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* Merge tag 'gcc-plugins-v4.9-rc1' of ↵Linus Torvalds2016-10-151-0/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull gcc plugins update from Kees Cook: "This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals" * tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: latent_entropy: Mark functions with __latent_entropy gcc-plugins: Add latent_entropy plugin
| * latent_entropy: Mark functions with __latent_entropyEmese Revfy2016-10-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __latent_entropy gcc attribute can be used only on functions and variables. If it is on a function then the plugin will instrument it for gathering control-flow entropy. If the attribute is on a variable then the plugin will initialize it with random contents. The variable must be an integer, an integer array type or a structure with integer fields. These specific functions have been selected because they are init functions (to help gather boot-time entropy), are called at unpredictable times, or they have variable loops, each of which provide some level of latent entropy. Signed-off-by: Emese Revfy <re.emese@gmail.com> [kees: expanded commit message] Signed-off-by: Kees Cook <keescook@chromium.org>
| * gcc-plugins: Add latent_entropy pluginEmese Revfy2016-10-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals. The need for very-early boot entropy tends to be very architecture or system design specific, so this plugin is more suited for those sorts of special cases. The existing kernel RNG already attempts to extract entropy from reliable runtime variation, but this plugin takes the idea to a logical extreme by permuting a global variable based on any variation in code execution (e.g. a different value (and permutation function) is used to permute the global based on loop count, case statement, if/then/else branching, etc). To do this, the plugin starts by inserting a local variable in every marked function. The plugin then adds logic so that the value of this variable is modified by randomly chosen operations (add, xor and rol) and random values (gcc generates separate static values for each location at compile time and also injects the stack pointer at runtime). The resulting value depends on the control flow path (e.g., loops and branches taken). Before the function returns, the plugin mixes this local variable into the latent_entropy global variable. The value of this global variable is added to the kernel entropy pool in do_one_initcall() and _do_fork(), though it does not credit any bytes of entropy to the pool; the contents of the global are just used to mix the pool. Additionally, the plugin can pre-initialize arrays with build-time random contents, so that two different kernel builds running on identical hardware will not have the same starting values. Signed-off-by: Emese Revfy <re.emese@gmail.com> [kees: expanded commit message and code comments] Signed-off-by: Kees Cook <keescook@chromium.org>
* | Merge branch 'for-4.9' of ↵Linus Torvalds2016-10-141-18/+20
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu updates from Tejun Heo: - Nick improved generic implementations of percpu operations which modify the variable and return so that they calculate the physical address only once. - percpu_ref percpu <-> atomic mode switching improvements. The patchset was originally posted about a year ago but fell through the crack. - misc non-critical fixes. * 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: mm/percpu.c: fix potential memory leakage for pcpu_embed_first_chunk() mm/percpu.c: correct max_distance calculation for pcpu_embed_first_chunk() percpu: eliminate two sparse warnings percpu: improve generic percpu modify-return implementation percpu-refcount: init ->confirm_switch member properly percpu_ref: allow operation mode switching operations to be called concurrently percpu_ref: restructure operation mode switching percpu_ref: unify staggered atomic switching wait behavior percpu_ref: reorganize __percpu_ref_switch_to_atomic() and relocate percpu_ref_switch_to_atomic() percpu_ref: remove unnecessary RCU grace period for staggered atomic switching confirmation
| * | mm/percpu.c: fix potential memory leakage for pcpu_embed_first_chunk()zijun_hu2016-10-051-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | in order to ensure the percpu group areas within a chunk aren't distributed too sparsely, pcpu_embed_first_chunk() goes to error handling path when a chunk spans over 3/4 VMALLOC area, however, during the error handling, it forget to free the memory allocated for all percpu groups by going to label @out_free other than @out_free_areas. it will cause memory leakage issue if the rare scene really happens, in order to fix the issue, we check chunk spanned area immediately after completing memory allocation for all percpu groups, we go to label @out_free_areas to free the memory then return if the checking is failed. in order to verify the approach, we dump all memory allocated then enforce the jump then dump all memory freed, the result is okay after checking whether we free all memory we allocate in this function. BTW, The approach is chosen after thinking over the below scenes - we don't go to label @out_free directly to fix this issue since we maybe free several allocated memory blocks twice - the aim of jumping after pcpu_setup_first_chunk() is bypassing free usable memory other than handling error, moreover, the function does not return error code in any case, it either panics due to BUG_ON() or return 0. Signed-off-by: zijun_hu <zijun_hu@htc.com> Tested-by: zijun_hu <zijun_hu@htc.