[PATCH v2 01/45] powerpc/kasan: Fix error detection on memory allocation

From: Christophe Leroy
Date: Wed May 06 2020 - 12:51:04 EST


In case (k_start & PAGE_MASK) doesn't equal (kstart), 'va' will never be
NULL allthough 'block' is NULL

Check the return of memblock_alloc() directly instead of
the resulting address in the loop.

Fixes: 509cd3f2b473 ("powerpc/32: Simplify KASAN init")
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/mm/kasan/kasan_init_32.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
index cbcad369fcb2..8b15fe09b967 100644
--- a/arch/powerpc/mm/kasan/kasan_init_32.c
+++ b/arch/powerpc/mm/kasan/kasan_init_32.c
@@ -76,15 +76,14 @@ static int __init kasan_init_region(void *start, size_t size)
return ret;

block = memblock_alloc(k_end - k_start, PAGE_SIZE);
+ if (!block)
+ return -ENOMEM;

for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_ptr_k(k_cur);
void *va = block + k_cur - k_start;
pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);

- if (!va)
- return -ENOMEM;
-
__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
}
flush_tlb_kernel_range(k_start, k_end);
--
2.25.0