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2018-04-13proc: revalidate misc dentriesAlexey Dobriyan1-1/+22
If module removes proc directory while another process pins it by chdir'ing to it, then subsequent recreation of proc entry and all entries down the tree will not be visible to any process until pinning process unchdir from directory and unpins everything. Steps to reproduce: proc_mkdir("aaa", NULL); proc_create("aaa/bbb", ...); chdir("/proc/aaa"); remove_proc_entry("aaa/bbb", NULL); remove_proc_entry("aaa", NULL); proc_mkdir("aaa", NULL); # inaccessible because "aaa" dentry still points # to the original "aaa". proc_create("aaa/bbb", ...); Fix is to implement ->d_revalidate and ->d_delete. Link: http://lkml.kernel.org/r/20180312201938.GA4871@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-12Merge tag 'xfs-4.17-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds37-205/+172
Pull more xfs updates from Darrick Wong: "Most of these are code cleanups, but there are a couple of notable use-after-free bug fixes. This series has been run through a full xfstests run over the week and through a quick xfstests run against this morning's master, with no major failures reported. - clean up unnecessary function call parameters - fix a use-after-free bug when aborting logging intents - refactor filestreams state data to avoid use-after-free bug - fix incorrect removal of cow extents when truncating extended attributes. - refactor open-coded __set_page_dirty in favor of using vfs function. - fix a deadlock when fstrim and fs shutdown race" * tag 'xfs-4.17-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: Force log to disk before reading the AGF during a fstrim Export __set_page_dirty xfs: only cancel cow blocks when truncating the data fork xfs: non-scrub - remove unused function parameters xfs: remove filestream item xfs_inode reference xfs: fix intent use-after-free on abort xfs: Remove "committed" argument of xfs_dir_ialloc
2018-04-12Merge tag 'gfs2-4.17.fixes2' of ↵Linus Torvalds3-21/+30
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull more gfs2 updates from Bob Peterson: "We decided to request the latest three patches to be merged into this merge window while it's still open. - The first patch adds a new function to lockref: lockref_put_not_zero - The second patch fixes GFS2's glock dump code so it uses the new lockref function. This fixes a problem whereby lock dumps could miss glocks. - I made a minor patch to update some comments and fix the lock ordering text in our gfs2-glocks.txt Documentation file" * tag 'gfs2-4.17.fixes2' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: GFS2: Minor improvements to comments and documentation gfs2: Stop using rhashtable_walk_peek lockref: Add lockref_put_not_zero
2018-04-12Merge tag 'nfs-for-4.17-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds13-341/+408
Pull NFS client updates from Anna Schumaker: "Stable bugfixes: - xprtrdma: Fix corner cases when handling device removal # v4.12+ - xprtrdma: Fix latency regression on NUMA NFS/RDMA clients # v4.15+ Features: - New sunrpc tracepoint for RPC pings - Finer grained NFSv4 attribute checking - Don't unnecessarily return NFS v4 delegations Other bugfixes and cleanups: - Several other small NFSoRDMA cleanups - Improvements to the sunrpc RTT measurements - A few sunrpc tracepoint cleanups - Various fixes for NFS v4 lock notifications - Various sunrpc and NFS v4 XDR encoding cleanups - Switch to the ida_simple API - Fix NFSv4.1 exclusive create - Forget acl cache after setattr operation - Don't advance the nfs_entry readdir cookie if xdr decoding fails" * tag 'nfs-for-4.17-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (47 commits) NFS: advance nfs_entry cookie only after decoding completes successfully NFSv3/acl: forget acl cache after setattr NFSv4.1: Fix exclusive create NFSv4: Declare the size up to date after it was set. nfs: Use ida_simple API NFSv4: Fix the nfs_inode_set_delegation() arguments NFSv4: Clean up CB_GETATTR encoding NFSv4: Don't ask for attributes when ACCESS is protected by a delegation NFSv4: Add a helper to encode/decode struct timespec NFSv4: Clean up encode_attrs NFSv4; Clean up XDR encoding of type bitmap4 NFSv4: Allow GFP_NOIO sleeps in decode_attr_owner/decode_attr_group SUNRPC: Add a helper for encoding opaque data inline SUNRPC: Add helpers for decoding opaque and string types NFSv4: Ignore change attribute invalidations if we hold a delegation NFS: More fine grained attribute tracking NFS: Don't force unnecessary cache invalidation in nfs_update_inode() NFS: Don't redirty the attribute cache in nfs_wcc_update_inode() NFS: Don't force a revalidation of all attributes if change is missing NFS: Convert NFS_INO_INVALID flags to unsigned long ...