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | mm/percpu.c: correct max_distance calculation for pcpu_embed_first_chunk()zijun_hu2016-10-051-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pcpu_embed_first_chunk() calculates the range a percpu chunk spans into @max_distance and uses it to ensure that a chunk is not too big compared to the total vmalloc area. However, during calculation, it used incorrect top address by adding a unit size to the highest group's base address. This can make the calculated max_distance slightly smaller than the actual distance although given the scale of values involved the error is very unlikely to have an actual impact. Fix this issue by adding the group's size instead of a unit size. BTW, The type of variable max_distance is changed from size_t to unsigned long too based on below consideration: - type unsigned long usually have same width with IP core registers and can be applied at here very well - make @max_distance type consistent with the operand calculated against it such as @ai->groups[i].base_offset and macro VMALLOC_TOTAL - type unsigned long is more universal then size_t, size_t is type defined to unsigned int or unsigned long among various ARCHs usually Signed-off-by: zijun_hu <zijun_hu@htc.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | | Disable the __builtin_return_address() warning globally after allLinus Torvalds2016-10-121-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This affectively reverts commit 377ccbb48373 ("Makefile: Mute warning for __builtin_return_address(>0) for tracing only") because it turns out that it really isn't tracing only - it's all over the tree. We already also had the warning disabled separately for mm/usercopy.c (which this commit also removes), and it turns out that we will also want to disable it for get_lock_parent_ip(), that is used for at least TRACE_IRQFLAGS. Which (when enabled) ends up being all over the tree. Steven Rostedt had a patch that tried to limit it to just the config options that actually triggered this, but quite frankly, the extra complexity and abstraction just isn't worth it. We have never actually had a case where the warning is actually useful, so let's just disable it globally and not worry about it. Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mappingCatalin Marinas2016-10-115-9/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a physical address to a virtual one using __va(). However, such physical addresses may sometimes be located in highmem and using __va() is incorrect, leading to inconsistent object tracking in kmemleak. The following functions have been added to the kmemleak API and they take a physical address as the object pointer. They only perform the corresponding action if the address has a lowmem mapping: kmemleak_alloc_phys kmemleak_free_part_phys kmemleak_not_leak_phys kmemleak_ignore_phys The affected calling places have been updated to use the new kmemleak API. Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2016-10-101-11/+11
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
| * \ \ Merge remote-tracking branch 'ovl/rename2' into for-linusAl Viro2016-10-1011-56/+60
| |\ \ \
| | * | | fs: rename "rename2" i_op to "rename"Miklos Szeredi2016-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generated patch: sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2` sed -i "s/\brename2\b/rename/g" `git grep -wl rename2` Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | | | fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani2016-09-271-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | Merge branch 'work.xattr' of ↵Linus Torvalds2016-10-101-15/+0
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs xattr updates from Al Viro: "xattr stuff from Andreas This completes the switch to xattr_handler ->get()/->set() from ->getxattr/->setxattr/->removexattr" * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Remove {get,set,remove}xattr inode operations xattr: Stop calling {get,set,remove}xattr inode operations vfs: Check for the IOP_XATTR flag in listxattr xattr: Add __vfs_{get,set,remove}xattr helpers libfs: Use IOP_XATTR flag for empty directory handling vfs: Use IOP_XATTR flag for bad-inode handling vfs: Add IOP_XATTR inode operations flag vfs: Move xattr_resolve_name to the front of fs/xattr.c ecryptfs: Switch to generic xattr handlers sockfs: Get rid of getxattr iop sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names kernfs: Switch to generic xattr handlers hfs: Switch to generic xattr handlers jffs2: Remove jffs2_{get,set,remove}xattr macros xattr: Remove unnecessary NULL attribute name check
| * | | | | vfs: Remove {get,set,remove}xattr inode operationsAndreas Gruenbacher2016-10-071-15/+0
| | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | These inode operations are no longer used; remove them. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | Merge branch 'work.splice_read' of ↵Linus Torvalds2016-10-101-1/+1
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull splice fixups from Al Viro: "A couple of fixups for interaction of pipe-backed iov_iter with O_DIRECT reads + constification of a couple of primitives in uio.h missed by previous rounds. Kudos to davej - his fuzzing has caught those bugs" * 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [btrfs] fix check_direct_IO() for non-iovec iterators constify iov_iter_count() and iter_is_iovec() fix ITER_PIPE interaction with direct_IO
| * | | | | fix ITER_PIPE interaction with direct_IOAl Viro2016-10-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | by making sure we call iov_iter_advance() on original iov_iter even if direct_IO (done on its copy) has returned 0. It's a no-op for old iov_iter flavours and does the right thing (== truncation of the stuff we'd allocated, but not filled) in ITER_PIPE case. Failures (e.g. -EIO) get caught and dealt with by cleanup in generic_file_read_iter(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | Merge branch 'work.misc' of ↵Linus Torvalds2016-10-101-1/+1
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
| * \ \ \ \ \ Merge remote-tracking branch 'jk/vfs' into work.miscAl Viro2016-10-081-1/+1
| |\ \ \ \ \ \ | | |_|/ / / / | |/| | | | |
| | * | | | | fs: Give dentry to inode_change_ok() instead of inodeJan Kara2016-09-221-1/+1
| | | |_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* | | | | | Merge branch 'mm-pkeys-for-linus' of ↵Linus Torvalds2016-10-101-5/+85
