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  1. 24 4月, 2015 5 次提交
    • L
      x86: fix special __probe_kernel_write() tail zeroing case · d869844b
      由 Linus Torvalds 提交于 
      Commit cae2a173 ("x86: clean up/fix 'copy_in_user()' tail zeroing")
fixed the failure case tail zeroing of one special case of the x86-64
generic user-copy routine, namely when used for the user-to-user case
("copy_in_user()").

But in the process it broke an even more unusual case: using the user
copy routine for kernel-to-kernel copying.

Now, normally kernel-kernel copies are obviously done using memcpy(),
but we have a couple of special cases when we use the user-copy
functions.  One is when we pass a kernel buffer to a regular user-buffer
routine, using set_fs(KERNEL_DS).  That's a "normal" case, and continued
to work fine, because it never takes any faults (with the possible
exception of a silent and successful vmalloc fault).

But Jan Beulich pointed out another, very unusual, special case: when we
use the user-copy routines not because it's a path that expects a user
pointer, but for a couple of ftrace/kgdb cases that want to do a kernel
copy, but do so using "unsafe" buffers, and use the user-copy routine to
gracefully handle faults.  IOW, for probe_kernel_write().

And that broke for the case of a faulting kernel destination, because we
saw the kernel destination and wanted to try to clear the tail of the
buffer.  Which doesn't work, since that's what faults.

This only triggers for things like kgdb and ftrace users (eg trying
setting a breakpoint on read-only memory), but it's definitely a bug.
The fix is to not compare against the kernel address start (TASK_SIZE),
but instead use the same limits "access_ok()" uses.
Reported-and-tested-by: NJan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org # 4.0
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d869844b
    • L
      nios2: rework cache · 1a70db49
      由 Ley Foon Tan 提交于 
      - flush dcache before flush instruction cache
- remork update_mmu_cache and flush_dcache_page
- add shmparam.h
Signed-off-by: NLey Foon Tan <lftan@altera.com>
      1a70db49
    • E
      nios2: Add types.h header required for __u32 type · 2009337e
      由 Ezequiel Garcia 提交于 
      Reported by the header checker (CONFIG_HEADERS_CHECK=y):

  CHECK   usr/include/asm/ (31 files)
./usr/include/asm/ptrace.h:77: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Acked-by: NLey Foon Tan <lftan@altera.com>
      2009337e
    • S
      eth: bf609 eth clock: add pclk clock for stmmac driver probe · d91e14b3
      由 Steven Miao 提交于 
      Signed-off-by: NSteven Miao <realmz6@gmail.com>
      d91e14b3
    • C
      blackfin: Wire up missing syscalls · 4f650a59
      由 Chen Gang 提交于 
      The related syscalls are below which may cause samples/kdbus building
break in next-20150401 tree, the related information and error:

    CALL    scripts/checksyscalls.sh
  <stdin>:1223:2: warning: #warning syscall kcmp not implemented [-Wcpp]
  <stdin>:1226:2: warning: #warning syscall finit_module not implemented [-Wcpp]
  <stdin>:1229:2: warning: #warning syscall sched_setattr not implemented [-Wcpp]
  <stdin>:1232:2: warning: #warning syscall sched_getattr not implemented [-Wcpp]
  <stdin>:1235:2: warning: #warning syscall renameat2 not implemented [-Wcpp]
  <stdin>:1238:2: warning: #warning syscall seccomp not implemented [-Wcpp]
  <stdin>:1241:2: warning: #warning syscall getrandom not implemented [-Wcpp]
  <stdin>:1244:2: warning: #warning syscall memfd_create not implemented [-Wcpp]
  <stdin>:1247:2: warning: #warning syscall bpf not implemented [-Wcpp]
  <stdin>:1250:2: warning: #warning syscall execveat not implemented [-Wcpp]
  [...]
    HOSTCC  samples/kdbus/kdbus-workers
  samples/kdbus/kdbus-workers.c: In function ‘prime_new’:
  samples/kdbus/kdbus-workers.c:930:18: error: ‘__NR_memfd_create’ undeclared (first use in this function)
    p->fd = syscall(__NR_memfd_create, "prime-area", MFD_CLOEXEC);
                    ^
  samples/kdbus/kdbus-workers.c:930:18: note: each undeclared identifier is reported only once for each function it appears in
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
      4f650a59
  3. 23 4月, 2015 17 次提交
  5. 22 4月, 2015 8 次提交
  7. 21 4月, 2015 10 次提交
    • N
      ARM: 8344/1: VDSO: honor CONFIG_VDSO in Makefile · f80f6531
      由 Nathan Lynch 提交于 
      When CONFIG_VDSO=n, the build normally does not enter arch/arm/vdso/
because arch/arm/Makefile does not add it to core-y.