2018-04-12Merge branch 'work.thaw' of ↵Linus Torvalds2-51/+79
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs thaw updates from Al Viro: "An ancient series that has fallen through the cracks in the previous cycle" * 'work.thaw' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: buffer.c: call thaw_super during emergency thaw vfs: factor sb iteration out of do_emergency_remount
2018-04-12Merge branch 'afs-dh' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds25-591/+2562
Pull AFS updates from Al Viro: "The AFS series posted by dhowells depended upon lookup_one_len() rework; now that prereq is in the mainline, that series had been rebased on top of it and got some exposure and testing..." * 'afs-dh' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: afs: Do better accretion of small writes on newly created content afs: Add stats for data transfer operations afs: Trace protocol errors afs: Locally edit directory data for mkdir/create/unlink/... afs: Adjust the directory XDR structures afs: Split the directory content defs into a header afs: Fix directory handling afs: Split the dynroot stuff out and give it its own ops tables afs: Keep track of invalid-before version for dentry coherency afs: Rearrange status mapping afs: Make it possible to get the data version in readpage afs: Init inode before accessing cache afs: Introduce a statistics proc file afs: Dump bad status record afs: Implement @cell substitution handling afs: Implement @sys substitution handling afs: Prospectively look up extra files when doing a single lookup afs: Don't over-increment the cell usage count when pinning it afs: Fix checker warnings vfs: Remove the const from dir_context::actor
2018-04-12GFS2: Minor improvements to comments and documentationBob Peterson2-2/+2
This patch simply fixes some comments and the gfs2-glocks.txt file: Places where i_rwsem was called i_mutex, and adding i_rw_mutex. Signed-off-by: Bob Peterson <[email protected]>
2018-04-12gfs2: Stop using rhashtable_walk_peekAndreas Gruenbacher1-19/+28
Function rhashtable_walk_peek is problematic because there is no guarantee that the glock previously returned still exists; when that key is deleted, rhashtable_walk_peek can end up returning a different key, which will cause an inconsistent glock dump. Fix this by keeping track of the current glock in the seq file iterator functions instead. Signed-off-by: Andreas Gruenbacher <[email protected]> Signed-off-by: Bob Peterson <[email protected]>
2018-04-11Merge tag 'tags/upstream-4.17-rc1' of git://git.infradead.org/linux-ubifsLinus Torvalds4-9/+12
Pull UBI and UBIFS updates from Richard Weinberger: "Minor bug fixes and improvements" * tag 'tags/upstream-4.17-rc1' of git://git.infradead.org/linux-ubifs: ubi: Reject MLC NAND ubifs: Remove useless parameter of lpt_heap_replace ubifs: Constify struct ubifs_lprops in scan_for_leb_for_idx ubifs: remove unnecessary assignment ubi: Fix error for write access ubi: fastmap: Don't flush fastmap work on detach ubifs: Check ubifs_wbuf_sync() return code
2018-04-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds38-453/+547
Merge more updates from Andrew Morton: - almost all of the rest of MM - kasan updates - lots of procfs work - misc things - lib/ updates - checkpatch - rapidio - ipc/shm updates - the start of willy's XArray conversion * emailed patches from Andrew Morton <[email protected]>: (140 commits) page cache: use xa_lock xarray: add the xa_lock to the radix_tree_root fscache: use appropriate radix tree accessors export __set_page_dirty unicore32: turn flush_dcache_mmap_lock into a no-op arm64: turn flush_dcache_mmap_lock into a no-op mac80211_hwsim: use DEFINE_IDA radix tree: use GFP_ZONEMASK bits of gfp_t for flags linux/const.h: refactor _BITUL and _BITULL a bit linux/const.h: move UL() macro to include/linux/const.h linux/const.h: prefix include guard of uapi/linux/const.h with _UAPI xen, mm: allow deferred page initialization for xen pv domains elf: enforce MAP_FIXED on overlaying elf segments fs, elf: drop MAP_FIXED usage from elf_map mm: introduce MAP_FIXED_NOREPLACE MAINTAINERS: update bouncing [email protected] addresses fs/dcache.c: add cond_resched() in shrink_dentry_list() include/linux/kfifo.h: fix comment ipc/shm.c: shm_split(): remove unneeded test for NULL shm_file_data.vm_ops kernel/sysctl.c: add kdoc comments to do_proc_do{u}intvec_minmax_conv_param ...
