Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 18 3月, 2011 34 次提交
  3. 16 3月, 2011 2 次提交
  5. 15 3月, 2011 4 次提交
    • M
      x86: stop_machine_text_poke() should issue sync_core() · 0e00f7ae
      由 Mathieu Desnoyers 提交于 
      Intel Archiecture Software Developer's Manual section 7.1.3 specifies that a
core serializing instruction such as "cpuid" should be executed on _each_ core
before the new instruction is made visible.

Failure to do so can lead to unspecified behavior (Intel XMC erratas include
General Protection Fault in the list), so we should avoid this at all cost.

This problem can affect modified code executed by interrupt handlers after
interrupt are re-enabled at the end of stop_machine, because no core serializing
instruction is executed between the code modification and the moment interrupts
are reenabled.

Because stop_machine_text_poke performs the text modification from the first CPU
decrementing stop_machine_first, modified code executed in thread context is
also affected by this problem. To explain why, we have to split the CPUs in two
categories: the CPU that initiates the text modification (calls text_poke_smp)
and all the others. The scheduler, executed on all other CPUs after
stop_machine, issues an "iret" core serializing instruction, and therefore
handles core serialization for all these CPUs. However, the text modification
initiator can continue its execution on the same thread and access the modified
text without any scheduler call. Given that the CPU that initiates the code
modification is not guaranteed to be the one actually performing the code
modification, it falls into the XMC errata.

Q: Isn't this executed from an IPI handler, which will return with IRET (a
   serializing instruction) anyway?
A: No, now stop_machine uses per-cpu workqueue, so that handler will be
   executed from worker threads. There is no iret anymore.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
LKML-Reference: <20110303160137.GB1590@Krystal>
Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: <stable@kernel.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      0e00f7ae
    • X
      x86, tlb, UV: Do small micro-optimization for native_flush_tlb_others() · 25542c64
      由 Xiao Guangrong 提交于 
      native_flush_tlb_others() is called from:

 flush_tlb_current_task()
 flush_tlb_mm()
 flush_tlb_page()

All these functions disable preemption explicitly, so we can use
smp_processor_id() instead of get_cpu() and put_cpu().
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Cliff Wickman <cpw@sgi.com>
LKML-Reference: <4D7EC791.4040003@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      25542c64
    • A
      x86: Add new syscalls for x86_64 · 6aae5f2b
      由 Aneesh Kumar K.V 提交于 
      This patch add new syscalls to x86_64
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      6aae5f2b
    • A
      x86: Add new syscalls for x86_32 · 7dadb755
      由 Aneesh Kumar K.V 提交于 
      This patch adds new syscalls to x86_32
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      7dadb755