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull protection keys syscall interface from Thomas Gleixner: "This is the final step of Protection Keys support which adds the syscalls so user space can actually allocate keys and protect memory areas with them. Details and usage examples can be found in the documentation. The mm side of this has been acked by Mel" * 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pkeys: Update documentation x86/mm/pkeys: Do not skip PKRU register if debug registers are not used x86/pkeys: Fix pkeys build breakage for some non-x86 arches x86/pkeys: Add self-tests x86/pkeys: Allow configuration of init_pkru x86/pkeys: Default to a restrictive init PKRU pkeys: Add details of system call use to Documentation/ generic syscalls: Wire up memory protection keys syscalls x86: Wire up protection keys system calls x86/pkeys: Allocation/free syscalls x86/pkeys: Make mprotect_key() mask off additional vm_flags mm: Implement new pkey_mprotect() system call x86/pkeys: Add fault handling for PF_PK page fault bit
| * | | | | | x86/pkeys: Allocation/free syscallsDave Hansen2016-09-091-6/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds two new system calls: int pkey_alloc(unsigned long flags, unsigned long init_access_rights) int pkey_free(int pkey); These implement an "allocator" for the protection keys themselves, which can be thought of as analogous to the allocator that the kernel has for file descriptors. The kernel tracks which numbers are in use, and only allows operations on keys that are valid. A key which was not obtained by pkey_alloc() may not, for instance, be passed to pkey_mprotect(). These system calls are also very important given the kernel's use of pkeys to implement execute-only support. These help ensure that userspace can never assume that it has control of a key unless it first asks the kernel. The kernel does not promise to preserve PKRU (right register) contents except for allocated pkeys. The 'init_access_rights' argument to pkey_alloc() specifies the rights that will be established for the returned pkey. For instance: pkey = pkey_alloc(flags, PKEY_DENY_WRITE); will allocate 'pkey', but also sets the bits in PKRU[1] such that writing to 'pkey' is already denied. The kernel does not prevent pkey_free() from successfully freeing in-use pkeys (those still assigned to a memory range by pkey_mprotect()). It would be expensive to implement the checks for this, so we instead say, "Just don't do it" since sane software will never do it anyway. Any piece of userspace calling pkey_alloc() needs to be prepared for it to fail. Why? pkey_alloc() returns the same error code (ENOSPC) when there are no pkeys and when pkeys are unsupported. They can be unsupported for a whole host of reasons, so apps must be prepared for this. Also, libraries or LD_PRELOADs might steal keys before an application gets access to them. This allocation mechanism could be implemented in userspace. Even if we did it in userspace, we would still need additional user/kernel interfaces to tell userspace which keys are being used by the kernel internally (such as for execute-only mappings). Having the kernel provide this facility completely removes the need for these additional interfaces, or having an implementation of this in userspace at all. Note that we have to make changes to all of the architectures that do not use mman-common.h because we use the new PKEY_DENY_ACCESS/WRITE macros in arch-independent code. 1. PKRU is the Protection Key Rights User register. It is a usermode-accessible register that controls whether writes and/or access to each individual pkey is allowed or denied. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: linux-arch@vger.kernel.org Cc: Dave Hansen <dave@sr71.net> Cc: arnd@arndb.de Cc: linux-api@vger.kernel.org Cc: linux-mm@kvack.org Cc: luto@kernel.org Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20160729163015.444FE75F@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | x86/pkeys: Make mprotect_key() mask off additional vm_flagsDave Hansen2016-09-091-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today, mprotect() takes 4 bits of data: PROT_READ/WRITE/EXEC/NONE. Three of those bits: READ/WRITE/EXEC get translated directly in to vma->vm_flags by calc_vm_prot_bits(). If a bit is unset in mprotect()'s 'prot' argument then it must be cleared in vma->vm_flags during the mprotect() call. We do this clearing today by first calculating the VMA flags we want set, then clearing the ones we do not want to inherit from the original VMA: vm_flags = calc_vm_prot_bits(prot, key); ... newflags = vm_flags; newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); However, we *also* want to mask off the original VMA's vm_flags in which we store the protection key. To do that, this patch adds a new macro: ARCH_VM_PKEY_FLAGS which allows the architecture to specify additional bits that it would like cleared. We use that to ensure that the VM_PKEY_BIT* bits get cleared. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Dave Hansen <dave@sr71.net> Cc: arnd@arndb.de Cc: linux-api@vger.kernel.org Cc: linux-mm@kvack.org Cc: luto@kernel.org Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20160729163013.E48D6981@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | mm: Implement new pkey_mprotect() system callDave Hansen2016-09-091-4/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pkey_mprotect() is just like mprotect, except it also takes a protection key as an argument. On systems that do not support protection keys, it still works, but requires that key=0. Otherwise it does exactly what mprotect does. I expect it to get used like this, if you want to guarantee that any mapping you create can *never* be accessed without the right protection keys set up. int real_prot = PROT_READ|PROT_WRITE; pkey = pkey_alloc(0, PKEY_DENY_ACCESS); ptr = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); ret = pkey_mprotect(ptr, PAGE_SIZE, real_prot, pkey); This way, there is *no* window where the mapping is accessible since it was always either PROT_NONE or had a protection key set that denied all access. We settled on 'unsigned long' for the type of the key here. We only need 4 bits on x86 today, but I figured that other architectures might need some more space. Semantically, we have a bit of a problem if we combine this syscall with our previously-introduced execute-only support: What do we do when we mix execute-only pkey use with pkey_mprotect() use? For instance: pkey_mprotect(ptr, PAGE_SIZE, PROT_WRITE, 6); // set pkey=6 mprotect(ptr, PAGE_SIZE, PROT_EXEC); // set pkey=X_ONLY_PKEY? mprotect(ptr, PAGE_SIZE, PROT_WRITE); // is pkey=6 again? To solve that, we make the plain-mprotect()-initiated execute-only support only apply to VMAs that have the default protection key (0) set on them. Proposed semantics: 1. protection key 0 is special and represents the default, "unassigned" protection key. It is always allocated. 