linux/include, branch v3.4.35

pstore: Avoid deadlock in panic and emergency-restart path

2013-03-03T22:06:43Z

commit 9f244e9cfd70c7c0f82d3c92ce772ab2a92d9f64 upstream. [Issue] When pstore is in panic and emergency-restart paths, it may be blocked in those paths because it simply takes spin_lock. This is an example scenario which pstore may hang up in a panic path: - cpuA grabs psinfo->buf_lock - cpuB panics and calls smp_send_stop - smp_send_stop sends IRQ to cpuA - after 1 second, cpuB gives up on cpuA and sends an NMI instead - cpuA is now in an NMI handler while still holding buf_lock - cpuB is deadlocked This case may happen if a firmware has a bug and cpuA is stuck talking with it more than one second. Also, this is a similar scenario in an emergency-restart path: - cpuA grabs psinfo->buf_lock and stucks in a firmware - cpuB kicks emergency-restart via either sysrq-b or hangcheck timer. And then, cpuB is deadlocked by taking psinfo->buf_lock again. [Solution] This patch avoids the deadlocking issues in both panic and emergency_restart paths by introducing a function, is_non_blocking_path(), to check if a cpu can be blocked in current path. With this patch, pstore is not blocked even if another cpu has taken a spin_lock, in those paths by changing from spin_lock_irqsave to spin_trylock_irqsave. In addition, according to a comment of emergency_restart() in kernel/sys.c, spin_lock shouldn't be taken in an emergency_restart path to avoid deadlock. This patch fits the comment below. /** * emergency_restart - reboot the system * * Without shutting down any hardware or taking any locks * reboot the system. This is called when we know we are in * trouble so this is our best effort to reboot. This is * safe to call in interrupt context. */ void emergency_restart(void) Signed-off-by: Seiji Aguchi Acked-by: Don Zickus Signed-off-by: Tony Luck Cc: CAI Qian Signed-off-by: Greg Kroah-Hartman

unbreak automounter support on 64-bit kernel with 32-bit userspace (v2)

2013-03-03T22:06:43Z

commit 4f4ffc3a5398ef9bdbb32db04756d7d34e356fcf upstream. automount-support is broken on the parisc architecture, because the existing #if list does not include a check for defined(__hppa__). The HPPA (parisc) architecture is similiar to other 64bit Linux targets where we have to define autofs_wqt_t (which is passed back and forth to user space) as int type which has a size of 32bit across 32 and 64bit kernels. During the discussion on the mailing list, H. Peter Anvin suggested to invert the #if list since only specific platforms (specifically those who do not have a 32bit userspace, like IA64 and Alpha) should have autofs_wqt_t as unsigned long type. This suggestion is probably the best way to go, since Arm64 (and maybe others?) seems to have a non-working automounter. So in the long run even for other new upcoming architectures this inverted check seem to be the best solution, since it will not require them to change this #if again (unless they are 64bit only). Signed-off-by: Helge Deller Acked-by: H. Peter Anvin Acked-by: Ian Kent Acked-by: Catalin Marinas CC: James Bottomley CC: Rolf Eike Beer Signed-off-by: Greg Kroah-Hartman

quota: autoload the quota_v2 module for QFMT_VFS_V1 quota format

2013-03-03T22:06:37Z

commit c3ad83d9efdfe6a86efd44945a781f00c879b7b4 upstream. Otherwise, ext4 file systems with the quota featured enable will get a very confusing "No such process" error message if the quota code is built as a module and the quota_v2 module has not been loaded. Signed-off-by: "Theodore Ts'o" Reviewed-by: Carlos Maiolino Acked-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

vlan: adjust vlan_set_encap_proto() for its callers

2013-02-28T14:59:06Z

[ Upstream commit da8c87241c26aac81a64c7e4d21d438a33018f4e ] There are two places to call vlan_set_encap_proto(): vlan_untag() and __pop_vlan_tci(). vlan_untag() assumes skb->data points after mac addr, otherwise the following code vhdr = (struct vlan_hdr *) skb->data; vlan_tci = ntohs(vhdr->h_vlan_TCI); __vlan_hwaccel_put_tag(skb, vlan_tci); skb_pull_rcsum(skb, VLAN_HLEN); won't be correct. But __pop_vlan_tci() assumes points _before_ mac addr. In vlan_set_encap_proto(), it looks for some magic L2 value after mac addr: rawp = skb->data; if (*(unsigned short *) rawp == 0xFFFF) ... Therefore __pop_vlan_tci() is obviously wrong. A quick fix is avoiding using skb->data in vlan_set_encap_proto(), use 'vhdr+1' is always correct in both cases. Signed-off-by: Cong Wang Cc: David S. Miller Cc: Jesse Gross Acked-by: Jesse Gross Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6: use a stronger hash for tcp

