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riscv: mm: Remove the copy operation of pmd

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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: Chuanhua Han <hanchuanhua@oppo.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Chuanhua Han 2022-03-31 19:43:20 -07:00 committed by Palmer Dabbelt
parent 3123109284
commit 7da9ca3f5b
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GPG Key ID: 2E1319F35FBB1889
1 changed files with 3 additions and 7 deletions
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10
arch/riscv/mm/fault.c
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@ -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) static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
{ {
pgd_t *pgd, *pgd_k; pgd_t *pgd, *pgd_k;
pud_t *pud, *pud_k; pud_t *pud_k;
p4d_t *p4d, *p4d_k; p4d_t *p4d_k;
pmd_t *pmd, *pmd_k; pmd_t *pmd_k;
pte_t *pte_k; pte_t *pte_k;
int index; int index;
unsigned long pfn; 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); set_pgd(pgd, *pgd_k);
p4d = p4d_offset(pgd, addr);
p4d_k = p4d_offset(pgd_k, addr); p4d_k = p4d_offset(pgd_k, addr);
if (!p4d_present(*p4d_k)) { if (!p4d_present(*p4d_k)) {
no_context(regs, addr); no_context(regs, addr);
return; return;
} }
pud = pud_offset(p4d, addr);
pud_k = pud_offset(p4d_k, addr); pud_k = pud_offset(p4d_k, addr);
if (!pud_present(*pud_k)) { if (!pud_present(*pud_k)) {
no_context(regs, addr); 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 * Since the vmalloc area is global, it is unnecessary
* to copy individual PTEs * to copy individual PTEs
*/ */
pmd = pmd_offset(pud, addr);
pmd_k = pmd_offset(pud_k, addr); pmd_k = pmd_offset(pud_k, addr);
if (!pmd_present(*pmd_k)) { if (!pmd_present(*pmd_k)) {
no_context(regs, addr); no_context(regs, addr);
return; return;
} }
set_pmd(pmd, *pmd_k);
/* /*
* Make sure the actual PTE exists as well to * Make sure the actual PTE exists as well to