2. mprotect() never affects a mapping's pkey_mprotect()-assigned protection key. A protection key of 0 (even if set explicitly) represents an unassigned protection key. 2a. mprotect(PROT_EXEC) on a mapping with an assigned protection key may or may not result in a mapping with execute-only properties. pkey_mprotect() plus pkey_set() on all threads should be used to _guarantee_ execute-only semantics if this is not a strong enough semantic. 3. mprotect(PROT_EXEC) may result in an "execute-only" mapping. The kernel will internally attempt to allocate and dedicate a protection key for the purpose of execute-only mappings. This may not be possible in cases where there are no free protection keys available. It can also happen, of course, in situations where there is no hardware support for protection keys. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: linux-arch@vger.kernel.org Cc: Dave Hansen <dave@sr71.net> Cc: arnd@arndb.de Cc: linux-api@vger.kernel.org Cc: linux-mm@kvack.org Cc: luto@kernel.org Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20160729163012.3DDD36C4@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2016-10-0734-873/+1250
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge updates from Andrew Morton: - fsnotify updates - ocfs2 updates - all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) console: don't prefer first registered if DT specifies stdout-path cred: simpler, 1D supplementary groups CREDITS: update Pavel's information, add GPG key, remove snail mail address mailmap: add Johan Hovold .gitattributes: set git diff driver for C source code files uprobes: remove function declarations from arch/{mips,s390} spelling.txt: "modeled" is spelt correctly nmi_backtrace: generate one-line reports for idle cpus arch/tile: adopt the new nmi_backtrace framework nmi_backtrace: do a local dump_stack() instead of a self-NMI nmi_backtrace: add more trigger_*_cpu_backtrace() methods min/max: remove sparse warnings when they're nested Documentation/filesystems/proc.txt: add more description for maps/smaps mm, proc: fix region lost in /proc/self/smaps proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self proc: add LSM hook checks to /proc/<tid>/timerslack_ns proc: relax /proc/<tid>/timerslack_ns capability requirements meminfo: break apart a very long seq_printf with #ifdefs seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char proc: faster /proc/*/status ...
| * | | | | | | seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not charJoe Perches2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow some seq_puts removals by taking a string instead of a single char. [akpm@linux-foundation.org: update vmstat_show(), per Joe] Link: http://lkml.kernel.org/r/667e1cf3d436de91a5698170a1e98d882905e956.1470704995.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | proc: much faster /proc/vmstatAlexey Dobriyan2016-10-071-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every current KDE system has process named ksysguardd polling files below once in several seconds: $ strace -e trace=open -p $(pidof ksysguardd) Process 1812 attached open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8 open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8 open("/proc/net/dev", O_RDONLY) = 8 open("/proc/net/wireless", O_RDONLY) = -1 ENOENT (No such file or directory) open("/proc/stat", O_RDONLY) = 8 open("/proc/vmstat", O_RDONLY) = 8 Hell knows what it is doing but speed up reading /proc/vmstat by 33%! Benchmark is open+read+close 1.000.000 times. BEFORE $ perf stat -r 10 taskset -c 3 ./proc-vmstat Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs): 13146.768464 task-clock (msec) # 0.960 CPUs utilized ( +- 0.60% ) 15 context-switches # 0.001 K/sec ( +- 1.41% ) 1 cpu-migrations # 0.000 K/sec ( +- 11.11% ) 104 page-faults # 0.008 K/sec ( +- 0.57% ) 45,489,799,349 cycles # 3.460 GHz ( +- 0.03% ) 9,970,175,743 stalled-cycles-frontend # 21.92% frontend cycles idle ( +- 0.10% ) 2,800,298,015 stalled-cycles-backend # 6.16% backend cycles idle ( +- 0.32% ) 79,241,190,850 instructions # 1.74 insn per cycle # 0.13 stalled cycles per insn ( +- 0.00% ) 17,616,096,146 branches # 1339.956 M/sec ( +- 0.00% ) 176,106,232 branch-misses # 1.00% of all branches ( +- 0.18% ) 13.691078109 seconds time elapsed ( +- 0.03% ) ^^^^^^^^^^^^ AFTER $ perf stat -r 10 taskset -c 3 ./proc-vmstat Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs): 8688.353749 task-clock (msec) # 0.950 CPUs utilized ( +- 1.25% ) 10 context-switches # 0.001 K/sec ( +- 2.13% ) 1 cpu-migrations # 0.000 K/sec 104 page-faults # 0.012 K/sec ( +- 0.56% ) 30,384,010,730 cycles # 3.497 GHz ( +- 0.07% ) 12,296,259,407 stalled-cycles-frontend # 40.47% frontend cycles idle ( +- 0.13% ) 3,370,668,651 stalled-cycles-backend # 11.09% backend cycles idle ( +- 0.69% ) 28,969,052,879 instructions # 0.95 insn per cycle # 0.42 stalled cycles per insn ( +- 0.01% ) 6,308,245,891 branches # 726.058 M/sec ( +- 0.00% ) 214,685,502 branch-misses # 3.40% of all branches ( +- 0.26% ) 9.146081052 seconds time elapsed ( +- 0.07% ) ^^^^^^^^^^^ vsnprintf() is slow because: 1. format_decode() is busy looking for format specifier: 2 branches per character (not in this case, but in others) 2. approximately million branches while parsing format mini language and everywhere 3. just look at what string() does /proc/vmstat is good case because most of its content are strings Link: http://lkml.kernel.org/r/20160806125455.GA1187@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: remove unnecessary condition in remove_inode_hugepageszhong jiang2016-10-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the huge page is added to the page cahce (huge_add_to_page_cache), the page private flag will be cleared. since this code (remove_inode_hugepages) will only be called for pages in the page