1. 02 Aug, 2018 1 commit
  2. 14 Jun, 2018 1 commit
  3. 26 May, 2018 2 commits
  4. 20 Apr, 2018 1 commit
    • Arnd Bergmann's avatar
      y2038: ipc: Report long times to user space · c2ab975c
      Arnd Bergmann authored
      The shmid64_ds/semid64_ds/msqid64_ds data structures have been extended
      to contain extra fields for storing the upper bits of the time stamps,
      this patch does the other half of the job and and fills the new fields on
      32-bit architectures as well as 32-bit tasks running on a 64-bit kernel
      in compat mode.
      
      There should be no change for native 64-bit tasks.
      Signed-off-by: 's avatarArnd Bergmann <arnd@arndb.de>
      c2ab975c
  5. 14 Apr, 2018 1 commit
    • Eric Biggers's avatar
      ipc/shm: fix use-after-free of shm file via remap_file_pages() · 3f05317d
      Eric Biggers authored
      syzbot reported a use-after-free of shm_file_data(file)->file->f_op in
      shm_get_unmapped_area(), called via sys_remap_file_pages().
      
      Unfortunately it couldn't generate a reproducer, but I found a bug which
      I think caused it.  When remap_file_pages() is passed a full System V
      shared memory segment, the memory is first unmapped, then a new map is
      created using the ->vm_file.  Between these steps, the shm ID can be
      removed and reused for a new shm segment.  But, shm_mmap() only checks
      whether the ID is currently valid before calling the underlying file's
      ->mmap(); it doesn't check whether it was reused.  Thus it can use the
      wrong underlying file, one that was already freed.
      
      Fix this by making the "outer" shm file (the one that gets put in
      ->vm_file) hold a reference to the real shm file, and by making
      __shm_open() require that the file associated with the shm ID matches
      the one associated with the "outer" file.
      
      Taking the reference to the real shm file is needed to fully solve the
      problem, since otherwise sfd->file could point to a freed file, which
      then could be reallocated for the reused shm ID, causing the wrong shm
      segment to be mapped (and without the required permission checks).
      
      Commit 1ac0b6de ("ipc/shm: handle removed segments gracefully in
      shm_mmap()") almost fixed this bug, but it didn't go far enough because
      it didn't consider the case where the shm ID is reused.
      
      The following program usually reproduces this bug:
      
      	#include <stdlib.h>
      	#include <sys/shm.h>
      	#include <sys/syscall.h>
      	#include <unistd.h>
      
      	int main()
      	{
      		int is_parent = (fork() != 0);
      		srand(getpid());
      		for (;;) {
      			int id = shmget(0xF00F, 4096, IPC_CREAT|0700);
      			if (is_parent) {
      				void *addr = shmat(id, NULL, 0);
      				usleep(rand() % 50);
      				while (!syscall(__NR_remap_file_pages, addr, 4096, 0, 0, 0));
      			} else {
      				usleep(rand() % 50);
      				shmctl(id, IPC_RMID, NULL);
      			}
      		}
      	}
      
      It causes the following NULL pointer dereference due to a 'struct file'
      being used while it's being freed.  (I couldn't actually get a KASAN
      use-after-free splat like in the syzbot report.  But I think it's
      possible with this bug; it would just take a more extraordinary race...)
      
      	BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
      	PGD 0 P4D 0
      	Oops: 0000 [#1] SMP NOPTI
      	CPU: 9 PID: 258 Comm: syz_ipc Not tainted 4.16.0-05140-gf8cf2f16 #189
      	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
      	RIP: 0010:d_inode include/linux/dcache.h:519 [inline]
      	RIP: 0010:touch_atime+0x25/0xd0 fs/inode.c:1724
      	[...]
      	Call Trace:
      	 file_accessed include/linux/fs.h:2063 [inline]
      	 shmem_mmap+0x25/0x40 mm/shmem.c:2149
      	 call_mmap include/linux/fs.h:1789 [inline]
      	 shm_mmap+0x34/0x80 ipc/shm.c:465
      	 call_mmap include/linux/fs.h:1789 [inline]
      	 mmap_region+0x309/0x5b0 mm/mmap.c:1712
      	 do_mmap+0x294/0x4a0 mm/mmap.c:1483
      	 do_mmap_pgoff include/linux/mm.h:2235 [inline]
      	 SYSC_remap_file_pages mm/mmap.c:2853 [inline]
      	 SyS_remap_file_pages+0x232/0x310 mm/mmap.c:2769
      	 do_syscall_64+0x64/0x1a0 arch/x86/entry/common.c:287
      	 entry_SYSCALL_64_after_hwframe+0x42/0xb7
      