2018-04-11page cache: use xa_lockMatthew Wilcox14-140/+134
Remove the address_space ->tree_lock and use the xa_lock newly added to the radix_tree_root. Rename the address_space ->page_tree to ->i_pages, since we don't really care that it's a tree. [[email protected]: fix nds32, fs/dax.c] Link: http://lkml.kernel.org/r/[email protected]: http://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox <[email protected]> Acked-by: Jeff Layton <[email protected]> Cc: Darrick J. Wong <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Ryusuke Konishi <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11xarray: add the xa_lock to the radix_tree_rootMatthew Wilcox1-1/+1
This results in no change in structure size on 64-bit machines as it fits in the padding between the gfp_t and the void *. 32-bit machines will grow the structure from 8 to 12 bytes. Almost all radix trees are protected with (at least) a spinlock, so as they are converted from radix trees to xarrays, the data structures will shrink again. Initialising the spinlock requires a name for the benefit of lockdep, so RADIX_TREE_INIT() now needs to know the name of the radix tree it's initialising, and so do IDR_INIT() and IDA_INIT(). Also add the xa_lock() and xa_unlock() family of wrappers to make it easier to use the lock. If we could rely on -fplan9-extensions in the compiler, we could avoid all of this syntactic sugar, but that wasn't added until gcc 4.6. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox <[email protected]> Reviewed-by: Jeff Layton <[email protected]> Cc: Darrick J. Wong <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Ryusuke Konishi <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11fscache: use appropriate radix tree accessorsMatthew Wilcox2-2/+2
Don't open-code accesses to data structure internals. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox <[email protected]> Reviewed-by: Jeff Layton <[email protected]> Cc: Darrick J. Wong <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Ryusuke Konishi <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11export __set_page_dirtyMatthew Wilcox2-14/+4
XFS currently contains a copy-and-paste of __set_page_dirty(). Export it from buffer.c instead. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox <[email protected]> Acked-by: Jeff Layton <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Cc: Ryusuke Konishi <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11elf: enforce MAP_FIXED on overlaying elf segmentsMichal Hocko1-3/+10
Anshuman has reported that with "fs, elf: drop MAP_FIXED usage from elf_map" applied, some ELF binaries in his environment fail to start with [ 23.423642] 9148 (sed): Uhuuh, elf segment at 0000000010030000 requested but the memory is mapped already [ 23.423706] requested [10030000, 10040000] mapped [10030000, 10040000] 100073 anon The reason is that the above binary has overlapping elf segments: LOAD 0x0000000000000000 0x0000000010000000 0x0000000010000000 0x0000000000013a8c 0x0000000000013a8c R E 10000 LOAD 0x000000000001fd40 0x000000001002fd40 0x000000001002fd40 0x00000000000002c0 0x00000000000005e8 RW 10000 LOAD 0x0000000000020328 0x0000000010030328 0x0000000010030328 0x0000000000000384 0x00000000000094a0 RW 10000 That binary has two RW LOAD segments, the first crosses a page border into the second 0x1002fd40 (LOAD2-vaddr) + 0x5e8 (LOAD2-memlen) == 0x10030328 (LOAD3-vaddr) Handle this situation by enforcing MAP_FIXED when we establish a temporary brk VMA to handle overlapping segments. All other mappings will still use MAP_FIXED_NOREPLACE. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Michal Hocko <[email protected]> Reported-by: Anshuman Khandual <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Cc: Andrei Vagin <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Kees Cook <[email protected]> Cc: Abdul Haleem <[email protected]> Cc: Joel Stanley <[email protected]> Cc: Stephen Rothwell <[email protected]> Cc: Mark Brown <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11fs, elf: drop MAP_FIXED usage from elf_mapMichal Hocko1-4/+9
Both load_elf_interp and load_elf_binary rely on elf_map to map segments on a controlled address and they use MAP_FIXED to enforce that. This is however dangerous thing prone to silent data corruption which can be even exploitable. Let's take CVE-2017-1000253 as an example. At the time (before commit eab09532d400: "binfmt_elf: use ELF_ET_DYN_BASE only for PIE") ELF_ET_DYN_BASE was at TASK_SIZE / 3 * 2 which is not that far away from the stack top on 32b (legacy) memory layout (only 1GB away). Therefore we could end up mapping over the existing stack with some luck. The issue has been fixed since then (a87938b2e246: "fs/binfmt_elf.c: fix bug in loading of PIE binaries"), ELF_ET_DYN_BASE moved moved much further from the stack (eab09532d400 and later by c715b72c1ba4: "mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes") and excessive stack consumption early during execve fully stopped by da029c11e6b1 ("exec: Limit arg stack to at most 75% of _STK_LIM"). So we should be safe and any attack should be impractical. On the other hand this is just too subtle assumption so it can break quite easily and hard to spot. I believe that the MAP_FIXED usage in load_elf_binary (et. al) is still fundamentally dangerous. Moreover it shouldn't be even needed. We are