However, if the user runs 'make arch/arm/vdso/' the VDSO targets will
get visited.  This is because the VDSO Makefile itself does not
consider the value of CONFIG_VDSO.

It is arguably better and more consistent behavior to generate an
empty built-in.o when CONFIG_VDSO=n and the user attempts to build
arch/arm/vdso/.  It's nicer because it doesn't try to build things
that Kconfig dependencies are there to prevent (e.g. the dependency on
AEABI), and it's less confusing than building objects that won't be
used in the final image.
Signed-off-by: NNathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      f80f6531
    • N
      ARM: 8343/1: VDSO: add build artifacts to .gitignore · 2b507a2d
      由 Nathan Lynch 提交于 
      vdsomunge and vdso.so.raw are outputs that don't get matched by the
normal ignore rules.
Signed-off-by: NNathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      2b507a2d
    • R
      ARM: Fix nommu booting · 0a9024e8
      由 Russell King 提交于 
      Commit bf35706f ("ARM: 8314/1: replace PROCINFO embedded branch with
relative offset") broke booting on nommu platforms as it didn't update
the nommu boot code.  This patch fixes that oversight.

Fixes: bf35706f ("ARM: 8314/1: replace PROCINFO embedded branch with relative offset")
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      0a9024e8
    • P
      KVM: PPC: Book3S HV: Use msgsnd for signalling threads on POWER8 · 66feed61
      由 Paul Mackerras 提交于 
      This uses msgsnd where possible for signalling other threads within
the same core on POWER8 systems, rather than IPIs through the XICS
interrupt controller.  This includes waking secondary threads to run
the guest, the interrupts generated by the virtual XICS, and the
interrupts to bring the other threads out of the guest when exiting.

Aggregated statistics from debugfs across vcpus for a guest with 32
vcpus, 8 threads/vcore, running on a POWER8, show this before the
change:

 rm_entry:     3387.6ns (228 - 86600, 1008969 samples)
  rm_exit:     4561.5ns (12 - 3477452, 1009402 samples)
  rm_intr:     1660.0ns (12 - 553050, 3600051 samples)

and this after the change:

 rm_entry:     3060.1ns (212 - 65138, 953873 samples)
  rm_exit:     4244.1ns (12 - 9693408, 954331 samples)
  rm_intr:     1342.3ns (12 - 1104718, 3405326 samples)

for a test of booting Fedora 20 big-endian to the login prompt.

The time taken for a H_PROD hcall (which is handled in the host
kernel) went down from about 35 microseconds to about 16 microseconds
with this change.

The noinline added to kvmppc_run_core turned out to be necessary for
good performance, at least with gcc 4.9.2 as packaged with Fedora 21
and a little-endian POWER8 host.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
      66feed61
    • P
      KVM: PPC: Book3S HV: Translate kvmhv_commence_exit to C · eddb60fb
      由 Paul Mackerras 提交于 
      This replaces the assembler code for kvmhv_commence_exit() with C code
in book3s_hv_builtin.c.  It also moves the IPI sending code that was
in book3s_hv_rm_xics.c into a new kvmhv_rm_send_ipi() function so it
can be used by kvmhv_commence_exit() as well as icp_rm_set_vcpu_irq().
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
      eddb60fb
    • P
      KVM: PPC: Book3S HV: Streamline guest entry and exit · 6af27c84
      由 Paul Mackerras 提交于 
      On entry to the guest, secondary threads now wait for the primary to
switch the MMU after loading up most of their state, rather than before.
This means that the secondary threads get into the guest sooner, in the
common case where the secondary threads get to kvmppc_hv_entry before
the primary thread.

