Unverified Commit 7da9ca3f authored by Chuanhua Han's avatar Chuanhua Han Committed by Palmer Dabbelt
Browse files

riscv: mm: Remove the copy operation of pmd 



Since all processes share the kernel address space,
we only need to copy pgd in case of a vmalloc page
fault exception, the other levels of page tables are
shared, so the operation of copying pmd is unnecessary.

Signed-off-by: default avatarChuanhua Han <hanchuanhua@oppo.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 31231092

arch/riscv/mm/fault.c

+3 −7
Original line number Diff line number Diff line
@@ -102,9 +102,9 @@ static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code 
static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)

{

	pgd_t *pgd, *pgd_k;

	pud_t *pud, *pud_k;

	p4d_t *p4d, *p4d_k;

	pmd_t *pmd, *pmd_k;

	pud_t *pud_k;

	p4d_t *p4d_k;

	pmd_t *pmd_k;

	pte_t *pte_k;

	int index;

	unsigned long pfn;
@@ -132,14 +132,12 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a 
	}

	set_pgd(pgd, *pgd_k);



	p4d = p4d_offset(pgd, addr);

	p4d_k = p4d_offset(pgd_k, addr);

	if (!p4d_present(*p4d_k)) {

		no_context(regs, addr);

		return;

	}



	pud = pud_offset(p4d, addr);

	pud_k = pud_offset(p4d_k, addr);

	if (!pud_present(*pud_k)) {

		no_context(regs, addr);
@@ -150,13 +148,11 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a 
	 * Since the vmalloc area is global, it is unnecessary

	 * to copy individual PTEs

	 */

	pmd = pmd_offset(pud, addr);

	pmd_k = pmd_offset(pud_k, addr);

	if (!pmd_present(*pmd_k)) {

		no_context(regs, addr);

		return;

	}

	set_pmd(pmd, *pmd_k);



	/*

	 * Make sure the actual PTE exists as well to