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authorDave Jiang <dave.jiang@intel.com>2018-07-26 16:37:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-07-26 19:38:03 -0700
commit15d36fecd0bdc7510b70a0e5ec6671140b3fce0c (patch)
treed0fed717ca47e0337028141b5c5860b3f0c57a4c /kernel/memremap.c
parent03758dbbe2b5c0627b361ad5b4a2c60f9964ccde (diff)
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mm: disallow mappings that conflict for devm_memremap_pages()
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@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Robert Elliott <elliott@hpe.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/memremap.c')
-rw-r--r--kernel/memremap.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 5857267a4af5..a734b1747466 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -176,10 +176,27 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
unsigned long pfn, pgoff, order;
pgprot_t pgprot = PAGE_KERNEL;
int error, nid, is_ram;
+ 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);
@@ -199,7 +216,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
mutex_lock(&pgmap_lock);
error = 0;
- align_end = align_start + align_size - 1;
foreach_order_pgoff(res, order, pgoff) {
error = __radix_tree_insert(&pgmap_radix,