      [ebiggers@google.com: add comment]
        Link: http://lkml.kernel.org/r/20180410192850.235835-1-ebiggers3@gmail.com
      Link: http://lkml.kernel.org/r/20180409043039.28915-1-ebiggers3@gmail.com
      Reported-by: syzbot+d11f321e7f1923157eac80aa990b446596f46439@syzkaller.appspotmail.com
      Fixes: c8d78c18 ("mm: replace remap_file_pages() syscall with emulation")
      Signed-off-by: 's avatarEric Biggers <ebiggers@google.com>
      Acked-by: 's avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Acked-by: 's avatarDavidlohr Bueso <dbueso@suse.de>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: "Eric W . Biederman" <ebiederm@xmission.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      3f05317d
  6. 11 Apr, 2018 2 commits
    • Andrew Morton's avatar
      ipc/shm.c: shm_split(): remove unneeded test for NULL shm_file_data.vm_ops · a61fc2cb
      Andrew Morton authored
      This was added by the recent "ipc/shm.c: add split function to
      shm_vm_ops", but it is not necessary.
      Reviewed-by: 's avatarMike Kravetz <mike.kravetz@oracle.com>
      Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      a61fc2cb
    • Davidlohr Bueso's avatar
      ipc/shm: introduce shmctl(SHM_STAT_ANY) · c21a6970
      Davidlohr Bueso authored
      Patch series "sysvipc: introduce STAT_ANY commands", v2.
      
      The following patches adds the discussed (see [1]) new command for shm
      as well as for sems and msq as they are subject to the same
      discrepancies for ipc object permission checks between the syscall and
      via procfs.  These new commands are justified in that (1) we are stuck
      with this semantics as changing syscall and procfs can break userland;
      and (2) some users can benefit from performance (for large amounts of
      shm segments, for example) from not having to parse the procfs
      interface.
      
      Once merged, I will submit the necesary manpage updates.  But I'm thinking
      something like:
      
      : diff --git a/man2/shmctl.2 b/man2/shmctl.2
      : index 7bb503999941..bb00bbe21a57 100644
      : --- a/man2/shmctl.2
      : +++ b/man2/shmctl.2
      : @@ -41,6 +41,7 @@
      :  .\" 2005-04-25, mtk -- noted aberrant Linux behavior w.r.t. new
      :  .\"	attaches to a segment that has already been marked for deletion.
      :  .\" 2005-08-02, mtk: Added IPC_INFO, SHM_INFO, SHM_STAT descriptions.
      : +.\" 2018-02-13, dbueso: Added SHM_STAT_ANY description.
      :  .\"
      :  .TH SHMCTL 2 2017-09-15 "Linux" "Linux Programmer's Manual"
      :  .SH NAME
      : @@ -242,6 +243,18 @@ However, the
      :  argument is not a segment identifier, but instead an index into
      :  the kernel's internal array that maintains information about
      :  all shared memory segments on the system.
      : +.TP
      : +.BR SHM_STAT_ANY " (Linux-specific)"
      : +Return a
      : +.I shmid_ds
      : +structure as for
      : +.BR SHM_STAT .
      : +However, the
      : +.I shm_perm.mode
      : +is not checked for read access for
      : +.IR shmid ,
      : +resembing the behaviour of
      : +/proc/sysvipc/shm.
      :  .PP
      :  The caller can prevent or allow swapping of a shared
      :  memory segment with the following \fIcmd\fP values:
      : @@ -287,7 +300,7 @@ operation returns the index of the highest used entry in the
      :  kernel's internal array recording information about all
      :  shared memory segments.
      :  (This information can be used with repeated
      : -.B SHM_STAT
      : +.B SHM_STAT/SHM_STAT_ANY
      :  operations to obtain information about all shared memory segments
      :  on the system.)
      :  A successful
      : @@ -328,7 +341,7 @@ isn't accessible.
      :  \fIshmid\fP is not a valid identifier, or \fIcmd\fP
      :  is not a valid command.
      :  Or: for a
      : -.B SHM_STAT
      : +.B SHM_STAT/SHM_STAT_ANY
      :  operation, the index value specified in
      :  .I shmid
      :  referred to an array slot that is currently unused.
      