2013-02-28T14:59:06Z

[ Upstream commit 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 ] It looks like its possible to open thousands of TCP IPv6 sessions on a server, all landing in a single slot of TCP hash table. Incoming packets have to lookup sockets in a very long list. We should hash all bits from foreign IPv6 addresses, using a salt and hash mix, not a simple XOR. inet6_ehashfn() can also separately use the ports, instead of xoring them. Reported-by: Neal Cardwell Signed-off-by: Eric Dumazet Cc: Yuchung Cheng Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: fix a compile error when SOCK_REFCNT_DEBUG is enabled

2013-02-28T14:59:06Z

[ Upstream commit dec34fb0f5b7873de45132a84a3af29e61084a6b ] When SOCK_REFCNT_DEBUG is enabled, below build error is met: kernel/sysctl_binary.o: In function `sk_refcnt_debug_release': include/net/sock.h:1025: multiple definition of `sk_refcnt_debug_release' kernel/sysctl.o:include/net/sock.h:1025: first defined here kernel/audit.o: In function `sk_refcnt_debug_release': include/net/sock.h:1025: multiple definition of `sk_refcnt_debug_release' kernel/sysctl.o:include/net/sock.h:1025: first defined here make[1]: *** [kernel/built-in.o] Error 1 make: *** [kernel] Error 2 So we decide to make sk_refcnt_debug_release static to eliminate the error. Signed-off-by: Ying Xue Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

fb: Yet another band-aid for fixing lockdep mess

2013-02-28T14:59:05Z

commit e93a9a868792ad71cdd09d75e5a02d8067473c4e upstream. I've still got lockdep warnings even after Alan's patch, and it seems that yet more band aids are required to paper over similar paths for unbind_con_driver() and unregister_con_driver(). After this hack, lockdep warnings are finally gone. Signed-off-by: Takashi Iwai Cc: Alan Cox Cc: Florian Tobias Schandinat Cc: Jiri Kosina Tested-by: Sedat Dilek Signed-off-by: Andrew Morton Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman

fb: rework locking to fix lock ordering on takeover

2013-02-28T14:59:05Z

commit 50e244cc793d511b86adea24972f3a7264cae114 upstream. Adjust the console layer to allow a take over call where the caller already holds the locks. Make the fb layer lock in order. This is partly a band aid, the fb layer is terminally confused about the locking rules it uses for its notifiers it seems. [akpm@linux-foundation.org: remove stray non-ascii char, tidy comment] [akpm@linux-foundation.org: export do_take_over_console()] [airlied: cleanup another non-ascii char] Signed-off-by: Alan Cox Cc: Florian Tobias Schandinat Cc: Stephen Rothwell Cc: Jiri Kosina Tested-by: Sedat Dilek Reviewed-by: Daniel Vetter Signed-off-by: Andrew Morton Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman

vgacon/vt: clear buffer attributes when we load a 512 character font (v2)

2013-02-28T14:59:03Z

commit 2a2483072393b27f4336ab068a1f48ca19ff1c1e upstream. When we switch from 256->512 byte font rendering mode, it means the current contents of the screen is being reinterpreted. The bit that holds the high bit of the 9-bit font, may have been previously set, and thus the new font misrenders. The problem case we see is grub2 writes spaces with the bit set, so it ends up with data like 0x820, which gets reinterpreted into 0x120 char which the font translates into G with a circumflex. This flashes up on screen at boot and is quite ugly. A current side effect of this patch though is that any rendering on the screen changes color to a slightly darker color, but at least the screen no longer corrupts. v2: as suggested by hpa, always clear the attribute space, whether we are are going to or from 512 chars. Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman

ALSA: usb: Fix Processing Unit Descriptor parsers

2013-02-28T14:59:02Z

commit b531f81b0d70ffbe8d70500512483227cc532608 upstream. Commit 99fc86450c439039d2ef88d06b222fd51a779176 "ALSA: usb-mixer: parse descriptors with structs" introduced a set of useful parsers for descriptors. Unfortunately the parses for the Processing Unit Descriptor came with a very subtle bug... Functions uac_processing_unit_iProcessing() and uac_processing_unit_specific() were indexing the baSourceID array forgetting the fields before the iProcessing and process-specific descriptors. The problem was observed with Sound Blaster Extigy mixer, where nNrModes in Up/Down-mix Processing Unit Descriptor was accessed at offset 10 of the descriptor (value 0) instead of offset 15 (value 7). In result the resulting control had interesting limit values: Simple mixer control 'Channel Routing Mode Select',0 Capabilities: volume volume-joined penum Playback channels: Mono Capture channels: Mono Limits: 0 - -1 Mono: -1 [100%] Fixed by starting from the bmControls, which was calculated correctly, instead of baSourceID. Now the mentioned control is fine: Simple mixer control 'Channel Routing Mode Select',0 Capabilities: volume volume-joined penum Playback channels: Mono Capture channels: Mono Limits: 0 - 6 Mono: 0 [0%] Signed-off-by: Pawel Moll Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman