- 01 Feb, 2017 10 commits
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Ard Biesheuvel authored
The build commands for the ARM and arm64 EFI stubs strip the .debug sections and other sections that may legally contain absolute relocations, in order to inspect the remaining sections for the presence of such relocations. This leaves us without debugging symbols in the stub for no good reason, considering that these sections are omitted from the kernel binary anyway, and that these relocations are thus only consumed by users of the ELF binary, such as debuggers. So move to 'strip' for performing the relocation check, and if it succeeds, invoke objcopy as before, but leaving the .debug sections in place. Note that these sections may refer to ksymtab/kcrctab contents, so leave those in place as well. Signed-off-by:
Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1485868902-20401-11-git-send-email-ard.biesheuvel@linaro.orgSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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Dave Young authored
It is not obvious if the reserved boot area are added correctly, add a efi_print_memmap() call to print the new memmap. Tested-by:
Nicolai Stange <nicstange@gmail.com> Signed-off-by:
Dave Young <dyoung@redhat.com> Signed-off-by:
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Dave Young authored
Before invoking the arch specific handler, efi_mem_reserve() reserves the given memory region through memblock. efi_bgrt_init() will call efi_mem_reserve() after mm_init(), at which time memblock is dead and should not be used anymore. The EFI BGRT code depends on ACPI initialization to get the BGRT ACPI table, so move parsing of the BGRT table to ACPI early boot code to ensure that efi_mem_reserve() in EFI BGRT code still use memblock safely. Tested-by:
Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by:
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Ard Biesheuvel authored
Instead of using void pointers, and casting them to correctly typed function pointers upon use, declare the runtime services pointers as function pointers using their respective prototypes, for which typedefs are already available. Signed-off-by:
Matt Fleming <matt@codeblueprint.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1485868902-20401-8-git-send-email-ard.biesheuvel@linaro.orgSigned-off-by:
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Colin Ian King authored
Signed-off-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
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Sai Praneeth authored
UEFI v2.6 introduces EFI_MEMORY_ATTRIBUTES_TABLE which describes memory protections that may be applied to the EFI Runtime code and data regions by the kernel. This enables the kernel to map these regions more strictly thereby increasing security. Presently, the only valid bits for the attribute field of a memory descriptor are EFI_MEMORY_RO and EFI_MEMORY_XP, hence use these bits to update the mappings in efi_pgd. The UEFI specification recommends to use this feature instead of EFI_PROPERTIES_TABLE and hence while updating EFI mappings we first check for EFI_MEMORY_ATTRIBUTES_TABLE and if it's present we update the mappings according to this table and hence disregarding EFI_PROPERTIES_TABLE even if it's published by the firmware. We consider EFI_PROPERTIES_TABLE only when EFI_MEMORY_ATTRIBUTES_TABLE is absent. Signed-off-by:
Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by:
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Sai Praneeth authored
UEFI v2.6 introduces a configuration table called EFI_MEMORY_ATTRIBUTES_TABLE which provides additional information about EFI runtime regions. Currently this table describes memory protections that may be applied to the EFI Runtime code and data regions by the kernel. Allocate a EFI_XXX bit to keep track of whether this feature is published by firmware or not. Signed-off-by:
Lee, Chun-Yi <jlee@suse.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1485868902-20401-5-git-send-email-ard.biesheuvel@linaro.orgSigned-off-by:
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Sai Praneeth authored
Since EFI_PROPERTIES_TABLE and EFI_MEMORY_ATTRIBUTES_TABLE deal with updating memory region attributes, it makes sense to call EFI_MEMORY_ATTRIBUTES_TABLE initialization function from the same place as EFI_PROPERTIES_TABLE. This also moves the EFI_MEMORY_ATTRIBUTES_TABLE initialization code to a more generic efi initialization path rather than ARM specific efi initialization. This is important because EFI_MEMORY_ATTRIBUTES_TABLE will be supported by x86 as well. Signed-off-by:
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Lukas Wunner authored
Eliminate the separate 32-bit and 64x- bit code paths by way of the shiny new efi_call_proto() macro. No functional change intended. Signed-off-by:
Lukas Wunner <lukas@wunner.de> Signed-off-by:
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Lukas Wunner authored
There's one ARM, one x86_32 and one x86_64 version which can be folded into a single shared version by masking their differences with the shiny new efi_call_proto() macro. No functional change intended. Signed-off-by:
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- 28 Jan, 2017 1 commit
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Jiri Kosina authored
Commit: 12976670 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode") stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode. It turns out though that there are 64-bit EFI implementations in the wild (this particular problem has been reported on a Lenovo Yoga 710-11IKB), which still make use of the first physical page for their own private use, even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory map. In case there is no mapping for this particular frame in the EFI pagetables, as soon as firmware tries to make use of it, a triple fault occurs and the system reboots (in case of the Yoga 710-11IKB this is very early during bootup). Fix that by always mapping the first page of physical memory into the EFI pagetables. We're free to hand this page to the BIOS, as trim_bios_range() will reserve the first page and isolate it away from memory allocators anyway. Note that just reverting 12976670 alone is not enough on v4.9-rc1+ to fix the regression on affected hardware, as this commit: ab72a27d ("x86/efi: Consolidate region mapping logic") later made the first physical frame not to be mapped anyway. Reported-by:
Hanka Pavlikova <hanka@ucw.cz> Signed-off-by:
Jiri Kosina <jkosina@suse.cz> Signed-off-by:
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- 25 Jan, 2017 27 commits
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Linus Torvalds authored
Merge fixes from Andrew Morton: "26 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (26 commits) MAINTAINERS: add Dan Streetman to zbud maintainers MAINTAINERS: add Dan Streetman to zswap maintainers mm: do not export ioremap_page_range symbol for external module mn10300: fix build error of missing fpu_save() romfs: use different way to generate fsid for BLOCK or MTD frv: add missing atomic64 operations mm, page_alloc: fix premature OOM when racing with cpuset mems update mm, page_alloc: move cpuset seqcount checking to slowpath mm, page_alloc: fix fast-path race with cpuset update or removal mm, page_alloc: fix check for NULL preferred_zone kernel/panic.c: add missing \n fbdev: color map copying bounds checking frv: add atomic64_add_unless() mm/mempolicy.c: do not put mempolicy before using its nodemask radix-tree: fix private list warnings Documentation/filesystems/proc.txt: add VmPin mm, memcg: do not retry precharge charges proc: add a schedule point in proc_pid_readdir() mm: alloc_contig: re-allow CMA to compact FS pages mm/slub.c: trace free objects at KERN_INFO ...
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Dan Streetman authored
Add myself as zbud maintainer. Link: http://lkml.kernel.org/r/20170124221705.26523-1-ddstreet@ieee.orgSigned-off-by:
Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjenning@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Dan Streetman authored
Add myself as zswap maintainer. Link: http://lkml.kernel.org/r/20170124212200.19052-1-ddstreet@ieee.orgSigned-off-by:
Seth Jennings <sjenning@redhat.com> Signed-off-by:
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zhong jiang authored
Recently, I've found cases in which ioremap_page_range was used incorrectly, in external modules, leading to crashes. This can be partly attributed to the fact that ioremap_page_range is lower-level, with fewer protections, as compared to the other functions that an external module would typically call. Those include: ioremap_cache ioremap_nocache ioremap_prot ioremap_uc ioremap_wc ioremap_wt ...each of which wraps __ioremap_caller, which in turn provides a safer way to achieve the mapping. Therefore, stop EXPORT-ing ioremap_page_range. Link: http://lkml.kernel.org/r/1485173220-29010-1-git-send-email-zhongjiang@huawei.comSigned-off-by:zhong jiang <zhongjiang@huawei.com> Reviewed-by:
John Hubbard <jhubbard@nvidia.com> Suggested-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
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Randy Dunlap authored
When CONFIG_FPU is not enabled on arch/mn10300, <asm/switch_to.h> causes a build error with a call to fpu_save(): kernel/built-in.o: In function `.L410': core.c:(.sched.text+0x28a): undefined reference to `fpu_save' Fix this by including <asm/fpu.h> in <asm/switch_to.h> so that an empty static inline fpu_save() is defined. Link: http://lkml.kernel.org/r/dc421c4f-4842-4429-1b99-92865c2f24b6@infradead.orgSigned-off-by:
Randy Dunlap <rdunlap@infradead.org> Reported-by:
kbuild test robot <fengguang.wu@intel.com> Reviewed-by:
David Howells <dhowells@redhat.com> Signed-off-by:
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Coly Li authored
Commit 8a59f5d2 ("fs/romfs: return f_fsid for statfs(2)") generates a 64bit id from sb->s_bdev->bd_dev. This is only correct when romfs is defined with CONFIG_ROMFS_ON_BLOCK. If romfs is only defined with CONFIG_ROMFS_ON_MTD, sb->s_bdev is NULL, referencing sb->s_bdev->bd_dev will triger an oops. Richard Weinberger points out that when CONFIG_ROMFS_BACKED_BY_BOTH=y, both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD are defined. Therefore when calling huge_encode_dev() to generate a 64bit id, I use the follow order to choose parameter, - CONFIG_ROMFS_ON_BLOCK defined use sb->s_bdev->bd_dev - CONFIG_ROMFS_ON_BLOCK undefined and CONFIG_ROMFS_ON_MTD defined use sb->s_dev when, - both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD undefined leave id as 0 When CONFIG_ROMFS_ON_MTD is defined and sb->s_mtd is not NULL, sb->s_dev is set to a device ID generated by MTD_BLOCK_MAJOR and mtd index, otherwise sb->s_dev is 0. This is a try-best effort to generate a uniq file system ID, if all the above conditions are not meet, f_fsid of this romfs instance will be 0. Generally only one romfs can be built on single MTD block device, this method is enough to identify multiple romfs instances in a computer. Link: http://lkml.kernel.org/r/1482928596-115155-1-git-send-email-colyli@suse.deSigned-off-by:
Coly Li <colyli@suse.de> Reported-by:
Nong Li <nongli1031@gmail.com> Tested-by:
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Sudip Mukherjee authored
Some more atomic64 operations were missing and as a result frv allmodconfig was failing. Add the missing operations. Link: http://lkml.kernel.org/r/1485193844-12850-1-git-send-email-sudip.mukherjee@codethink.co.ukSigned-off-by:
Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Cc: David Howells <dhowells@redhat.com> Signed-off-by:
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Vlastimil Babka authored
Ganapatrao Kulkarni reported that the LTP test cpuset01 in stress mode triggers OOM killer in few seconds, despite lots of free memory. The test attempts to repeatedly fault in memory in one process in a cpuset, while changing allowed nodes of the cpuset between 0 and 1 in another process. The problem comes from insufficient protection against cpuset changes, which can cause get_page_from_freelist() to consider all zones as non-eligible due to nodemask and/or current->mems_allowed. This was masked in the past by sufficient retries, but since commit 682a3385 ("mm, page_alloc: inline the fast path of the zonelist iterator") we fix the preferred_zoneref once, and don't iterate over the whole zonelist in further attempts, thus the only eligible zones might be placed in the zonelist before our starting point and we always miss them. A previous patch fixed this problem for current->mems_allowed. However, cpuset changes also update the task's mempolicy nodemask. The fix has two parts. We have to repeat the preferred_zoneref search when we detect cpuset update by way of seqcount, and we have to check the seqcount before considering OOM. [akpm@linux-foundation.org: fix typo in comment] Link: http://lkml.kernel.org/r/20170120103843.24587-5-vbabka@suse.cz Fixes: c33d6c06 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Reported-by:
Ganapatrao Kulkarni <gpkulkarni@gmail.com> Acked-by:
Mel Gorman <mgorman@techsingularity.net> Acked-by:
Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Vlastimil Babka authored
