Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
接近 2 年 前同步成功

通知 170
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 20 3月, 2018 5 次提交
  3. 17 3月, 2018 3 次提交
  5. 16 3月, 2018 3 次提交
  7. 15 3月, 2018 1 次提交
  9. 14 3月, 2018 2 次提交
  11. 12 3月, 2018 3 次提交
  13. 09 3月, 2018 8 次提交
    • F
      x86/kprobes: Fix kernel crash when probing .entry_trampoline code · c07a8f8b
      由 Francis Deslauriers 提交于 
      Disable the kprobe probing of the entry trampoline:

.entry_trampoline is a code area that is used to ensure page table
isolation between userspace and kernelspace.

At the beginning of the execution of the trampoline, we load the
kernel's CR3 register. This has the effect of enabling the translation
of the kernel virtual addresses to physical addresses. Before this
happens most kernel addresses can not be translated because the running
process' CR3 is still used.

If a kprobe is placed on the trampoline code before that change of the
CR3 register happens the kernel crashes because int3 handling pages are
not accessible.

To fix this, add the .entry_trampoline section to the kprobe blacklist
to prohibit the probing of code before all the kernel pages are
accessible.
Signed-off-by: NFrancis Deslauriers <francis.deslauriers@efficios.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: mathieu.desnoyers@efficios.com
Cc: mhiramat@kernel.org
Link: http://lkml.kernel.org/r/1520565492-4637-2-git-send-email-francis.deslauriers@efficios.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      c07a8f8b
    • K
      perf/x86/intel: Disable userspace RDPMC usage for large PEBS · 1af22eba
      由 Kan Liang 提交于 
      Userspace RDPMC cannot possibly work for large PEBS, which was introduced in:

  b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)")

When the PEBS interrupt threshold is larger than one, there is no way
to get exact auto-reload times and value for userspace RDPMC.  Disable
the userspace RDPMC usage when large PEBS is enabled.

The only exception is when the PEBS interrupt threshold is 1, in which
case user-space RDPMC works well even with auto-reload events.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Fixes: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)")
Link: http://lkml.kernel.org/r/1518474035-21006-6-git-send-email-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1af22eba
    • K
      perf/x86/intel: Fix PMU read for auto-reload · ceb90d9e
      由 Kan Liang 提交于 
      Auto-reload events needs to be specially handled in event count read.

Auto-reload is only available for intel_pmu.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Fixes: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)")
Link: http://lkml.kernel.org/r/1518474035-21006-5-git-send-email-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      ceb90d9e
    • K
      perf/x86/intel/ds: Introduce ->read() function for auto-reload events and... · 5bee2cc6
      由 Kan Liang 提交于 
      perf/x86/intel/ds: Introduce ->read() function for auto-reload events and flush the PEBS buffer there

There is no way to get exact auto-reload times and values which are needed
for event updates unless we flush the PEBS buffer.

Introduce intel_pmu_auto_reload_read() to drain the PEBS buffer for
auto reload event. To prevent races with the hardware, we can only
call drain_pebs() when the PMU is disabled.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Link: http://lkml.kernel.org/r/1518474035-21006-4-git-send-email-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      5bee2cc6
    • K
      perf/x86: Introduce a ->read() callback in 'struct x86_pmu' · bcfbe5c4
      由 Kan Liang 提交于 
      Auto-reload needs to be specially handled when reading event counts.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Link: http://lkml.kernel.org/r/1518474035-21006-3-git-send-email-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      bcfbe5c4
    • K
      perf/x86/intel: Fix event update for auto-reload · d31fc13f
      由 Kan Liang 提交于 
      There is a bug when reading event->count with large PEBS enabled.

Here is an example:

  # ./read_count
  0x71f0
  0x122c0
  0x1000000001c54
  0x100000001257d
  0x200000000bdc5

In fixed period mode, the auto-reload mechanism could be enabled for
PEBS events, but the calculation of event->count does not take the
auto-reload values into account.

Anyone who reads event->count will get the wrong result, e.g x86_pmu_read().

This bug was introduced with the auto-reload mechanism enabled since
commit:

  851559e3 ("perf/x86/intel: Use the PEBS auto reload mechanism when possible")

Introduce intel_pmu_save_and_restart_reload() to calculate the
event->count only for auto-reload.

Since the counter increments a negative counter value and overflows on
the sign switch, giving the interval:

        [-period, 0]

the difference between two consequtive reads is:

 A) value2 - value1;
    when no overflows have happened in between,
 B) (0 - value1) + (value2 - (-period));
    when one overflow happened in between,
 C) (0 - value1) + (n - 1) * (period) + (value2 - (-period));
    when @n overflows happened in between.

Here A) is the obvious difference, B) is the extension to the discrete
interval, where the first term is to the top of the interval and the
second term is from the bottom of the next interval and C) the extension
to multiple intervals, where the middle term is the whole intervals
covered.

The equation for all cases is:

    value2 - value1 + n * period

Previously the event->count is updated right before the sample output.
But for case A, there is no PEBS record ready. It needs to be specially
handled.

Remove the auto-reload code from x86_perf_event_set_period() since
we'll not longer call that function in this case.

Based-on-code-from: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Fixes: 851559e3 ("perf/x86/intel: Use the PEBS auto reload mechanism when possible")
Link: http://lkml.kernel.org/r/1518474035-21006-2-git-send-email-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      d31fc13f
    • K
      perf/x86/intel: Properly save/restore the PMU state in the NMI handler · 82d71ed0
      由 Kan Liang 提交于 
      The PMU is disabled in intel_pmu_handle_irq(), but cpuc->enabled is not updated
accordingly.

This is fine in current usage because no-one checks it - but fix it
for future code: for example, the drain_pebs() will be modified to
fix an auto-reload bug.

Properly save/restore the old PMU state.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: kernel test robot <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/6f44ee84-56f8-79f1-559b-08e371eaeb78@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      82d71ed0
    • K
      perf/x86/intel: Fix large period handling on Broadwell CPUs · f605cfca
      由 Kan Liang 提交于 
      Large fixed period values could be truncated on Broadwell, for example:

  perf record -e cycles -c 10000000000

Here the fixed period is 0x2540BE400, but the period which finally applied is
0x540BE400 - which is wrong.

The reason is that x86_pmu::limit_period() uses an u32 parameter, so the
high 32 bits of 'period' get truncated.

This bug was introduced in:

  commit 294fe0f5 ("perf/x86/intel: Add INST_RETIRED.ALL workarounds")

It's safe to use u64 instead of u32:

 - Although the 'left' is s64, the value of 'left' must be positive when
   calling limit_period().

 - bdw_limit_period() only modifies the lowest 6 bits, it doesn't touch
   the higher 32 bits.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 294fe0f5 ("perf/x86/intel: Add INST_RETIRED.ALL workarounds")
Link: http://lkml.kernel.org/r/1519926894-3520-1-git-send-email-kan.liang@linux.intel.com
[ Rewrote unacceptably bad changelog. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      f605cfca
  15. 08 3月, 2018 12 次提交
  17. 07 3月, 2018 3 次提交