1. 30 Mar, 2009 1 commit
  2. 08 Jan, 2009 1 commit
    • David Howells's avatar
      NOMMU: Make VMAs per MM as for MMU-mode linux · 8feae131
      David Howells authored
      
      
      Make VMAs per mm_struct as for MMU-mode linux.  This solves two problems:
      
       (1) In SYSV SHM where nattch for a segment does not reflect the number of
           shmat's (and forks) done.
      
       (2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
           exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
           that a VMA might be shared and already have its vm_mm assigned to another
           process or a dead process.
      
      A new struct (vm_region) is introduced to track a mapped region and to remember
      the circumstances under which it may be shared and the vm_list_struct structure
      is discarded as it's no longer required.
      
      This patch makes the following additional changes:
      
       (1) Regions are now allocated with alloc_pages() rather than kmalloc() and
           with no recourse to __GFP_COMP, so the pages are not composite.  Instead,
           each page has a reference on it held by the region.  Anything else that is
           interested in such a page will have to get a reference on it to retain it.
           When the pages are released due to unmapping, each page is passed to
           put_page() and will be freed when the page usage count reaches zero.
      
       (2) Excess pages are trimmed after an allocation as the allocation must be
           made as a power-of-2 quantity of pages.
      
       (3) VMAs are added to the parent MM's R/B tree and mmap lists.  As an MM may
           end up with overlapping VMAs within the tree, the VMA struct address is
           appended to the sort key.
      
       (4) Non-anonymous VMAs are now added to the backing inode's prio list.
      
       (5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
           the backing region.  The VMA and region structs will be split if
           necessary.
      
       (6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
           segment instead of all the attachments at that addresss.  Multiple
           shmat()'s return the same address under NOMMU-mode instead of different
           virtual addresses as under MMU-mode.
      
       (7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
      
       (8) /proc/maps is now the global list of mapped regions, and may list bits
           that aren't actually mapped anywhere.
      
       (9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
           of RAM currently allocated by mmap to hold mappable regions that can't be
           mapped directly.  These are copies of the backing device or file if not
           anonymous.
      
      These changes make NOMMU mode more similar to MMU mode.  The downside is that
      NOMMU mode requires some extra memory to track things over NOMMU without this
      patch (VMAs are no longer shared, and there are now region structs).
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Tested-by: default avatarMike Frysinger <vapier.adi@gmail.com>
      Acked-by: default avatarPaul Mundt <lethal@linux-sh.org>
      8feae131
  3. 23 Oct, 2008 2 commits
  4. 09 Oct, 2008 1 commit
  5. 25 Jul, 2008 2 commits
  6. 29 Apr, 2008 3 commits
  7. 07 Mar, 2008 1 commit
    • Pavel Emelyanov's avatar
      [NET]: Make /proc/net a symlink on /proc/self/net (v3) · e9720acd
      Pavel Emelyanov authored
      
      
      Current /proc/net is done with so called "shadows", but current
      implementation is broken and has little chances to get fixed.
      
      The problem is that dentries subtree of /proc/net directory has
      fancy revalidation rules to make processes living in different
      net namespaces see different entries in /proc/net subtree, but
      currently, tasks see in the /proc/net subdir the contents of any
      other namespace, depending on who opened the file first.
      
      The proposed fix is to turn /proc/net into a symlink, which points
      to /proc/self/net, which in turn shows what previously was in
      /proc/net - the network-related info, from the net namespace the
      appropriate task lives in.
      
      # ls -l /proc/net
      lrwxrwxrwx  1 root root 8 Mar  5 15:17 /proc/net -> self/net
      
      In other words - this behaves like /proc/mounts, but unlike
      "mounts", "net" is not a file, but a directory.
      
      Changes from v2:
      * Fixed discrepancy of /proc/net nlink count and selinux labeling
        screwup pointed out by Stephen.
      
        To get the correct nlink count the ->getattr callback for /proc/net
        is overridden to read one from the net->proc_net entry.
      
        To make selinux still work the net->proc_net entry is initialized
        properly, i.e. with the "net" name and the proc_net parent.
      
      Selinux fixes are
      Acked-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
      
      Changes from v1:
      * Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.
      Signed-off-by: default avatarPavel Emelyanov <xemul@openvz.org>
      Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e9720acd
  8. 14 Feb, 2008 1 commit
  9. 08 Feb, 2008 3 commits
  10. 05 Feb, 2008 2 commits
  11. 02 Jan, 2008 1 commit
  12. 29 Nov, 2007 1 commit
    • Alexey Dobriyan's avatar
      proc: fix NULL ->i_fop oops · c2319540
      Alexey Dobriyan authored
      proc_kill_inodes() can clear ->i_fop in the middle of vfs_readdir resulting in
      NULL dereference during "file->f_op->readdir(file, buf, filler)".
      
      The solution is to remove proc_kill_inodes() completely:
      
      a) we don't have tricky modules implementing their tricky readdir hooks which
         could keeping this revoke from hell.
      
      b) In a situation when module is gone but PDE still alive, standard
         readdir will return only "." and "..", because pde->next was cleared by
         remove_proc_entry().
      
      c) the race proc_kill_inode() destined to prevent is not completely
         fixed, just race window made smaller, because vfs_readdir() is run
         without sb_lock held and without file_list_lock held.  Effectively,
         ->i_fop is cleared at random moment, which can't fix properly anything.
      