cahce, PagePrivate(page) will always be false. The patch remove the code without any functional change. Link: http://lkml.kernel.org/r/1475113323-29368-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Tested-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: warn about allocations which stall for too longMichal Hocko2016-10-071-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we do warn only about allocation failures but small allocations are basically nofail and they might loop in the page allocator for a long time. Especially when the reclaim cannot make any progress - e.g. GFP_NOFS cannot invoke the oom killer and rely on a different context to make a forward progress in case there is a lot memory used by filesystems. Give us at least a clue when something like this happens and warn about allocations which take more than 10s. Print the basic allocation context information along with the cumulative time spent in the allocation as well as the allocation stack. Repeat the warning after every 10 seconds so that we know that the problem is permanent rather than ephemeral. Link: http://lkml.kernel.org/r/20160929084407.7004-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: consolidate warn_alloc_failed usersMichal Hocko2016-10-072-23/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | warn_alloc_failed is currently used from the page and vmalloc allocators. This is a good reuse of the code except that vmalloc would appreciate a slightly different warning message. This is already handled by the fmt parameter except that "%s: page allocation failure: order:%u, mode:%#x(%pGg)" is printed anyway. This might be quite misleading because it might be a vmalloc failure which leads to the warning while the page allocator is not the culprit here. Fix this by always using the fmt string and only print the context that makes sense for the particular context (e.g. order makes only very little sense for the vmalloc context). Rename the function to not miss any user and also because a later patch will reuse it also for !failure cases. Link: http://lkml.kernel.org/r/20160929084407.7004-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | vfs,mm: fix a dead loop in truncate_inode_pages_range()Wei Fang2016-10-071-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We triggered a deadloop in truncate_inode_pages_range() on 32 bits architecture with the test case bellow: ... fd = open(); write(fd, buf, 4096); preadv64(fd, &iovec, 1, 0xffffffff000); ftruncate(fd, 0); ... Then ftruncate() will not return forever. The filesystem used in this case is ubifs, but it can be triggered on many other filesystems. When preadv64() is called with offset=0xffffffff000, a page with index=0xffffffff will be added to the radix tree of ->mapping. Then this page can be found in ->mapping with pagevec_lookup(). After that, truncate_inode_pages_range(), which is called in ftruncate(), will fall into an infinite loop: - find a page with index=0xffffffff, since index>=end, this page won't be truncated - index++, and index become 0 - the page with index=0xffffffff will be found again The data type of index is unsigned long, so index won't overflow to 0 on 64 bits architecture in this case, and the dead loop won't happen. Since truncate_inode_pages_range() is executed with holding lock of inode->i_rwsem, any operation related with this lock will be blocked, and a hung task will happen, e.g.: INFO: task truncate_test:3364 blocked for more than 120 seconds. ... call_rwsem_down_write_failed+0x17/0x30 generic_file_write_iter+0x32/0x1c0 ubifs_write_iter+0xcc/0x170 __vfs_write+0xc4/0x120 vfs_write+0xb2/0x1b0 SyS_write+0x46/0xa0 The page with index=0xffffffff added to ->mapping is useless. Fix this by checking the read position before allocating pages. Link: http://lkml.kernel.org/r/1475151010-40166-1-git-send-email-fangwei1@huawei.com Signed-off-by: Wei Fang <fangwei1@huawei.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm/hugetlb: introduce ARCH_HAS_GIGANTIC_PAGEYisheng Xie2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid making ifdef get pretty unwieldy if many ARCHs support gigantic page. No functional change with this patch. Link: http://lkml.kernel.org/r/1475227569-63446-2-git-send-email-xieyisheng1@huawei.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | oom: print nodemask in the oom reportMichal Hocko2016-10-071-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have received a hard to explain oom report from a customer. The oom triggered regardless there is a lot of free memory: PoolThread invoked oom-killer: gfp_mask=0x280da, order=0, oom_adj=0, oom_score_adj=0 PoolThread cpuset=/ mems_allowed=0-7 Pid: 30055, comm: PoolThread Tainted: G E X 3.0.101-80-default #1 Call Trace: dump_trace+0x75/0x300 dump_stack+0x69/0x6f dump_header+0x8e/0x110 oom_kill_process+0xa6/0x350 out_of_memory+0x2b7/0x310 __alloc_pages_slowpath+0x7dd/0x820 __alloc_pages_nodemask+0x1e9/0x200 alloc_pages_vma+0xe1/0x290 do_anonymous_page+0x13e/0x300 do_page_fault+0x1fd/0x4c0 page_fault+0x25/0x30 [...] active_anon:1135959151 inactive_anon:1051962 isolated_anon:0 active_file:13093 inactive_file:222506 isolated_file:0 unevictable:262144 dirty:2 writeback:0 unstable:0 free:432672819 slab_reclaimable:7917 slab_unreclaimable:95308 mapped:261139 shmem:166297 pagetables:2228282 bounce:0 [...] Node 0 DMA free:15896kB min:0kB low:0kB high:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15672kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes lowmem_reserve[]: 0 2892 775542 775542 Node 0 DMA32 free:2783784kB min:28kB low:32kB high:40kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:2961572kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes lowmem_reserve[]: 0 0 772650 772650 Node 0 Normal free:8120kB min:8160kB low:10200kB high:12240kB active_anon:779334960kB inactive_anon:2198744kB active_file:0kB inactive_file:180kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:791193600kB mlocked:131072kB dirty:0kB writeback:0kB mapped:372940kB shmem:361480kB slab_reclaimable:4536kB slab_unreclaimable:68472kB kernel_stack:10104kB pagetables:1414820kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:2280 all_unreclaimable? yes lowmem_reserve[]: 0 0 0 0 Node 1 Normal