      This patch (of 3):
      
      There is a permission discrepancy when consulting shm ipc object metadata
      between /proc/sysvipc/shm (0444) and the SHM_STAT shmctl command.  The
      later does permission checks for the object vs S_IRUGO.  As such there can
      be cases where EACCESS is returned via syscall but the info is displayed
      anyways in the procfs files.
      
      While this might have security implications via info leaking (albeit no
      writing to the shm metadata), this behavior goes way back and showing all
      the objects regardless of the permissions was most likely an overlook - so
      we are stuck with it.  Furthermore, modifying either the syscall or the
      procfs file can cause userspace programs to break (ie ipcs).  Some
      applications require getting the procfs info (without root privileges) and
      can be rather slow in comparison with a syscall -- up to 500x in some
      reported cases.
      
      This patch introduces a new SHM_STAT_ANY command such that the shm ipc
      object permissions are ignored, and only audited instead.  In addition,
      I've left the lsm security hook checks in place, as if some policy can
      block the call, then the user has no other choice than just parsing the
      procfs file.
      
      [1] https://lkml.org/lkml/2017/12/19/220
      
      Link: http://lkml.kernel.org/r/20180215162458.10059-2-dave@stgolabs.netSigned-off-by: 's avatarDavidlohr Bueso <dbueso@suse.de>
      Acked-by: 's avatarMichal Hocko <mhocko@suse.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Robert Kettler <robert.kettler@outlook.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      c21a6970
  7. 02 Apr, 2018 3 commits
  8. 28 Mar, 2018 2 commits
    • Mike Kravetz's avatar
      ipc/shm.c: add split function to shm_vm_ops · 3d942ee0
      Mike Kravetz authored
      If System V shmget/shmat operations are used to create a hugetlbfs
      backed mapping, it is possible to munmap part of the mapping and split
      the underlying vma such that it is not huge page aligned.  This will
      untimately result in the following BUG:
      
        kernel BUG at /build/linux-jWa1Fv/linux-4.15.0/mm/hugetlb.c:3310!
        Oops: Exception in kernel mode, sig: 5 [#1]
        LE SMP NR_CPUS=2048 NUMA PowerNV
        Modules linked in: kcm nfc af_alg caif_socket caif phonet fcrypt
        CPU: 18 PID: 43243 Comm: trinity-subchil Tainted: G         C  E 4.15.0-10-generic #11-Ubuntu
        NIP:  c00000000036e764 LR: c00000000036ee48 CTR: 0000000000000009
        REGS: c000003fbcdcf810 TRAP: 0700   Tainted: G         C  E (4.15.0-10-generic)
        MSR:  9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24002222  XER: 20040000
        CFAR: c00000000036ee44 SOFTE: 1
        NIP __unmap_hugepage_range+0xa4/0x760
        LR __unmap_hugepage_range_final+0x28/0x50
        Call Trace:
          0x7115e4e00000 (unreliable)
          __unmap_hugepage_range_final+0x28/0x50
          unmap_single_vma+0x11c/0x190
          unmap_vmas+0x94/0x140
          exit_mmap+0x9c/0x1d0
          mmput+0xa8/0x1d0
          do_exit+0x360/0xc80
          do_group_exit+0x60/0x100
          SyS_exit_group+0x24/0x30
          system_call+0x58/0x6c
        ---[ end trace ee88f958a1c62605 ]---
      
      This bug was introduced by commit 31383c68 ("mm, hugetlbfs:
      introduce ->split() to vm_operations_struct").  A split function was
      added to vm_operations_struct to determine if a mapping can be split.
      This was mostly for device-dax and hugetlbfs mappings which have
      specific alignment constraints.
      
