| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20200508144043.13893-3-joro@8bytes.org>
Date: Fri, 8 May 2020 16:40:38 +0200
From: Joerg Roedel <joro@...tes.org>
To: x86@...nel.org
Cc: hpa@...or.com, Dave Hansen <dave.hansen@...ux.intel.com>,
Andy Lutomirski <luto@...nel.org>,
Peter Zijlstra <peterz@...radead.org>, rjw@...ysocki.net,
Arnd Bergmann <arnd@...db.de>,
Andrew Morton <akpm@...ux-foundation.org>,
Steven Rostedt <rostedt@...dmis.org>,
Vlastimil Babka <vbabka@...e.cz>,
Michal Hocko <mhocko@...nel.org>,
Joerg Roedel <jroedel@...e.de>, joro@...tes.org,
linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org,
linux-arch@...r.kernel.org, linux-mm@...ck.org
Subject: [RFC PATCH 2/7] mm/vmalloc: Track which page-table levels were modified
From: Joerg Roedel <jroedel@...e.de>
Track at which levels in the page-table entries were modified by
vmap/vunmap. After the page-table has been modified, use that
information do decide whether the new arch_sync_kernel_mappings()
needs to be called.
Signed-off-by: Joerg Roedel <jroedel@...e.de>
---
include/linux/vmalloc.h | 11 ++++++
mm/vmalloc.c | 88 ++++++++++++++++++++++++++++++-----------
2 files changed, 75 insertions(+), 24 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index a95d3cc74d79..eb364000cb03 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -144,6 +144,17 @@ extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
void vmalloc_sync_mappings(void);
void vmalloc_sync_unmappings(void);
+/*
+ * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values
+ * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings()
+ * needs to be called.
+ */
+#ifndef ARCH_PAGE_TABLE_SYNC_MASK
+#define ARCH_PAGE_TABLE_SYNC_MASK 0
+#endif
+
+void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
+
/*
* Lowlevel-APIs (not for driver use!)
*/
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 9a8227afa073..184f5a556cf7 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -69,7 +69,8 @@ static void free_work(struct work_struct *w)
/*** Page table manipulation functions ***/
-static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
+static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+ pgtbl_mod_mask *mask)
{
pte_t *pte;
@@ -78,73 +79,104 @@ static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
WARN_ON(!pte_none(ptent) && !pte_present(ptent));
} while (pte++, addr += PAGE_SIZE, addr != end);
+ *mask |= PGTBL_PTE_MODIFIED;
}
-static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
+static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
+ pgtbl_mod_mask *mask)
{
pmd_t *pmd;
unsigned long next;
+ int cleared;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
- if (pmd_clear_huge(pmd))
+
+ cleared = pmd_clear_huge(pmd);
+ if (cleared || pmd_bad(*pmd))
+ *mask |= PGTBL_PMD_MODIFIED;
+
+ if (cleared)
continue;
if (pmd_none_or_clear_bad(pmd))
continue;
- vunmap_pte_range(pmd, addr, next);
+ vunmap_pte_range(pmd, addr, next, mask);
} while (pmd++, addr = next, addr != end);
}
-static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end)
+static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
+ pgtbl_mod_mask *mask)
{
pud_t *pud;
unsigned long next;
+ int cleared;
pud = pud_offset(p4d, addr);
do {
next = pud_addr_end(addr, end);
- if (pud_clear_huge(pud))
+
+ cleared = pud_clear_huge(pud);
+ if (cleared || pud_bad(*pud))
+ *mask |= PGTBL_PUD_MODIFIED;
+
+ if (cleared)
continue;
if (pud_none_or_clear_bad(pud))
continue;
- vunmap_pmd_range(pud, addr, next);
+ vunmap_pmd_range(pud, addr, next, mask);
} while (pud++, addr = next, addr != end);
}
-static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end)
+static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
+ pgtbl_mod_mask *mask)
{
p4d_t *p4d;
unsigned long next;
