1. 23 Jun, 2008 4 commits
    • Nick Piggin's avatar
      mm: fix race in COW logic · 945754a1
      Nick Piggin authored
      There is a race in the COW logic.  It contains a shortcut to avoid the
      COW and reuse the page if we have the sole reference on the page,
      however it is possible to have two racing do_wp_page()ers with one
      causing the other to mistakenly believe it is safe to take the shortcut
      when it is not.  This could lead to data corruption.
      
      Process 1 and process2 each have a wp pte of the same anon page (ie.
      one forked the other).  The page's mapcount is 2.  Then they both
      attempt to write to it around the same time...
      
        proc1				proc2 thr1			proc2 thr2
        CPU0				CPU1				CPU3
        do_wp_page()			do_wp_page()
      				 trylock_page()
      				  can_share_swap_page()
      				   load page mapcount (==2)
      				  reuse = 0
      				 pte unlock
      				 copy page to new_page
      				 pte lock
      				 page_remove_rmap(page);
         trylock_page()
          can_share_swap_page()
           load page mapcount (==1)
          reuse = 1
         ptep_set_access_flags (allow W)
      
        write private key into page
      								read from page
      				ptep_clear_flush()
      				set_pte_at(pte of new_page)
      
      Fix this by moving the page_remove_rmap of the old page after the pte
      clear and flush.  Potentially the entire branch could be moved down
      here, but in order to stay consistent, I won't (should probably move all
      the *_mm_counter stuff with one patch).
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Acked-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      945754a1
    • Linus Torvalds's avatar
      Fix ZERO_PAGE breakage with vmware · 672ca28e
      Linus Torvalds authored
      Commit 89f5b7da ("Reinstate ZERO_PAGE
      optimization in 'get_user_pages()' and fix XIP") broke vmware, as
      reported by Jeff Chua:
      
        "This broke vmware 6.0.4.
         Jun 22 14:53:03.845: vmx| NOT_IMPLEMENTED
         /build/mts/release/bora-93057/bora/vmx/main/vmmonPosix.c:774"
      
      and the reason seems to be that there's an old bug in how we handle do
      FOLL_ANON on VM_SHARED areas in get_user_pages(), but since it only
      triggered if the whole page table was missing, nobody had apparently hit
      it before.
      
      The recent changes to 'follow_page()' made the FOLL_ANON logic trigger
      not just for whole missing page tables, but for individual pages as
      well, and exposed this problem.
      
      This fixes it by making the test for when FOLL_ANON is used more
      careful, and also makes the code easier to read and understand by moving
      the logic to a separate inline function.
      Reported-and-tested-by: default avatarJeff Chua <jeff.chua.linux@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      672ca28e
    • Gustavo Fernando Padovan's avatar
      removed unused var real_tty on n_tty_ioctl() · 96a331b1
      Gustavo Fernando Padovan authored
      I noted that the 'struct tty_struct *real_tty' is not used in this
      function, so I removed the code about 'real_tty'.
      Signed-off-by: default avatarGustavo Fernando Padovan <gustavo@las.ic.unicamp.br>
      Acked-by: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      96a331b1
    • Alan Cox's avatar
      tty_driver: Update required method documentation · 36c7343b
      Alan Cox authored
      Some of the requirement rules are now more relaxed. Also correct a
      contradiction in the previous update
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      36c7343b
  2. 22 Jun, 2008 1 commit
  3. 21 Jun, 2008 9 commits
    • Christoph Lameter's avatar
      Slab: Fix memory leak in fallback_alloc() · 481c5346
      Christoph Lameter authored
      The zonelist patches caused the loop that checks for available
      objects in permitted zones to not terminate immediately. One object
      per zone per allocation may be allocated and then abandoned.
      
      Break the loop when we have successfully allocated one object.
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      481c5346
    • Linus Torvalds's avatar
      Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 62a8efe6
      Linus Torvalds authored
      * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        Ext4: Fix online resize block group descriptor corruption
      62a8efe6
    • Linus Torvalds's avatar
      Merge branch 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6 · bec95aab
      Linus Torvalds authored
      * 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6:
        hwmon: (lm75) sensor reading bugfix
        hwmon: (abituguru3) update driver detection
        hwmon: (w83791d) new maintainer
        hwmon: (abituguru3) Identify Abit AW8D board as such
        hwmon: Update the sysfs interface documentation
        hwmon: (adt7473) Initialize max_duty_at_overheat before use
        hwmon: (lm85) Fix function RANGE_TO_REG()
      bec95aab
    • Bernhard Walle's avatar
      Add return value to reserve_bootmem_node() · 71c2742f
      Bernhard Walle authored
      This patch changes the function reserve_bootmem_node() from void to int,
      returning -ENOMEM if the allocation fails.
      
      This fixes a build problem on x86 with CONFIG_KEXEC=y and
      CONFIG_NEED_MULTIPLE_NODES=y
      Signed-off-by: default avatarBernhard Walle <bwalle@suse.de>
      Reported-by: default avatarAdrian Bunk <bunk@kernel.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      71c2742f
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 · a1921443
      Linus Torvalds authored
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
        netns: Don't receive new packets in a dead network namespace.
        sctp: Make sure N * sizeof(union sctp_addr) does not overflow.
        pppoe: warning fix
        ipv6: Drop packets for loopback address from outside of the box.
        ipv6: Remove options header when setsockopt's optlen is 0
        mac80211: detect driver tx bugs
      a1921443
    • Eric W. Biederman's avatar
      netns: Don't receive new packets in a dead network namespace. · b9f75f45
      Eric W. Biederman authored
      Alexey Dobriyan <adobriyan@gmail.com> writes:
      > Subject: ICMP sockets destruction vs ICMP packets oops
      
