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  1. 24 8月, 2009 6 次提交
    • G
      sh: kgdb: do not reload VBR while handling debugger breackpoint · 27a30f53
      由 Giuseppe Cavallaro 提交于 
      Save the VBR allowing GDB to dump full registers set but do not reload it
as soon as the kgdb_handle_exception is invoked.
Signed-off-by: NGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      27a30f53
    • D
      sh: Allow use of GENERIC_IOMAP · 15444a89
      由 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
      由 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
      由 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
      由 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
      由 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
  3. 23 8月, 2009 14 次提交
  5. 22 8月, 2009 14 次提交
  7. 21 8月, 2009 6 次提交
    • M
      sh: Handle the DWARF op, DW_CFA_undefined · 5580e904
      由 Matt Fleming 提交于 
      Allow a DWARF register to have an undefined value. When applied to the
DWARF return address register this lets lets us label a function as
having no direct caller, e.g. kernel_thread_helper().
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
      5580e904
    • M
      sh: Fix bug calculating the end of the FDE instructions · 5480675d
      由 Matt Fleming 提交于 
      The 'end' member of struct dwarf_fde denotes one byte past the end of
the CFA instruction stream for an FDE. The value of 'end' was being
calcualted incorrectly, it was being set too high. This resulted in
dwarf_cfa_execute_insns() interpreting data past the end of valid
instructions, thus causing all sorts of weird crashes.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
      5480675d
    • M
      sh: Setup the frame pointer in handle_interrupt · fe98dd31
      由 Matt Fleming 提交于 
      When CONFIG_DWARF_UNWINDER is enabled setup r14 in handle_interrupt, so
that we can figure out what function was running when we were
interrupted.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
      fe98dd31
    • M
      sh: unwinder: Introduce UNWINDER_BUG() and UNWINDER_BUG_ON() · b344e24a
      由 Matt Fleming 提交于 
      We can't assume that if we execute the unwinder code and the unwinder
was already running that it has faulted. Clearly two kernel threads can
invoke the unwinder at the same time and may be running simultaneously.

The previous approach used BUG() and BUG_ON() in the unwinder code to
detect whether the unwinder was incapable of unwinding the stack, and
that the next available unwinder should be used instead. A better
approach is to explicitly invoke a trap handler to switch unwinders when
the current unwinder cannot continue.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
      b344e24a
    • M
      sh: unwinder: Set the flags for DW_CFA_val_offset ops as DWARF_VAL_OFFSET · 97efbbd5
      由 Matt Fleming 提交于 
      The handling of DW_CFA_val_offset ops was incorrectly using the
DWARF_REG_OFFSET flag but the register's value cannot be calculated
using the DWARF_REG_OFFSET method. Create a new flag to indicate that a
different method must be used to calculate the register's value even
though there is no implementation for DWARF_VAL_OFFSET yet; it's mainly
just a place holder.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
      97efbbd5
    • M
      sh: unwinder: Fix memory leak and create our own kmem cache · fb3f3e7f
      由 Matt Fleming 提交于 
      Plug a memory leak in dwarf_unwinder_dump() where we didn't free the
memory that we had previously allocated for the DWARF frames and DWARF
registers.

Now is also a opportune time to implement our own mempool and kmem
cache. It's a good idea to have a certain number of frame and register
objects in reserve at all times, so that we are guaranteed to have our
allocation satisfied even when memory is scarce. Since we have pools to
allocate from we can implement the registers for each frame as a linked
list as opposed to a sparsely populated array. Whilst it's true that the
lookup time for a linked list is larger than for arrays, there's only
usually a maximum of 8 registers per frame. So the overhead isn't that
much of a concern.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
      fb3f3e7f