      Mappings initiated via shmget/shmat have their original vm_ops
      overwritten with shm_vm_ops.  shm_vm_ops functions will call back to the
      original vm_ops if needed.  Add such a split function to shm_vm_ops.
      
      Link: http://lkml.kernel.org/r/20180321161314.7711-1-mike.kravetz@oracle.com
      Fixes: 31383c68 ("mm, hugetlbfs: introduce ->split() to vm_operations_struct")
      Signed-off-by: 's avatarMike Kravetz <mike.kravetz@oracle.com>
      Reported-by: 's avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
      Reviewed-by: 's avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
      Tested-by: 's avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
      Reviewed-by: 's avatarDan Williams <dan.j.williams@intel.com>
      Acked-by: 's avatarMichal Hocko <mhocko@suse.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      3d942ee0
    • Eric W. Biederman's avatar
      ipc/shm: Fix pid freeing. · 2236d4d3
      Eric W. Biederman authored
      The 0day kernel test build report reported an oops:
      >
      >  IP: put_pid+0x22/0x5c
      >  PGD 19efa067 P4D 19efa067 PUD 0
      >  Oops: 0000 [#1]
      >  CPU: 0 PID: 727 Comm: trinity Not tainted 4.16.0-rc2-00010-g98f929b1 #1
      >  RIP: 0010:put_pid+0x22/0x5c
      >  RSP: 0018:ffff986719f73e48 EFLAGS: 00010202
      >  RAX: 00000006d765f710 RBX: ffff98671a4fa4d0 RCX: ffff986719f73d40
      >  RDX: 000000006f6e6125 RSI: 0000000000000000 RDI: ffffffffa01e6d21
      >  RBP: ffffffffa0955fe0 R08: 0000000000000020 R09: 0000000000000000
      >  R10: 0000000000000078 R11: ffff986719f73e76 R12: 0000000000001000
      >  R13: 00000000ffffffea R14: 0000000054000fb0 R15: 0000000000000000
      >  FS:  00000000028c2880(0000) GS:ffffffffa06ad000(0000) knlGS:0000000000000000
      >  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      >  CR2: 0000000677846439 CR3: 0000000019fc1005 CR4: 00000000000606b0
      >  Call Trace:
      >   ? ipc_update_pid+0x36/0x3e
      >   ? newseg+0x34c/0x3a6
      >   ? ipcget+0x5d/0x528
      >   ? entry_SYSCALL_64_after_hwframe+0x52/0xb7
      >   ? SyS_shmget+0x5a/0x84
      >   ? do_syscall_64+0x194/0x1b3
      >   ? entry_SYSCALL_64_after_hwframe+0x42/0xb7
      >  Code: ff 05 e7 20 9b 03 58 c9 c3 48 ff 05 85 21 9b 03 48 85 ff 74 4f 8b 47 04 8b 17 48 ff 05 7c 21 9b 03 48 83 c0 03 48 c1 e0 04 ff ca <48> 8b 44 07 08 74 1f 48 ff 05 6c 21 9b 03 ff 0f 0f 94 c2 48 ff
      >  RIP: put_pid+0x22/0x5c RSP: ffff986719f73e48
      >  CR2: 0000000677846439
      >  ---[ end trace ab8c5cb4389d37c5 ]---
      >  Kernel panic - not syncing: Fatal exception
      
      In newseg when changing shm_cprid and shm_lprid from pid_t to struct
      pid* I misread the kvmalloc as kvzalloc and thought shp was
      initialized to 0.  As that is not the case it is not safe to for the
      error handling to address shm_cprid and shm_lprid before they are
      initialized.
      
      Therefore move the cleanup of shm_cprid and shm_lprid from the no_file
      error cleanup path to the no_id error cleanup path.  Ensuring that an
      early error exit won't cause the oops above.
      Reported-by: 's avatarkernel test robot <fengguang.wu@intel.com>
      Reviewed-by: 's avatarNagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com>
      Signed-off-by: 's avatarEric W. Biederman <ebiederm@xmission.com>
      2236d4d3
  9. 27 Mar, 2018 2 commits
    • Eric W. Biederman's avatar
      ipc: Directly call the security hook in ipc_ops.associate · 50ab44b1
      Eric W. Biederman authored
      After the last round of cleanups the shm, sem, and msg associate
      operations just became trivial wrappers around the appropriate security
      method.  Simplify things further by just calling the security method
      directly.
      Signed-off-by: 's avatar"Eric W. Biederman" <ebiederm@xmission.com>
      50ab44b1
    • Eric W. Biederman's avatar
      ipc/shm: Fix shmctl(..., IPC_STAT, ...) between pid namespaces. · 98f929b1
      Eric W. Biederman authored
      Today shm_cpid and shm_lpid are remembered in the pid namespace of the
      creator and the processes that last touched a sysvipc shared memory
      segment.   If you have processes in multiple pid namespaces that
      is just wrong, and I don't know how this has been over-looked for
      so long.
      
