The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From d4b09acf924b84bae77cad090a9d108e70b43643 Mon Sep 17 00:00:00 2001
From: Vasily Averin <vvs(a)virtuozzo.com>
Date: Mon, 24 Dec 2018 14:44:52 +0300
Subject: [PATCH] sunrpc: use-after-free in svc_process_common()
if node have NFSv41+ mounts inside several net namespaces
it can lead to use-after-free in svc_process_common()
svc_process_common()
/* Setup reply header */
rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp); <<< HERE
svc_process_common() can use incorrect rqstp->rq_xprt,
its caller function bc_svc_process() takes it from serv->sv_bc_xprt.
The problem is that serv is global structure but sv_bc_xprt
is assigned per-netnamespace.
According to Trond, the whole "let's set up rqstp->rq_xprt
for the back channel" is nothing but a giant hack in order
to work around the fact that svc_process_common() uses it
to find the xpt_ops, and perform a couple of (meaningless
for the back channel) tests of xpt_flags.
All we really need in svc_process_common() is to be able to run
rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr()
Bruce J Fields points that this xpo_prep_reply_hdr() call
is an awfully roundabout way just to do "svc_putnl(resv, 0);"
in the tcp case.
This patch does not initialiuze rqstp->rq_xprt in bc_svc_process(),
now it calls svc_process_common() with rqstp->rq_xprt = NULL.
To adjust reply header svc_process_common() just check
rqstp->rq_prot and calls svc_tcp_prep_reply_hdr() for tcp case.
To handle rqstp->rq_xprt = NULL case in functions called from
svc_process_common() patch intruduces net namespace pointer
svc_rqst->rq_bc_net and adjust SVC_NET() definition.
Some other function was also adopted to properly handle described case.
Signed-off-by: Vasily Averin <vvs(a)virtuozzo.com>
Cc: stable(a)vger.kernel.org
Fixes: 23c20ecd4475 ("NFS: callback up - users counting cleanup")
Signed-off-by: J. Bruce Fields <bfields(a)redhat.com>
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 73e130a840ce..fdb6b317d974 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -295,9 +295,12 @@ struct svc_rqst {
struct svc_cacherep * rq_cacherep; /* cache info */
struct task_struct *rq_task; /* service thread */
spinlock_t rq_lock; /* per-request lock */
+ struct net *rq_bc_net; /* pointer to backchannel's
+ * net namespace
+ */
};
-#define SVC_NET(svc_rqst) (svc_rqst->rq_xprt->xpt_net)
+#define SVC_NET(rqst) (rqst->rq_xprt ? rqst->rq_xprt->xpt_net : rqst->rq_bc_net)
/*
* Rigorous type checking on sockaddr type conversions
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 28e384186c35..8617f4fd6b70 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -569,7 +569,8 @@ TRACE_EVENT(svc_process,
__field(u32, vers)
__field(u32, proc)
__string(service, name)
- __string(addr, rqst->rq_xprt->xpt_remotebuf)
+ __string(addr, rqst->rq_xprt ?
+ rqst->rq_xprt->xpt_remotebuf : "(null)")
),
TP_fast_assign(
@@ -577,7 +578,8 @@ TRACE_EVENT(svc_process,
__entry->vers = rqst->rq_vers;
__entry->proc = rqst->rq_proc;
__assign_str(service, name);
- __assign_str(addr, rqst->rq_xprt->xpt_remotebuf);
+ __assign_str(addr, rqst->rq_xprt ?
+ rqst->rq_xprt->xpt_remotebuf : "(null)");
),
TP_printk("addr=%s xid=0x%08x service=%s vers=%u proc=%u",
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index d13e05f1a990..fb647bc01fc5 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1172,7 +1172,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
clear_bit(RQ_DROPME, &rqstp->rq_flags);
/* Setup reply header */
- rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp);
+ if (rqstp->rq_prot == IPPROTO_TCP)
+ svc_tcp_prep_reply_hdr(rqstp);
svc_putu32(resv, rqstp->rq_xid);
@@ -1244,7 +1245,7 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
* for lower versions. RPC_PROG_MISMATCH seems to be the closest
* fit.
*/
- if (versp->vs_need_cong_ctrl &&
+ if (versp->vs_need_cong_ctrl && rqstp->rq_xprt &&
!test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
goto err_bad_vers;
@@ -1336,7 +1337,7 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
return 0;
close:
- if (test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
+ if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
svc_close_xprt(rqstp->rq_xprt);
dprintk("svc: svc_process close\n");
return 0;
@@ -1459,10 +1460,10 @@ bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
dprintk("svc: %s(%p)\n", __func__, req);
/* Build the svc_rqst used by the common processing routine */
- rqstp->rq_xprt = serv->sv_bc_xprt;
rqstp->rq_xid = req->rq_xid;
rqstp->rq_prot = req->rq_xprt->prot;
rqstp->rq_server = serv;
+ rqstp->rq_bc_net = req->rq_xprt->xprt_net;
rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 51d36230b6e3..bd42da287c26 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -468,10 +468,11 @@ static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
*/
void svc_reserve(struct svc_rqst *rqstp, int space)
{
+ struct svc_xprt *xprt = rqstp->rq_xprt;
+
space += rqstp->rq_res.head[0].iov_len;
- if (space < rqstp->rq_reserved) {
- struct svc_xprt *xprt = rqstp->rq_xprt;
+ if (xprt && space < rqstp->rq_reserved) {
atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
rqstp->rq_reserved = space;
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 986f3ed7d1a2..793149ba1bda 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1173,7 +1173,7 @@ static int svc_tcp_sendto(struct svc_rqst *rqstp)
/*
* Setup response header. TCP has a 4B record length field.
