1. 24 8月, 2009 5 次提交
    • D
      sh: Allow use of GENERIC_IOMAP · 15444a89
      David McKay 提交于
      The synopsys PCI cell used in the later STMicro chips requires code to
      be run in order to do IO cycles, rather than just memory mapping the IO
      space. Rather than extending the existing SH infrastructure to allow
      this, use the GENERIC_IOMAP implmentation to save re-inventing the
      wheel.
      
      This set of changes allows the SH to be built with GENERIC_IOMAP
      enabled, it just ifdef's out the functions provided by the GENERIC_IOMAP
      implementation, and provides a few required missing functions.
      Signed-off-by: NDavid McKay <david.mckay@st.com>
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      15444a89
    • C
      sh: Improve unwind info for signals · 2fc742f8
      Carl Shaw 提交于
      GCC does not issue unwind information for function epilogues.
      Unfortunately we can catch a signal during an epilogue.  The signal
      handler writes the current context and signal return code onto the stack
      overwriting previous contents.  During unwinding, libgcc can try to
      restore registers from the stack and restores corrupted ones. This can
      lead to segmentation, misaligned access and sigbus faults.
      
      For example, consider the following code:
      
          mov.l   r12,@-r15
          mov.l   r14,@-r15
          sts.l   pr,@-r15
          mov     r15,r14
      
          <do stuff>
      
          mov r14, r15
          lds.l @r15+, pr
      	<<< SIGNAL HERE
          mov.l @r15+, r14
          mov.l @r15+, r12
          rts
      
      Unwind is aware that pr was pushed to stack in prolog, so tries to
      restore it.  Unfortunately it restores the last word of the signal
      handler code placed on the stack by the kernel.
      
      This patch tries to avoid the problem by adding a guard region on the
      stack between where the function pushes data and where the signal handler
      pushes its return code.  We probably don't see this problem often because
      exception handling unwinding in an epilogue only occurs due to a pthread
      cancel signal.  Also the kernel signal stack handler alignment of 8 bytes
      could hide the occurance of this problem sometimes as the stack may not
      be trampled at a particular required word.
      
      This is not guaranteed to always work.  It relies on a frame pointer
      existing for the function (so it can get the correct sp value) which is
      not always the case for the SH4.
      
      Modifications will also be made to libgcc for the case where there is no
      fp.
      Signed-off-by: NCarl Shaw <carl.shaw@st.com>
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      2fc742f8
    • A
      sh: cleanup of do_address_error() · 5a0ab35e
      Andre Draszik 提交于
      This patch fixes a few problems with the existing code in do_address_error().
      
      a) the variable used to printk()d the offending instruction wasn't
         initialized correctly. This is a fix to bug 5727
      
      b) behaviour for CONFIG_CPU_SH2A wasn't correct
      
      c) the 'ignore address error' behaviour didn't update the PC, causing an
         infinite loop.
      Signed-off-by: NAndre Draszik <andre.draszik@st.com>
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      5a0ab35e
    • A
      sh: Allow user control over misaligned fixup handling · 7436cde6
      Andre Draszik 提交于
      This patch brings the SH4 misaligned trap handler in line with what
      happens on ARM:
      Add a /proc/cpu/alignment which can be read from to get alignment
      trap statistics and written to to influence the behaviour of the
      alignment trap handling. The value to write is a bitfield, which
      has the following meaning: 1 warn, 2 fixup, 4 signal
      In addition, we add a /proc/cpu/kernel_alignment, to enable or
      disable warnings in case of kernel code causing alignment errors.
      
      Signed-off by: Andre Draszik <andre.draszik@st.com>
      Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      7436cde6
    • A
      sh: ratelimit unaligned fixups · 9a4af027
      Andre Draszik 提交于
      This patch makes sure we see messages about unaligned access fixups
      every now and then. Else especially userspace apps suffering from
      bad programming won't ever be noticed...
      
      Signed-off by: Andre Draszik <andre.draszik@st.com>
      Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      9a4af027
  2. 23 8月, 2009 14 次提交
  3. 22 8月, 2009 14 次提交
  4. 21 8月, 2009 7 次提交