- 02 Jun, 2020 40 commits
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Joerg Roedel authored
Track at which levels in the page-table entries were modified by vmap/vunmap. After the page-table has been modified, use that information do decide whether the new arch_sync_kernel_mappings() needs to be called. [akpm@linux-foundation.org: map_kernel_range_noflush() needs the arch_sync_kernel_mappings() call] Signed-off-by:
Joerg Roedel <jroedel@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Acked-by:
Andy Lutomirski <luto@kernel.org> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Link: http://lkml.kernel.org/r/20200515140023.25469-3-joro@8bytes.orgSigned-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Joerg Roedel authored
Patch series "mm: Get rid of vmalloc_sync_(un)mappings()", v3. After the recent issue with vmalloc and tracing code[1] on x86 and a long history of previous issues related to the vmalloc_sync_mappings() interface, I thought the time has come to remove it. Please see [2], [3], and [4] for some other issues in the past. The patches add tracking of page-table directory changes to the vmalloc and ioremap code. Depending on which page-table levels changes have been made, a new per-arch function is called: arch_sync_kernel_mappings(). On x86-64 with 4-level paging, this function will not be called more than 64 times in a systems runtime (because vmalloc-space takes 64 PGD entries which are only populated, but never cleared). As a side effect this also allows to get rid of vmalloc faults on x86, making it safe to touch vmalloc'ed memory in the page-fault handler. Note that this potentially includes per-cpu memory. This patch (of 7): Add page-table allocation functions which will keep track of changed directory entries. They are needed for new PGD, P4D, PUD, and PMD entries and will be used in vmalloc and ioremap code to decide whether any changes in the kernel mappings need to be synchronized between page-tables in the system. Signed-off-by:
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Christoph Hellwig authored
stack_alloc can use a slightly higher level vmalloc function. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com> Acked-by:
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Christoph Hellwig authored
alloc_vm_stack can use a slightly higher level vmalloc function. Signed-off-by:
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Christoph Hellwig authored
arch_alloc_vmap_stack can use a slightly higher level vmalloc function. Signed-off-by:
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Christoph Hellwig authored
Open code it in __bpf_map_area_alloc, which is the only caller. Also clean up __bpf_map_area_alloc to have a single vmalloc call with slightly different flags instead of the current two different calls. For this to compile for the nommu case add a __vmalloc_node_range stub to nommu.c. [akpm@linux-foundation.org: fix nommu.c build] Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Kelley <mikelley@microsoft.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200414131348.444715-27-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
No need to export the very low-level __vmalloc_node_range when the test module can use a slightly higher level variant. [akpm@linux-foundation.org: add missing `node' arg] [akpm@linux-foundation.org: fix riscv nommu build] Signed-off-by:
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Christoph Hellwig authored
Just use __vmalloc_node instead which gets and extra argument. To be able to to use __vmalloc_node in all caller make it available outside of vmalloc and implement it in nommu.c. [akpm@linux-foundation.org: fix nommu build] Signed-off-by:
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Christoph Hellwig authored
The real version just had a few callers that can open code it and remove one layer of indirection. The nommu stub was public but only had a single caller, so remove it and avoid a CONFIG_MMU ifdef in vmalloc.h. Signed-off-by:
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Christoph Hellwig authored
This is always PAGE_KERNEL now. Signed-off-by:
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Christoph Hellwig authored
The pgprot argument to __vmalloc is always PAGE_KERNEL now, so remove it. Signed-off-by:
Wei Liu <wei.liu@kernel.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200414131348.444715-22-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