*/
-static void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
+void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
{
struct kvec *resv = &rqstp->rq_res.head[0];
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From c86aa7bbfd5568ba8a82d3635d8f7b8a8e06fe54 Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz(a)oracle.com>
Date: Fri, 28 Dec 2018 00:39:42 -0800
Subject: [PATCH] hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race
hugetlbfs page faults can race with truncate and hole punch operations.
Current code in the page fault path attempts to handle this by 'backing
out' operations if we encounter the race. One obvious omission in the
current code is removing a page newly added to the page cache. This is
pretty straight forward to address, but there is a more subtle and
difficult issue of backing out hugetlb reservations. To handle this
correctly, the 'reservation state' before page allocation needs to be
noted so that it can be properly backed out. There are four distinct
possibilities for reservation state: shared/reserved, shared/no-resv,
private/reserved and private/no-resv. Backing out a reservation may
require memory allocation which could fail so that needs to be taken into
account as well.
Instead of writing the required complicated code for this rare occurrence,
just eliminate the race. i_mmap_rwsem is now held in read mode for the
duration of page fault processing. Hold i_mmap_rwsem longer in truncation
and hold punch code to cover the call to remove_inode_hugepages.
With this modification, code in remove_inode_hugepages checking for races
becomes 'dead' as it can not longer happen. Remove the dead code and
expand comments to explain reasoning. Similarly, checks for races with
truncation in the page fault path can be simplified and removed.
[mike.kravetz(a)oracle.com: incorporat suggestions from Kirill]
Link: http://lkml.kernel.org/r/20181222223013.22193-3-mike.kravetz@oracle.com
Link: http://lkml.kernel.org/r/20181218223557.5202-3-mike.kravetz@oracle.com
Fixes: ebed4bfc8da8 ("hugetlb: fix absurd HugePages_Rsvd")
Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com>
Cc: Michal Hocko <mhocko(a)kernel.org>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Naoya Horiguchi <n-horiguchi(a)ah.jp.nec.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar(a)linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Davidlohr Bueso <dave(a)stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa(a)oracle.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 32920a10100e..a2fcea5f8225 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -383,17 +383,16 @@ hugetlb_vmdelete_list(struct rb_root_cached *root, pgoff_t start, pgoff_t end)
* truncation is indicated by end of range being LLONG_MAX
* In this case, we first scan the range and release found pages.
* After releasing pages, hugetlb_unreserve_pages cleans up region/reserv
- * maps and global counts. Page faults can not race with truncation
- * in this routine. hugetlb_no_page() prevents page faults in the
- * truncated range. It checks i_size before allocation, and again after
- * with the page table lock for the page held. The same lock must be
- * acquired to unmap a page.
+ * maps and global counts.
* hole punch is indicated if end is not LLONG_MAX
* In the hole punch case we scan the range and release found pages.
* Only when releasing a page is the associated region/reserv map
* deleted. The region/reserv map for ranges without associated
- * pages are not modified. Page faults can race with hole punch.
- * This is indicated if we find a mapped page.
+ * pages are not modified.
+ *
+ * Callers of this routine must hold the i_mmap_rwsem in write mode to prevent
+ * races with page faults.
+ *
* Note: If the passed end of range value is beyond the end of file, but
* not LLONG_MAX this routine still performs a hole punch operation.
*/
@@ -423,32 +422,14 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
for (i = 0; i < pagevec_count(&pvec); ++i) {
struct page *page = pvec.pages[i];
- u32 hash;
index = page->index;
- hash = hugetlb_fault_mutex_hash(h, current->mm,
- &pseudo_vma,
- mapping, index, 0);
- mutex_lock(&hugetlb_fault_mutex_table[hash]);
-
/*
- * If page is mapped, it was faulted in after being
- * unmapped in caller. Unmap (again) now after taking
- * the fault mutex. The mutex will prevent faults
- * until we finish removing the page.
- *
- * This race can only happen in the hole punch case.
- * Getting here in a truncate operation is a bug.
+ * A mapped page is impossible as callers should unmap
+ * all references before calling. And, i_mmap_rwsem
+ * prevents the creation of additional mappings.