This is a preparation for the following patch to make review simpler. While the primary motivation is a bug fix, this also simplifies the fast path, although the moved code is only enabled when cpusets are in use. Link: http://lkml.kernel.org/r/20170120103843.24587-4-vbabka@suse.czSigned-off-by:
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Vlastimil Babka authored
Ganapatrao Kulkarni reported that the LTP test cpuset01 in stress mode triggers OOM killer in few seconds, despite lots of free memory. The test attempts to repeatedly fault in memory in one process in a cpuset, while changing allowed nodes of the cpuset between 0 and 1 in another process. One possible cause is that in the fast path we find the preferred zoneref according to current mems_allowed, so that it points to the middle of the zonelist, skipping e.g. zones of node 1 completely. If the mems_allowed is updated to contain only node 1, we never reach it in the zonelist, and trigger OOM before checking the cpuset_mems_cookie. This patch fixes the particular case by redoing the preferred zoneref search if we switch back to the original nodemask. The condition is also slightly changed so that when the last non-root cpuset is removed, we don't miss it. Note that this is not a full fix, and more patches will follow. Link: http://lkml.kernel.org/r/20170120103843.24587-3-vbabka@suse.cz Fixes: 682a3385 ("mm, page_alloc: inline the fast path of the zonelist iterator") Signed-off-by:
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Vlastimil Babka authored
Patch series "fix premature OOM regression in 4.7+ due to cpuset races". This is v2 of my attempt to fix the recent report based on LTP cpuset stress test [1]. The intention is to go to stable 4.9 LTSS with this, as triggering repeated OOMs is not nice. That's why the patches try to be not too intrusive. Unfortunately why investigating I found that modifying the testcase to use per-VMA policies instead of per-task policies will bring the OOM's back, but that seems to be much older and harder to fix problem. I have posted a RFC [2] but I believe that fixing the recent regressions has a higher priority. Longer-term we might try to think how to fix the cpuset mess in a better and less error prone way. I was for example very surprised to learn, that cpuset updates change not only task->mems_allowed, but also nodemask of mempolicies. Until now I expected the parameter to alloc_pages_nodemask() to be stable. I wonder why do we then treat cpusets specially in get_page_from_freelist() and distinguish HARDWALL etc, when there's unconditional intersection between mempolicy and cpuset. I would expect the nodemask adjustment for saving overhead in g_p_f(), but that clearly doesn't happen in the current form. So we have both crazy complexity and overhead, AFAICS. [1] https://lkml.kernel.org/r/CAFpQJXUq-JuEP=QPidy4p_=FN0rkH5Z-kfB4qBvsf6jMS87Edg@mail.gmail.com [2] https://lkml.kernel.org/r/7c459f26-13a6-a817-e508-b65b903a8378@suse.cz This patch (of 4): Since commit c33d6c06 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") we have a wrong check for NULL preferred_zone, which can theoretically happen due to concurrent cpuset modification. We check the zoneref pointer which is never NULL and we should check the zone pointer. Also document this in first_zones_zonelist() comment per Michal Hocko. Fixes: c33d6c06 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Link: http://lkml.kernel.org/r/20170120103843.24587-2-vbabka@suse.czSigned-off-by:
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Jiri Slaby authored
When a system panics, the "Rebooting in X seconds.." message is never printed because it lacks a new line. Fix it. Link: http://lkml.kernel.org/r/20170119114751.2724-1-jslaby@suse.czSigned-off-by:
Jiri Slaby <jslaby@suse.cz> Signed-off-by:
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Kees Cook authored
Copying color maps to userspace doesn't check the value of to->start, which will cause kernel heap buffer OOB read due to signedness wraps. CVE-2016-8405 Link: http://lkml.kernel.org/r/20170105224249.GA50925@beast Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
Kees Cook <keescook@chromium.org> Reported-by: Peter Pi (@heisecode) of Trend Micro Cc: Min Chong <mchong@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Sudip Mukherjee authored