at the early process stage and so there shouldn't be unrelated mappings (except for stack and loader) existing so mmap for a given address should succeed even without MAP_FIXED. Something is terribly wrong if this is not the case and we should rather fail than silently corrupt the underlying mapping. Address this issue by changing MAP_FIXED to the newly added MAP_FIXED_NOREPLACE. This will mean that mmap will fail if there is an existing mapping clashing with the requested one without clobbering it. [[email protected]: fix build] [[email protected]: coding-style fixes] [[email protected]: don't use the same value for MAP_FIXED_NOREPLACE and MAP_SYNC] Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Michal Hocko <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Michal Hocko <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Acked-by: Michael Ellerman <[email protected]> Acked-by: Kees Cook <[email protected]> Cc: Abdul Haleem <[email protected]> Cc: Joel Stanley <[email protected]> Cc: Anshuman Khandual <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11fs/dcache.c: add cond_resched() in shrink_dentry_list()Nikolay Borisov1-3/+2
As previously reported (https://patchwork.kernel.org/patch/8642031/) it's possible to call shrink_dentry_list with a large number of dentries (> 10000). This, in turn, could trigger the softlockup detector and possibly trigger a panic. In addition to the unmount path being vulnerable to this scenario, at SuSE we've observed similar situation happening during process exit on processes that touch a lot of dentries. Here is an excerpt from a crash dump. The number after the colon are the number of dentries on the list passed to shrink_dentry_list: PID 99760: 10722 PID 107530: 215 PID 108809: 24134 PID 108877: 21331 PID 141708: 16487 So we want to kill between 15k-25k dentries without yielding. And one possible call stack looks like: 4 [ffff8839ece41db0] _raw_spin_lock at ffffffff8152a5f8 5 [ffff8839ece41db0] evict at ffffffff811c3026 6 [ffff8839ece41dd0] __dentry_kill at ffffffff811bf258 7 [ffff8839ece41df0] shrink_dentry_list at ffffffff811bf593 8 [ffff8839ece41e18] shrink_dcache_parent at ffffffff811bf830 9 [ffff8839ece41e50] proc_flush_task at ffffffff8120dd61 10 [ffff8839ece41ec0] release_task at ffffffff81059ebd 11 [ffff8839ece41f08] do_exit at ffffffff8105b8ce 12 [ffff8839ece41f78] sys_exit at ffffffff8105bd53 13 [ffff8839ece41f80] system_call_fastpath at ffffffff81532909 While some of the callers of shrink_dentry_list do use cond_resched, this is not sufficient to prevent softlockups. So just move cond_resched into shrink_dentry_list from its callers. David said: I've found hundreds of occurrences of warnings that we emit when need_resched stays set for a prolonged period of time with the stack trace that is included in the change log. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Nikolay Borisov <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Acked-by: David Rientjes <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Goldwyn Rodrigues <[email protected]> Cc: Jeff Mahoney <[email protected]> Cc: Davidlohr Bueso <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11fs/proc/proc_sysctl.c: fix typo in sysctl_check_table_array()Waiman Long1-1/+1
Patch series "ipc: Clamp *mni to the real IPCMNI limit", v3. The sysctl parameters msgmni, shmmni and semmni have an inherent limit of IPC_MNI (32k). However, users may not be aware of that because they can write a value much higher than that without getting any error or notification. Reading the parameters back will show the newly written values which are not real. Enforcing the limit by failing sysctl parameter write, however, can break existing user applications. To address this delemma, a new flags field is introduced into the ctl_table. The value CTL_FLAGS_CLAMP_RANGE can be added to any ctl_table entries to enable a looser range clamping without returning any error. For example, .flags = CTL_FLAGS_CLAMP_RANGE, This flags value are now used for the range checking of shmmni, msgmni and semmni without breaking existing applications. If any out of range value is written to those sysctl parameters, the following warning will be printed instead. Kernel parameter "shmmni" was set out of range [0, 32768], clamped to 32768. Reading the values back will show 32768 instead of some fake values. This patch (of 6): Fix a typo. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Waiman Long <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Acked-by: Luis R. Rodriguez <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Manfred Spraul <[email protected]> Cc: Kees Cook <[email protected]> Cc: Al Viro <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Randy Dunlap <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11exec: pin stack limit during execKees Cook1-12/+15