*/
- if (unlikely(page_mapped(page))) {
- BUG_ON(truncate_op);
-
- i_mmap_lock_write(mapping);
- hugetlb_vmdelete_list(&mapping->i_mmap,
- index * pages_per_huge_page(h),
- (index + 1) * pages_per_huge_page(h));
- i_mmap_unlock_write(mapping);
- }
+ VM_BUG_ON(page_mapped(page));
lock_page(page);
/*
@@ -470,7 +451,6 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
}
unlock_page(page);
- mutex_unlock(&hugetlb_fault_mutex_table[hash]);
}
huge_pagevec_release(&pvec);
cond_resched();
@@ -482,9 +462,20 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
static void hugetlbfs_evict_inode(struct inode *inode)
{
+ struct address_space *mapping = inode->i_mapping;
struct resv_map *resv_map;
+ /*
+ * The vfs layer guarantees that there are no other users of this
+ * inode. Therefore, it would be safe to call remove_inode_hugepages
+ * without holding i_mmap_rwsem. We acquire and hold here to be
+ * consistent with other callers. Since there will be no contention
+ * on the semaphore, overhead is negligible.
+ */
+ i_mmap_lock_write(mapping);
remove_inode_hugepages(inode, 0, LLONG_MAX);
+ i_mmap_unlock_write(mapping);
+
resv_map = (struct resv_map *)inode->i_mapping->private_data;
/* root inode doesn't have the resv_map, so we should check it */
if (resv_map)
@@ -505,8 +496,8 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
i_mmap_lock_write(mapping);
if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))
hugetlb_vmdelete_list(&mapping->i_mmap, pgoff, 0);
- i_mmap_unlock_write(mapping);
remove_inode_hugepages(inode, offset, LLONG_MAX);
+ i_mmap_unlock_write(mapping);
return 0;
}
@@ -540,8 +531,8 @@ static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
hugetlb_vmdelete_list(&mapping->i_mmap,
hole_start >> PAGE_SHIFT,
hole_end >> PAGE_SHIFT);
- i_mmap_unlock_write(mapping);
remove_inode_hugepages(inode, hole_start, hole_end);
+ i_mmap_unlock_write(mapping);
inode_unlock(inode);
}
@@ -624,7 +615,11 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
/* addr is the offset within the file (zero based) */
addr = index * hpage_size;
- /* mutex taken here, fault path and hole punch */
+ /*
+ * fault mutex taken here, protects against fault path
+ * and hole punch. inode_lock previously taken protects
+ * against truncation.
+ */
hash = hugetlb_fault_mutex_hash(h, mm, &pseudo_vma, mapping,
index, addr);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 87fd3ab809c6..e37efd5d8318 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3755,16 +3755,16 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
}
/*
- * Use page lock to guard against racing truncation
- * before we get page_table_lock.
+ * We can not race with truncation due to holding i_mmap_rwsem.
+ * Check once here for faults beyond end of file.
*/
+ size = i_size_read(mapping->host) >> huge_page_shift(h);
+ if (idx >= size)
+ goto out;
+
retry:
page = find_lock_page(mapping, idx);
if (!page) {
- size = i_size_read(mapping->host) >> huge_page_shift(h);
- if (idx >= size)
- goto out;
-
/*
* Check for page in userfault range
*/
@@ -3854,9 +3854,6 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
}
ptl = huge_pte_lock(h, mm, ptep);
- size = i_size_read(mapping->host) >> huge_page_shift(h);
- if (idx >= size)
- goto backout;
ret = 0;
if (!huge_pte_none(huge_ptep_get(ptep)))
@@ -3959,8 +3956,10 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
/*
* Acquire i_mmap_rwsem before calling huge_pte_alloc and hold
- * until finished with ptep. This prevents huge_pmd_unshare from
- * being called elsewhere and making the ptep no longer valid.
+ * until finished with ptep. This serves two purposes:
+ * 1) It prevents huge_pmd_unshare from being called elsewhere
+ * and making the ptep no longer valid.
+ * 2) It synchronizes us with file truncation.
*
* ptep could have already be assigned via huge_pte_offset. That
* is OK, as huge_pte_alloc will return the same value unless
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b43a9990055958e70347c56f90ea2ae32c67334c Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz(a)oracle.com>
Date: Fri, 28 Dec 2018 00:39:38 -0800
Subject: [PATCH] hugetlbfs: use i_mmap_rwsem for more pmd sharing
synchronization
While looking at BUGs associated with invalid huge page map counts, it was
discovered and observed that a huge pte pointer could become 'invalid' and
point to another task's page table. Consider the following:
A task takes a page fault on a shared hugetlbfs file and calls
huge_pte_alloc to get a ptep. Suppose the returned ptep points to a
shared pmd.
Now, another task truncates the hugetlbfs file. As part of truncation, it
unmaps everyone who has the file mapped. If the range being truncated is
covered by a shared pmd, huge_pmd_unshare will be called. For all but the
last user of the shared pmd, huge_pmd_unshare will clear the pud pointing
to the pmd. If the task in the middle of the page fault is not the last
user, the ptep returned by huge_pte_alloc now points to another task's
page table or worse. This leads to bad things such as incorrect page
map/reference counts or invalid memory references.