free:476718144kB min:8192kB low:10240kB high:12288kB active_anon:307623696kB inactive_anon:283620kB active_file:10392kB inactive_file:69908kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:794296320kB mlocked:131072kB dirty:4kB writeback:0kB mapped:257208kB shmem:189896kB slab_reclaimable:3868kB slab_unreclaimable:44756kB kernel_stack:1848kB pagetables:1369432kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 Node 2 Normal free:386002452kB min:8192kB low:10240kB high:12288kB active_anon:398563752kB inactive_anon:68184kB active_file:10292kB inactive_file:29936kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:794296320kB mlocked:131072kB dirty:0kB writeback:0kB mapped:32084kB shmem:776kB slab_reclaimable:6888kB slab_unreclaimable:60056kB kernel_stack:8208kB pagetables:1282880kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 Node 3 Normal free:196406760kB min:8192kB low:10240kB high:12288kB active_anon:587445640kB inactive_anon:164396kB active_file:5716kB inactive_file:709844kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:794296320kB mlocked:131072kB dirty:0kB writeback:0kB mapped:291776kB shmem:111416kB slab_reclaimable:5152kB slab_unreclaimable:44516kB kernel_stack:2168kB pagetables:1455956kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 Node 4 Normal free:425338880kB min:8192kB low:10240kB high:12288kB active_anon:359695204kB inactive_anon:43216kB active_file:5748kB inactive_file:14772kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:794296320kB mlocked:131072kB dirty:0kB writeback:0kB mapped:24708kB shmem:1120kB slab_reclaimable:1884kB slab_unreclaimable:41060kB kernel_stack:1856kB pagetables:1100208kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 Node 5 Normal free:11140kB min:8192kB low:10240kB high:12288kB active_anon:784240872kB inactive_anon:1217164kB active_file:28kB inactive_file:48kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:794296320kB mlocked:131072kB dirty:0kB writeback:0kB mapped:11408kB shmem:0kB slab_reclaimable:2008kB slab_unreclaimable:49220kB kernel_stack:1360kB pagetables:531600kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:1202 all_unreclaimable? yes lowmem_reserve[]: 0 0 0 0 Node 6 Normal free:243395332kB min:8192kB low:10240kB high:12288kB active_anon:542015544kB inactive_anon:40208kB active_file:968kB inactive_file:8484kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:794296320kB mlocked:131072kB dirty:0kB writeback:0kB mapped:19992kB shmem:496kB slab_reclaimable:1672kB slab_unreclaimable:37052kB kernel_stack:2088kB pagetables:750264kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 Node 7 Normal free:10768kB min:8192kB low:10240kB high:12288kB active_anon:784916936kB inactive_anon:192316kB active_file:19228kB inactive_file:56852kB unevictable:131072kB isolated(anon):0kB isolated(file):0kB present:794296320kB mlocked:131072kB dirty:4kB writeback:0kB mapped:34440kB shmem:4kB slab_reclaimable:5660kB slab_unreclaimable:36100kB kernel_stack:1328kB pagetables:1007968kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 So all nodes but Node 0 have a lot of free memory which should suggest that there is an available memory especially when mems_allowed=0-7. One could speculate that a massive process has managed to terminate and free up a lot of memory while racing with the above allocation request. Although this is highly unlikely it cannot be ruled out. A further debugging, however shown that the faulting process had mempolicy (not cpuset) to bind to Node 0. We cannot see that information from the report though. mems_allowed turned out to be more confusing than really helpful. Fix this by always priting the nodemask. It is either mempolicy mask (and non-null) or the one defined by the cpusets. The new output for the above oom report would be PoolThread invoked oom-killer: gfp_mask=0x280da(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=0, order=0, oom_adj=0, oom_score_adj=0 This patch doesn't touch show_mem and the node filtering based on the cpuset node mask because mempolicy is always a subset of cpusets and seeing the full cpuset oom context might be helpful for tunning more specific mempolicies inside cpusets (e.g. when they turn out to be too restrictive). To prevent from ugly ifdefs the mask is printed even for !NUMA configurations but this should be OK (a single node will be printed). Link: http://lkml.kernel.org/r/20160930214146.28600-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Sellami Abdelkader <abdelkader.sellami@sap.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Sellami Abdelkader <abdelkader.sellami@sap.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: clarify why we avoid page_mapcount() for slab pages in dump_page()Kirill A. Shutemov2016-10-071-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's add comment on why we skip page_mapcount() for sl[aou]b pages. Link: http://lkml.kernel.org/r/20160922105532.GB24593@node Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: vma_merge: correct false positive from __vma_unlink->validate_mm_rbAndrea Arcangeli2016-10-071-18/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old code was always doing: vma->vm_end = next->vm_end vma_rb_erase(next) // in __vma_unlink vma->vm_next = next->vm_next // in __vma_unlink next = vma->vm_next vma_gap_update(next) The new code still does the above for remove_next == 1 and 2, but for remove_next == 3 it has been changed and it does: next->vm_start = vma->vm_start vma_rb_erase(vma) // in __vma_unlink vma_gap_update(next) In the latter case, while unlinking "vma", validate_mm_rb() is told to ignore "vma" that is being removed, but next->vm_start was reduced instead. So for the new case, to avoid the false positive from validate_mm_rb, it should be "next" that is ignored when "vma" is being unlinked. "vma" and "next" in the above comment, considered pre-swap(). Link: http://lkml.kernel.org/r/1474492522-2261-4-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Vorlicek <janvorli@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: vma_adjust: minor comment correctionAndrea Arcangeli2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cases are three not two. Link: http://lkml.kernel.org/r/1474492522-2261-3-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Vorlicek <janvorli@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: vma_adjust: remove superfluous check for next not NULLAndrea Arcangeli2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If next would be NULL we couldn't reach such code path. Link: http://lkml.kernel.org/r/1474309513-20313-2-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Vorlicek <janvorli@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: vma_merge: fix vm_page_prot SMP race condition against rmap_walkAndrea Arcangeli2016-10-072-27/+131
