4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dave Jiang <dave.jiang@xxxxxxxxx>
commit 15d36fecd0bdc7510b70a0e5ec6671140b3fce0c upstream.
When pmem namespaces created are smaller than section size, this can
cause an issue during removal and gpf was observed:
general protection fault: 0000 1 SMP PTI
CPU: 36 PID: 3941 Comm: ndctl Tainted: G W 4.14.28-1.el7uek.x86_64 #2
task: ffff88acda150000 task.stack: ffffc900233a4000
RIP: 0010:__put_page+0x56/0x79
Call Trace:
devm_memremap_pages_release+0x155/0x23a
release_nodes+0x21e/0x260
devres_release_all+0x3c/0x48
device_release_driver_internal+0x15c/0x207
device_release_driver+0x12/0x14
unbind_store+0xba/0xd8
drv_attr_store+0x27/0x31
sysfs_kf_write+0x3f/0x46
kernfs_fop_write+0x10f/0x18b
__vfs_write+0x3a/0x16d
vfs_write+0xb2/0x1a1
SyS_write+0x55/0xb9
do_syscall_64+0x79/0x1ae
entry_SYSCALL_64_after_hwframe+0x3d/0x0
Add code to check whether we have a mapping already in the same section
and prevent additional mappings from being created if that is the case.
Link: http://lkml.kernel.org/r/152909478401.50143.312364396244072931.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Robert Elliott <elliott@xxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/memremap.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -355,10 +355,27 @@ void *devm_memremap_pages(struct device
struct dev_pagemap *pgmap;
struct page_map *page_map;
int error, nid, is_ram, i = 0;
+ struct dev_pagemap *conflict_pgmap;
align_start = res->start & ~(SECTION_SIZE - 1);
align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
- align_start;
+ align_end = align_start + align_size - 1;
+
+ conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_start), NULL);
+ if (conflict_pgmap) {
+ dev_WARN(dev, "Conflicting mapping in same section\n");
+ put_dev_pagemap(conflict_pgmap);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_end), NULL);
+ if (conflict_pgmap) {
+ dev_WARN(dev, "Conflicting mapping in same section\n");
+ put_dev_pagemap(conflict_pgmap);
+ return ERR_PTR(-ENOMEM);
+ }
+
is_ram = region_intersects(align_start, align_size,
IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
@@ -396,7 +413,6 @@ void *devm_memremap_pages(struct device
mutex_lock(&pgmap_lock);
error = 0;
- align_end = align_start + align_size - 1;
foreach_order_pgoff(res, order, pgoff) {
struct dev_pagemap *dup;