Since the stack rlimit is used in multiple places during exec and it can be changed via other threads (via setrlimit()) or processes (via prlimit()), the assumption that the value doesn't change cannot be made. This leads to races with mm layout selection and argument size calculations. This changes the exec path to use the rlimit stored in bprm instead of in current. Before starting the thread, the bprm stack rlimit is stored back to current. Link: http://lkml.kernel.org/r/[email protected] Fixes: 64701dee4178e ("exec: Use sane stack rlimit under secureexec") Signed-off-by: Kees Cook <[email protected]> Reported-by: Ben Hutchings <[email protected]> Reported-by: Andy Lutomirski <[email protected]> Reported-by: Brad Spengler <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Ben Hutchings <[email protected]> Cc: Greg KH <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: "Jason A. Donenfeld" <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Willy Tarreau <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11exec: introduce finalize_exec() before start_thread()Kees Cook5-0/+10
Provide a final callback into fs/exec.c before start_thread() takes over, to handle any last-minute changes, like the coming restoration of the stack limit. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Kees Cook <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ben Hutchings <[email protected]> Cc: Ben Hutchings <[email protected]> Cc: Brad Spengler <[email protected]> Cc: Greg KH <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: "Jason A. Donenfeld" <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Willy Tarreau <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11exec: pass stack rlimit into mm layout functionsKees Cook1-1/+7
Patch series "exec: Pin stack limit during exec". Attempts to solve problems with the stack limit changing during exec continue to be frustrated[1][2]. In addition to the specific issues around the Stack Clash family of flaws, Andy Lutomirski pointed out[3] other places during exec where the stack limit is used and is assumed to be unchanging. Given the many places it gets used and the fact that it can be manipulated/raced via setrlimit() and prlimit(), I think the only way to handle this is to move away from the "current" view of the stack limit and instead attach it to the bprm, and plumb this down into the functions that need to know the stack limits. This series implements the approach. [1] 04e35f4495dd ("exec: avoid RLIMIT_STACK races with prlimit()") [2] 779f4e1c6c7c ("Revert "exec: avoid RLIMIT_STACK races with prlimit()"") [3] to [email protected], "Subject: existing rlimit races?" This patch (of 3): Since it is possible that the stack rlimit can change externally during exec (either via another thread calling setrlimit() or another process calling prlimit()), provide a way to pass the rlimit down into the per-architecture mm layout functions so that the rlimit can stay in the bprm structure instead of sitting in the signal structure until exec is finalized. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Kees Cook <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Ben Hutchings <[email protected]> Cc: Willy Tarreau <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: "Jason A. Donenfeld" <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Greg KH <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ben Hutchings <[email protected]> Cc: Brad Spengler <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11seq_file: account everything to kmemcgAlexey Dobriyan1-4/+4
All it takes to open a file and read 1 byte from it. seq_file will be allocated along with any private allocations, and more importantly seq file buffer which is 1 page by default. Link: http://lkml.kernel.org/r/20180310085252.GB17121@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Al Viro <[email protected]> Cc: Glauber Costa <[email protected]> Cc: Vladimir Davydov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11seq_file: allocate seq_file from kmem_cacheAlexey Dobriyan1-2/+10
For fine-grained debugging and usercopy protection. Link: http://lkml.kernel.org/r/20180310085027.GA17121@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Al Viro <[email protected]> Cc: Glauber Costa <[email protected]> Cc: Vladimir Davydov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11fs/reiserfs/journal.c: add missing resierfs_warning() argAndrew Morton1-1/+1
One use of the reiserfs_warning() macro in journal_init_dev() is missing a parameter, causing the following warning: REISERFS warning (device loop0): journal_init_dev: Cannot open '%s': %i journal_init_dev: This also causes a WARN_ONCE() warning in the vsprintf code, and then a panic if panic_on_warn is set. Please remove unsupported %/ in format string WARNING: CPU: 1 PID: 4480 at lib/vsprintf.c:2138 format_decode+0x77f/0x830 lib/vsprintf.c:2138 Kernel panic - not syncing: panic_on_warn set ... Just add another string argument to the macro invocation. Addresses https://syzkaller.appspot.com/bug?id=0627d4551fdc39bf1ef5d82cd9eef587047f7718 Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Randy Dunlap <[email protected]> Reported-by: <[email protected]> Tested-by: Randy Dunlap <[email protected]> Acked-by: Jeff Mahoney <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Jan Kara <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11autofs4: use wait_event_killableMatthew Wilcox1-27/+2
This playing with signals to allow only fatal signals appears to predate the introduction of wait_event_killable(), and I'm fairly sure that wait_event_killable is what was meant to happen here. [[email protected]: use wake_up() instead of wake_up_interruptible] Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox <[email protected]> Acked-by: Ian Kent <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Stephen Rothwell <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: use slower rb_first()Alexey Dobriyan4-19/+17
