On 09/01/2020 03:14 PM, Aneesh Kumar K.V wrote:
> 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 <aneesh.ku...@linux.ibm.com>
> ---
> arch/powerpc/Kconfig | 1 -
> 1 file changed, 1 deletion(-)
>
> 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
>
If support for powerpc is being dropped, please update the features file
here as well. They should be in sync.
Documentation/features/debug/debug-vm-pgtable/arch-support.txt
