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| author | Sven Schnelle <svens@linux.ibm.com> | 2023-07-26 12:10:19 +0300 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2023-07-27 14:10:56 +0300 |
| commit | edc1e4b6e26536868ef819a735e04a5b32c10589 (patch) | |
| tree | ca388ac3b3bb6331d2e5e91b9d435d8cb7a09585 /arch/s390 | |
| parent | 6eaae198076080886b9e7d57f4ae06fa782f90ef (diff) | |
| download | linux-edc1e4b6e26536868ef819a735e04a5b32c10589.tar.xz | |
s390/vmem: split pages when debug pagealloc is enabled
Since commit bb1520d581a3 ("s390/mm: start kernel with DAT enabled")
the kernel crashes early during boot when debug pagealloc is enabled:
mem auto-init: stack:off, heap alloc:off, heap free:off
addressing exception: 0005 ilc:2 [#1] SMP DEBUG_PAGEALLOC
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-09759-gc5666c912155 #630
[..]
Krnl Code: 00000000001325f6: ec5600248064 cgrj %r5,%r6,8,000000000013263e
00000000001325fc: eb880002000c srlg %r8,%r8,2
#0000000000132602: b2210051 ipte %r5,%r1,%r0,0
>0000000000132606: b90400d1 lgr %r13,%r1
000000000013260a: 41605008 la %r6,8(%r5)
000000000013260e: a7db1000 aghi %r13,4096
0000000000132612: b221006d ipte %r6,%r13,%r0,0
0000000000132616: e3d0d0000171 lay %r13,4096(%r13)
Call Trace:
__kernel_map_pages+0x14e/0x320
__free_pages_ok+0x23a/0x5a8)
free_low_memory_core_early+0x214/0x2c8
memblock_free_all+0x28/0x58
mem_init+0xb6/0x228
mm_core_init+0xb6/0x3b0
start_kernel+0x1d2/0x5a8
startup_continue+0x36/0x40
Kernel panic - not syncing: Fatal exception: panic_on_oops
This is caused by using large mappings on machines with EDAT1/EDAT2. Add
the code to split the mappings into 4k pages if debug pagealloc is enabled
by CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT or the debug_pagealloc kernel
command line option.
Fixes: bb1520d581a3 ("s390/mm: start kernel with DAT enabled")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/mm/vmem.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index b26649233d12..24a66670f5c3 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -763,6 +763,8 @@ void __init vmem_map_init(void) if (static_key_enabled(&cpu_has_bear)) set_memory_nx(0, 1); set_memory_nx(PAGE_SIZE, 1); + if (debug_pagealloc_enabled()) + set_memory_4k(0, ident_map_size >> PAGE_SHIFT); pr_info("Write protected kernel read-only data: %luk\n", (unsigned long)(__end_rodata - _stext) >> 10); |