In a typical for /proc "open+read+close" usecase, dentry is looked up successfully on open only to be killed in dput() on close. In fact dentries which aren't /proc/*/... and /proc/sys/* were almost NEVER CACHED. Simple printk in proc_lookup_de() shows that. Now that ->delete hook intelligently picks which dentries should live in dcache and which should not, rbtree caching is not necessary as dcache does it job, at last! As a side effect, struct proc_dir_entry shrinks by one pointer which can go into inline name. Link: http://lkml.kernel.org/r/20180314231032.GA15854@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Acked-by: Davidlohr Bueso <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: switch struct proc_dir_entry::count to refcountAlexey Dobriyan3-5/+6
->count is honest reference count unlike ->in_use. Link: http://lkml.kernel.org/r/20180313174550.GA4332@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: reject "." and ".." as filenamesAlexey Dobriyan1-0/+8
Various subsystems can create files and directories in /proc with names directly controlled by userspace. Which means "/", "." and ".." are no-no. "/" split is already taken care of, do the other 2 prohibited names. Link: http://lkml.kernel.org/r/20180310001223.GB12443@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Acked-by: Florian Westphal <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Cong Wang <[email protected]> Cc: Pavel Machek <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: do mmput ASAP for /proc/*/map_filesAlexey Dobriyan1-1/+1
mm_struct is not needed while printing as all the data was already extracted. Link: http://lkml.kernel.org/r/20180309223120.GC3843@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: faster /proc/cmdlineAlexey Dobriyan1-1/+2
Use seq_puts() and skip format string processing. Link: http://lkml.kernel.org/r/20180309222948.GB3843@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: register filesystem lastAlexey Dobriyan1-6/+2
As soon as register_filesystem() exits, filesystem can be mounted. It is better to present fully operational /proc. Of course it doesn't matter because /proc is not modular but do it anyway. Drop error check, it should be handled by panicking. Link: http://lkml.kernel.org/r/20180309222709.GA3843@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: fix /proc/*/map_files lookup some moreAlexey Dobriyan1-0/+4
I totally forgot that _parse_integer() accepts arbitrary amount of leading zeroes leading to the following lookups: OK # readlink /proc/1/map_files/56427ecba000-56427eddc000 /lib/systemd/systemd bogus # readlink /proc/1/map_files/00000000000056427ecba000-56427eddc000 /lib/systemd/systemd # readlink /proc/1/map_files/56427ecba000-00000000000056427eddc000 /lib/systemd/systemd Link: http://lkml.kernel.org/r/20180303215130.GA23480@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Cyrill Gorcunov <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Pavel Emelyanov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: move "struct proc_dir_entry" into kmem cacheAlexey Dobriyan5-23/+52
"struct proc_dir_entry" is variable sized because of 0-length trailing array for name, however, because of SLAB padding allocations it is possible to make "struct proc_dir_entry" fixed sized and allocate same amount of memory. It buys fine-grained debugging with poisoning and usercopy protection which is not possible with kmalloc-* caches. Currently, on 32-bit 91+ byte allocations go into kmalloc-128 and on 64-bit 147+ byte allocations go to kmalloc-192 anyway. Additional memory is allocated only for 38/46+ byte long names which are rare or may not even exist in the wild. Link: http://lkml.kernel.org/r/20180223205504.GA17139@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11fs/proc/proc_sysctl.c: remove redundant link check in proc_sys_link_fill_cache()Danilo Krummrich1-6/+3
proc_sys_link_fill_cache() does not need to check whether we're called for a link - it's already done by scan(). Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Danilo Krummrich <[email protected]> Acked-by: Kees Cook <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Cc: "Luis R . Rodriguez" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11fs/proc/proc_sysctl.c: fix potential page fault while unregistering sysctl tableDanilo Krummrich1-0/+3
proc_sys_link_fill_cache() does not take currently unregistering sysctl tables into account, which might result into a page fault in sysctl_follow_link() - add a check to fix it. This bug has been present since v3.4. Link: http://lkml.kernel.org/r/[email protected] Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: Danilo Krummrich <[email protected]> Acked-by: Kees Cook <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: "Luis R . Rodriguez" <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Cc: Alexey Dobriyan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: use set_puts() at /proc/*/wchanAlexey Dobriyan1-1/+1
Link: http://lkml.kernel.org/r/20180217072011.GB16074@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: Rasmus Villemoes <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: check permissions earlier for /proc/*/wchanAlexey Dobriyan1-5/+8
