Impact: remove dead code

If we take a closer look at the rff_trace/rff_action ret_from_fork code,
we have to realize that it does all the wrong things: for example it
checks the TIF flag - while later on jumping back to the ret-from-syscall
path - duplicating the check needlessly.

But checking for _TIF_SYSCALL_TRACE is completely unnecessary here because
we clear that flag for every freshly forked task. So the whole "tracing"
code here, for which there is a out of line jump optimization that makes
it even harder to read, is in reality completely dead code ...
Reported-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Cyrill Gorcunov <gorcunov@gmail.com>

We merge this branch because x86/debug touches code that we started
cleaning up in x86/irq. The two branches started out independent,
but as unexpected amount of activity went into x86/irq, they became
dependent. Resolve that by this cross-merge.

Impact: cleanup
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

child_rip is called not by its name but indirectly
rather so make it global and aligned.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

entry_32.S is now the only user of KPROBE_ENTRY / KPROBE_END,
treewide. This patch reorders entry_64.S and explicitly generates
a separate section for functions that need the protection. The
generated code before and after the patch is equal.

The KPROBE_ENTRY and KPROBE_END macro's are removed too.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: clean up assembly macros and annotations - with some object impact

entry_64.S is the only user of KPROBE_ENTRY / KPROBE_END on
x86_64. This patch reorders entry_64.S and explicitly generates
a separate section for functions that need the protection. The
generated code before and after the patch is equal.

Implicitly changing sections in assembly files makes it more
difficult to follow why the assembler is doing certain things.
For example,

.p2align 5
KPROBE_ENTRY(...)

was not doing what you would expect. Other section changes
(__ex_table, .fixup, .init.rodata) are done explicitly already.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: improve backtrace quality

avoid the confusion in call trace because of the lack of padding at the
tail of function.

When do_exit gets called, the return address behind call instruction is
pushed into stack. If something get wrong in do_exit, for x86_64, the
entry "kernel_execve +0x00/0xXX" rather than "child_rip +0xYY/0xZZ" is
in the call trace.

That looks confusing, so add a u2d to make the return address still part
of the original call site. (This also catches any instances of us returning
from that function somehow.)
Signed-off-by: jia zhang <jia.zhang2008@gmail.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: make ENTRY()/END() macros more capable

It's usefull to catch unbalanced or messed or mixed declarations of ENTRY and
KPROBES. These macros would help a bit.

For example the following code would compile without problems

        ENTRY_X86(mcount)
                retq
        END_X86(mcount)

But if you forget and mess the following form

        ENTRY_X86(mcount)
                retq
        END(mcount)

        ENTRY_X86(ftrace_caller)

The assembler will issue the following message:
Error: ENTRY_X86/KPROBE_X86 unbalanced,missed,mixed

Actually the checking is performed at every _X86 macro
so maybe it's good idea to put ENTRY_KPROBE_FINAL_X86
at the end of .S file to be sure you didn't miss anything.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Alexander van Heukelum <heukelum@mailshack.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: move some code out of .kprobes.text

KPROBE_ENTRY switches code generation to .kprobes.text, and KPROBE_END
uses .popsection to get back to the previous section (.text, normally).
Also replace ENDPROC by END, for consistency.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup of entry_64.S

Except for the order and the place of the functions, this
patch should not change the generated code.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

Move recently introduced dwarf2 macros to dwarf2.h file.
It allow us to not duplicate them in assembly files.

Active usage of _cfi macros don't make assembly files
more obvious to understand but we already have a lot of
macros there which requires to search the definitions
of them *anyway*. But at least it make every cfi usage
one line shorter.

Also some code alignment is done.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

Simplify the irq-sampled stack overflow debug check:

 - eliminate an #idef

 - use WARN_ONCE() to emit a single warning (all bets are off
   after the first such warning anyway)
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: make stack overflow debug check and printout narrower

stack_overflow_check() should consider the stack usage of pt_regs, and
thus it could warn us in advance. Additionally, it looks better for
the warning time to start at INITIAL_JIFFIES.

Assuming that rsp gets close to the check point before interrupt
arrives: when interrupt really happens, thread_info will be partly
overrode.
Signed-off-by: jia zhang <jia.zhang2008@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix bootup crash

Even though it tested fine for me, there was still a bug in the
first patch: I have overlooked a call to ptregscall_common. This
patch fixes that, I think, but the code is never executed for
me while running a debian install... (I tested this by putting
an "1:jmp 1b" in there.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

DISABLE_INTERRUPTS(CLBR_NONE)/TRACE_IRQS_OFF is now always
executed just before paranoid_exit. Move it there.