To fix, expand the use of i_mmap_rwsem as follows:
- i_mmap_rwsem is held in read mode whenever huge_pmd_share is called.
huge_pmd_share is only called via huge_pte_alloc, so callers of
huge_pte_alloc take i_mmap_rwsem before calling. In addition, callers
of huge_pte_alloc continue to hold the semaphore until finished with the
ptep.
- i_mmap_rwsem is held in write mode whenever huge_pmd_unshare is
called.
[mike.kravetz(a)oracle.com: add explicit check for mapping != null]
Link: http://lkml.kernel.org/r/20181218223557.5202-2-mike.kravetz@oracle.com
Fixes: 39dde65c9940 ("shared page table for hugetlb page")
Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com>
Cc: Michal Hocko <mhocko(a)kernel.org>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Naoya Horiguchi <n-horiguchi(a)ah.jp.nec.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar(a)linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Davidlohr Bueso <dave(a)stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa(a)oracle.com>
Cc: Colin Ian King <colin.king(a)canonical.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 12000ba5c868..87fd3ab809c6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3238,6 +3238,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
struct page *ptepage;
unsigned long addr;
int cow;
+ struct address_space *mapping = vma->vm_file->f_mapping;
struct hstate *h = hstate_vma(vma);
unsigned long sz = huge_page_size(h);
struct mmu_notifier_range range;
@@ -3249,13 +3250,23 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
mmu_notifier_range_init(&range, src, vma->vm_start,
vma->vm_end);
mmu_notifier_invalidate_range_start(&range);
+ } else {
+ /*
+ * For shared mappings i_mmap_rwsem must be held to call
+ * huge_pte_alloc, otherwise the returned ptep could go
+ * away if part of a shared pmd and another thread calls
+ * huge_pmd_unshare.
+ */
+ i_mmap_lock_read(mapping);
}
for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
spinlock_t *src_ptl, *dst_ptl;
+
src_pte = huge_pte_offset(src, addr, sz);
if (!src_pte)
continue;
+
dst_pte = huge_pte_alloc(dst, addr, sz);
if (!dst_pte) {
ret = -ENOMEM;
@@ -3326,6 +3337,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
if (cow)
mmu_notifier_invalidate_range_end(&range);
+ else
+ i_mmap_unlock_read(mapping);
return ret;
}
@@ -3771,14 +3784,18 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
};
/*
- * hugetlb_fault_mutex must be dropped before
- * handling userfault. Reacquire after handling
- * fault to make calling code simpler.
+ * hugetlb_fault_mutex and i_mmap_rwsem must be
+ * dropped before handling userfault. Reacquire
+ * after handling fault to make calling code simpler.
*/
hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping,
idx, haddr);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
+
ret = handle_userfault(&vmf, VM_UFFD_MISSING);
+
+ i_mmap_lock_read(mapping);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
goto out;
}
@@ -3926,6 +3943,11 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
ptep = huge_pte_offset(mm, haddr, huge_page_size(h));
if (ptep) {
+ /*
+ * Since we hold no locks, ptep could be stale. That is
+ * OK as we are only making decisions based on content and
+ * not actually modifying content here.
+ */
entry = huge_ptep_get(ptep);
if (unlikely(is_hugetlb_entry_migration(entry))) {
migration_entry_wait_huge(vma, mm, ptep);
@@ -3933,20 +3955,31 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
return VM_FAULT_HWPOISON_LARGE |
VM_FAULT_SET_HINDEX(hstate_index(h));
- } else {
- ptep = huge_pte_alloc(mm, haddr, huge_page_size(h));
- if (!ptep)
- return VM_FAULT_OOM;
}
+ /*
+ * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold
+ * until finished with ptep. This prevents huge_pmd_unshare from
+ * being called elsewhere and making the ptep no longer valid.
+ *
+ * ptep could have already be assigned via huge_pte_offset. That
+ * is OK, as huge_pte_alloc will return the same value unless
+ * something changed.
+ */
mapping = vma->vm_file->f_mapping;
- idx = vma_hugecache_offset(h, vma, haddr);
+ i_mmap_lock_read(mapping);
+ ptep = huge_pte_alloc(mm, haddr, huge_page_size(h));
+ if (!ptep) {
+ i_mmap_unlock_read(mapping);
+ return VM_FAULT_OOM;
+ }
/*
* Serialize hugepage allocation and instantiation, so that we don't
* get spurious allocation failures if two CPUs race to instantiate
* the same page in the page cache.
*/
+ idx = vma_hugecache_offset(h, vma, haddr);
hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, idx, haddr);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -4034,6 +4067,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
}
out_mutex:
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
/*
* Generally it's safe to hold refcount during waiting page lock. But
* here we just wait to defer the next page fault to avoid busy loop and
@@ -4638,10 +4672,12 @@ void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
* Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
* and returns the corresponding pte. While this is not necessary for the
* !shared pmd case because we can allocate the pmd later as well, it makes the
- * code much cleaner. pmd allocation is essential for the shared case because
- * pud has to be populated inside the same i_mmap_rwsem section - otherwise
- * racing tasks could either miss the sharing (see huge_pte_offset) or select a
- * bad pmd for sharing.
