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  1. 26 5月, 2011 3 次提交
  3. 23 5月, 2011 3 次提交
    • R
      ARM: consolidate SMP cross call implementation · 0f7b332f
      由 Russell King 提交于 
      Rather than having each platform class provide a mach/smp.h header for
smp_cross_call(), arrange for them to register the function with the
core ARM SMP code instead.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      0f7b332f
    • G
      arm/dt: probe for platforms via the device tree · 93c02ab4
      由 Grant Likely 提交于 
      If a dtb is passed to the kernel then the kernel needs to iterate
through compiled-in mdescs looking for one that matches and move the
dtb data to a safe location before it gets accidentally overwritten by
the kernel.

This patch creates a new function, setup_machine_fdt() which is
analogous to the setup_machine_atags() created in the previous patch.
It does all the early setup needed to use a device tree machine
description.

v5: - Print warning with neither dtb nor atags are passed to the kernel
    - Fix bug in setting of __machine_arch_type to the selected machine,
      not just the last machine in the list.
Reported-by: NTixy <tixy@yxit.co.uk>
    - Copy command line directly into boot_command_line instead of cmd_line
v4: - Dump some output when a matching machine_desc cannot be found
v3: - Added processing of reserved list.
    - Backed out the v2 change that copied instead of reserved the
      dtb.  dtb is reserved again and the real problem was fixed by
      using alloc_bootmem_align() for early allocation of RAM for
      unflattening the tree.
    - Moved cmd_line and initrd changes to earlier patch to make series
      bisectable.
v2: Changed to save the dtb by copying into an allocated buffer.
    - Since the dtb will very likely be passed in the first 16k of ram
      where the interrupt vectors live, memblock_reserve() is
      insufficient to protect the dtb data.

[based on work originally written by Jeremy Kerr <jeremy.kerr@canonical.com>]
Tested-by: NTony Lindgren <tony@atomide.com>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
      93c02ab4
    • G
      arm/dt: consolidate atags setup into setup_machine_atags · 6291319d
      由 Grant Likely 提交于 
      In preparation for adding device tree support, this patch consolidates
all of the atag-specific setup into a single function.

v5: - drop double printk("Machine; %s\n", ...); call.
    - leave copying boot_command_line in setup_arch() since it isn't
      atags specific.
v4: - adapt to the removal of lookup_machine_type()
    - break out dump of machine_desc table into dump_machine_table()
      because the device tree probe code will use it.
    - Add for_each_machine_desc() macro
Tested-by: NTony Lindgren <tony@atomide.com>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
      6291319d
  5. 21 5月, 2011 1 次提交
  7. 15 5月, 2011 1 次提交
  9. 14 5月, 2011 1 次提交
  11. 12 5月, 2011 2 次提交
    • A
      ARM: 6892/1: handle ptrace requests to change PC during interrupted system calls · 2af68df0
      由 Arnd Bergmann 提交于 
      GDB's interrupt.exp test cases currenly fail on ARM.  The problem is how do_signal
handled restarting interrupted system calls:

The entry.S assembler code determines that we come from a system call; and that
information is passed as "syscall" parameter to do_signal.  That routine then
calls get_signal_to_deliver [*] and if a signal is to be delivered, calls into
handle_signal.  If a system call is to be restarted either after the signal
handler returns, or if no handler is to be called in the first place, the PC
is updated after the get_signal_to_deliver call, either in handle_signal (if
we have a handler) or at the end of do_signal (otherwise).

Now the problem is that during [*], the call to get_signal_to_deliver, a ptrace
intercept may happen.  During this intercept, the debugger may change registers,
including the PC.  This is done by GDB if it wants to execute an "inferior call",
i.e. the execution of some code in the debugged program triggered by GDB.

To this purpose, GDB will save all registers, allocate a stack frame, set up
PC and arguments as appropriate for the call, and point the link register to
a dummy breakpoint instruction.  Once the process is restarted, it will execute
the call and then trap back to the debugger, at which point GDB will restore
all registers and continue original execution.

This generally works fine.  However, now consider what happens when GDB attempts
to do exactly that while the process was interrupted during execution of a to-be-
restarted system call:  do_signal is called with the syscall flag set; it calls
get_signal_to_deliver, at which point the debugger takes over and changes the PC
to point to a completely different place.  Now get_signal_to_deliver returns
without a signal to deliver; but now do_signal decides it should be restarting
a system call, and decrements the PC by 2 or 4 -- so it now points to 2 or 4
bytes before the function GDB wants to call -- which leads to a subsequent crash.

To fix this problem, two things need to be supported:
- do_signal must be able to recognize that get_signal_to_deliver changed the PC
  to a different location, and skip the restart-syscall sequence
- once the debugger has restored all registers at the end of the inferior call
  sequence, do_signal must recognize that *now* it needs to restart the pending
  system call, even though it was now entered from a breakpoint instead of an
  actual svc instruction

This set of issues is solved on other platforms, usually by one of two
mechanisms:

- The status information "do_signal is handling a system call that may need
  restarting" is itself carried in some register that can be accessed via
  ptrace.  This is e.g. on Intel the "orig_eax" register; on Sparc the kernel
  defines a magic extra bit in the flags register for this purpose.
  This allows GDB to manage that state: reset it when doing an inferior call,
  and restore it after the call is finished.

- On s390, do_signal transparently handles this problem without requiring
  GDB interaction, by performing system call restarting in the following
  way: first, adjust the PC as necessary for restarting the call.  Then,
  call get_signal_to_deliver; and finally just continue execution at the
  PC.  This way, if GDB does not change the PC, everything is as before.
  If GDB *does* change the PC, execution will simply continue there --
  and once GDB restores the PC it saved at that point, it will automatically
  point to the *restarted* system call.  (There is the minor twist how to
  handle system calls that do *not* need restarting -- do_signal will undo
  the PC change in this case, after get_signal_to_deliver has returned, and
  only if ptrace did not change the PC during that call.)

Because there does not appear to be any obvious register to carry the
syscall-restart information on ARM, we'd either have to introduce a new
artificial ptrace register just for that purpose, or else handle the issue
transparently like on s390.  The patch below implements the second option;
using this patch makes the interrupt.exp test cases pass on ARM, with no
regression in the GDB test suite otherwise.

Cc: patches@linaro.org
Signed-off-by: NUlrich Weigand <ulrich.weigand@linaro.org>
Signed-off-by: NArnd Bergmann <arnd.bergmann@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      2af68df0
    • V
      ARM: 6893/1: Allow for kernel command line concatenation · 4394c124
      由 Victor Boivie 提交于 
      This patch allows the provided CONFIG_CMDLINE to be concatenated
with the one provided by the boot loader. This is useful to
merge the static values defined in CONFIG_CMDLINE with the
boot loader's (possibly) more dynamic values, such as startup
reasons and more.
Signed-off-by: NVictor Boivie <victor.boivie@sonyericsson.com>
Reviewed-by: NBjorn Andersson <bjorn.andersson@sonyericsson.com>
Signed-off-by: NOskar Andero <oskar.andero@sonyericsson.com>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      4394c124
  13. 11 5月, 2011 2 次提交
  15. 29 4月, 2011 27 次提交