Split out paranoidzeroentry, paranoiderrorentry, and
paranoidzeroentry_ist to get more readable macro's.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup, shrink kernel image size

Also expand the paranoid_exit0 macro into nmi_exit inside the
nmi stub in the case of enabled irq-tracing.

This gives a few hundred bytes code size reduction.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

The save_rest function completes a partial stack frame for use
by the PTREGSCALL macro. This also avoids the indirect call in
PTREGSCALLs.

This adds the macro movq_cfi_restore to hide the CFI_RESTORE
annotation when restoring a register from the stack frame.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

Rename:

   CFI_PUSHQ  =>  pushq_cfi
   CFI_POPQ   =>  popq_cfi
   CFI_MOVQ   =>  movq_cfi

To make it blend better into regular assembly code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: build fix

The break builds with older binutils (2.16.1):

 arch/x86/kernel/entry_64.S: Assembler messages:
 arch/x86/kernel/entry_64.S:282: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:283: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:284: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:285: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:286: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:287: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:288: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:289: Error: too many positional arguments
 arch/x86/kernel/entry_64.S:290: Error: too many positional arguments

Took some time to figure out the detail that GAS chokes on: it's
negative offsets. Rearrange the calculations to make sure we never
go negative.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] xen: fix xen_get_eflags.
  [IA64] ia64/pv_ops/pv_cpu_ops: fix _IA64_REG_IP case.
  [IA64] remove duplicate include iommu.h
  [IA64] use mprintk instead of printk, in ia64_mca_modify_original_stack
  [IA64] Rationalize kernel mode alignment checking

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
  USB: ACE1001 patch for cp2101.c
  USB: usbmon: fix read(2)
  USB: gadget rndis: send notifications
  USB: gadget rndis: stop windows self-immolation
  USB: storage: update unusual_devs entries for Nokia 5300 and 5310
  USB: storage: updates unusual_devs entry for the Nokia 6300
  usb: musb: fix bug in musb_schedule
  USB: fix SB700 usb subsystem hang bug

fix xen_get_eflags. It doesn't take any argument.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>

pv_cpu_ops.getreg(_IA64_REG_IP) returned constant.
But the returned ip valued should be the one in the caller, not of the callee.
This patch fixes that.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/pci-dma.c only needs to include iommu once.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Using printk from MCA/INIT context is unsafe since it can cause deadlock.
The ia64_mca_modify_original_stack is called from both of mca handler and
init handler, so it should use mprintk instead of printk.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Itanium processors can handle some misaligned data accesses. They
also provide a mode where all such accesses are forced to trap. The
kernel was schizophrenic about use of this mode:

* Base kernel code ran in permissive mode where the only traps
  generated were from those cases that the h/w could not handle.
* Interrupt, syscall and trap code ran in strict mode where all
  unaligned accesses caused traps to the 0x5a00 unaligned reference
  vector.

Use strict alignment checking throughout the kernel, but make
sure that we continue to let user mode use more relaxed mode
as the default.
Signed-off-by: Tony Luck <tony.luck@intel.com>

When we migrate an interrupt from one CPU to another, we set the
move_in_progress flag and clean up the vectors later once they're not
being used.  If you're unlucky and call destroy_irq() before the vectors
become un-used, the move_in_progress flag is never cleared, which causes
the interrupt to become unusable.

This was discovered by Jesse Brandeburg for whom it manifested as an
MSI-X device refusing to use MSI-X mode when the driver was unloaded
and reloaded repeatedly.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix a regression reported by Max Kellermann whereby kernel profiling
showed that his clients were spending 45% of their time in
rpcauth_lookup_credcache.

It turns out that although his processes had identical uid/gid/groups,
generic_match() was failing to detect this, because the task->group_info
pointers were not shared. This again lead to the creation of a huge number
of identical credentials at the RPC layer.

The regression is fixed by comparing the contents of task->group_info
if the actual pointers are not identical.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  [CIFS] Do not attempt to close invalidated file handles
  [CIFS] fix check for dead tcon in smb_init

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  MIPS: csrc-r4k: Fix declaration depending on the wrong CONFIG_ symbol.
  MIPS: csrc-r4k: Fix spelling mistake.
  MIPS: RB532: Provide functions for gpio configuration
  MIPS: IP22: Make indy_sc_ops variable static
  MIPS: RB532: GPIO register offsets are relative to GPIOBASE
  MIPS: Malta: Fix include paths in malta-amon.c

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  intel-iommu: fix compile warnings