      BUG: unable to handle kernel NULL pointer dereference at virtual address 00000018
      printing eip: c1061205 *pdpt = 0000000005b22001 *pde = 0000000000000000
      Oops: 0000 [#1] PREEMPT SMP
      Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw sr_mod k8temp cdrom hwmon amd_rng
      Pid: 2033, comm: find Not tainted (2.6.24-rc1-b1d08ac0
      
       #2)
      EIP: 0060:[<c1061205>] EFLAGS: 00010246 CPU: 0
      EIP is at vfs_readdir+0x47/0x74
      EAX: c6b6a780 EBX: 00000000 ECX: c1061040 EDX: c5decf94
      ESI: c6b6a780 EDI: fffffffe EBP: c9797c54 ESP: c5decf78
       DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
      Process find (pid: 2033, ti=c5dec000 task=c64bba90 task.ti=c5dec000)
      Stack: c5decf94 c1061040 fffffff7 0805ffbc 00000000 c6b6a780 c1061295 0805ffbc
             00000000 00000400 00000000 00000004 0805ffbc 4588eff4 c5dec000 c10026ba
             00000004 0805ffbc 00000400 0805ffbc 4588eff4 bfdc6c70 000000dc 0000007b
      Call Trace:
       [<c1061040>] filldir64+0x0/0xc5
       [<c1061295>] sys_getdents64+0x63/0xa5
       [<c10026ba>] sysenter_past_esp+0x5f/0x85
       =======================
      Code: 49 83 78 18 00 74 43 8d 6b 74 bf fe ff ff ff 89 e8 e8 b8 c0 12 00 f6 83 2c 01 00 00 10 75 22 8b 5e 10 8b 4c 24 04 89 f0 8b 14 24 <ff> 53 18 f6 46 1a 04 89 c7 75 0b 8b 56 0c 8b 46 08 e8 c8 66 00
      EIP: [<c1061205>] vfs_readdir+0x47/0x74 SS:ESP 0068:c5decf78
      
      hch: "Nice, getting rid of this is a very good step formwards.
            Unfortunately we have another copy of this junk in
            security/selinux/selinuxfs.c:sel_remove_entries() which would need the
            same treatment."
      Signed-off-by: default avatarAlexey Dobriyan <adobriyan@sw.ru>
      Acked-by: default avatarChristoph Hellwig <hch@infradead.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Stephen Smalley <sds@tycho.nsa.gov>
      Cc: James Morris <jmorris@namei.org>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c2319540
  13. 14 Nov, 2007 1 commit
  14. 10 Oct, 2007 1 commit
    • Eric W. Biederman's avatar
      [NET]: Make /proc/net per network namespace · 457c4cbc
      Eric W. Biederman authored
      
      
      This patch makes /proc/net per network namespace.  It modifies the global
      variables proc_net and proc_net_stat to be per network namespace.
      The proc_net file helpers are modified to take a network namespace argument,
      and all of their callers are fixed to pass &init_net for that argument.
      This ensures that all of the /proc/net files are only visible and
      usable in the initial network namespace until the code behind them
      has been updated to be handle multiple network namespaces.
      
      Making /proc/net per namespace is necessary as at least some files
      in /proc/net depend upon the set of network devices which is per
      network namespace, and even more files in /proc/net have contents
      that are relevant to a single network namespace.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      457c4cbc
  15. 08 May, 2007 1 commit
    • Kees Cook's avatar
      proc: maps protection · 5096add8
      Kees Cook authored
      The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive
      information about the memory location and usage of processes.  Issues:
      
      - maps should not be world-readable, especially if programs expect any
        kind of ASLR protection from local attackers.
      - maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc
        check the maps when %n is in a *printf call, and a setuid(getuid())
        process wouldn't be able to read its own maps file.  (For reference
        see http://lkml.org/lkml/2006/1/22/150
      
      )
      - a system-wide toggle is needed to allow prior behavior in the case of
        non-root applications that depend on access to the maps contents.
      
      This change implements a check using "ptrace_may_attach" before allowing
      access to read the maps contents.  To control this protection, the new knob
      /proc/sys/kernel/maps_protect has been added, with corresponding updates to
      the procfs documentation.
      
      [akpm@linux-foundation.org: build fixes]
      [akpm@linux-foundation.org: New sysctl numbers are old hat]
      Signed-off-by: default avatarKees Cook <kees@outflux.net>
      Cc: Arjan van de Ven <arjan@infradead.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5096add8
  16. 02 Apr, 2007 1 commit
  17. 14 Feb, 2007 1 commit
    • Eric W. Biederman's avatar
      [PATCH] sysctl: reimplement the sysctl proc support · 77b14db5
      Eric W. Biederman authored
      
      
      With this change the sysctl inodes can be cached and nothing needs to be done
      when removing a sysctl table.
      
      For a cost of 2K code we will save about 4K of static tables (when we remove
      de from ctl_table) and 70K in proc_dir_entries that we will not allocate, or
      about half that on a 32bit arch.
      
      The speed feels about the same, even though we can now cache the sysctl
      dentries :(
      
      We get the core advantage that we don't need to have a 1 to 1 mapping between
      ctl table entries and proc files.  Making it possible to have /proc/sys vary
      depending on the namespace you are in.  The currently merged namespaces don't
      have an issue here but the network namespace under /proc/sys/net needs to have
      different directories depending on which network adapters are visible.  By
      simply being a cache different directories being visible depending on who you
      are is trivial to implement.
      
      [akpm@osdl.org: fix uninitialised var]
      [akpm@osdl.org: fix ARM build]
      [bunk@stusta.de: make things static]
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      77b14db5
  18. 12 Feb, 2007 1 commit
  19. 27 Sep, 2006 1 commit
  20. 26 Jun, 2006 4 commits
  21. 28 Mar, 2006 1 commit
  22. 08 Jan, 2006 1 commit
  23. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4