+ int cleared;
p4d = p4d_offset(pgd, addr);
do {
next = p4d_addr_end(addr, end);
- if (p4d_clear_huge(p4d))
+
+ cleared = p4d_clear_huge(p4d);
+ if (cleared || p4d_bad(*p4d))
+ *mask |= PGTBL_P4D_MODIFIED;
+
+ if (cleared)
continue;
if (p4d_none_or_clear_bad(p4d))
continue;
- vunmap_pud_range(p4d, addr, next);
+ vunmap_pud_range(p4d, addr, next, mask);
} while (p4d++, addr = next, addr != end);
}
-static void vunmap_page_range(unsigned long addr, unsigned long end)
+static void vunmap_page_range(unsigned long start, unsigned long end)
{
pgd_t *pgd;
+ unsigned long addr = start;
unsigned long next;
+ pgtbl_mod_mask mask = 0;
BUG_ON(addr >= end);
+ start = addr;
pgd = pgd_offset_k(addr);
do {
next = pgd_addr_end(addr, end);
+ if (pgd_bad(*pgd))
+ mask |= PGTBL_PGD_MODIFIED;
if (pgd_none_or_clear_bad(pgd))
continue;
- vunmap_p4d_range(pgd, addr, next);
+ vunmap_p4d_range(pgd, addr, next, &mask);
} while (pgd++, addr = next, addr != end);
+
+ if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
+ arch_sync_kernel_mappings(start, end);
}
static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
- unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+ pgtbl_mod_mask *mask)
{
pte_t *pte;
@@ -153,7 +185,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
* callers keep track of where we're up to.
*/
- pte = pte_alloc_kernel(pmd, addr);
+ pte = pte_alloc_kernel_track(pmd, addr, mask);
if (!pte)
return -ENOMEM;
do {
@@ -166,55 +198,59 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
(*nr)++;
} while (pte++, addr += PAGE_SIZE, addr != end);
+ *mask |= PGTBL_PTE_MODIFIED;
return 0;
}
static int vmap_pmd_range(pud_t *pud, unsigned long addr,
- unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+ pgtbl_mod_mask *mask)
{
pmd_t *pmd;
unsigned long next;
- pmd = pmd_alloc(&init_mm, pud, addr);
+ pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
if (!pmd)
return -ENOMEM;
do {
next = pmd_addr_end(addr, end);
- if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
+ if (vmap_pte_range(pmd, addr, next, prot, pages, nr, mask))
return -ENOMEM;
} while (pmd++, addr = next, addr != end);
return 0;
}
static int vmap_pud_range(p4d_t *p4d, unsigned long addr,
- unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+ pgtbl_mod_mask *mask)
{
pud_t *pud;
unsigned long next;
- pud = pud_alloc(&init_mm, p4d, addr);
+ pud = pud_alloc_track(&init_mm, p4d, addr, mask);
if (!pud)
return -ENOMEM;
do {
next = pud_addr_end(addr, end);
- if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
+ if (vmap_pmd_range(pud, addr, next, prot, pages, nr, mask))
return -ENOMEM;
} while (pud++, addr = next, addr != end);
return 0;
}
static int vmap_p4d_range(pgd_t *pgd, unsigned long addr,
- unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+ pgtbl_mod_mask *mask)
{
p4d_t *p4d;
unsigned long next;
- p4d = p4d_alloc(&init_mm, pgd, addr);
+ p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
if (!p4d)
return -ENOMEM;
do {
next = p4d_addr_end(addr, end);
- if (vmap_pud_range(p4d, addr, next, prot, pages, nr))
+ if (vmap_pud_range(p4d, addr, next, prot, pages, nr, mask))
return -ENOMEM;
} while (p4d++, addr = next, addr != end);
return 0;
@@ -234,16 +270,20 @@ static int vmap_page_range_noflush(unsigned long start, unsigned long end,
unsigned long addr = start;
int err = 0;
int nr = 0;
+ pgtbl_mod_mask mask = 0;
BUG_ON(addr >= end);
pgd = pgd_offset_k(addr);
do {
next = pgd_addr_end(addr, end);
- err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr);
+ err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
if (err)
return err;
} while (pgd++, addr = next, addr != end);
+ if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
+ arch_sync_kernel_mappings(start, end);
+
return nr;
}
--
2.17.1
Powered by blists - more mailing lists