The build of frv allmodconfig was failing with the error: lib/atomic64_test.c:209:9: error: implicit declaration of function 'atomic64_add_unless' All the atomic64 operations were defined in frv, but atomic64_add_unless() was not done. Implement atomic64_add_unless() as done in other arches. Link: http://lkml.kernel.org/r/1484781236-6698-1-git-send-email-sudipm.mukherjee@gmail.comSigned-off-by:
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Vlastimil Babka authored
Since commit be97a41b ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma") alloc_pages_vma() can potentially free a mempolicy by mpol_cond_put() before accessing the embedded nodemask by __alloc_pages_nodemask(). The commit log says it's so "we can use a single exit path within the function" but that's clearly wrong. We can still do that when doing mpol_cond_put() after the allocation attempt. Make sure the mempolicy is not freed prematurely, otherwise __alloc_pages_nodemask() can end up using a bogus nodemask, which could lead e.g. to premature OOM. Fixes: be97a41b ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma") Link: http://lkml.kernel.org/r/20170118141124.8345-1-vbabka@suse.czSigned-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by:
David Rientjes <rientjes@google.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by:
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Matthew Wilcox authored
The newly introduced warning in radix_tree_free_nodes() was testing the wrong variable; it should have been 'old' instead of 'node'. Fixes: ea07b862 ("mm: workingset: fix use-after-free in shadow node shrinker") Link: http://lkml.kernel.org/r/20170118163746.GA32495@cmpxchg.orgSigned-off-by:
Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Fabian Frederick authored
Commit bc3e53f6 ("mm: distinguish between mlocked and pinned pages") added VmPin in /proc/<pid>/status. Report that in Documentation/filesystems/proc.txt Also move Umask after Name to keep correct order. Link: http://lkml.kernel.org/r/20170114201219.30387-1-fabf@skynet.beSigned-off-by:
Fabian Frederick <fabf@skynet.be> Cc: Christoph Lameter <cl@linux.com> Signed-off-by:
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David Rientjes authored
When memory.move_charge_at_immigrate is enabled and precharges are depleted during move, mem_cgroup_move_charge_pte_range() will attempt to increase the size of the precharge. Prevent precharges from ever looping by setting __GFP_NORETRY. This was probably the intention of the GFP_KERNEL & ~__GFP_NORETRY, which is pointless as written. Fixes: 0029e19e ("mm: memcontrol: remove explicit OOM parameter in charge path") Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701130208510.69402@chino.kir.corp.google.comSigned-off-by:
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Eric Dumazet authored
We have seen proc_pid_readdir() invocations holding cpu for more than 50 ms. Add a cond_resched() to be gentle with other tasks. [akpm@linux-foundation.org: coding style fix] Link: http://lkml.kernel.org/r/1484238380.15816.42.camel@edumazet-glaptop3.roam.corp.google.comSigned-off-by:
Eric Dumazet <edumazet@google.com> Signed-off-by:
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Lucas Stach authored
Commit 73e64c51 ("mm, compaction: allow compaction for GFP_NOFS requests") changed compation to skip FS pages if not explicitly allowed to touch them, but missed to update the CMA compact_control. This leads to a very high isolation failure rate, crippling performance of CMA even on a lightly loaded system. Re-allow CMA to compact FS pages by setting the correct GFP flags, restoring CMA behavior and performance to the kernel 4.9 level. Fixes: 73e64c51 (mm, compaction: allow compaction for GFP_NOFS requests) Link: http://lkml.kernel.org/r/20170113115155.24335-1-l.stach@pengutronix.deSigned-off-by:
Lucas Stach <l.stach@pengutronix.de> Acked-by:
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Daniel Thompson authored
Currently when trace is enabled (e.g. slub_debug=T,kmalloc-128 ) the trace messages are mostly output at KERN_INFO. However the trace code also calls print_section() to hexdump the head of a free object. This is hard coded to use KERN_ERR, meaning the console is deluged with trace messages even if we've asked for quiet. Fix this the obvious way but adding a level parameter to print_section(), allowing calls from the trace code to use the same trace level as other trace messages. Link: http://lkml.kernel.org/r/20170113154850.518-1-daniel.thompson@linaro.orgSigned-off-by:
Daniel Thompson <daniel.thompson@linaro.org> Acked-by:
Christoph Lameter <cl@linux.com> Acked-by:
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Andrea Arcangeli authored
With >=32 CPUs the userfaultfd selftest triggered a graceful but unexpected SIGBUS because VM_FAULT_RETRY was returned by handle_userfault() despite the UFFDIO_COPY wasn't completed. This seems caused by rwsem waking the thread blocked in handle_userfault() and we can't run up_read() before the wait_event sequence is complete. Keeping the wait_even sequence identical to the first one, would require running userfaultfd_must_wait() again to know if the loop should be repeated, and it would also require retaking the rwsem and revalidating the whole vma status. It seems simpler to wait the targeted wakeup so that if false wakeups materialize we still wait for our specific wakeup event, unless of course there are signals or the uffd was released. Debug code collecting the stack trace of the wakeup showed this: $ ./userfaultfd 100 99999 nr_pages: 25600, nr_pages_per_cpu: 800 bounces: 99998, mode: racing ver poll, userfaults: 32 35 90 232 30 138 69 82 34 30 139 40 40 31 20 19 43 13 15 28 27 38 21 43 56 22 1 17 31 8 4 2 bounces: 99997, mode: rnd ver poll, Bus error (core dumped) save_stack_trace+0x2b/0x50 try_to_wake_up+0x2a6/0x580 wake_up_q+0x32/0x70 rwsem_wake+0xe0/0x120 call_rwsem_wake+0x1b/0x30 up_write+0x3b/0x40 vm_mmap_pgoff+0x9c/0xc0 SyS_mmap_pgoff+0x1a9/0x240 SyS_mmap+0x22/0x30 entry_SYSCALL_64_fastpath+0x1f/0xbd 0xffffffffffffffff FAULT_FLAG_ALLOW_RETRY missing 70 CPU: 24 PID: 1054 Comm: userfaultfd Tainted: G W 4.8.0+ #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 Call Trace: dump_stack+0xb8/0x112 handle_userfault+0x572/0x650 handle_mm_fault+0x12cb/0x1520 __do_page_fault+0x175/0x500 trace_do_page_fault+0x61/0x270 do_async_page_fault+0x19/0x90 async_page_fault+0x25/0x30 This always happens when the main userfault selftest thread is running clone() while glibc runs either mprotect or mmap (both taking mmap_sem down_write()) to allocate the thread stack of the background threads, while locking/userfault threads already run at full throttle and are susceptible to false wakeups that may cause handle_userfault() to return before than expected (which results in graceful SIGBUS at the next attempt). This was reproduced only with >=32 CPUs because the loop to start the thread where clone() is too quick with fewer CPUs, while with 32 CPUs there's already significant activity on ~32 locking and userfault threads when the last background threads are started with clone(). This >=32 CPUs SMP race condition is likely reproducible only with the selftest because of the much heavier userfault load it generates if compared to real apps. We'll have to allow "one more" VM_FAULT_RETRY for the WP support and a patch floating around that provides it also hidden this problem but in reality only is successfully at hiding the problem. False wakeups could still happen again the second time handle_userfault() is invoked, even if it's a so rare race condition that getting false wakeups twice in a row is impossible to reproduce. This full fix is needed for correctness, the only alternative would be to allow VM_FAULT_RETRY to be returned infinitely. With this fix the WP support can stick to a strict "one more" VM_FAULT_RETRY logic (no need of returning it infinite times to avoid the SIGBUS). Link: http://lkml.kernel.org/r/20170111005535.13832-2-aarcange@redhat.comSigned-off-by:Andrea Arcangeli <aarcange@redhat.com> Reported-by:
Shubham Kumar Sharma <shubham.kumar.sharma@oracle.com> Tested-by:
Mike Kravetz <mike.kravetz@oracle.com> Acked-by:
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Arnd Bergmann authored
gcc-7 produces a harmless false-postive warning about a possible NULL pointer access: drivers/memstick/core/memstick.c: In function 'h_memstick_read_dev_id': drivers/memstick/core/memstick.c:309:3: error: argument 2 null where non-null expected [-Werror=nonnull] memcpy(mrq->data, buf, mrq->data_len); This can't happen because the caller sets the command to 'MS_TPC_READ_REG', which causes the data direction to be 'READ' and the NULL pointer not accessed. As a simple workaround for the warning, we can pass a pointer to the data that we actually want to read into. This is not needed here, but also harmless, and lets the compiler know that the access is ok. Link: http://lkml.kernel.org/r/20170111144143.548867-1-arnd@arndb.deSigned-off-by:Arnd Bergmann <arnd@arndb.de> Cc: Alex Dubov <oakad@yahoo.com> Signed-off-by:
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Don Zickus authored
On an overloaded system, it is possible that a change in the watchdog threshold can be delayed long enough to trigger a false positive. This can easily be achieved by having a cpu spinning indefinitely on a task, while another cpu updates watchdog threshold. What happens is while trying to park the watchdog threads, the hrtimers on the other cpus trigger and reprogram themselves with the new slower watchdog threshold. Meanwhile, the nmi watchdog is still programmed with the old faster threshold. Because the one cpu is blocked, it prevents the thread parking on the other cpus from completing, which is needed to shutdown the nmi watchdog and reprogram it correctly. As a result, a false positive from the nmi watchdog is reported. Fix this by setting a park_in_progress flag to block all lockups until the parking is complete. Fix provided by Ulrich Obergfell. [akpm@linux-foundation.org: s/park_in_progress/watchdog_park_in_progress/] Link: http://lkml.kernel.org/r/1481041033-192236-1-git-send-email-dzickus@redhat.comSigned-off-by:
Don Zickus <dzickus@redhat.com> Reviewed-by:
Aaron Tomlin <atomlin@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by:
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Ross Zwisler authored
As reported by Arnd: https://lkml.org/lkml/2017/1/10/756 Compiling with the following configuration: # CONFIG_EXT2_FS is not set # CONFIG_EXT4_FS is not set # CONFIG_XFS_FS is not set # CONFIG_FS_IOMAP depends on the above filesystems, as is not set CONFIG_FS_DAX=y generates build warnings about unused functions in fs/dax.c: fs/dax.c:878:12: warning: `dax_insert_mapping' defined but not used [-Wunused-function] static int dax_insert_mapping(struct address_space *mapping, ^~~~~~~~~~~~~~~~~~ fs/dax.c:572:12: warning: `copy_user_dax' defined but not used [-Wunused-function] static int copy_user_dax(struct block_device *bdev, sector_t sector, size_t size, ^~~~~~~~~~~~~ fs/dax.c:542:12: warning: `dax_load_hole' defined but not used [-Wunused-function] static int dax_load_hole(struct address_space *mapping, void **entry, ^~~~~~~~~~~~~ fs/dax.c:312:14: warning: `grab_mapping_entry' defined but not used [-Wunused-function] static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, ^~~~~~~~~~~~~~~~~~ Now that the struct buffer_head based DAX fault paths and I/O path have been removed we really depend on iomap support being present for DAX. Make this explicit by selecting FS_IOMAP if we compile in DAX support. This allows us to remove conditional selections of FS_IOMAP when FS_DAX was present for ext2 and ext4, and to remove an #ifdef in fs/dax.c. Link: http://lkml.kernel.org/r/1484087383-29478-1-git-send-email-ross.zwisler@linux.intel.comSigned-off-by:
Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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Keno Fischer authored
In commit 19be0eaf ("mm: remove gup_flags FOLL_WRITE games from __get_user_pages()"), the mm code was changed from unsetting FOLL_WRITE after a COW was resolved to setting the (newly introduced) FOLL_COW instead. Simultaneously, the check in gup.c was updated to still allow writes with FOLL_FORCE set if FOLL_COW had also been set. However, a similar check in huge_memory.c was forgotten. As a result, remote memory writes to ro regions of memory backed by transparent huge pages cause an infinite loop in the kernel (handle_mm_fault sets FOLL_COW and returns 0 causing a retry, but follow_trans_huge_pmd bails out immidiately because `(flags & FOLL_WRITE) && !pmd_write(*pmd)` is true. While in this state the process is stil SIGKILLable, but little else works (e.g. no ptrace attach, no other signals). This is easily reproduced with the following code (assuming thp are set to always): #include <assert.h> #include <fcntl.h> #include <stdint.h> #include <stdio.h> #include <string.h> #include <sys/mman.h> #include <sys/stat.h> #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> #define TEST_SIZE 5 * 1024 * 1024 int main(void) { int status; pid_t child; int fd = open("/proc/self/mem", O_RDWR); void *addr = mmap(NULL, TEST_SIZE, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); assert(addr != MAP_FAILED); pid_t parent_pid = getpid(); if ((child = fork()) == 0) { void *addr2 = mmap(NULL, TEST_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); assert(addr2 != MAP_FAILED); memset(addr2, 'a', TEST_SIZE); pwrite(fd, addr2, TEST_SIZE, (uintptr_t)addr); return 0; } assert(child == waitpid(child, &status, 0)); assert(WIFEXITED(status) && WEXITSTATUS(status) == 0); return 0; } Fix this by updating follow_trans_huge_pmd in huge_memory.c analogously to the update in gup.c in the original commit. The same pattern exists in follow_devmap_pmd. However, we should not be able to reach that check with FOLL_COW set, so add WARN_ONCE to make sure we notice if we ever do. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170106015025.GA38411@juliacomputing.comSigned-off-by:
