1. 15 10月, 2014 2 次提交
    • A
      powerpc: Rename __get_SP() to current_stack_pointer() · acf620ec
      Anton Blanchard 提交于
      Michael points out that __get_SP() is a pretty horrible
      function name. Let's give it a better name.
      Signed-off-by: NAnton Blanchard <anton@samba.org>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      acf620ec
    • A
      powerpc: Reimplement __get_SP() as a function not a define · bfe9a2cf
      Anton Blanchard 提交于
      Li Zhong points out an issue with our current __get_SP()
      implementation. If ftrace function tracing is enabled (ie -pg
      profiling using _mcount) we spill a stack frame on 64bit all the
      time.
      
      If a function calls __get_SP() and later calls a function that is
      tail call optimised, we will pop the stack frame and the value
      returned by __get_SP() is no longer valid. An example from Li can
      be found in save_stack_trace -> save_context_stack:
      
      c0000000000432c0 <.save_stack_trace>:
      c0000000000432c0:       mflr    r0
      c0000000000432c4:       std     r0,16(r1)
      c0000000000432c8:       stdu    r1,-128(r1) <-- stack frame for _mcount
      c0000000000432cc:       std     r3,112(r1)
      c0000000000432d0:       bl      <._mcount>
      c0000000000432d4:       nop
      
      c0000000000432d8:       mr      r4,r1 <-- __get_SP()
      
      c0000000000432dc:       ld      r5,632(r13)
      c0000000000432e0:       ld      r3,112(r1)
      c0000000000432e4:       li      r6,1
      
      c0000000000432e8:       addi    r1,r1,128 <-- pop stack frame
      
      c0000000000432ec:       ld      r0,16(r1)
      c0000000000432f0:       mtlr    r0
      c0000000000432f4:       b       <.save_context_stack> <-- tail call optimized
      
      save_context_stack ends up with a stack pointer below the current
      one, and it is likely to be scribbled over.
      
      Fix this by making __get_SP() a function which returns the
      callers stack frame. Also replace inline assembly which grabs
      the stack pointer in save_stack_trace and show_stack with
      __get_SP().
      
      This also fixes an issue with perf_arch_fetch_caller_regs().
      It currently unwinds the stack once, which will skip a
      valid stack frame on a leaf function. With the __get_SP() fixes
      in this patch, we never need to unwind the stack frame to get
      to the first interesting frame.
      
      We have to export __get_SP() because perf_arch_fetch_caller_regs()
      (which is used in modules) calls it from a header file.
      Reported-by: NLi Zhong <zhong@linux.vnet.ibm.com>
      Signed-off-by: NAnton Blanchard <anton@samba.org>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      bfe9a2cf
  2. 13 10月, 2014 3 次提交
  3. 10 10月, 2014 2 次提交
    • M
      powerpc/book3s: Don't clear MSR_RI in hmi handler. · c675c7db
      Mahesh Salgaonkar 提交于
      In HMI interrupt handler we don't touch SRR0/SRR1, instead we touch
      HSRR0/HSRR1. Hence we don't need to clear MSR_RI bit.
      Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      c675c7db
    • R
      powerpc: Fix sys_call_table declaration to enable syscall tracing · 1028ccf5
      Romeo Cane 提交于
      Declaring sys_call_table as a pointer causes the compiler to generate
      the wrong lookup code in arch_syscall_addr().
      
           <arch_syscall_addr>:
              lis     r9,-16384
              rlwinm  r3,r3,2,0,29
        -     lwz     r11,30640(r9)
        -     lwzx    r3,r11,r3
        +     addi    r9,r9,30640
        +     lwzx    r3,r9,r3
              blr
      
      The actual sys_call_table symbol, declared in assembler, is an
      array. If we lie about that to the compiler we get the wrong code
      generated, as above.
      
      This definition seems only to be used by the syscall tracing code in
      kernel/trace/trace_syscalls.c. With this patch I can successfully use
      the syscall tracepoints:
      
        bash-3815  [002] ....   333.239082: sys_write -> 0x2
        bash-3815  [002] ....   333.239087: sys_dup2(oldfd: a, newfd: 1)
        bash-3815  [002] ....   333.239088: sys_dup2 -> 0x1
        bash-3815  [002] ....   333.239092: sys_fcntl(fd: a, cmd: 1, arg: 0)
        bash-3815  [002] ....   333.239093: sys_fcntl -> 0x1
        bash-3815  [002] ....   333.239094: sys_close(fd: a)
        bash-3815  [002] ....   333.239094: sys_close -> 0x0
      Signed-off-by: NRomeo Cane <romeo.cane.ext@coriant.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      1028ccf5
  4. 09 10月, 2014 1 次提交
  5. 08 10月, 2014 16 次提交
  6. 07 10月, 2014 5 次提交
  7. 04 10月, 2014 1 次提交
  8. 03 10月, 2014 5 次提交
  9. 02 10月, 2014 5 次提交