Unverified Commit 2da073c1 authored by Alexandre Ghiti's avatar Alexandre Ghiti Committed by Palmer Dabbelt
Browse files

riscv: Cleanup KASAN_VMALLOC support 



When KASAN vmalloc region is populated, there is no userspace process and
the page table in use is swapper_pg_dir, so there is no need to read
SATP. Then we can use the same scheme used by kasan_populate_p*d
functions to go through the page table, which harmonizes the code.

In addition, make use of set_pgd that goes through all unused page table
levels, contrary to p*d_populate functions, which makes this function work
whatever the number of page table levels.

Signed-off-by: default avatarAlexandre Ghiti <alex@ghiti.fr>
Reviewed-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent f35bb4b8

arch/riscv/mm/kasan_init.c

+18 −41
Original line number Diff line number Diff line
@@ -11,18 +11,6 @@ 
#include <asm/fixmap.h>

#include <asm/pgalloc.h>



static __init void *early_alloc(size_t size, int node)

{

	void *ptr = memblock_alloc_try_nid(size, size,

		__pa(MAX_DMA_ADDRESS), MEMBLOCK_ALLOC_ACCESSIBLE, node);



	if (!ptr)

		panic("%pS: Failed to allocate %zu bytes align=%zx nid=%d from=%llx\n",

			__func__, size, size, node, (u64)__pa(MAX_DMA_ADDRESS));



	return ptr;

}



extern pgd_t early_pg_dir[PTRS_PER_PGD];

asmlinkage void __init kasan_early_init(void)

{
@@ -155,38 +143,27 @@ static void __init kasan_populate(void *start, void *end) 
	memset(start, KASAN_SHADOW_INIT, end - start);

}



void __init kasan_shallow_populate(void *start, void *end)

static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end)

{

	unsigned long vaddr = (unsigned long)start & PAGE_MASK;

	unsigned long vend = PAGE_ALIGN((unsigned long)end);

	unsigned long pfn;

	int index;

	unsigned long next;

	void *p;

	pud_t *pud_dir, *pud_k;

	pgd_t *pgd_dir, *pgd_k;

	p4d_t *p4d_dir, *p4d_k;



	while (vaddr < vend) {

		index = pgd_index(vaddr);

		pfn = csr_read(CSR_SATP) & SATP_PPN;

		pgd_dir = (pgd_t *)pfn_to_virt(pfn) + index;

		pgd_k = init_mm.pgd + index;

		pgd_dir = pgd_offset_k(vaddr);

		set_pgd(pgd_dir, *pgd_k);



		p4d_dir = p4d_offset(pgd_dir, vaddr);

		p4d_k  = p4d_offset(pgd_k, vaddr);



		vaddr = (vaddr + PUD_SIZE) & PUD_MASK;

		pud_dir = pud_offset(p4d_dir, vaddr);

		pud_k = pud_offset(p4d_k, vaddr);



		if (pud_present(*pud_dir)) {

			p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);

			pud_populate(&init_mm, pud_dir, p);

	pgd_t *pgd_k = pgd_offset_k(vaddr);



	do {

		next = pgd_addr_end(vaddr, end);

		if (pgd_page_vaddr(*pgd_k) == (unsigned long)lm_alias(kasan_early_shadow_pmd)) {

			p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);

			set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));

		}

		vaddr += PAGE_SIZE;

	} while (pgd_k++, vaddr = next, vaddr != end);

}



static void __init kasan_shallow_populate(void *start, void *end)

{

	unsigned long vaddr = (unsigned long)start & PAGE_MASK;

	unsigned long vend = PAGE_ALIGN((unsigned long)end);



	kasan_shallow_populate_pgd(vaddr, vend);

}



void __init kasan_init(void)