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rmap_walk can access vm_page_prot (and potentially vm_flags in the pte/pmd manipulations). So it's not safe to wait the caller to update the vm_page_prot/vm_flags after vma_merge returned potentially removing the "next" vma and extending the "current" vma over the next->vm_start,vm_end range, but still with the "current" vma vm_page_prot, after releasing the rmap locks. The vm_page_prot/vm_flags must be transferred from the "next" vma to the current vma while vma_merge still holds the rmap locks. The side effect of this race condition is pte corruption during migrate as remove_migration_ptes when run on a address of the "next" vma that got removed, used the vm_page_prot of the current vma. migrate mprotect ------------ ------------- migrating in "next" vma vma_merge() # removes "next" vma and # extends "current" vma # current vma is not with # vm_page_prot updated remove_migration_ptes read vm_page_prot of current "vma" establish pte with wrong permissions vm_set_page_prot(vma) # too late! change_protection in the old vma range only, next range is not updated This caused segmentation faults and potentially memory corruption in heavy mprotect loads with some light page migration caused by compaction in the background. Hugh Dickins pointed out the comment about the Odd case 8 in vma_merge which confirms the case 8 is only buggy one where the race can trigger, in all other vma_merge cases the above cannot happen. This fix removes the oddness factor from case 8 and it converts it from: AAAA PPPPNNNNXXXX -> PPPPNNNNNNNN to: AAAA PPPPNNNNXXXX -> PPPPXXXXXXXX XXXX has the right vma properties for the whole merged vma returned by vma_adjust, so it solves the problem fully. It has the added benefits that the callers could stop updating vma properties when vma_merge succeeds however the callers are not updated by this patch (there are bits like VM_SOFTDIRTY that still need special care for the whole range, as the vma merging ignores them, but as long as they're not processed by rmap walks and instead they're accessed with the mmap_sem at least for reading, they are fine not to be updated within vma_adjust before releasing the rmap_locks). Link: http://lkml.kernel.org/r/1474309513-20313-1-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Aditya Mandaleeka <adityam@microsoft.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Vorlicek <janvorli@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: vma_adjust: remove superfluous confusing update in remove_next == 1 caseAndrea Arcangeli2016-10-071-2/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mm->highest_vm_end doesn't need any update. After finally removing the oddness from vma_merge case 8 that was causing: 1) constant risk of trouble whenever anybody would check vma fields from rmap_walks, like it happened when page migration was introduced and it read the vma->vm_page_prot from a rmap_walk 2) the callers of vma_merge to re-initialize any value different from the current vma, instead of vma_merge() more reliably returning a vma that already matches all fields passed as parameter .. it is also worth to take the opportunity of cleaning up superfluous code in vma_adjust(), that if not removed adds up to the hard readability of the function. Link: http://lkml.kernel.org/r/1474492522-2261-5-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Vorlicek <janvorli@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: vm_page_prot: update with WRITE_ONCE/READ_ONCEAndrea Arcangeli2016-10-074-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vma->vm_page_prot is read lockless from the rmap_walk, it may be updated concurrently and this prevents the risk of reading intermediate values. Link: http://lkml.kernel.org/r/1474660305-19222-1-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Vorlicek <janvorli@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm,ksm: add __GFP_HIGH to the allocation in alloc_stable_node()zhong jiang2016-10-071-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to Hugh's suggestion, alloc_stable_node() with GFP_KERNEL can in rare cases cause a hung task warning. At present, if alloc_stable_node() allocation fails, two break_cows may want to allocate a couple of pages, and the issue will come up when free memory is under pressure. We fix it by adding __GFP_HIGH to GFP, to grant access to memory reserves, increasing the likelihood of allocation success. [akpm@linux-foundation.org: tweak comment] Link: http://lkml.kernel.org/r/1474354484-58233-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm/page_isolation: fix typo: "paes" -> "pages"Yisheng Xie2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix typo in comment. Link: http://lkml.kernel.org/r/1474788764-5774-1-git-send-email-ysxie@foxmail.