+ * code much cleaner.
+ *
+ * This routine must be called with i_mmap_rwsem held in at least read mode.
+ * For hugetlbfs, this prevents removal of any page table entries associated
+ * with the address space. This is important as we are setting up sharing
+ * based on existing page table entries (mappings).
*/
pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
{
@@ -4658,7 +4694,6 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
if (!vma_shareable(vma, addr))
return (pte_t *)pmd_alloc(mm, pud, addr);
- i_mmap_lock_write(mapping);
vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
if (svma == vma)
continue;
@@ -4688,7 +4723,6 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
spin_unlock(ptl);
out:
pte = (pte_t *)pmd_alloc(mm, pud, addr);
- i_mmap_unlock_write(mapping);
return pte;
}
@@ -4699,7 +4733,7 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
* indicated by page_count > 1, unmap is achieved by clearing pud and
* decrementing the ref count. If count == 1, the pte page is not shared.
*
- * called with page table lock held.
+ * Called with page table lock held and i_mmap_rwsem held in write mode.
*
* returns: 1 successfully unmapped a shared pte page
* 0 the underlying pte page is not shared, or it is the last user
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 7c72f2a95785..6379fff1a5ff 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -966,7 +966,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
struct address_space *mapping;
LIST_HEAD(tokill);
- bool unmap_success;
+ bool unmap_success = true;
int kill = 1, forcekill;
struct page *hpage = *hpagep;
bool mlocked = PageMlocked(hpage);
@@ -1028,7 +1028,19 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
if (kill)
collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
- unmap_success = try_to_unmap(hpage, ttu);
+ if (!PageHuge(hpage)) {
+ unmap_success = try_to_unmap(hpage, ttu);
+ } else if (mapping) {
+ /*
+ * For hugetlb pages, try_to_unmap could potentially call
+ * huge_pmd_unshare. Because of this, take semaphore in
+ * write mode here and set TTU_RMAP_LOCKED to indicate we
+ * have taken the lock at this higer level.
+ */
+ i_mmap_lock_write(mapping);
+ unmap_success = try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
+ i_mmap_unlock_write(mapping);
+ }
if (!unmap_success)
pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
pfn, page_mapcount(hpage));
diff --git a/mm/migrate.c b/mm/migrate.c
index 4389696fba0e..5d1839a9148d 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1324,8 +1324,19 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
goto put_anon;
if (page_mapped(hpage)) {
+ struct address_space *mapping = page_mapping(hpage);
+
+ /*
+ * try_to_unmap could potentially call huge_pmd_unshare.
+ * Because of this, take semaphore in write mode here and
+ * set TTU_RMAP_LOCKED to let lower levels know we have
+ * taken the lock.
+ */
+ i_mmap_lock_write(mapping);
try_to_unmap(hpage,
- TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+ TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS|
+ TTU_RMAP_LOCKED);
+ i_mmap_unlock_write(mapping);
page_was_mapped = 1;
}
diff --git a/mm/rmap.c b/mm/rmap.c
index 68a1a5b869a5..21a26cf51114 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -25,6 +25,7 @@
* page->flags PG_locked (lock_page)
* hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
* mapping->i_mmap_rwsem
+ * hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
* anon_vma->rwsem
* mm->page_table_lock or pte_lock
* zone_lru_lock (in mark_page_accessed, isolate_lru_page)
@@ -1378,6 +1379,9 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
/*
* If sharing is possible, start and end will be adjusted
* accordingly.
+ *
+ * If called for a huge page, caller must hold i_mmap_rwsem
+ * in write mode as it is possible to call huge_pmd_unshare.
*/
adjust_range_if_pmd_sharing_possible(vma, &range.start,
&range.end);
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 458acda96f20..48368589f519 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -267,10 +267,14 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
VM_BUG_ON(dst_addr & ~huge_page_mask(h));
/*
- * Serialize via hugetlb_fault_mutex
+ * Serialize via i_mmap_rwsem and hugetlb_fault_mutex.
+ * i_mmap_rwsem ensures the dst_pte remains valid even
+ * in the case of shared pmds. fault mutex prevents
+ * races with other faulting threads.
