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Code Issues Releases Wiki Activity

mm: pagewalk: fix walk for hugepage tables 

Pagewalk ignores hugepd entries and walk down the tables as if it was
traditionnal entries, leading to crazy result.

Add walk_hugepd_range() and use it to walk hugepage tables.

Link: https://lkml.kernel.org/r/38d04410700c8d02f28ba37e020b62c55d6f3d2c.1624597695.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Steven Price <steven.price@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Daniel Axtens <dja@axtens.net>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christophe Leroy 2021-06-28 19:36:43 -07:00 committed by Linus Torvalds
parent a458b76a41
commit e17eae2b83
1 changed files with 53 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
mm/pagewalk.c
View File

@ -58,6 +58,45 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
return err;
}
#ifdef CONFIG_ARCH_HAS_HUGEPD
static int walk_hugepd_range(hugepd_t *phpd, unsigned long addr,
unsigned long end, struct mm_walk *walk, int pdshift)
{
int err = 0;
const struct mm_walk_ops *ops = walk->ops;
int shift = hugepd_shift(*phpd);
int page_size = 1 << shift;
if (!ops->pte_entry)
return 0;
if (addr & (page_size - 1))
return 0;
for (;;) {
pte_t *pte;
spin_lock(&walk->mm->page_table_lock);
pte = hugepte_offset(*phpd, addr, pdshift);
err = ops->pte_entry(pte, addr, addr + page_size, walk);
spin_unlock(&walk->mm->page_table_lock);
if (err)
break;
if (addr >= end - page_size)
break;
addr += page_size;
}
return err;
}
#else
static int walk_hugepd_range(hugepd_t *phpd, unsigned long addr,
unsigned long end, struct mm_walk *walk, int pdshift)
{
return 0;
}
#endif
static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
@ -108,7 +147,10 @@ again:
goto again;
}
err = walk_pte_range(pmd, addr, next, walk);
if (is_hugepd(__hugepd(pmd_val(*pmd))))
err = walk_hugepd_range((hugepd_t *)pmd, addr, next, walk, PMD_SHIFT);
else
err = walk_pte_range(pmd, addr, next, walk);
if (err)
break;
} while (pmd++, addr = next, addr != end);
@ -157,7 +199,10 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
if (pud_none(*pud))
goto again;
err = walk_pmd_range(pud, addr, next, walk);
if (is_hugepd(__hugepd(pud_val(*pud))))
err = walk_hugepd_range((hugepd_t *)pud, addr, next, walk, PUD_SHIFT);
else
err = walk_pmd_range(pud, addr, next, walk);
if (err)
break;
} while (pud++, addr = next, addr != end);
@ -189,7 +234,9 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
if (err)
break;
}
if (ops->pud_entry || ops->pmd_entry || ops->pte_entry)
if (is_hugepd(__hugepd(p4d_val(*p4d))))
err = walk_hugepd_range((hugepd_t *)p4d, addr, next, walk, P4D_SHIFT);
else if (ops->pud_entry || ops->pmd_entry || ops->pte_entry)
err = walk_pud_range(p4d, addr, next, walk);
if (err)
break;
@ -224,8 +271,9 @@ static int walk_pgd_range(unsigned long addr, unsigned long end,
if (err)
break;
}
if (ops->p4d_entry || ops->pud_entry || ops->pmd_entry ||
ops->pte_entry)
if (is_hugepd(__hugepd(pgd_val(*pgd))))
err = walk_hugepd_range((hugepd_t *)pgd, addr, next, walk, PGDIR_SHIFT);
else if (ops->p4d_entry || ops->pud_entry || ops->pmd_entry || ops->pte_entry)
err = walk_p4d_range(pgd, addr, next, walk);
if (err)
break;