Re: KASAN debug kernel fails to boot at early stage when CONFIG_SMP=y is set (kernel 6.5-rc5, PowerMac G4 3,6)
From: Christophe Leroy <hidden>
Date: 2023-08-22 07:33:13
Le 18/08/2023 à 18:23, Erhard Furtner a écrit :
On Fri, 18 Aug 2023 15:47:38 +0000 Christophe Leroy [off-list ref] wrote:quoted
I'm wondering if the problem is just linked to the kernel being built with CONFIG_SMP or if it is the actual startup of a secondary CPU that cause the freeze. Please leave the btext_unmap() in place because I think it is important to keep it, and start the kernel with the following parameter: nr_cpus=1With btext_unmap() back and place and nr_cpus=1 set the freeze still happens after the 1st btext_unmap:129 on cold boots: [ 0.000000] printk: bootconsole [udbg0] enabled [ 0.000000] Total memory = 2048MB; using 4096kB for hash table [ 0.000000] mapin_ram:125 [ 0.000000] mmu_mapin_ram:169 0 30000000 1400000 2000000 [ 0.000000] __mmu_mapin_ram:146 0 1400000 [ 0.000000] __mmu_mapin_ram:155 1400000 [ 0.000000] __mmu_mapin_ram:146 1400000 30000000 [ 0.000000] __mmu_mapin_ram:155 20000000 [ 0.000000] __mapin_ram_chunk:107 20000000 30000000 [ 0.000000] __mapin_ram_chunk:117 [ 0.000000] mapin_ram:134 [ 0.000000] kasan_mmu_init:129 [ 0.000000] kasan_mmu_init:132 0 [ 0.000000] kasan_mmu_init:137 [ 0.000000] btext_unmap:129
Thanks, Can you replace the call to btext_unmap() by a call to btext_map() at the end of MMU_init() ? If that gives no interesting result, can you leave the call to btext_unmap() and add a call to btext_map() at the very begining of function start_kernel() in init/main.c (You may have to add a include of asm/btext.h) With that I hope we can see more stuff. Christophe