get_wchan() accesses stack page before permissions are checked, let's not play this game. Link: http://lkml.kernel.org/r/20180217071923.GA16074@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: Rasmus Villemoes <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: replace seq_printf by seq_put_smth to speed up /proc/pid/statusAndrei Vagin1-5/+11
seq_printf() works slower than seq_puts, seq_puts, etc. == test_proc.c int main(int argc, char **argv) { int n, i, fd; char buf[16384]; n = atoi(argv[1]); for (i = 0; i < n; i++) { fd = open(argv[2], O_RDONLY); if (fd < 0) return 1; if (read(fd, buf, sizeof(buf)) <= 0) return 1; close(fd); } return 0; } == $ time ./test_proc 1000000 /proc/1/status == Before path == real 0m5.171s user 0m0.328s sys 0m4.783s == After patch == real 0m4.761s user 0m0.334s sys 0m4.366s Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Andrei Vagin <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: optimize single-symbol delimiters to spead up seq_put_decimal_ullAndrei Vagin1-12/+12
A delimiter is a string which is printed before a number. A syngle-symbol delimiters can be printed by set_putc() and this works faster than printing by set_puts(). == test_proc.c int main(int argc, char **argv) { int n, i, fd; char buf[16384]; n = atoi(argv[1]); for (i = 0; i < n; i++) { fd = open(argv[2], O_RDONLY); if (fd < 0) return 1; if (read(fd, buf, sizeof(buf)) <= 0) return 1; close(fd); } return 0; } == $ time ./test_proc 1000000 /proc/1/stat == Before patch == real 0m3.820s user 0m0.337s sys 0m3.394s == After patch == real 0m3.110s user 0m0.324s sys 0m2.700s Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Andrei Vagin <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: replace seq_printf on seq_putc to speed up /proc/pid/smapsAndrei Vagin1-2/+3
seq_putc() works much faster than seq_printf() == Before patch == $ time python test_smaps.py real 0m3.828s user 0m0.413s sys 0m3.408s == After patch == $ time python test_smaps.py real 0m3.405s user 0m0.401s sys 0m3.003s == Before patch == - 75.51% 4.62% python [kernel.kallsyms] [k] show_smap.isra.33 - 70.88% show_smap.isra.33 + 24.82% seq_put_decimal_ull_aligned + 19.78% __walk_page_range + 12.74% seq_printf + 11.08% show_map_vma.isra.23 + 1.68% seq_puts == After patch == - 69.16% 5.70% python [kernel.kallsyms] [k] show_smap.isra.33 - 63.46% show_smap.isra.33 + 25.98% seq_put_decimal_ull_aligned + 20.90% __walk_page_range + 12.60% show_map_vma.isra.23 1.56% seq_putc + 1.55% seq_puts Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Andrei Vagin <[email protected]> Reviewed-by: Alexey Dobriyan <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: add seq_put_decimal_ull_width to speed up /proc/pid/smapsAndrei Vagin3-96/+74
seq_put_decimal_ull_w(m, str, val, width) prints a decimal number with a specified minimal field width. It is equivalent of seq_printf(m, "%s%*d", str, width, val), but it works much faster. == test_smaps.py num = 0 with open("/proc/1/smaps") as f: for x in xrange(10000): data = f.read() f.seek(0, 0) == == Before patch == $ time python test_smaps.py real 0m4.593s user 0m0.398s sys 0m4.158s == After patch == $ time python test_smaps.py real 0m3.828s user 0m0.413s sys 0m3.408s $ perf -g record python test_smaps.py == Before patch == - 79.01% 3.36% python [kernel.kallsyms] [k] show_smap.isra.33 - 75.65% show_smap.isra.33 + 48.85% seq_printf + 15.75% __walk_page_range + 9.70% show_map_vma.isra.23 0.61% seq_puts == After patch == - 75.51% 4.62% python [kernel.kallsyms] [k] show_smap.isra.33 - 70.88% show_smap.isra.33 + 24.82% seq_put_decimal_ull_w + 19.78% __walk_page_range + 12.74% seq_printf + 11.08% show_map_vma.isra.23 + 1.68% seq_puts [[email protected]: fix drivers/of/unittest.c build] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Andrei Vagin <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: account "struct pde_opener"Alexey Dobriyan1-1/+1
The allocation is persistent in fact as any fool can open a file in /proc and sit on it. Link: http://lkml.kernel.org/r/20180214082409.GC17157@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Cc: Al Viro <[email protected]> Cc: Kees Cook <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: move "struct pde_opener" to kmem cacheAlexey Dobriyan3-6/+10
"struct pde_opener" is fixed size and we can have more granular approach to debugging. For those who don't know, per cache SLUB poisoning and red zoning don't work if there is at least one object allocated which is hopeless in case of kmalloc-64 but not in case of standalone cache. Although systemd opens 2 files from the get go, so it is hopeless after all. Link: http://lkml.kernel.org/r/20180214082306.GB17157@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Cc: Al Viro <[email protected]> Cc: Kees Cook <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: randomize "struct pde_opener"Alexey Dobriyan1-1/+1
The more the merrier. Link: http://lkml.kernel.org/r/20180214081935.GA17157@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Cc: Al Viro <[email protected]> Cc: Kees Cook <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: faster open/close of files without ->release hookAlexey Dobriyan1-18/+23