      > After icmp_sk_exit() nuked ICMP sockets, we get an interrupt.
      > icmp_reply() wants ICMP socket.
      >
      > Steps to reproduce:
      >
      > 	launch shell in new netns
      > 	move real NIC to netns
      > 	setup routing
      > 	ping -i 0
      > 	exit from shell
      >
      > BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
      > IP: [<ffffffff803fce17>] icmp_sk+0x17/0x30
      > PGD 17f3cd067 PUD 17f3ce067 PMD 0 
      > Oops: 0000 [1] PREEMPT SMP DEBUG_PAGEALLOC
      > CPU 0 
      > Modules linked in: usblp usbcore
      > Pid: 0, comm: swapper Not tainted 2.6.26-rc6-netns-ct #4
      > RIP: 0010:[<ffffffff803fce17>]  [<ffffffff803fce17>] icmp_sk+0x17/0x30
      > RSP: 0018:ffffffff8057fc30  EFLAGS: 00010286
      > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff81017c7db900
      > RDX: 0000000000000034 RSI: ffff81017c7db900 RDI: ffff81017dc41800
      > RBP: ffffffff8057fc40 R08: 0000000000000001 R09: 000000000000a815
      > R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff8057fd28
      > R13: ffffffff8057fd00 R14: ffff81017c7db938 R15: ffff81017dc41800
      > FS:  0000000000000000(0000) GS:ffffffff80525000(0000) knlGS:0000000000000000
      > CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
      > CR2: 0000000000000000 CR3: 000000017fcda000 CR4: 00000000000006e0
      > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
      > Process swapper (pid: 0, threadinfo ffffffff8053a000, task ffffffff804fa4a0)
      > Stack:  0000000000000000 ffff81017c7db900 ffffffff8057fcf0 ffffffff803fcfe4
      >  ffffffff804faa38 0000000000000246 0000000000005a40 0000000000000246
      >  000000000001ffff ffff81017dd68dc0 0000000000005a40 0000000055342436
      > Call Trace:
      >  <IRQ>  [<ffffffff803fcfe4>] icmp_reply+0x44/0x1e0
      >  [<ffffffff803d3a0a>] ? ip_route_input+0x23a/0x1360
      >  [<ffffffff803fd645>] icmp_echo+0x65/0x70
      >  [<ffffffff803fd300>] icmp_rcv+0x180/0x1b0
      >  [<ffffffff803d6d84>] ip_local_deliver+0xf4/0x1f0
      >  [<ffffffff803d71bb>] ip_rcv+0x33b/0x650
      >  [<ffffffff803bb16a>] netif_receive_skb+0x27a/0x340
      >  [<ffffffff803be57d>] process_backlog+0x9d/0x100
      >  [<ffffffff803bdd4d>] net_rx_action+0x18d/0x250
      >  [<ffffffff80237be5>] __do_softirq+0x75/0x100
      >  [<ffffffff8020c97c>] call_softirq+0x1c/0x30
      >  [<ffffffff8020f085>] do_softirq+0x65/0xa0
      >  [<ffffffff80237af7>] irq_exit+0x97/0xa0
      >  [<ffffffff8020f198>] do_IRQ+0xa8/0x130
      >  [<ffffffff80212ee0>] ? mwait_idle+0x0/0x60
      >  [<ffffffff8020bc46>] ret_from_intr+0x0/0xf
      >  <EOI>  [<ffffffff80212f2c>] ? mwait_idle+0x4c/0x60
      >  [<ffffffff80212f23>] ? mwait_idle+0x43/0x60
      >  [<ffffffff8020a217>] ? cpu_idle+0x57/0xa0
      >  [<ffffffff8040f380>] ? rest_init+0x70/0x80
      > Code: 10 5b 41 5c 41 5d 41 5e c9 c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 53
      > 48 83 ec 08 48 8b 9f 78 01 00 00 e8 2b c7 f1 ff 89 c0 <48> 8b 04 c3 48 83 c4 08
      > 5b c9 c3 66 66 66 66 66 2e 0f 1f 84 00
      > RIP  [<ffffffff803fce17>] icmp_sk+0x17/0x30
      >  RSP <ffffffff8057fc30>
      > CR2: 0000000000000000
      > ---[ end trace ea161157b76b33e8 ]---
      > Kernel panic - not syncing: Aiee, killing interrupt handler!
      
      Receiving packets while we are cleaning up a network namespace is a
      racy proposition. It is possible when the packet arrives that we have
      removed some but not all of the state we need to fully process it.  We
      have the choice of either playing wack-a-mole with the cleanup routines
      or simply dropping packets when we don't have a network namespace to
      handle them.
      
      Since the check looks inexpensive in netif_receive_skb let's just
      drop the incoming packets.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b9f75f45
    • David S. Miller's avatar
      sctp: Make sure N * sizeof(union sctp_addr) does not overflow. · 735ce972
      David S. Miller authored
      As noticed by Gabriel Campana, the kmalloc() length arg
      passed in by sctp_getsockopt_local_addrs_old() can overflow
      if ->addr_num is large enough.
      
      Therefore, enforce an appropriate limit.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      735ce972
    • Stephen Hemminger's avatar
      pppoe: warning fix · 2645a3c3
      Stephen Hemminger authored
      Fix warning:
      drivers/net/pppoe.c: In function 'pppoe_recvmsg':
      drivers/net/pppoe.c:945: warning: comparison of distinct pointer types lacks a cast
      because skb->len is unsigned int and total_len is size_t
      Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2645a3c3
    • Linus Torvalds's avatar
      b732d968
  4. 20 Jun, 2008 26 commits