On exit, the first thread out increments the exit count and interrupts
the other threads (to get them out of the guest) before saving most
of its state, rather than after.  That means that the other threads
exit sooner and means that the first thread doesn't spend so much
time waiting for the other threads at the point where the MMU gets
switched back to the host.

This pulls out the code that increments the exit count and interrupts
other threads into a separate function, kvmhv_commence_exit().
This also makes sure that r12 and vcpu->arch.trap are set correctly
in some corner cases.

Statistics from /sys/kernel/debug/kvm/vm*/vcpu*/timings show the
improvement.  Aggregating across vcpus for a guest with 32 vcpus,
8 threads/vcore, running on a POWER8, gives this before the change:

 rm_entry:     avg 4537.3ns (222 - 48444, 1068878 samples)
  rm_exit:     avg 4787.6ns (152 - 165490, 1010717 samples)
  rm_intr:     avg 1673.6ns (12 - 341304, 3818691 samples)

and this after the change:

 rm_entry:     avg 3427.7ns (232 - 68150, 1118921 samples)
  rm_exit:     avg 4716.0ns (12 - 150720, 1119477 samples)
  rm_intr:     avg 1614.8ns (12 - 522436, 3850432 samples)

showing a substantial reduction in the time spent per guest entry in
the real-mode guest entry code, and smaller reductions in the real
mode guest exit and interrupt handling times.  (The test was to start
the guest and boot Fedora 20 big-endian to the login prompt.)
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
      6af27c84
    • P
      KVM: PPC: Book3S HV: Use bitmap of active threads rather than count · 7d6c40da
      由 Paul Mackerras 提交于 
      Currently, the entry_exit_count field in the kvmppc_vcore struct
contains two 8-bit counts, one of the threads that have started entering
the guest, and one of the threads that have started exiting the guest.
This changes it to an entry_exit_map field which contains two bitmaps
of 8 bits each.  The advantage of doing this is that it gives us a
bitmap of which threads need to be signalled when exiting the guest.
That means that we no longer need to use the trick of setting the
HDEC to 0 to pull the other threads out of the guest, which led in
some cases to a spurious HDEC interrupt on the next guest entry.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
      7d6c40da
    • P
      KVM: PPC: Book3S HV: Use decrementer to wake napping threads · fd6d53b1
      由 Paul Mackerras 提交于 
      This arranges for threads that are napping due to their vcpu having
ceded or due to not having a vcpu to wake up at the end of the guest's
timeslice without having to be poked with an IPI.  We do that by
arranging for the decrementer to contain a value no greater than the
number of timebase ticks remaining until the end of the timeslice.
In the case of a thread with no vcpu, this number is in the hypervisor
decrementer already.  In the case of a ceded vcpu, we use the smaller
of the HDEC value and the DEC value.

Using the DEC like this when ceded means we need to save and restore
the guest decrementer value around the nap.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
      fd6d53b1
    • P
      KVM: PPC: Book3S HV: Don't wake thread with no vcpu on guest IPI · ccc07772
      由 Paul Mackerras 提交于 
      When running a multi-threaded guest and vcpu 0 in a virtual core
is not running in the guest (i.e. it is busy elsewhere in the host),
thread 0 of the physical core will switch the MMU to the guest and
then go to nap mode in the code at kvm_do_nap.  If the guest sends
an IPI to thread 0 using the msgsndp instruction, that will wake
up thread 0 and cause all the threads in the guest to exit to the
host unnecessarily.  To avoid the unnecessary exit, this arranges
for the PECEDP bit to be cleared in this situation.  When napping
due to a H_CEDE from the guest, we still set PECEDP so that the
thread will wake up on an IPI sent using msgsndp.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
      ccc07772
    • P
      KVM: PPC: Book3S HV: Get rid of vcore nap_count and n_woken · 5d5b99cd
      由 Paul Mackerras 提交于 
      We can tell when a secondary thread has finished running a guest by
the fact that it clears its kvm_hstate.kvm_vcpu pointer, so there
is no real need for the nap_count field in the kvmppc_vcore struct.
This changes kvmppc_wait_for_nap to poll the kvm_hstate.kvm_vcpu
pointers of the secondary threads rather than polling vc->nap_count.
Besides reducing the size of the kvmppc_vcore struct by 8 bytes,
this also means that we can tell which secondary threads have got
stuck and thus print a more informative error message.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
      5d5b99cd