301168] Bye!
[    0.000000] Booting Linux on physical CPU 0x0000000003 [0x410fd0f0]
[    0.000000] Linux version 5.6.0-rc4-00003-gc780b890948a (crimar01@e120937-lin) (gcc version 8.3.0 (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36))) #105 SMP PREEMPT Fri Mar 6 17:00:42 GMT 2020
[    0.000000] Machine model: Foundation-v8A
[    0.000000] earlycon: pl11 at MMIO 0x000000001c090000 (options '')
[    0.000000] printk: bootconsole [pl11] enabled
.....
[    0.138024] rcu: Hierarchical SRCU implementation.
[    0.153472] its@2f020000: unable to locate ITS domain
[    0.154078] its@2f020000: Unable to locate ITS domain
[    0.157541] EFI services will not be available.
[    0.175395] smp: Bringing up secondary CPUs ...
[    0.209182] psci: failed to boot CPU1 (-22)
[    0.209377] CPU1: failed to boot: -22
[    0.274598] Detected PIPT I-cache on CPU2
[    0.278707] GICv3: CPU2: found redistributor 1 region 0:0x000000002f120000
[    0.285212] CPU2: Booted secondary processor 0x0000000001 [0x410fd0f0]
[    0.369053] Detected PIPT I-cache on CPU3
[    0.372947] GICv3: CPU3: found redistributor 2 region 0:0x000000002f140000
[    0.378664] CPU3: Booted secondary processor 0x0000000002 [0x410fd0f0]
[    0.401707] smp: Brought up 1 node, 3 CPUs
[    0.404057] SMP: Total of 3 processors activated.

Make crash_smp_send_stop() account also for the online status of the
calling CPU while evaluating how many CPUs are effectively online: this way
the right number of STOPs is sent and all other stopped-cores's registers
are properly saved.

Fixes: 78fd584 ("arm64: kdump: implement machine_crash_shutdown()")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Mar 27, 2020
commit f50b7da upstream.

On a system configured to trigger a crash_kexec() reboot, when only one CPU
is online and another CPU panics while starting-up, crash_smp_send_stop()
will fail to send any STOP message to the other already online core,
resulting in fail to freeze and registers not properly saved.

Moreover even if the proper messages are sent (case CPUs > 2)
it will similarly fail to account for the booting CPU when executing
the final stop wait-loop, so potentially resulting in some CPU not
been waited for shutdown before rebooting.

A tangible effect of this behaviour can be observed when, after a panic
with kexec enabled and loaded, on the following reboot triggered by kexec,
the cpu that could not be successfully stopped fails to come back online:

[  362.291022] ------------[ cut here ]------------
[  362.291525] kernel BUG at arch/arm64/kernel/cpufeature.c:886!
[  362.292023] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[  362.292400] Modules linked in:
[  362.292970] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Not tainted 5.6.0-rc4-00003-gc780b890948a #105
[  362.293136] Hardware name: Foundation-v8A (DT)
[  362.293382] pstate: 200001c5 (nzCv dAIF -PAN -UAO)
[  362.294063] pc : has_cpuid_feature+0xf0/0x348
[  362.294177] lr : verify_local_elf_hwcaps+0x84/0xe8
[  362.294280] sp : ffff800011b1bf60
[  362.294362] x29: ffff800011b1bf60 x28: 0000000000000000
[  362.294534] x27: 0000000000000000 x26: 0000000000000000
[  362.294631] x25: 0000000000000000 x24: ffff80001189a25c
[  362.294718] x23: 0000000000000000 x22: 0000000000000000
[  362.294803] x21: ffff8000114aa018 x20: ffff800011156a00
[  362.294897] x19: ffff800010c944a0 x18: 0000000000000004
[  362.294987] x17: 0000000000000000 x16: 0000000000000000
[  362.295073] x15: 00004e53b831ae3c x14: 00004e53b831ae3c
[  362.295165] x13: 0000000000000384 x12: 0000000000000000
[  362.295251] x11: 0000000000000000 x10: 00400032b5503510
[  362.295334] x9 : 0000000000000000 x8 : ffff800010c7e204
[  362.295426] x7 : 00000000410fd0f0 x6 : 0000000000000001
[  362.295508] x5 : 00000000410fd0f0 x4 : 0000000000000000
[  362.295592] x3 : 0000000000000000 x2 : ffff8000100939d8
[  362.295683] x1 : 0000000000180420 x0 : 0000000000180480
[  362.296011] Call trace:
[  362.296257]  has_cpuid_feature+0xf0/0x348
[  362.296350]  verify_local_elf_hwcaps+0x84/0xe8
[  362.296424]  check_local_cpu_capabilities+0x44/0x128
[  362.296497]  secondary_start_kernel+0xf4/0x188
[  362.296998] Code: 52805001 72a00301 6b01001f 54000ec0 (d4210000)
[  362.298652] SMP: stopping secondary CPUs
[  362.300615] Starting crashdump kernel...
[  362.301168] Bye!
[    0.000000] Booting Linux on physical CPU 0x0000000003 [0x410fd0f0]
[    0.000000] Linux version 5.6.0-rc4-00003-gc780b890948a (crimar01@e120937-lin) (gcc version 8.3.0 (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36))) #105 SMP PREEMPT Fri Mar 6 17:00:42 GMT 2020
[    0.000000] Machine model: Foundation-v8A
[    0.000000] earlycon: pl11 at MMIO 0x000000001c090000 (options '')
[    0.000000] printk: bootconsole [pl11] enabled
.....
[    0.138024] rcu: Hierarchical SRCU implementation.
[    0.153472] its@2f020000: unable to locate ITS domain
[    0.154078] its@2f020000: Unable to locate ITS domain
[    0.157541] EFI services will not be available.
[    0.175395] smp: Bringing up secondary CPUs ...
[    0.209182] psci: failed to boot CPU1 (-22)
[    0.209377] CPU1: failed to boot: -22
[    0.274598] Detected PIPT I-cache on CPU2
[    0.278707] GICv3: CPU2: found redistributor 1 region 0:0x000000002f120000
[    0.285212] CPU2: Booted secondary processor 0x0000000001 [0x410fd0f0]
[    0.369053] Detected PIPT I-cache on CPU3
[    0.372947] GICv3: CPU3: found redistributor 2 region 0:0x000000002f140000
[    0.378664] CPU3: Booted secondary processor 0x0000000002 [0x410fd0f0]
[    0.401707] smp: Brought up 1 node, 3 CPUs
[    0.404057] SMP: Total of 3 processors activated.

