[PATCH] powerpc64/kasan: Pass virtual addresses to kasan_init_phys_region()

[PATCH] powerpc64/kasan: Pass virtual addresses to kasan_init_phys_region()

[Benjamin Gray]

The kasan_init_phys_region() function maps shadow pages necessary for
the ranges of the linear map backed by physical pages. Currently
kasan_init_phys_region() is being passed physical addresses, but
kasan_mem_to_shadow() expects virtual addresses.

It works right now because the lower bits (12:64) of the
kasan_mem_to_shadow() calculation are the same for the real and virtual
addresses, so the actual PTE value is the same in the end. But virtual
addresses are the intended input, so fix it.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
---
 arch/powerpc/mm/kasan/init_book3e_64.c | 2 +-
 arch/powerpc/mm/kasan/init_book3s_64.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/kasan/init_book3e_64.c b/arch/powerpc/mm/kasan/init_book3e_64.c
index 11519e88dc6b..43c03b84ff32 100644
--- a/arch/powerpc/mm/kasan/init_book3e_64.c
+++ b/arch/powerpc/mm/kasan/init_book3e_64.c
@@ -112,7 +112,7 @@ void __init kasan_init(void)
 	pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL_RO);
 
 	for_each_mem_range(i, &start, &end)
-		kasan_init_phys_region((void *)start, (void *)end);
+		kasan_init_phys_region(phys_to_virt(start), phys_to_virt(end));
 
 	if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
 		kasan_remove_zero_shadow((void *)VMALLOC_START, VMALLOC_SIZE);
diff --git a/arch/powerpc/mm/kasan/init_book3s_64.c b/arch/powerpc/mm/kasan/init_book3s_64.c
index 9300d641cf9a..3fb5ce4f48f4 100644
--- a/arch/powerpc/mm/kasan/init_book3s_64.c
+++ b/arch/powerpc/mm/kasan/init_book3s_64.c
@@ -62,7 +62,7 @@ void __init kasan_init(void)
 	}
 
 	for_each_mem_range(i, &start, &end)
-		kasan_init_phys_region((void *)start, (void *)end);
+		kasan_init_phys_region(phys_to_virt(start), phys_to_virt(end));
 
 	for (i = 0; i < PTRS_PER_PTE; i++)
 		__set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page,
-- 
2.43.0

Re: [PATCH] powerpc64/kasan: Pass virtual addresses to kasan_init_phys_region()

[Michael Ellerman]

On Mon, 12 Feb 2024 15:50:20 +1100, Benjamin Gray wrote:
> The kasan_init_phys_region() function maps shadow pages necessary for
> the ranges of the linear map backed by physical pages. Currently
> kasan_init_phys_region() is being passed physical addresses, but
> kasan_mem_to_shadow() expects virtual addresses.
> 
> It works right now because the lower bits (12:64) of the
> kasan_mem_to_shadow() calculation are the same for the real and virtual
> addresses, so the actual PTE value is the same in the end. But virtual
> addresses are the intended input, so fix it.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc64/kasan: Pass virtual addresses to kasan_init_phys_region()
      https://git.kernel.org/powerpc/c/295454eda97b9c5f7a64ac5c2bb827fd15efb623

cheers