Keno Fischer <keno@juliacomputing.com> Acked-by:
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Yasuaki Ishimatsu authored
online_{kernel|movable} is used to change the memory zone to ZONE_{NORMAL|MOVABLE} and online the memory. To check that memory zone can be changed, zone_can_shift() is used. Currently the function returns minus integer value, plus integer value and 0. When the function returns minus or plus integer value, it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}. But when the function returns 0, there are two meanings. One of the meanings is that the memory zone does not need to be changed. For example, when memory is in ZONE_NORMAL and onlined by online_kernel the memory zone does not need to be changed. Another meaning is that the memory zone cannot be changed. When memory is in ZONE_NORMAL and onlined by online_movable, the memory zone may not be changed to ZONE_MOVALBE due to memory online limitation(see Documentation/memory-hotplug.txt). In this case, memory must not be onlined. The patch changes the return type of zone_can_shift() so that memory online operation fails when memory zone cannot be changed as follows: Before applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 8388608 managed 8388608 online_movable operation succeeded. But memory is onlined as ZONE_NORMAL, not ZONE_MOVABLE. After applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state bash: echo: write error: Invalid argument # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 online_movable operation failed because of failure of changing the memory zone from ZONE_NORMAL to ZONE_MOVABLE Fixes: df429ac0 ("memory-hotplug: more general validation of zone during online") Link: http://lkml.kernel.org/r/2f9c3837-33d7-b6e5-59c0-6ca4372b2d84@gmail.comSigned-off-by:Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by:
Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by:
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- 24 Jan, 2017 2 commits
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git://git.infradead.org/linux-platform-drivers-x86Linus Torvalds authored
Pull x86 platform-driver fixes from Andy Shevchenko: "This is my first pull request since I become a co-maintainer of Platform Drivers x86 subsystem. It's a bit bigger than usual due to material collected for almost two weeks in a row. MAINTAINERS: - Add myself to X86 PLATFORM DRIVERS as a co-maintainer ideapad-laptop: - handle ACPI event 1 intel_mid_powerbtn: - Set IRQ_ONESHOT surface3-wmi: - fix uninitialized symbol - Shut up unused-function warning mlx-platform: - free first dev on error" * tag 'platform-drivers-x86-v4.10-4' of git://git.infradead.org/linux-platform-drivers-x86: MAINTAINERS: Add myself to X86 PLATFORM DRIVERS as a co-maintainer platform/x86: ideapad-laptop: handle ACPI event 1 platform/x86: intel_mid_powerbtn: Set IRQ_ONESHOT platform/x86: surface3-wmi: fix uninitialized symbol platform/x86: surface3-wmi: Shut up unused-function warning platform/x86: mlx-platform: free first dev on error
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git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespaceLinus Torvalds authored
Pull namespace fix from Eric Biederman: "This has a single brown bag fix. The possible deadlock with dec_pid_namespaces that I had thought was fixed earlier turned out only to have been moved. So instead of being cleaver this change takes ucounts_lock with irqs disabled. So dec_ucount can be used from any context without fear of deadlock. The items accounted for dec_ucount and inc_ucount are all comparatively heavy weight objects so I don't exepct this will have any measurable performance impact" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: userns: Make ucounts lock irq-safe
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