The non-cached vmalloc mapping was initially added as a hack for the first-gen amigaone platform (6xx/book32s), isn't fully supported upstream, and which used the legacy radeon driver together with non-coherent DMA. However this only ever worked reliably for DRI . Remove the hack as it is the last user of __vmalloc passing a page protection flag other than PAGE_KERNEL and didn't do anything for other platforms with non-coherent DMA. Signed-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by:
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Christoph Hellwig authored
To help enforcing the W^X protection don't allow remapping existing pages as executable. x86 bits from Peter Zijlstra, arm64 bits from Mark Rutland. Signed-off-by:
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Christoph Hellwig authored
This is always PAGE_KERNEL - for long term mappings with other properties vmap should be used. Signed-off-by:
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Christoph Hellwig authored
This function just has a single caller, open code it there. Signed-off-by:
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Christoph Hellwig authored
Switch all callers to map_kernel_range, which symmetric to the unmap side (as well as the _noflush versions). Signed-off-by:
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Christoph Hellwig authored
None of the callers needs the number of pages, and a 0 / -errno return value is a lot more intuitive. Signed-off-by:
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Christoph Hellwig authored
This matches the map_kernel_range_noflush API. Also change to pass a size instead of the end, similar to the noflush version. Signed-off-by:
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Christoph Hellwig authored
These have non-static aliases called map_kernel_range_noflush and unmap_kernel_range_noflush that just differ slightly in the calling conventions that pass addr + size instead of an end. Signed-off-by:
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Christoph Hellwig authored
Ever use of addr in vb_free casts to unsigned long first, and the caller has an unsigned long version of the address available anyway. Just pass that and avoid all the casts. Signed-off-by:
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Christoph Hellwig authored
This allows to unexport map_vm_area and unmap_kernel_range, which are rather deep internal and should not be available to modules, as they for example allow fine grained control of mapping permissions, and also allow splitting the setup of a vmalloc area and the actual mapping and thus expose vmalloc internals. zsmalloc is typically built-in and continues to work (just like the percpu-vm code using a similar patter), while modular zsmalloc also continues to work, but must use copies. Signed-off-by:
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Christoph Hellwig authored
Rename the Kconfig variable to clarify the scope. Signed-off-by:
Minchan Kim <minchan@kernel.org> Acked-by:
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Christoph Hellwig authored
There are no modular users of this function. Signed-off-by:
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Christoph Hellwig authored
Switch the two remaining callers to use __get_vm_area_caller instead. Signed-off-by:
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Christoph Hellwig authored
These helpers are only used for remapping the ISA I/O base. Replace the mapping side with a remap_isa_range helper in isa-bridge.c that hard codes all the known arguments, and just remove __iounmap_at in favour of open coding it in the only caller. Signed-off-by:
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Christoph Hellwig authored
Factor code shared between pci_64 and electra_cf into a ioremap_pbh helper that follows the normal ioremap semantics, and returns a useful __iomem pointer. Note that it opencodes __ioremap_at as we know from the callers the slab is available. Switch pci_64 to also store the result as __iomem pointer, and unmap the result using iounmap instead of force casting and using vmalloc APIs. Signed-off-by:
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Christoph Hellwig authored
Replace the open coded instance of vmap with the actual function. In the non-contiguous (IOMMU) case this requires an extra find_vm_area, but given that this isn't a fast path function that is a small price to pay. Signed-off-by:
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Christoph Hellwig authored
Just use vmap instead of messing with vmalloc internals. Signed-off-by:
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Christoph Hellwig authored
vm_map_ram can keep mappings around after the vm_unmap_ram. Using that with non-PAGE_KERNEL mappings can lead to all kinds of aliasing issues. Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by:
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Christoph Hellwig authored
vmap does not take a gfp_t, the flags argument is for VM_* flags. Signed-off-by:
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Christoph Hellwig authored
Patch series "decruft the vmalloc API", v2. Peter noticed that with some dumb luck you can toast the kernel address space with exported vmalloc symbols. I used this as an opportunity to decruft the vmalloc.c API and make it much more systematic. This also removes any chance to create vmalloc mappings outside the designated areas or using executable permissions from modules. Besides that it removes more than 300 lines of code. This patch (of 29): Use the designated helper for allocating executable kernel memory, and remove the now unused PAGE_KERNEL_RX define. Signed-off-by:
Michael Kelley <mikelley@microsoft.com> Acked-by:
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Wetp Zhang authored
Some processes dont't want to be killed early, but in "Action Required" case, those also may be killed by BUS_MCEERR_AO when sharing memory with other which is accessing the fail memory. And sending SIGBUS with BUS_MCEERR_AO for action required error is strange, so ignore the non-current processes here. Suggested-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by:
Wetp Zhang <wetp.zy@linux.alibaba.com> Signed-off-by:
Pankaj Gupta <pankaj.gupta.linux@gmail.com> Link: http://lkml.kernel.org/r/1590817116-21281-1-git-send-email-wetp.zy@linux.alibaba.comSigned-off-by:
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chenqiwu authored
Since commit 25b2995a ("mm: remove MEMORY_DEVICE_PUBLIC support"), the assignment to 'page' for pte_devmap case has been unnecessary. Let's remove it. [willy@infradead.org: changelog] Signed-off-by:
chenqiwu <chenqiwu@xiaomi.com> Signed-off-by:
Matthew Wilcox <willy@infradead.org> Acked-by:
Michal Hocko <mhocko@suse.com> Link: http://lkml.kernel.org/r/1587349685-31712-1-git-send-email-qiwuchen55@gmail.comSigned-off-by:
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Huang Ying authored
Now, when reading /proc/PID/smaps, the PMD migration entry in page table is simply ignored. To improve the accuracy of /proc/PID/smaps, its parsing and processing is added. To test the patch, we run pmbench to eat 400 MB memory in background, then run /usr/bin/migratepages and `cat /proc/PID/smaps` every second. The issue as follows can be reproduced within 60 seconds. Before the patch, for the fully populated 400 MB anonymous VMA, some THP pages under migration may be lost as below. 7f3f6a7e5000-7f3f837e5000 rw-p 00000000 00:00 0 Size: 409600 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Rss: 407552 kB Pss: 407552 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 0 kB Private_Dirty: 407552 kB Referenced: 301056 kB Anonymous: 407552 kB LazyFree: 0 kB AnonHugePages: 405504 kB ShmemPmdMapped: 0 kB FilePmdMapped: 0 kB Shared_Hugetlb: 0 kB Private_Hugetlb: 0 kB Swap: 0 kB SwapPss: 0 kB Locked: 0 kB THPeligible: 1 VmFlags: rd wr mr mw me ac After the patch, it will be always, 7f3f6a7e5000-7f3f837e5000 rw-p 00000000 00:00 0 Size: 409600 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Rss: 409600 kB Pss: 409600 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 0 kB Private_Dirty: 409600 kB Referenced: 294912 kB Anonymous: 409600 kB LazyFree: 0 kB AnonHugePages: 407552 kB ShmemPmdMapped: 0 kB FilePmdMapped: 0 kB Shared_Hugetlb: 0 kB Private_Hugetlb: 0 kB Swap: 0 kB SwapPss: 0 kB Locked: 0 kB THPeligible: 1 VmFlags: rd wr mr mw me ac Signed-off-by:
"Huang, Ying" <ying.huang@intel.com> Signed-off-by:
Zi Yan <ziy@nvidia.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Link: http://lkml.kernel.org/r/20200403123059.1846960-1-ying.huang@intel.comSigned-off-by:
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Steven Price authored
The page table entry is passed in the 'val' argument to note_page(), however this was previously an "unsigned long" which is fine on 64-bit platforms. But for 32 bit x86 it is not always big enough to contain a page table entry which may be 64 bits. Change the type to u64 to ensure that it is always big enough. [akpm@linux-foundation.org: fix riscv] Reported-by:
Jan Beulich <jbeulich@suse.com> Signed-off-by:
Steven Price <steven.price@arm.com> Signed-off-by:
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Steven Price authored
