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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-07 14:11:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-07 14:11:54 -0700
commit63bef48fd6c9d3f1ba4f0e23b4da1e007db6a3c0 (patch)
treef27c1ea7686b2ee30eea6b973a430f1c102bb03f /mm/mprotect.c
parent04de788e61a576820baf03ff8accc246ca146cb3 (diff)
parent1cd377baa91844b9f87a2b72eabf7ff783946b5e (diff)
downloadnet-63bef48fd6c9d3f1ba4f0e23b4da1e007db6a3c0.tar.gz
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton: - a lot more of MM, quite a bit more yet to come: (memcg, pagemap, vmalloc, pagealloc, migration, thp, ksm, madvise, virtio, userfaultfd, memory-hotplug, shmem, rmap, zswap, zsmalloc, cleanups) - various other subsystems (procfs, misc, MAINTAINERS, bitops, lib, checkpatch, epoll, binfmt, kallsyms, reiserfs, kmod, gcov, kconfig, ubsan, fault-injection, ipc) * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (158 commits) ipc/shm.c: make compat_ksys_shmctl() static ipc/mqueue.c: fix a brace coding style issue lib/Kconfig.debug: fix a typo "capabilitiy" -> "capability" ubsan: include bug type in report header kasan: unset panic_on_warn before calling panic() ubsan: check panic_on_warn drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks ubsan: split "bounds" checker from other options ubsan: add trap instrumentation option init/Kconfig: clean up ANON_INODES and old IO schedulers options kernel/gcov/fs.c: replace zero-length array with flexible-array member gcov: gcc_3_4: replace zero-length array with flexible-array member gcov: gcc_4_7: replace zero-length array with flexible-array member kernel/kmod.c: fix a typo "assuems" -> "assumes" reiserfs: clean up several indentation issues kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() samples/hw_breakpoint: drop use of kallsyms_lookup_name() samples/hw_breakpoint: drop HW_BREAKPOINT_R when reporting writes fs/binfmt_elf.c: don't free interpreter's ELF pheaders on common path fs/binfmt_elf.c: allocate less for static executable ...
Diffstat (limited to 'mm/mprotect.c')
-rw-r--r--mm/mprotect.c76
1 files changed, 51 insertions, 25 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 311c0dadf71c9f..1d823b0503299b 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -37,12 +37,16 @@
static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end, pgprot_t newprot,
- int dirty_accountable, int prot_numa)
+ unsigned long cp_flags)
{
pte_t *pte, oldpte;
spinlock_t *ptl;
unsigned long pages = 0;
int target_node = NUMA_NO_NODE;
+ bool dirty_accountable = cp_flags & MM_CP_DIRTY_ACCT;
+ bool prot_numa = cp_flags & MM_CP_PROT_NUMA;
+ bool uffd_wp = cp_flags & MM_CP_UFFD_WP;
+ bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE;
/*
* Can be called with only the mmap_sem for reading by
@@ -98,7 +102,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
* it cannot move them all from MIGRATE_ASYNC
* context.
*/
- if (page_is_file_cache(page) && PageDirty(page))
+ if (page_is_file_lru(page) && PageDirty(page))
continue;
/*
@@ -114,6 +118,19 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
if (preserve_write)
ptent = pte_mk_savedwrite(ptent);
+ if (uffd_wp) {
+ ptent = pte_wrprotect(ptent);
+ ptent = pte_mkuffd_wp(ptent);
+ } else if (uffd_wp_resolve) {
+ /*
+ * Leave the write bit to be handled
+ * by PF interrupt handler, then
+ * things like COW could be properly
+ * handled.
+ */
+ ptent = pte_clear_uffd_wp(ptent);
+ }
+
/* Avoid taking write faults for known dirty pages */
if (dirty_accountable && pte_dirty(ptent) &&
(pte_soft_dirty(ptent) ||
@@ -122,11 +139,11 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
}
ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent);
pages++;
- } else if (IS_ENABLED(CONFIG_MIGRATION)) {
+ } else if (is_swap_pte(oldpte)) {
swp_entry_t entry = pte_to_swp_entry(oldpte);
+ pte_t newpte;
if (is_write_migration_entry(entry)) {
- pte_t newpte;
/*
* A protection check is difficult so
* just be safe and disable write
@@ -135,22 +152,28 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
newpte = swp_entry_to_pte(entry);
if (pte_swp_soft_dirty(oldpte))
newpte = pte_swp_mksoft_dirty(newpte);
- set_pte_at(vma->vm_mm, addr, pte, newpte);
-
- pages++;
- }
-
- if (is_write_device_private_entry(entry)) {
- pte_t newpte;
-
+ if (pte_swp_uffd_wp(oldpte))
+ newpte = pte_swp_mkuffd_wp(newpte);
+ } else if (is_write_device_private_entry(entry)) {
/*
* We do not preserve soft-dirtiness. See
* copy_one_pte() for explanation.
