[PATCH v3] powerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc
From: Aneesh Kumar K.V <hidden>
Date: 2020-09-02 04:06:11
Subsystem:
documentation, linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
The test is broken w.r.t page table update rules and results in kernel
crash as below. Disable the support until we get the tests updated.
[ 21.083519] kernel BUG at arch/powerpc/mm/pgtable.c:304!
cpu 0x0: Vector: 700 (Program Check) at [c000000c6d1e76c0]
pc: c00000000009a5ec: assert_pte_locked+0x14c/0x380
lr: c0000000005eeeec: pte_update+0x11c/0x190
sp: c000000c6d1e7950
msr: 8000000002029033
current = 0xc000000c6d172c80
paca = 0xc000000003ba0000 irqmask: 0x03 irq_happened: 0x01
pid = 1, comm = swapper/0
kernel BUG at arch/powerpc/mm/pgtable.c:304!
[link register ] c0000000005eeeec pte_update+0x11c/0x190
[c000000c6d1e7950] 0000000000000001 (unreliable)
[c000000c6d1e79b0] c0000000005eee14 pte_update+0x44/0x190
[c000000c6d1e7a10] c000000001a2ca9c pte_advanced_tests+0x160/0x3d8
[c000000c6d1e7ab0] c000000001a2d4fc debug_vm_pgtable+0x7e8/0x1338
[c000000c6d1e7ba0] c0000000000116ec do_one_initcall+0xac/0x5f0
[c000000c6d1e7c80] c0000000019e4fac kernel_init_freeable+0x4dc/0x5a4
[c000000c6d1e7db0] c000000000012474 kernel_init+0x24/0x160
[c000000c6d1e7e20] c00000000000cbd0 ret_from_kernel_thread+0x5c/0x6c
With DEBUG_VM disabled
[ 20.530152] BUG: Kernel NULL pointer dereference on read at 0x00000000
[ 20.530183] Faulting instruction address: 0xc0000000000df330
cpu 0x33: Vector: 380 (Data SLB Access) at [c000000c6d19f700]
pc: c0000000000df330: memset+0x68/0x104
lr: c00000000009f6d8: hash__pmdp_huge_get_and_clear+0xe8/0x1b0
sp: c000000c6d19f990
msr: 8000000002009033
dar: 0
current = 0xc000000c6d177480
paca = 0xc00000001ec4f400 irqmask: 0x03 irq_happened: 0x01
pid = 1, comm = swapper/0
[link register ] c00000000009f6d8 hash__pmdp_huge_get_and_clear+0xe8/0x1b0
[c000000c6d19f990] c00000000009f748 hash__pmdp_huge_get_and_clear+0x158/0x1b0 (unreliable)
[c000000c6d19fa10] c0000000019ebf30 pmd_advanced_tests+0x1f0/0x378
[c000000c6d19fab0] c0000000019ed088 debug_vm_pgtable+0x79c/0x1244
[c000000c6d19fba0] c0000000000116ec do_one_initcall+0xac/0x5f0
[c000000c6d19fc80] c0000000019a4fac kernel_init_freeable+0x4dc/0x5a4
[c000000c6d19fdb0] c000000000012474 kernel_init+0x24/0x160
[c000000c6d19fe20] c00000000000cbd0 ret_from_kernel_thread+0x5c/0x6c
33:mon>
Signed-off-by: Aneesh Kumar K.V <redacted>
---
Documentation/features/debug/debug-vm-pgtable/arch-support.txt | 2 +-
arch/powerpc/Kconfig | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/Documentation/features/debug/debug-vm-pgtable/arch-support.txt b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt
index 53da483c8326..1c49723e7534 100644
--- a/Documentation/features/debug/debug-vm-pgtable/arch-support.txt
+++ b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt@@ -22,7 +22,7 @@ | nios2: | TODO | | openrisc: | TODO | | parisc: | TODO | - | powerpc: | ok | + | powerpc: | TODO | | riscv: | ok | | s390: | ok | | sh: | TODO |
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 65bed1fdeaad..787e829b6f25 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig@@ -116,7 +116,6 @@ config PPC # select ARCH_32BIT_OFF_T if PPC32 select ARCH_HAS_DEBUG_VIRTUAL - select ARCH_HAS_DEBUG_VM_PGTABLE select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FORTIFY_SOURCE
--
2.26.2