BMC/Intel-BMC/linux.git/kernel/memremap.c, branch dev-4.17

mm: disallow mappings that conflict for devm_memremap_pages()

2018-08-03T05:47:31+00:00

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@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang Cc: Dan Williams Cc: Robert Elliott Cc: Jeff Moyer Cc: Matthew Wilcox Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

kernel/memremap: Remove stale devres_free() call

2018-03-06T18:58:54+00:00

devm_memremap_pages() was re-worked in e8d513483300 "memremap: change devm_memremap_pages interface to use struct dev_pagemap" to take a caller allocated struct dev_pagemap as a function parameter. A call to devres_free() was left in the error cleanup path which results in a kernel panic if the remap fails for some reason. Remove it to fix the panic and let devm_memremap_pages() fail gracefully. Fixes: e8d513483300 ("memremap: change devm_memremap_pages interface...") Signed-off-by: Oliver O'Halloran Reviewed-by: Christoph Hellwig Reviewed-by: Logan Gunthorpe Signed-off-by: Dan Williams

memremap: fix softlockup reports at teardown

2018-03-03T03:34:50+00:00

The cond_resched() currently in the setup path needs to be duplicated in the teardown path. Rather than require each instance of for_each_device_pfn() to open code the same sequence, embed it in the helper. Link: https://github.com/intel/ixpdimm_sw/issues/11 Cc: "Jérôme Glisse" Cc: Michal Hocko Cc: Christoph Hellwig Cc: Fixes: 71389703839e ("mm, zone_device: Replace {get, put}_zone_device_page()...") Signed-off-by: Dan Williams

mm: Fix devm_memremap_pages() collision handling

2018-01-20T00:29:56+00:00

If devm_memremap_pages() detects a collision while adding entries to the radix-tree, we call pgmap_radix_release(). Unfortunately, the function removes *all* entries for the range -- including the entries that caused the collision in the first place. Modify pgmap_radix_release() to take an additional argument to indicate where to stop, so that only newly added entries are removed from the tree. Cc: Fixes: 9476df7d80df ("mm: introduce find_dev_pagemap()") Signed-off-by: Jan H. Schönherr Signed-off-by: Dan Williams

mm: Fix memory size alignment in devm_memremap_pages_release()

2018-01-20T00:29:48+00:00

The functions devm_memremap_pages() and devm_memremap_pages_release() use different ways to calculate the section-aligned amount of memory. The latter function may use an incorrect size if the memory region is small but straddles a section border. Use the same code for both. Cc: Fixes: 5f29a77cd957 ("mm: fix mixed zone detection in devm_memremap_pages") Signed-off-by: Jan H. Schönherr Signed-off-by: Dan Williams

memremap: merge find_dev_pagemap into get_dev_pagemap

2018-01-08T19:46:23+00:00

There is only one caller of the trivial function find_dev_pagemap left, so just merge it into the caller. Signed-off-by: Christoph Hellwig Signed-off-by: Dan Williams

memremap: change devm_memremap_pages interface to use struct dev_pagemap

2018-01-08T19:46:23+00:00

This new interface is similar to how struct device (and many others) work. The caller initializes a 'struct dev_pagemap' as required and calls 'devm_memremap_pages'. This allows the pagemap structure to be embedded in another structure and thus container_of can be used. In this way application specific members can be stored in a containing struct. This will be used by the P2P infrastructure and HMM could probably be cleaned up to use it as well (instead of having it's own, similar 'hmm_devmem_pages_create' function). Signed-off-by: Logan Gunthorpe Signed-off-by: Christoph Hellwig Signed-off-by: Dan Williams

memremap: drop private struct page_map

2018-01-08T19:46:23+00:00

'struct page_map' is a private structure of 'struct dev_pagemap' but the latter replicates all the same fields as the former so there isn't much value in it. Thus drop it in favour of a completely public struct. This is a clean up in preperation for a more generally useful 'devm_memeremap_pages' interface. Signed-off-by: Logan Gunthorpe Signed-off-by: Christoph Hellwig Signed-off-by: Dan Williams

memremap: simplify duplicate region handling in devm_memremap_pages

2018-01-08T19:46:23+00:00

__radix_tree_insert already checks for duplicates and returns -EEXIST in that case, so remove the duplicate (and racy) duplicates check. Signed-off-by: Christoph Hellwig Reviewed-by: Logan Gunthorpe Signed-off-by: Dan Williams

memremap: remove to_vmem_altmap

2018-01-08T19:46:23+00:00

All callers are gone now. Signed-off-by: Christoph Hellwig Signed-off-by: Dan Williams