*/
- idx = linear_page_index(dst_vma, dst_addr);
mapping = dst_vma->vm_file->f_mapping;
+ i_mmap_lock_read(mapping);
+ idx = linear_page_index(dst_vma, dst_addr);
hash = hugetlb_fault_mutex_hash(h, dst_mm, dst_vma, mapping,
idx, dst_addr);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -279,6 +283,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h));
if (!dst_pte) {
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
goto out_unlock;
}
@@ -286,6 +291,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_pteval = huge_ptep_get(dst_pte);
if (!huge_pte_none(dst_pteval)) {
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
goto out_unlock;
}
@@ -293,6 +299,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_addr, src_addr, &page);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
vm_alloc_shared = vm_shared;
cond_resched();
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b43a9990055958e70347c56f90ea2ae32c67334c Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz(a)oracle.com>
Date: Fri, 28 Dec 2018 00:39:38 -0800
Subject: [PATCH] hugetlbfs: use i_mmap_rwsem for more pmd sharing
synchronization
While looking at BUGs associated with invalid huge page map counts, it was
discovered and observed that a huge pte pointer could become 'invalid' and
point to another task's page table. Consider the following:
A task takes a page fault on a shared hugetlbfs file and calls
huge_pte_alloc to get a ptep. Suppose the returned ptep points to a
shared pmd.
Now, another task truncates the hugetlbfs file. As part of truncation, it
unmaps everyone who has the file mapped. If the range being truncated is
covered by a shared pmd, huge_pmd_unshare will be called. For all but the
last user of the shared pmd, huge_pmd_unshare will clear the pud pointing
to the pmd. If the task in the middle of the page fault is not the last
user, the ptep returned by huge_pte_alloc now points to another task's
page table or worse. This leads to bad things such as incorrect page
map/reference counts or invalid memory references.
To fix, expand the use of i_mmap_rwsem as follows:
- i_mmap_rwsem is held in read mode whenever huge_pmd_share is called.
huge_pmd_share is only called via huge_pte_alloc, so callers of
huge_pte_alloc take i_mmap_rwsem before calling. In addition, callers
of huge_pte_alloc continue to hold the semaphore until finished with the
ptep.
- i_mmap_rwsem is held in write mode whenever huge_pmd_unshare is
called.
[mike.kravetz(a)oracle.com: add explicit check for mapping != null]
Link: http://lkml.kernel.org/r/20181218223557.5202-2-mike.kravetz@oracle.com
Fixes: 39dde65c9940 ("shared page table for hugetlb page")
Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com>
Cc: Michal Hocko <mhocko(a)kernel.org>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Naoya Horiguchi <n-horiguchi(a)ah.jp.nec.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar(a)linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Davidlohr Bueso <dave(a)stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa(a)oracle.com>
Cc: Colin Ian King <colin.king(a)canonical.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 12000ba5c868..87fd3ab809c6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3238,6 +3238,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
struct page *ptepage;
unsigned long addr;
int cow;
+ struct address_space *mapping = vma->vm_file->f_mapping;
struct hstate *h = hstate_vma(vma);
unsigned long sz = huge_page_size(h);
struct mmu_notifier_range range;
@@ -3249,13 +3250,23 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
mmu_notifier_range_init(&range, src, vma->vm_start,
vma->vm_end);
mmu_notifier_invalidate_range_start(&range);
+ } else {
+ /*
+ * For shared mappings i_mmap_rwsem must be held to call
+ * huge_pte_alloc, otherwise the returned ptep could go
+ * away if part of a shared pmd and another thread calls
+ * huge_pmd_unshare.
+ */
+ i_mmap_lock_read(mapping);
}
for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
spinlock_t *src_ptl, *dst_ptl;
+
src_pte = huge_pte_offset(src, addr, sz);
if (!src_pte)
continue;
+
dst_pte = huge_pte_alloc(dst, addr, sz);
if (!dst_pte) {
ret = -ENOMEM;
@@ -3326,6 +3337,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
if (cow)
mmu_notifier_invalidate_range_end(&range);
+ else
+ i_mmap_unlock_read(mapping);
return ret;
}
@@ -3771,14 +3784,18 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
};
/*
- * hugetlb_fault_mutex must be dropped before
- * handling userfault. Reacquire after handling
- * fault to make calling code simpler.
+ * hugetlb_fault_mutex and i_mmap_rwsem must be
+ * dropped before handling userfault. Reacquire
+ * after handling fault to make calling code simpler.
*/
hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping,
idx, haddr);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
+
ret = handle_userfault(&vmf, VM_UFFD_MISSING);
+
+ i_mmap_lock_read(mapping);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
goto out;
}
@@ -3926,6 +3943,11 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
ptep = huge_pte_offset(mm, haddr, huge_page_size(h));
if (ptep) {
+ /*
+ * Since we hold no locks, ptep could be stale. That is
+ * OK as we are only making decisions based on content and
+ * not actually modifying content here.
+ */
entry = huge_ptep_get(ptep);
if (unlikely(is_hugetlb_entry_migration(entry))) {
migration_entry_wait_huge(vma, mm, ptep);
@@ -3933,20 +3955,31 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
return VM_FAULT_HWPOISON_LARGE |
VM_FAULT_SET_HINDEX(hstate_index(h));
- } else {
- ptep = huge_pte_alloc(mm, haddr, huge_page_size(h));
- if (!ptep)
- return VM_FAULT_OOM;
}
+ /*
+ * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold
+ * until finished with ptep. This prevents huge_pmd_unshare from
+ * being called elsewhere and making the ptep no longer valid.