Patch series "Fix W+X debug feature on x86" Jan alerted me[1] that the W+X detection debug feature was broken in x86 by my change[2] to switch x86 to use the generic ptdump infrastructure. Fundamentally the approach of trying to move the calculation of effective permissions into note_page() was broken because note_page() is only called for 'leaf' entries and the effective permissions are passed down via the internal nodes of the page tree. The solution I've taken here is to create a new (optional) callback which is called for all nodes of the page tree and therefore can calculate the effective permissions. Secondly on some configurations (32 bit with PAE) "unsigned long" is not large enough to store the table entries. The fix here is simple - let's just use a u64. [1] https://lore.kernel.org/lkml/d573dc7e-e742-84de-473d-f971142fa319@suse.com/ [2] 2ae27137 ("x86: mm: convert dump_pagetables to use walk_page_range") This patch (of 2): By switching the x86 page table dump code to use the generic code the effective permissions are no longer calculated correctly because the note_page() function is only called for *leaf* entries. To calculate the actual effective permissions it is necessary to observe the full hierarchy of the page tree. Introduce a new callback for ptdump which is called for every entry and can therefore update the prot_levels array correctly. note_page() can then simply access the appropriate element in the array. [steven.price@arm.com: make the assignment conditional on val != 0] Link: http://lkml.kernel.org/r/430c8ab4-e7cd-6933-dde6-087fac6db872@arm.com Fixes: 2ae27137 ("x86: mm: convert dump_pagetables to use walk_page_range") Reported-by:
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Zefan Li authored
While trying to use remote memcg charging in an out-of-tree kernel module I found it's not working, because the current thread is a workqueue thread. As we will probably encounter this issue in the future as the users of memalloc_use_memcg() grow, and it's nothing wrong for this usage, it's better we fix it now. Signed-off-by:
Zefan Li <lizefan@huawei.com> Signed-off-by:
Roman Gushchin <guro@fb.com> Reviewed-by:
Shakeel Butt <shakeelb@google.com> Acked-by:
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Jakub Kicinski authored
Add a memory.swap.high knob, which can be used to protect the system from SWAP exhaustion. The mechanism used for penalizing is similar to memory.high penalty (sleep on return to user space). That is not to say that the knob itself is equivalent to memory.high. The objective is more to protect the system from potentially buggy tasks consuming a lot of swap and impacting other tasks, or even bringing the whole system to stand still with complete SWAP exhaustion. Hopefully without the need to find per-task hard limits. Slowing misbehaving tasks down gradually allows user space oom killers or other protection mechanisms to react. oomd and earlyoom already do killing based on swap exhaustion, and memory.swap.high protection will help implement such userspace oom policies more reliably. We can use one counter for number of pages allocated under pressure to save struct task space and avoid two separate hierarchy walks on the hot path. The exact overage is calculated on return to user space, anyway. Take the new high limit into account when determining if swap is "full". Borrowing the explanation from Johannes: The idea behind "swap full" is that as long as the workload has plenty of swap space available and it's not changing its memory contents, it makes sense to generously hold on to copies of data in the swap device, even after the swapin. A later reclaim cycle can drop the page without any IO. Trading disk space for IO. But the only two ways to reclaim a swap slot is when they're faulted in and the references go away, or by scanning the virtual address space like swapoff does - which is very expensive (one could argue it's too expensive even for swapoff, it's often more practical to just reboot). So at some point in the fill level, we have to start freeing up swap slots on fault/swapin. Otherwise we could eventually run out of swap slots while they're filled with copies of data that is also in RAM. We don't want to OOM a workload because its available swap space is filled with redundant cache. Signed-off-by:
Jakub Kicinski <kuba@kernel.org> Signed-off-by:
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Jakub Kicinski authored
High memory limit is currently recorded directly in struct mem_cgroup. We are about to add a high limit for swap, move the field to struct page_counter and add some helpers. Signed-off-by:
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Jakub Kicinski authored
We will want to call calculate_high_delay() twice - once for memory and once for swap, and we should apply the clamp value to sum of the penalties. Clamping has to be applied outside of calculate_high_delay(). Signed-off-by:
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