| 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
| ||
|
Date: Mon, 5 Feb 2018 02:27:08 +0100
From: Davidlohr Bueso <dbueso@...e.de>
To: akpm@...ux-foundation.org, mingo@...nel.org
Cc: peterz@...radead.org, ldufour@...ux.vnet.ibm.com, jack@...e.cz,
mhocko@...nel.org, kirill.shutemov@...ux.intel.com,
mawilcox@...rosoft.com, mgorman@...hsingularity.net,
dave@...olabs.net, linux-mm@...ck.org,
linux-kernel@...r.kernel.org, Davidlohr Bueso <dbueso@...e.de>
Subject: [PATCH 18/64] mm/ksm: teach about range locking
From: Davidlohr Bueso <dave@...olabs.net>
Conversion is straightforward as most calls use mmap_sem
within the same function context. No changes in semantics.
Signed-off-by: Davidlohr Bueso <dbueso@...e.de>
---
mm/ksm.c | 40 +++++++++++++++++++++++-----------------
1 file changed, 23 insertions(+), 17 deletions(-)
diff --git a/mm/ksm.c b/mm/ksm.c
index 66c350cd9799..c7d62c367ffc 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -526,11 +526,11 @@ static void break_cow(struct rmap_item *rmap_item)
*/
put_anon_vma(rmap_item->anon_vma);
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_mergeable_vma(mm, addr);
if (vma)
break_ksm(vma, addr, &mmrange);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
}
static struct page *get_mergeable_page(struct rmap_item *rmap_item)
@@ -539,8 +539,9 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item)
unsigned long addr = rmap_item->address;
struct vm_area_struct *vma;
struct page *page;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_mergeable_vma(mm, addr);
if (!vma)
goto out;
@@ -556,7 +557,7 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item)
out:
page = NULL;
}
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return page;
}
@@ -936,7 +937,7 @@ static int unmerge_and_remove_all_rmap_items(void)
for (mm_slot = ksm_scan.mm_slot;
mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot) {
mm = mm_slot->mm;
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (ksm_test_exit(mm))
break;
@@ -949,7 +950,7 @@ static int unmerge_and_remove_all_rmap_items(void)
}
remove_trailing_rmap_items(mm_slot, &mm_slot->rmap_list);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
spin_lock(&ksm_mmlist_lock);
ksm_scan.mm_slot = list_entry(mm_slot->mm_list.next,
@@ -972,7 +973,7 @@ static int unmerge_and_remove_all_rmap_items(void)
return 0;
error:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
spin_lock(&ksm_mmlist_lock);
ksm_scan.mm_slot = &ksm_mm_head;
spin_unlock(&ksm_mmlist_lock);
@@ -1251,8 +1252,9 @@ static int try_to_merge_with_ksm_page(struct rmap_item *rmap_item,
struct mm_struct *mm = rmap_item->mm;
struct vm_area_struct *vma;
int err = -EFAULT;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_mergeable_vma(mm, rmap_item->address);
if (!vma)
goto out;
@@ -1268,7 +1270,7 @@ static int try_to_merge_with_ksm_page(struct rmap_item *rmap_item,
rmap_item->anon_vma = vma->anon_vma;
get_anon_vma(vma->anon_vma);
out:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return err;
}
@@ -2071,12 +2073,13 @@ static void cmp_and_merge_page(struct page *page, struct rmap_item *rmap_item)
*/
if (ksm_use_zero_pages && (checksum == zero_checksum)) {
struct vm_area_struct *vma;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_mergeable_vma(mm, rmap_item->address);
err = try_to_merge_one_page(vma, page,
ZERO_PAGE(rmap_item->address));
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
/*
* In case of failure, the page was not really empty, so we
* need to continue. Otherwise we're done.
@@ -2154,6 +2157,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
struct vm_area_struct *vma;
struct rmap_item *rmap_item;
int nid;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
if (list_empty(&ksm_mm_head.mm_list))
return NULL;
@@ -2210,7 +2214,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
}
mm = slot->mm;
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
if (ksm_test_exit(mm))
vma = NULL;
else
@@ -2244,7 +2248,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
ksm_scan.address += PAGE_SIZE;
} else
put_page(*page);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return rmap_item;
}
put_page(*page);
@@ -2282,10 +2286,10 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
free_mm_slot(slot);
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
mmdrop(mm);
} else {
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
/*
* up_read(&mm->mmap_sem) first because after
* spin_unlock(&ksm_mmlist_lock) run, the "mm" may
@@ -2474,8 +2478,10 @@ void __ksm_exit(struct mm_struct *mm)
clear_bit(MMF_VM_MERGEABLE, &mm->flags);
mmdrop(mm);
} else if (mm_slot) {
- down_write(&mm->mmap_sem);
- up_write(&mm->mmap_sem);
+ DEFINE_RANGE_LOCK_FULL(mmrange);
+
+ mm_write_lock(mm, &mmrange);
+ mm_write_unlock(mm, &mmrange);
}
}
--
2.13.6
Powered by blists - more mailing lists