Make crash_smp_send_stop() account also for the online status of the
calling CPU while evaluating how many CPUs are effectively online: this way
the right number of STOPs is sent and all other stopped-cores's registers
are properly saved.

Fixes: 78fd584 ("arm64: kdump: implement machine_crash_shutdown()")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
herrnst pushed a commit to herrnst/linux-raspberrypi that referenced this issue Apr 19, 2022
On PREEMPT_RT kernel and KASAN is enabled.  the kasan_record_aux_stack()
may call alloc_pages(), and the rt-spinlock will be acquired, if currently
in atomic context, will trigger warning:

  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 239, name: bootlogd
  Preemption disabled at:
  [<ffffffffbab1a531>] rt_mutex_slowunlock+0xa1/0x4e0
  CPU: 3 PID: 239 Comm: bootlogd Tainted: G        W 5.17.1-rt17-yocto-preempt-rt+ raspberrypi#105
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
  Call Trace:
     __might_resched.cold+0x13b/0x173
     rt_spin_lock+0x5b/0xf0
     get_page_from_freelist+0x20c/0x1610
     __alloc_pages+0x25e/0x5e0
     __stack_depot_save+0x3c0/0x4a0
     kasan_save_stack+0x3a/0x50
     __kasan_record_aux_stack+0xb6/0xc0
     kasan_record_aux_stack+0xe/0x10
     irq_work_queue_on+0x6a/0x1c0
     pull_rt_task+0x631/0x6b0
     do_balance_callbacks+0x56/0x80
     __balance_callbacks+0x63/0x90
     rt_mutex_setprio+0x349/0x880
     rt_mutex_slowunlock+0x22a/0x4e0
     rt_spin_unlock+0x49/0x80
     uart_write+0x186/0x2b0
     do_output_char+0x2e9/0x3a0
     n_tty_write+0x306/0x800
     file_tty_write.isra.0+0x2af/0x450
     tty_write+0x22/0x30
     new_sync_write+0x27c/0x3a0
     vfs_write+0x3f7/0x5d0
     ksys_write+0xd9/0x180
     __x64_sys_write+0x43/0x50
     do_syscall_64+0x44/0x90
     entry_SYSCALL_64_after_hwframe+0x44/0xae

Fix it by using kasan_record_aux_stack_noalloc() to avoid the call to
alloc_pages().

Link: https://lkml.kernel.org/r/20220402142555.2699582-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
herrnst pushed a commit to herrnst/linux-raspberrypi that referenced this issue Apr 28, 2022
[ Upstream commit 25934fc ]

On PREEMPT_RT kernel and KASAN is enabled.  the kasan_record_aux_stack()
may call alloc_pages(), and the rt-spinlock will be acquired, if currently
in atomic context, will trigger warning:

  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 239, name: bootlogd
  Preemption disabled at:
  [<ffffffffbab1a531>] rt_mutex_slowunlock+0xa1/0x4e0
  CPU: 3 PID: 239 Comm: bootlogd Tainted: G        W 5.17.1-rt17-yocto-preempt-rt+ raspberrypi#105
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
  Call Trace:
     __might_resched.cold+0x13b/0x173
     rt_spin_lock+0x5b/0xf0
     get_page_from_freelist+0x20c/0x1610
     __alloc_pages+0x25e/0x5e0
     __stack_depot_save+0x3c0/0x4a0
     kasan_save_stack+0x3a/0x50
     __kasan_record_aux_stack+0xb6/0xc0
     kasan_record_aux_stack+0xe/0x10
     irq_work_queue_on+0x6a/0x1c0
     pull_rt_task+0x631/0x6b0
     do_balance_callbacks+0x56/0x80
     __balance_callbacks+0x63/0x90
     rt_mutex_setprio+0x349/0x880
     rt_mutex_slowunlock+0x22a/0x4e0
     rt_spin_unlock+0x49/0x80
     uart_write+0x186/0x2b0
     do_output_char+0x2e9/0x3a0
     n_tty_write+0x306/0x800
     file_tty_write.isra.0+0x2af/0x450
     tty_write+0x22/0x30
     new_sync_write+0x27c/0x3a0
     vfs_write+0x3f7/0x5d0
     ksys_write+0xd9/0x180
     __x64_sys_write+0x43/0x50
     do_syscall_64+0x44/0x90
     entry_SYSCALL_64_after_hwframe+0x44/0xae

Fix it by using kasan_record_aux_stack_noalloc() to avoid the call to
alloc_pages().

Link: https://lkml.kernel.org/r/20220402142555.2699582-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
0lxb pushed a commit to 0lxb/rpi_linux that referenced this issue Jan 30, 2024
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