*/
make_device_private_entry_read(&entry);
newpte = swp_entry_to_pte(entry);
- set_pte_at(vma->vm_mm, addr, pte, newpte);
+ if (pte_swp_uffd_wp(oldpte))
+ newpte = pte_swp_mkuffd_wp(newpte);
+ } else {
+ newpte = oldpte;
+ }
+
+ if (uffd_wp)
+ newpte = pte_swp_mkuffd_wp(newpte);
+ else if (uffd_wp_resolve)
+ newpte = pte_swp_clear_uffd_wp(newpte);
+ if (!pte_same(oldpte, newpte)) {
+ set_pte_at(vma->vm_mm, addr, pte, newpte);
pages++;
}
}
@@ -188,7 +211,7 @@ static inline int pmd_none_or_clear_bad_unless_trans_huge(pmd_t *pmd)
static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
pud_t *pud, unsigned long addr, unsigned long end,
- pgprot_t newprot, int dirty_accountable, int prot_numa)
+ pgprot_t newprot, unsigned long cp_flags)
{
pmd_t *pmd;
unsigned long next;
@@ -229,7 +252,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
__split_huge_pmd(vma, pmd, addr, false, NULL);
} else {
int nr_ptes = change_huge_pmd(vma, pmd, addr,
- newprot, prot_numa);
+ newprot, cp_flags);
if (nr_ptes) {
if (nr_ptes == HPAGE_PMD_NR) {
@@ -244,7 +267,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
/* fall through, the trans huge pmd just split */
}
this_pages = change_pte_range(vma, pmd, addr, next, newprot,
- dirty_accountable, prot_numa);
+ cp_flags);
pages += this_pages;
next:
cond_resched();
@@ -260,7 +283,7 @@ next:
static inline unsigned long change_pud_range(struct vm_area_struct *vma,
p4d_t *p4d, unsigned long addr, unsigned long end,
- pgprot_t newprot, int dirty_accountable, int prot_numa)
+ pgprot_t newprot, unsigned long cp_flags)
{
pud_t *pud;
unsigned long next;
@@ -272,7 +295,7 @@ static inline unsigned long change_pud_range(struct vm_area_struct *vma,
if (pud_none_or_clear_bad(pud))
continue;
pages += change_pmd_range(vma, pud, addr, next, newprot,
- dirty_accountable, prot_numa);
+ cp_flags);
} while (pud++, addr = next, addr != end);
return pages;
@@ -280,7 +303,7 @@ static inline unsigned long change_pud_range(struct vm_area_struct *vma,
static inline unsigned long change_p4d_range(struct vm_area_struct *vma,
pgd_t *pgd, unsigned long addr, unsigned long end,
- pgprot_t newprot, int dirty_accountable, int prot_numa)
+ pgprot_t newprot, unsigned long cp_flags)
{
p4d_t *p4d;
unsigned long next;
@@ -292,7 +315,7 @@ static inline unsigned long change_p4d_range(struct vm_area_struct *vma,
if (p4d_none_or_clear_bad(p4d))
continue;
pages += change_pud_range(vma, p4d, addr, next, newprot,
- dirty_accountable, prot_numa);
+ cp_flags);
} while (p4d++, addr = next, addr != end);
return pages;
@@ -300,7 +323,7 @@ static inline unsigned long change_p4d_range(struct vm_area_struct *vma,
static unsigned long change_protection_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end, pgprot_t newprot,
- int dirty_accountable, int prot_numa)
+ unsigned long cp_flags)
{
struct mm_struct *mm = vma->vm_mm;
pgd_t *pgd;
@@ -317,7 +340,7 @@ static unsigned long change_protection_range(struct vm_area_struct *vma,
if (pgd_none_or_clear_bad(pgd))
continue;
pages += change_p4d_range(vma, pgd, addr, next, newprot,
- dirty_accountable, prot_numa);
+ cp_flags);
} while (pgd++, addr = next, addr != end);
/* Only flush the TLB if we actually modified any entries: */
@@ -330,14 +353,17 @@ static unsigned long change_protection_range(struct vm_area_struct *vma,
unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgprot_t newprot,
- int dirty_accountable, int prot_numa)
+ unsigned long cp_flags)
{
unsigned long pages;
+ BUG_ON((cp_flags & MM_CP_UFFD_WP_ALL) == MM_CP_UFFD_WP_ALL);
+
if (is_vm_hugetlb_page(vma))
pages = hugetlb_change_protection(vma, start, end, newprot);
else
- pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa);
+ pages = change_protection_range(vma, start, end, newprot,
+ cp_flags);
return pages;
}
@@ -459,7 +485,7 @@ success:
vma_set_page_prot(vma);
change_protection(vma, start, end, vma->vm_page_prot,
- dirty_accountable, 0);
+ dirty_accountable ? MM_CP_DIRTY_ACCT : 0);
/*
* Private VM_LOCKED VMA becoming writable: trigger COW to avoid major
generated by cgit 1.2.3-korg (git 2.43.0) at 2025-12-09 13:39:30 +0000