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm/hugetlb: improve locking in dissolve_free_huge_pages()Gerald Schaefer2016-10-071-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For every pfn aligned to minimum_order, dissolve_free_huge_pages() will call dissolve_free_huge_page() which takes the hugetlb spinlock, even if the page is not huge at all or a hugepage that is in-use. Improve this by doing the PageHuge() and page_count() checks already in dissolve_free_huge_pages() before calling dissolve_free_huge_page(). In dissolve_free_huge_page(), when holding the spinlock, those checks need to be revalidated. Link: http://lkml.kernel.org/r/20160926172811.94033-4-gerald.schaefer@de.ibm.com Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Rui Teng <rui.teng@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm/hugetlb: check for reserved hugepages during memory offlineGerald Schaefer2016-10-072-6/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In dissolve_free_huge_pages(), free hugepages will be dissolved without making sure that there are enough of them left to satisfy hugepage reservations. Fix this by adding a return value to dissolve_free_huge_pages() and checking h->free_huge_pages vs. h->resv_huge_pages. Note that this may lead to the situation where dissolve_free_huge_page() returns an error and all free hugepages that were dissolved before that error are lost, while the memory block still cannot be set offline. Fixes: c8721bbb ("mm: memory-hotplug: enable memory hotplug to handle hugepage") Link: http://lkml.kernel.org/r/20160926172811.94033-3-gerald.schaefer@de.ibm.com Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Rui Teng <rui.teng@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm/hugetlb: fix memory offline with hugepage size > memory block sizeGerald Schaefer2016-10-071-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm/hugetlb: memory offline issues with hugepages", v4. This addresses several issues with hugepages and memory offline. While the first patch fixes a panic, and is therefore rather important, the last patch is just a performance optimization. The second patch fixes a theoretical issue with reserved hugepages, while still leaving some ugly usability issue, see description. This patch (of 3): dissolve_free_huge_pages() will either run into the VM_BUG_ON() or a list corruption and addressing exception when trying to set a memory block offline that is part (but not the first part) of a "gigantic" hugetlb page with a size > memory block size. When no other smaller hugetlb page sizes are present, the VM_BUG_ON() will trigger directly. In the other case we will run into an addressing exception later, because dissolve_free_huge_page() will not work on the head page of the compound hugetlb page which will result in a NULL hstate from page_hstate(). To fix this, first remove the VM_BUG_ON() because it is wrong, and then use the compound head page in dissolve_free_huge_page(). This means that an unused pre-allocated gigantic page that has any part of itself inside the memory block that is going offline will be dissolved completely. Losing an unused gigantic hugepage is preferable to failing the memory offline, for example in the situation where a (possibly faulty) memory DIMM needs to go offline. Fixes: c8721bbb ("mm: memory-hotplug: enable memory hotplug to handle hugepage") Link: http://lkml.kernel.org/r/20160926172811.94033-2-gerald.schaefer@de.ibm.com Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Rui Teng <rui.teng@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: nobootmem: move the comment of free_all_bootmemWanlong Gao2016-10-071-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b4def3509d18 ("mm, nobootmem: clean-up of free_low_memory_core_early()") removed the unnecessary nodeid argument, after that, this comment becomes more confused. We should move it to the right place. Fixes: b4def3509d18c1db9 ("mm, nobootmem: clean-up of free_low_memory_core_early()") Link: http://lkml.kernel.org/r/1473996082-14603-1-git-send-email-wanlong.gao@gmail.com Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm/shmem.c: constify anon_opsRasmus Villemoes2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every other dentry_operations instance is const, and this one might as well be. Link: http://lkml.kernel.org/r/1473890528-7009-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: memcontrol: consolidate cgroup socket trackingJohannes Weiner2016-10-071-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cgroup core and the memory controller need to track socket ownership for different purposes, but the tracking sites being entirely different is kind of ugly. Be a better citizen and rename the memory controller callbacks to match the cgroup core callbacks, then move them to the same place. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20160914194846.11153-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm/page_io.c: replace some BUG_ON()s with VM_BUG_ON_PAGE()Andrew Morton2016-10-071-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So they are CONFIG_DEBUG_VM-only and more informative. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@fb.com> Cc: Joe Perches <joe@perches.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rik van Riel <riel@redhat.com> Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm: don't emit warning from pagefault_out_of_memory()Tetsuo Handa2016-10-071-11/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c32b3cbe0d06 ("oom, PM: make OOM detection in the freezer path raceless") inserted a WARN_ON() into pagefault_out_of_memory() in order to warn when we raced with disabling the OOM killer. Now, patch "oom, suspend: fix oom_killer_disable vs. pm suspend properly" introduced a timeout for oom_killer_disable(). Even if we raced with disabling the OOM killer and the system is OOM livelocked, the OOM killer will be enabled eventually (in 20 seconds by default) and the OOM livelock will be solved. Therefore, we no longer need to warn when we raced with disabling the OOM killer. Link: http://lkml.kernel.org/r/1473442120-7246-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | mm, compaction: restrict fragindex to costly ordersVlastimil Babka2016-10-071-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fragmentation index and the vm.extfrag_threshold sysctl is meant as a heuristic to prevent excessive compaction for costly orders (i.e. THP). It's unlikely to make any difference for non-costly orders, especially with the default threshold. But we cannot afford any uncertainty for the non-costly orders where the only alternative to successful reclaim/compaction is OOM. After the recent patches we are guaranteed maximum effort without heuristics from compaction before deciding OOM, and fragindex is the last remaining heuristic. Therefore skip fragindex altogether for non-costly orders. Suggested-by: Michal Hocko <mhocko@suse.com> Link: http://lkml.kernel.org/r/20160926162025.21555-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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