[PATCH 2/5] powerpc/ptdump: fix walk_pagetables() address mismatch
From: Christophe Leroy <hidden>
Date: 2019-08-14 12:36:13
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
walk_pagetables() always walk the entire pgdir from address 0 but considers PAGE_OFFSET or KERN_VIRT_START as the starting address of the walk, resulting in a possible mismatch in the displayed addresses. Ex: on PPC32, when KERN_VIRT_START was locally defined as PAGE_OFFSET, ptdump displayed 0x80000000 instead of 0xc0000000 for the first kernel page, because 0xc0000000 + 0xc0000000 = 0x80000000 Start the walk at st->start_address instead of starting at 0. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/mm/ptdump/ptdump.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 3ad64fc11419..74ff2bff4ea0 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c@@ -299,17 +299,15 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) static void walk_pagetables(struct pg_state *st) { - pgd_t *pgd = pgd_offset_k(0UL); unsigned int i; - unsigned long addr; - - addr = st->start_address; + unsigned long addr = st->start_address & PGDIR_MASK; + pgd_t *pgd = pgd_offset_k(addr); /* * Traverse the linux pagetable structure and dump pages that are in * the hash pagetable. */ - for (i = 0; i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) { + for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) { if (!pgd_none(*pgd) && !pgd_is_leaf(*pgd)) /* pgd exists */ walk_pud(st, pgd, addr);
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2.13.3