mainlining shenanigans
d0bab0c39e
On a system with only one CPU online, when another one CPU panics while
starting-up, smp_send_stop() will fail to send any STOP message to the
other already online core, resulting in a system still responsive and
alive at the end of the panic procedure.
[ 186.700083] CPU3: shutdown
[ 187.075462] CPU2: shutdown
[ 187.162869] CPU1: shutdown
[ 188.689998] ------------[ cut here ]------------
[ 188.691645] kernel BUG at arch/arm64/kernel/cpufeature.c:886!
[ 188.692079] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[ 188.692444] Modules linked in:
[ 188.693031] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.6.0-rc4-00001-g338d25c35a98 #104
[ 188.693175] Hardware name: Foundation-v8A (DT)
[ 188.693492] pstate: 200001c5 (nzCv dAIF -PAN -UAO)
[ 188.694183] pc : has_cpuid_feature+0xf0/0x348
[ 188.694311] lr : verify_local_elf_hwcaps+0x84/0xe8
[ 188.694410] sp : ffff800011b1bf60
[ 188.694536] x29: ffff800011b1bf60 x28: 0000000000000000
[ 188.694707] x27: 0000000000000000 x26: 0000000000000000
[ 188.694801] x25: 0000000000000000 x24: ffff80001189a25c
[ 188.694905] x23: 0000000000000000 x22: 0000000000000000
[ 188.694996] x21: ffff8000114aa018 x20: ffff800011156a38
[ 188.695089] x19: ffff800010c944a0 x18: 0000000000000004
[ 188.695187] x17: 0000000000000000 x16: 0000000000000000
[ 188.695280] x15: 0000249dbde5431e x14: 0262cbe497efa1fa
[ 188.695371] x13: 0000000000000002 x12: 0000000000002592
[ 188.695472] x11: 0000000000000080 x10: 00400032b5503510
[ 188.695572] x9 : 0000000000000000 x8 : ffff800010c80204
[ 188.695659] x7 : 00000000410fd0f0 x6 : 0000000000000001
[ 188.695750] x5 : 00000000410fd0f0 x4 : 0000000000000000
[ 188.695836] x3 : 0000000000000000 x2 : ffff8000100939d8
[ 188.695919] x1 : 0000000000180420 x0 : 0000000000180480
[ 188.696253] Call trace:
[ 188.696410] has_cpuid_feature+0xf0/0x348
[ 188.696504] verify_local_elf_hwcaps+0x84/0xe8
[ 188.696591] check_local_cpu_capabilities+0x44/0x128
[ 188.696666] secondary_start_kernel+0xf4/0x188
[ 188.697150] Code: 52805001 72a00301 6b01001f 54000ec0 (d4210000)
[ 188.698639] ---[ end trace 3f12ca47652f7b72 ]---
[ 188.699160] Kernel panic - not syncing: Attempted to kill the idle task!
[ 188.699546] Kernel Offset: disabled
[ 188.699828] CPU features: 0x00004,20c02008
[ 188.700012] Memory Limit: none
[ 188.700538] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---
[root@arch ~]# echo Helo
Helo
[root@arch ~]# cat /proc/cpuinfo | grep proce
processor : 0
Make 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, so enforcing a proper freeze of the system at the
end of panic even under the above conditions.
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.