The whole point of code in fs/proc/inode.c is to make sure ->release hook is called either at close() or at rmmod time. All if it is unnecessary if there is no ->release hook. Save allocation+list manipulations under spinlock in that case. Link: http://lkml.kernel.org/r/20180214063033.GA15579@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Cc: Al Viro <[email protected]> Cc: Kees Cook <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: move /proc/sysvipc creation to where it belongsAlexey Dobriyan1-4/+0
Move the proc_mkdir() call within the sysvipc subsystem such that we avoid polluting proc_root_init() with petty cpp. [[email protected]: contributed changelog] Link: http://lkml.kernel.org/r/20180216161732.GA10297@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Acked-by: Davidlohr Bueso <[email protected]> Cc: Manfred Spraul <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: do less stuff under ->pde_unload_lockAlexey Dobriyan1-5/+9
Commit ca469f35a8e9ef ("deal with races between remove_proc_entry() and proc_reg_release()") moved too much stuff under ->pde_unload_lock making a problem described at series "[PATCH v5] procfs: Improve Scaling in proc" worse. While RCU is being figured out, move kfree() out of ->pde_unload_lock. On my potato, difference is only 0.5% speedup with concurrent open+read+close of /proc/cmdline, but the effect should be more noticeable on more capable machines. $ perf stat -r 16 -- ./proc-j 16 Performance counter stats for './proc-j 16' (16 runs): 130569.502377 task-clock (msec) # 15.872 CPUs utilized ( +- 0.05% ) 19,169 context-switches # 0.147 K/sec ( +- 0.18% ) 15 cpu-migrations # 0.000 K/sec ( +- 3.27% ) 437 page-faults # 0.003 K/sec ( +- 1.25% ) 300,172,097,675 cycles # 2.299 GHz ( +- 0.05% ) 96,793,267,308 instructions # 0.32 insn per cycle ( +- 0.04% ) 22,798,342,298 branches # 174.607 M/sec ( +- 0.04% ) 111,764,687 branch-misses # 0.49% of all branches ( +- 0.47% ) 8.226574400 seconds time elapsed ( +- 0.05% ) ^^^^^^^^^^^ $ perf stat -r 16 -- ./proc-j 16 Performance counter stats for './proc-j 16' (16 runs): 129866.777392 task-clock (msec) # 15.869 CPUs utilized ( +- 0.04% ) 19,154 context-switches # 0.147 K/sec ( +- 0.66% ) 14 cpu-migrations # 0.000 K/sec ( +- 1.73% ) 431 page-faults # 0.003 K/sec ( +- 1.09% ) 298,556,520,546 cycles # 2.299 GHz ( +- 0.04% ) 96,525,366,833 instructions # 0.32 insn per cycle ( +- 0.04% ) 22,730,194,043 branches # 175.027 M/sec ( +- 0.04% ) 111,506,074 branch-misses # 0.49% of all branches ( +- 0.18% ) 8.183629778 seconds time elapsed ( +- 0.04% ) ^^^^^^^^^^^ Link: http://lkml.kernel.org/r/20180213132911.GA24298@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11proc: get rid of task lock/unlock pair to read umask for the "status" fileMateusz Guzik1-18/+5
get_task_umask locks/unlocks the task on its own. The only caller does the same thing immediately after. Utilize the fact the task has to be locked anyway and just do it once. Since there are no other users and the code is short, fold it in. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Mateusz Guzik <[email protected]> Reviewed-by: Alexey Dobriyan <[email protected]> Cc: Konstantin Khlebnikov <[email protected]> Cc: Jerome Marchand <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11procfs: optimize seq_pad() to speed up /proc/pid/mapsAndrei Vagin1-2/+8
seq_printf() is slow and it can be replaced by memset() in this case. == test.py num = 0 with open("/proc/1/maps") as f: while num < 10000 : data = f.read() f.seek(0, 0) num = num + 1 == == Before patch == $ time python test.py real 0m0.986s user 0m0.279s sys 0m0.707s == After patch == $ time python test.py real 0m0.932s user 0m0.261s sys 0m0.669s $ perf record -g python test.py == Before patch == - 47.35% 3.38% python [kernel.kallsyms] [k] show_map_vma.isra.23 - 43.97% show_map_vma.isra.23 + 20.84% seq_path - 15.73% show_vma_header_prefix + 6.96% seq_pad + 2.94% __GI___libc_read == After patch == - 44.01% 0.34% python [kernel.kallsyms] [k] show_pid_map - 43.67% show_pid_map - 42.91% show_map_vma.isra.23 + 21.55% seq_path - 15.68% show_vma_header_prefix + 2.08% seq_pad 0.55% seq_putc Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Andrei Vagin <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-04-11procfs: add seq_put_hex_ll to speed up /proc/pid/mapsAndrei Vagin2-9/+58
seq_put_hex_ll() prints a number in hexadecimal notation and works faster than seq_printf(). == test.py num = 0 with open("/proc/1/maps") as f: while num < 10000 : data = f.read() f.seek(0, 0) num = num + 1 == == Before patch == $ time python test.py real 0m1.561s user 0m0.257s sys 0m1.302s == After patch == $ time python test.py real 0m0.986s user 0m0.279s sys 0m0.707s $ perf -g record python test.py: == Before patch == - 67.42% 2.82% python [kernel.kallsyms] [k] show_map_vma.isra.22 - 64.60% show_map_vma.isra.22 - 44.98% seq_printf - seq_vprintf - vsnprintf + 14.85% number + 12.22% format_decode 5.56% memcpy_erms + 15.06% seq_path + 4.42% seq_pad + 2.45% __GI___libc_read == After patch == - 47.35% 3.38% python [kernel.kallsyms] [k] show_map_vma.isra.23 - 43.97% show_map_vma.isra.23 + 20.84% seq_path - 15.73% show_vma_header_prefix 10.55% seq_put_hex_ll + 2.65% seq_put_decimal_ull 0.95% seq_putc + 6.96% seq_pad + 2.94% __GI___libc_read [[email protected]: use unsigned int instead of int where it is suitable] Link: http://lkml.kernel.org/r/[email protected] [[email protected]: v2] Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Andrei Vagin <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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