kernel/linux.git/include/linux, branch v3.4.38

exec: use -ELOOP for max recursion depth

2013-03-28T19:12:28+00:00

commit d740269867021faf4ce38a449353d2b986c34a67 upstream. To avoid an explosion of request_module calls on a chain of abusive scripts, fail maximum recursion with -ELOOP instead of -ENOEXEC. As soon as maximum recursion depth is hit, the error will fail all the way back up the chain, aborting immediately. This also has the side-effect of stopping the user's shell from attempting to reexecute the top-level file as a shell script. As seen in the dash source: if (cmd != path_bshell && errno == ENOEXEC) { *argv-- = cmd; *argv = cmd = path_bshell; goto repeat; } The above logic was designed for running scripts automatically that lacked the "#!" header, not to re-try failed recursion. On a legitimate -ENOEXEC, things continue to behave as the shell expects. Additionally, when tracking recursion, the binfmt handlers should not be involved. The recursion being tracked is the depth of calls through search_binary_handler(), so that function should be exclusively responsible for tracking the depth. Signed-off-by: Kees Cook Cc: halfdog Cc: P J P Cc: Alexander Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

tcp: fix skb_availroom()

2013-03-28T19:11:53+00:00

[ Upstream commit 16fad69cfe4adbbfa813de516757b87bcae36d93 ] Chrome OS team reported a crash on a Pixel ChromeBook in TCP stack : https://code.google.com/p/chromium/issues/detail?id=182056 commit a21d45726acac (tcp: avoid order-1 allocations on wifi and tx path) did a poor choice adding an 'avail_size' field to skb, while what we really needed was a 'reserved_tailroom' one. It would have avoided commit 22b4a4f22da (tcp: fix retransmit of partially acked frames) and this commit. Crash occurs because skb_split() is not aware of the 'avail_size' management (and should not be aware) Signed-off-by: Eric Dumazet Reported-by: Mukesh Agrawal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

perf,x86: fix link failure for non-Intel configs

2013-03-20T20:05:00+00:00

commit 6c4d3bc99b3341067775efd4d9d13cc8e655fd7c upstream. Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after suspend/resume") introduces a link failure since perf_restore_debug_store() is only defined for CONFIG_CPU_SUP_INTEL: arch/x86/power/built-in.o: In function `restore_processor_state': (.text+0x45c): undefined reference to `perf_restore_debug_store' Fix it by defining the dummy function appropriately. Signed-off-by: David Rientjes Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

perf,x86: fix kernel crash with PEBS/BTS after suspend/resume

2013-03-20T20:04:59+00:00

commit 1d9d8639c063caf6efc2447f5f26aa637f844ff6 upstream. This patch fixes a kernel crash when using precise sampling (PEBS) after a suspend/resume. Turns out the CPU notifier code is not invoked on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly by the kernel and keeps it power-on/resume value of 0 causing any PEBS measurement to crash when running on CPU0. The workaround is to add a hook in the actual resume code to restore the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0, the DS_AREA will be restored twice but this is harmless. Reported-by: Linus Torvalds Signed-off-by: Stephane Eranian Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

pstore: Avoid deadlock in panic and emergency-restart path

2013-03-03T22:06:43+00:00

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)

2013-03-03T22:06:43+00:00

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

2013-03-03T22:06:37+00:00

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

2013-02-28T14:59:06+00:00

[ 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

fb: Yet another band-aid for fixing lockdep mess

2013-02-28T14:59:05+00:00

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

2013-02-28T14:59:05+00:00

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