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (23 commits)
  net: fix tiny output corruption of /proc/net/snmp6
  atl2: don't request irq on resume if netif running
  ipv6: use seq_release_private for ip6mr.c /proc entries
  pkt_sched: fix missing check for packet overrun in qdisc_dump_stab()
  smc911x: Fix printf format typo in smc911x driver.
  asix: Fix asix-based cards connecting to 10/100Mbs LAN.
  mv643xx_eth: fix recycle check bound
  mv643xx_eth: fix the order of mdiobus_{unregister, free}() calls
  sh: sh_eth: Update to change of mii_bus
  TPROXY: supply a struct flowi->flags argument in inet_sk_rebuild_header()
  TPROXY: fill struct flowi->flags in udp_sendmsg()
  net: ipg.c fix bracing on endian swapping
  phylib: Fix auto-negotiation restart avoidance
  net: jme.c rxdesc.flags is __le16, other missing endian swaps
  phylib: fix phy name example in documentation
  net: Do not fire linkwatch events until the device is registered.
  phonet: fix compilation with gcc-3.4
  ixgbe: fix compilation with gcc-3.4
  pktgen: fix multiple queue warning
  net: fix ip_mr_init() error path
  ...

Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: fix dyn ftrace filter selection
  ftrace: make filtered functions effective on setting
  ftrace: fix set_ftrace_filter
  trace: introduce missing mutex_unlock()
  tracing: kernel/trace/trace.c: introduce missing kfree()

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: uaccess_64: fix return value in __copy_from_user()
  x86: quirk for reboot stalls on a Dell Optiplex 330

Commit 81e192d6 ("parisc: convert to
generic compat_sys_ptrace") introduced a bug which segfaults the parisc
64bit kernel when stracing 32bit applications:

  Kernel Fault: Code=15 regs=00000000bafa42b0 (Addr=00000001baf5ab57)
       YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
  PSW: 00001000000001101111111100001011 Tainted: G        W
  r00-03  000000ff0806ff0b 000000004068edc0 00000000401203f8 00000000fb3e2508
  r04-07  0000000040686dc0 00000000baf5a800 fffffffffffffffc fffffffffb3e2508
  r08-11  00000000baf5a800 000000000004b068 00000000000402b0 0000000000040d68
  r12-15  0000000000042a9c 0000000000040a9c 0000000000040d60 0000000000042e9c
  r16-19  000000000004b060 000000000004b058 0000000000042d9c ffffffffffffffff
  r20-23  000000000800000b 0000000000000000 000000000800000b fffffffffb3e2508
  r24-27  00000000fffffffc 0000000000000003 00000000fffffffc 0000000040686dc0
  r28-31  00000001baf5a7ff 00000000bafa4280 00000000bafa42b0 00000000000001d7
  sr00-03  0000000000fca000 0000000000000000 0000000000000000 0000000000fca000
  sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

  IASQ: 0000000000000000 0000000000000000 IAOQ: 0000000040120400 0000000040120404
   IIR: 4b9a06b0    ISR: 0000000000000000  IOR: 00000001baf5ab57
   CPU:        0   CR30: 00000000bafa4000 CR31: 00000000d22344e0
   ORIG_R28: 00000000fb3e2248
   IAOQ[0]: compat_arch_ptrace+0xb8/0x160
   IAOQ[1]: compat_arch_ptrace+0xbc/0x160
   RP(r2): compat_arch_ptrace+0xb0/0x160
  Backtrace:
   [<00000000401612ac>] compat_sys_ptrace+0x15c/0x180
   [<0000000040104ef8>] syscall_exit+0x0/0x14

The problem is that compat_arch_ptrace() enters with an addr value of
type compat_ulong_t and calls translate_usr_offset() to translate the
address offset into a struct pt_regs offset like this:

	addr = translate_usr_offset(addr)

this means that any return value of translate_usr_offset() is stored
back as compat_ulong_t type into the addr variable.

But since translate_usr_offset() returns -1 for invalid offsets, addr
can now get the value 0xffffffff which then fails the next return-value
sanity check and thus the kernel tries to access invalid memory:

	if (addr < 0)
		break;

Fix this bug by modifying translate_usr_offset() to take and return
values of type compat_ulong_t, and by returning the value
"sizeof(struct pt_regs)" as an error indicator.

Additionally change the sanity check to check for return values
for >= sizeof(struct pt_regs).

This patch survived my compile and run-tests.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If a connection with open file handles has gone down
and come back up and reconnected without reopening
the file handle yet, do not attempt to send an SMB close
request for this handle in cifs_close.  We were
checking for the connection being invalid in cifs_close
but since the connection may have been reconnected
we also need to check whether the file handle
was marked invalid (otherwise we could close the
wrong file handle by accident).
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>