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authorChristophe Leroy <christophe.leroy@csgroup.eu>2021-06-29 05:36:43 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-29 20:53:49 +0300
commite17eae2b839937817d771e2f5d2b30e5e2b81bb7 (patch)
tree45cea23f133717e79fcd16c259a6aff0ab16fa8a /mm/pagewalk.c
parenta458b76a4171f893efa7657dc079924580a8746a (diff)
downloadlinux-e17eae2b839937817d771e2f5d2b30e5e2b81bb7.tar.xz
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>
Diffstat (limited to 'mm/pagewalk.c')
-rw-r--r--mm/pagewalk.c58
1 files changed, 53 insertions, 5 deletions
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index e81640d9f177..9b3db11a4d1d 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -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;