      As only creation and shared memory attach and shared memory detach
      update the pids I do not expect there to be a repeat of the issues
      when struct pid was attached to each af_unix skb, which in some
      notable cases cut the performance in half.  The problem was threads of
      the same process updating same struct pid from different cpus causing
      the cache line to be highly contended and bounce between cpus.
      
      As creation, attach, and detach are expected to be rare operations for
      sysvipc shared memory segments I do not expect that kind of cache line
      ping pong to cause probems.  In addition because the pid is at a fixed
      location in the structure instead of being dynamic on a skb, the
      reference count of the pid does not need to be updated on each
      operation if the pid is the same.  This ability to simply skip the pid
      reference count changes if the pid is unchanging further reduces the
      likelihood of the a cache line holding a pid reference count
      ping-ponging between cpus.
      
      Fixes: b488893a ("pid namespaces: changes to show virtual ids to user")
      Reviewed-by: 's avatarNagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com>
      Signed-off-by: 's avatar"Eric W. Biederman" <ebiederm@xmission.com>
      98f929b1
  10. 24 Mar, 2018 1 commit
  11. 23 Mar, 2018 1 commit
  12. 07 Feb, 2018 1 commit
  13. 18 Nov, 2017 1 commit
  14. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: 's avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: 's avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: 's avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  15. 11 Oct, 2017 1 commit
  16. 26 Sep, 2017 1 commit
  17. 21 Sep, 2017 1 commit
    • Will Deacon's avatar
      ipc/shm: Fix order of parameters when calling copy_compat_shmid_to_user · 58aff0af
      Will Deacon authored
      Commit 553f770e ("ipc: move compat shmctl to native") moved the
      compat IPC syscall handling into ipc/shm.c and refactored the struct
      accessors in the process. Unfortunately, the call to
      copy_compat_shmid_to_user when handling a compat {IPC,SHM}_STAT command
      gets the arguments the wrong way round, passing a kernel stack address
      as the user buffer (destination) and the user buffer as the kernel stack
      address (source).
      
      This patch fixes the parameter ordering so the buffers are accessed
      correctly.
      
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: 's avatarAl Viro <viro@zeniv.linux.org.uk>
      58aff0af
  18. 09 Sep, 2017 1 commit
    • Guillaume Knispel's avatar
      ipc: optimize semget/shmget/msgget for lots of keys · 0cfb6aee
      Guillaume Knispel authored
      ipc_findkey() used to scan all objects to look for the wanted key.  This
      is slow when using a high number of keys.  This change adds an rhashtable
      of kern_ipc_perm objects in ipc_ids, so that one lookup cease to be O(n).
      
      This change gives a 865% improvement of benchmark reaim.jobs_per_min on a
      56 threads Intel(R) Xeon(R) CPU E5-2695 v3 @ 2.30GHz with 256G memory [1]
      
      Other (more micro) benchmark results, by the author: On an i5 laptop, the
      following loop executed right after a reboot took, without and with this
      change:
      
          for (int i = 0, k=0x424242; i < KEYS; ++i)
              semget(k++, 1, IPC_CREAT | 0600);
      
                       total       total          max single  max single
         KEYS        without        with        call without   call with
      
            1            3.5         4.9   µs            3.5         4.9
           10            7.6         8.6   µs            3.7         4.7
           32           16.2        15.9   µs            4.3         5.3
          100           72.9        41.8   µs            3.7         4.7
         1000        5,630.0       502.0   µs             *           *
        10000    1,340,000.0     7,240.0   µs             *           *
        31900   17,600,000.0    22,200.0   µs             *           *
      