+ *
+ * ptep could have already be assigned via huge_pte_offset. That
+ * is OK, as huge_pte_alloc will return the same value unless
+ * something changed.
+ */
mapping = vma->vm_file->f_mapping;
- idx = vma_hugecache_offset(h, vma, haddr);
+ i_mmap_lock_read(mapping);
+ ptep = huge_pte_alloc(mm, haddr, huge_page_size(h));
+ if (!ptep) {
+ i_mmap_unlock_read(mapping);
+ return VM_FAULT_OOM;
+ }
/*
* Serialize hugepage allocation and instantiation, so that we don't
* get spurious allocation failures if two CPUs race to instantiate
* the same page in the page cache.
*/
+ idx = vma_hugecache_offset(h, vma, haddr);
hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, idx, haddr);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -4034,6 +4067,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
}
out_mutex:
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
/*
* Generally it's safe to hold refcount during waiting page lock. But
* here we just wait to defer the next page fault to avoid busy loop and
@@ -4638,10 +4672,12 @@ void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
* Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
* and returns the corresponding pte. While this is not necessary for the
* !shared pmd case because we can allocate the pmd later as well, it makes the
- * code much cleaner. pmd allocation is essential for the shared case because
- * pud has to be populated inside the same i_mmap_rwsem section - otherwise
- * racing tasks could either miss the sharing (see huge_pte_offset) or select a
- * bad pmd for sharing.
+ * code much cleaner.
+ *
+ * This routine must be called with i_mmap_rwsem held in at least read mode.
+ * For hugetlbfs, this prevents removal of any page table entries associated
+ * with the address space. This is important as we are setting up sharing
+ * based on existing page table entries (mappings).
*/
pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
{
@@ -4658,7 +4694,6 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
if (!vma_shareable(vma, addr))
return (pte_t *)pmd_alloc(mm, pud, addr);
- i_mmap_lock_write(mapping);
vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
if (svma == vma)
continue;
@@ -4688,7 +4723,6 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
spin_unlock(ptl);
out:
pte = (pte_t *)pmd_alloc(mm, pud, addr);
- i_mmap_unlock_write(mapping);
return pte;
}
@@ -4699,7 +4733,7 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
* indicated by page_count > 1, unmap is achieved by clearing pud and
* decrementing the ref count. If count == 1, the pte page is not shared.
*
- * called with page table lock held.
+ * Called with page table lock held and i_mmap_rwsem held in write mode.
*
* returns: 1 successfully unmapped a shared pte page
* 0 the underlying pte page is not shared, or it is the last user
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 7c72f2a95785..6379fff1a5ff 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -966,7 +966,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
struct address_space *mapping;
LIST_HEAD(tokill);
- bool unmap_success;
+ bool unmap_success = true;
int kill = 1, forcekill;
struct page *hpage = *hpagep;
bool mlocked = PageMlocked(hpage);
@@ -1028,7 +1028,19 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
if (kill)
collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
- unmap_success = try_to_unmap(hpage, ttu);
+ if (!PageHuge(hpage)) {
+ unmap_success = try_to_unmap(hpage, ttu);
+ } else if (mapping) {
+ /*
+ * For hugetlb pages, try_to_unmap could potentially call
+ * huge_pmd_unshare. Because of this, take semaphore in
+ * write mode here and set TTU_RMAP_LOCKED to indicate we
+ * have taken the lock at this higer level.
+ */
+ i_mmap_lock_write(mapping);
+ unmap_success = try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
+ i_mmap_unlock_write(mapping);
+ }
if (!unmap_success)
pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
pfn, page_mapcount(hpage));
diff --git a/mm/migrate.c b/mm/migrate.c
index 4389696fba0e..5d1839a9148d 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1324,8 +1324,19 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
goto put_anon;
if (page_mapped(hpage)) {
+ struct address_space *mapping = page_mapping(hpage);
+
+ /*
+ * try_to_unmap could potentially call huge_pmd_unshare.
+ * Because of this, take semaphore in write mode here and
+ * set TTU_RMAP_LOCKED to let lower levels know we have
+ * taken the lock.
+ */
+ i_mmap_lock_write(mapping);
try_to_unmap(hpage,
- TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+ TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS|
+ TTU_RMAP_LOCKED);
+ i_mmap_unlock_write(mapping);
page_was_mapped = 1;
}
diff --git a/mm/rmap.c b/mm/rmap.c
index 68a1a5b869a5..21a26cf51114 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -25,6 +25,7 @@
* page->flags PG_locked (lock_page)
* hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
* mapping->i_mmap_rwsem
+ * hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
* anon_vma->rwsem
* mm->page_table_lock or pte_lock
* zone_lru_lock (in mark_page_accessed, isolate_lru_page)
@@ -1378,6 +1379,9 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
/*
* If sharing is possible, start and end will be adjusted
* accordingly.
+ *
+ * If called for a huge page, caller must hold i_mmap_rwsem
+ * in write mode as it is possible to call huge_pmd_unshare.
