linux_dsm_epyc7002/arch/parisc/mm
Helge Deller bf71bc16e0 parisc: Fix kernel panic in mem_init()
The Debian kernel v5.6 triggers this kernel panic:

 Kernel panic - not syncing: Bad Address (null pointer deref?)
 Bad Address (null pointer deref?): Code=26 (Data memory access rights trap) at addr 0000000000000000
 CPU: 0 PID: 0 Comm: swapper Not tainted 5.6.0-2-parisc64 #1 Debian 5.6.14-1
  IAOQ[0]: mem_init+0xb0/0x150
  IAOQ[1]: mem_init+0xb4/0x150
  RP(r2): start_kernel+0x6c8/0x1190
 Backtrace:
  [<0000000040101ab4>] start_kernel+0x6c8/0x1190
  [<0000000040108574>] start_parisc+0x158/0x1b8

on a HP-PARISC rp3440 machine with this memory layout:
 Memory Ranges:
  0) Start 0x0000000000000000 End 0x000000003fffffff Size   1024 MB
  1) Start 0x0000004040000000 End 0x00000040ffdfffff Size   3070 MB

Fix the crash by avoiding virt_to_page() and similar functions in
mem_init() until the memory zones have been fully set up.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.0+
2020-05-29 15:47:55 +02:00
..
fault.c mm: allow VM_FAULT_RETRY for multiple times 2020-04-02 09:35:30 -07:00
fixmap.c parisc: use pgtable-nopXd instead of 4level-fixup 2019-12-04 19:44:15 -08:00
hugetlbpage.c parisc/hugetlb: use pgtable-nopXd instead of 4level-fixup 2019-12-04 19:44:15 -08:00
init.c parisc: Fix kernel panic in mem_init() 2020-05-29 15:47:55 +02:00
ioremap.c parisc: remove __ioremap 2019-11-11 17:19:49 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00