       *: unreliable measure: high variance
      
      The duration for a lookup-only usage was obtained by the same loop once
      the keys are present:
      
                       total       total          max single  max single
         KEYS        without        with        call without   call with
      
            1            2.1         2.5   µs            2.1         2.5
           10            4.5         4.8   µs            2.2         2.3
           32           13.0        10.8   µs            2.3         2.8
          100           82.9        25.1   µs             *          2.3
         1000        5,780.0       217.0   µs             *           *
        10000    1,470,000.0     2,520.0   µs             *           *
        31900   17,400,000.0     7,810.0   µs             *           *
      
      Finally, executing each semget() in a new process gave, when still
      summing only the durations of these syscalls:
      
      creation:
                       total       total
         KEYS        without        with
      
            1            3.7         5.0   µs
           10           32.9        36.7   µs
           32          125.0       109.0   µs
          100          523.0       353.0   µs
         1000       20,300.0     3,280.0   µs
        10000    2,470,000.0    46,700.0   µs
        31900   27,800,000.0   219,000.0   µs
      
      lookup-only:
                       total       total
         KEYS        without        with
      
            1            2.5         2.7   µs
           10           25.4        24.4   µs
           32          106.0        72.6   µs
          100          591.0       352.0   µs
         1000       22,400.0     2,250.0   µs
        10000    2,510,000.0    25,700.0   µs
        31900   28,200,000.0   115,000.0   µs
      
      [1] http://lkml.kernel.org/r/20170814060507.GE23258@yexl-desktop
      
      Link: http://lkml.kernel.org/r/20170815194954.ck32ta2z35yuzpwp@debixSigned-off-by: 's avatarGuillaume Knispel <guillaume.knispel@supersonicimagine.com>
      Reviewed-by: 's avatarMarc Pardo <marc.pardo@supersonicimagine.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
      Cc: Serge Hallyn <serge@hallyn.com>
      Cc: Andrey Vagin <avagin@openvz.org>
      Cc: Guillaume Knispel <guillaume.knispel@supersonicimagine.com>
      Cc: Marc Pardo <marc.pardo@supersonicimagine.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      0cfb6aee
  19. 04 Sep, 2017 1 commit
  20. 03 Aug, 2017 1 commit
  21. 16 Jul, 2017 4 commits
  22. 12 Jul, 2017 6 commits
  23. 05 Jul, 2017 1 commit
  24. 09 May, 2017 1 commit
  25. 28 Feb, 2017 1 commit
    • Davidlohr Bueso's avatar
      ipc/shm: Fix shmat mmap nil-page protection · 95e91b83
      Davidlohr Bueso authored
      The issue is described here, with a nice testcase:
      
          https://bugzilla.kernel.org/show_bug.cgi?id=192931
      
      The problem is that shmat() calls do_mmap_pgoff() with MAP_FIXED, and
      the address rounded down to 0.  For the regular mmap case, the
      protection mentioned above is that the kernel gets to generate the
      address -- arch_get_unmapped_area() will always check for MAP_FIXED and
      return that address.  So by the time we do security_mmap_addr(0) things
      get funky for shmat().
      
      The testcase itself shows that while a regular user crashes, root will
      not have a problem attaching a nil-page.  There are two possible fixes
      to this.  The first, and which this patch does, is to simply allow root
      to crash as well -- this is also regular mmap behavior, ie when hacking
      up the testcase and adding mmap(...  |MAP_FIXED).  While this approach
      is the safer option, the second alternative is to ignore SHM_RND if the
      rounded address is 0, thus only having MAP_SHARED flags.  This makes the
      behavior of shmat() identical to the mmap() case.  The downside of this
      is obviously user visible, but does make sense in that it maintains
      semantics after the round-down wrt 0 address and mmap.
      
      Passes shm related ltp tests.
      
      Link: http://lkml.kernel.org/r/1486050195-18629-1-git-send-email-dave@stgolabs.netSigned-off-by: 's avatarDavidlohr Bueso <dbueso@suse.de>
      Reported-by: 's avatarGareth Evans <gareth.evans@contextis.co.uk>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      95e91b83
  26. 25 Feb, 2017 1 commit