*/
adjust_range_if_pmd_sharing_possible(vma, &range.start,
&range.end);
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 458acda96f20..48368589f519 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -267,10 +267,14 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
VM_BUG_ON(dst_addr & ~huge_page_mask(h));
/*
- * Serialize via hugetlb_fault_mutex
+ * Serialize via i_mmap_rwsem and hugetlb_fault_mutex.
+ * i_mmap_rwsem ensures the dst_pte remains valid even
+ * in the case of shared pmds. fault mutex prevents
+ * races with other faulting threads.
*/
- idx = linear_page_index(dst_vma, dst_addr);
mapping = dst_vma->vm_file->f_mapping;
+ i_mmap_lock_read(mapping);
+ idx = linear_page_index(dst_vma, dst_addr);
hash = hugetlb_fault_mutex_hash(h, dst_mm, dst_vma, mapping,
idx, dst_addr);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -279,6 +283,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h));
if (!dst_pte) {
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
goto out_unlock;
}
@@ -286,6 +291,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_pteval = huge_ptep_get(dst_pte);
if (!huge_pte_none(dst_pteval)) {
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
goto out_unlock;
}
@@ -293,6 +299,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_addr, src_addr, &page);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
vm_alloc_shared = vm_shared;
cond_resched();
Hi,
After upgrading kernel from 4.14.40 to 4.14.88,I found that 'HP FlexFabric 10Gb 2-port 554FLB Adapter' device is not in use. There are erros in dmesg log.
The Server is 'HP FlexServer B390'.
Device info:
lspci -n | grep 04:00
04:00.2 0c04: 19a2:0714 (rev 01)
...
04:00.2 Fibre Channel: Emulex Corporation OneConnect 10Gb FCoE Initiator (be3) (rev 01)
Subsystem: Hewlett-Packard Company NC554FLB 10Gb 2-port FlexFabric Converged Network Adapter
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR- FastB2B- DisINTx+
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0, Cache Line Size: 64 bytes
Interrupt: pin C routed to IRQ 95
...
Kernel driver in use: lpfc
The error info:
[ 1046.980480] lpfc 0000:04:00.3: 1:1303 Link Up Event x1 received Data: x1 x0 x4 x0 x0 x0 0
[ 1046.980482] lpfc 0000:04:00.3: 1:(0):2753 PLOGI failure DID:020009 Status:x3/x103
[ 1050.435167] lpfc 0000:04:00.2: 0:(0):2753 PLOGI failure DID:010012 Status:x3/x103
[ 1065.713327] lpfc 0000:04:00.3: 1:(0):2753 PLOGI failure DID:040002 Status:x3/x103
[ 1072.331933] lpfc 0000:04:00.2: 0:(0):2753 PLOGI failure DID:030003 Status:x3/x103
[ 1137.628132] lpfc 0000:04:00.2: 0:(0):0748 abort handler timed out waiting for aborting I/O (xri:x64) to complete: ret 0x2003, ID 2, LUN 0
[ 1137.644257] lpfc 0000:04:00.2: 0:(0):0713 SCSI layer issued Device Reset (2, 0) return x2002
[ 1139.676124] lpfc 0000:04:00.3: 1:(0):0748 abort handler timed out waiting for aborting I/O (xri:x464) to complete: ret 0x2003, ID 4, LUN 0
[ 1139.692242] lpfc 0000:04:00.3: 1:(0):0713 SCSI layer issued Device Reset (4, 0) return x2002
[ 1197.664150] lpfc 0000:04:00.2: 0:(0):0724 I/O flush failure for context LUN : cnt x1
[ 1197.664344] lpfc 0000:04:00.2: 0:(0):0723 SCSI layer issued Target Reset (2, 0) return x2002
[ 1199.704116] lpfc 0000:04:00.3: 1:(0):0724 I/O flush failure for context LUN : cnt x1
[ 1199.704368] lpfc 0000:04:00.3: 1:(0):0723 SCSI layer issued Target Reset (4, 0) return x2002
At the beginning, I thought the lpfc driver itself is the cause of the error.But,the error is still seen when 'lpfc driver' updates to the latest version.
To find the root cause and fix it, we checked the kernel version from 4.14.41 to 4.14.88, built and tested the kernel for booting.
The commit that caused error after bisect is ef86f3a72adb8a7931f67335560740a7ad696d1d,when I removed the commit the issue went away.
Commit info:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=…
During the test, I also found another issue that the system of 'HP FlexServer B390' server failed to boot by "hpsa driver timeout",basically, looks like the hpsa didn't detect the hard drives and udevd is stalled.
After upgrading from v4.14.54 to 4.14.55, hp system didn't boot ,but the system is ok when using the v4.14.55 kernel that has removed the commit.
The commit of ef86f3a72adb8a7931f67335560740a7ad696d1d also affects the HP Smart Array P220i RAID device.Because the v4.14.88 kernel is ok, I think that subsequent commits may have fixed the hpsa driver issue, but lpfc driver issue is not.
If there is any more info I can provide, just ask what would be useful. Any suggestions?
Thanks
Liang