Re: [PATCH v1 06/46] powerpc/kasan: Refactor update of early shadow mappings

From: Christophe Leroy
Date: Thu Apr 02 2020 - 06:19:23 EST


Michael,

Le 16/03/2020 Ã 13:35, Christophe Leroy a ÃcritÂ:
kasan_remap_early_shadow_ro() and kasan_unmap_early_shadow_vmalloc()
are both updating the early shadow mapping: the first one sets
the mapping read-only while the other clears the mapping.

Refactor and create kasan_update_early_region()

There is a trivial conflict with this patch on powerpc/next.
Do you plan to take this series for 5.7 ? I so, I can repost the series now with the fix, or just this patch ?

Otherwise, what are your plans ? This series (Patches 18 and 19) will conflict with the 40x removal series as both do things about that PTE_ATOMIC_UPDATE stuff. Which series would go first ?

Thanks
Christophe


Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/mm/kasan/kasan_init_32.c | 39 +++++++++++++--------------
1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
index c9d053078c37..65fd8b891f8e 100644
--- a/arch/powerpc/mm/kasan/kasan_init_32.c
+++ b/arch/powerpc/mm/kasan/kasan_init_32.c
@@ -79,45 +79,42 @@ static int __init kasan_init_region(void *start, size_t size)
return 0;
}
-static void __init kasan_remap_early_shadow_ro(void)
+static void __init
+kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte)
{
- pgprot_t prot = kasan_prot_ro();
- unsigned long k_start = KASAN_SHADOW_START;
- unsigned long k_end = KASAN_SHADOW_END;
unsigned long k_cur;
phys_addr_t pa = __pa(kasan_early_shadow_page);
- kasan_populate_pte(kasan_early_shadow_pte, prot);
-
- for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
+ for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_ptr_k(k_cur);
pte_t *ptep = pte_offset_kernel(pmd, k_cur);
if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
continue;
- __set_pte_at(&init_mm, k_cur, ptep, pfn_pte(PHYS_PFN(pa), prot), 0);
+ __set_pte_at(&init_mm, k_cur, ptep, pte, 0);
}
- flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ flush_tlb_kernel_range(k_start, k_end);
}
-static void __init kasan_unmap_early_shadow_vmalloc(void)
+static void __init kasan_remap_early_shadow_ro(void)
{
- unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
- unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
- unsigned long k_cur;
+ pgprot_t prot = kasan_prot_ro();
phys_addr_t pa = __pa(kasan_early_shadow_page);
- for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
- pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
- pte_t *ptep = pte_offset_kernel(pmd, k_cur);
+ kasan_populate_pte(kasan_early_shadow_pte, prot);
- if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
- continue;
+ kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END,
+ pfn_pte(PHYS_PFN(pa), prot));
+}
- __set_pte_at(&init_mm, k_cur, ptep, __pte(0), 0);
- }
- flush_tlb_kernel_range(k_start, k_end);
+static void __init kasan_unmap_early_shadow_vmalloc(void)
+{
+ unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
+ unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
+
+ kasan_update_early_region(k_start, k_end, __pte(0));
}
static void __init kasan_mmu_init(void)