From 16f22981b6d7ea6815d2e4527b82cac5e2f65c89 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 14 Feb 2024 13:29:23 +0100 Subject: arm64: ptdump: Disregard unaddressable VA space Configurations built with support for 52-bit virtual addressing can also run on CPUs that only support 48 bits of VA space, in which case only that part of swapper_pg_dir that represents the 48-bit addressable region is relevant, and everything else is ignored by the hardware. Our software pagetable walker has little in the way of input address validation, and so it will happily start a walk from an address that is not representable by the number of paging levels that are actually active, resulting in lots of bogus output from the page table dumper unless we take care to start at a valid address. So define the start address at runtime based on vabits_actual. Signed-off-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20240214122845.2033971-82-ardb+git@google.com Signed-off-by: Catalin Marinas --- arch/arm64/mm/ptdump.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c index 5f0849528ccf..16d0cf1d85c4 100644 --- a/arch/arm64/mm/ptdump.c +++ b/arch/arm64/mm/ptdump.c @@ -313,7 +313,6 @@ static void __init ptdump_initialize(void) static struct ptdump_info kernel_ptdump_info __ro_after_init = { .mm = &init_mm, - .base_addr = PAGE_OFFSET, }; void ptdump_check_wx(void) @@ -329,7 +328,7 @@ void ptdump_check_wx(void) .ptdump = { .note_page = note_page, .range = (struct ptdump_range[]) { - {PAGE_OFFSET, ~0UL}, + {_PAGE_OFFSET(vabits_actual), ~0UL}, {0, 0} } } @@ -370,6 +369,7 @@ static int __init ptdump_init(void) static struct addr_marker address_markers[ARRAY_SIZE(m)] __ro_after_init; kernel_ptdump_info.markers = memcpy(address_markers, m, sizeof(m)); + kernel_ptdump_info.base_addr = page_offset; ptdump_initialize(); ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); -- cgit v1.2.3