1. 31 Oct, 2008 7 commits
    • Michael Neuling's avatar
      powerpc: Fix swapcontext system for VSX + old ucontext size · 16c29d18
      Michael Neuling authored
      Since VSX support was added, we now have two sizes of ucontext_t;
      the older, smaller size without the extra VSX state, and the new
      larger size with the extra VSX state.  A program using the
      sys_swapcontext system call and supplying smaller ucontext_t
      structures will currently get an EINVAL error if the task has
      used VSX (e.g. because of calling library code that uses VSX) and
      the old_ctx argument is non-NULL (i.e. the program is asking for
      its current context to be saved).  Thus the program will start
      getting EINVAL errors on calls that previously worked.
      
      This commit changes this behaviour so that we don't send an EINVAL in
      this case.  It will now return the smaller context but the VSX MSR bit
      will always be cleared to indicate that the ucontext_t doesn't include
      the extra VSX state, even if the task has executed VSX instructions.
      
      Both 32 and 64 bit cases are updated.
      
      [paulus@samba.org - also fix some access_ok() and get_user() calls]
      
      Thanks to Ben Herrenschmidt for noticing this problem.
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      16c29d18
    • Michael Neuling's avatar
      powerpc: Fix compiler warning for the relocatable kernel · b160544c
      Michael Neuling authored
      Fixes this warning:
       arch/powerpc/kernel/setup_64.c:447:5: warning: "kernstart_addr" is not defined
      
      which arises because PHYSICAL_START is no longer a constant when
      CONFIG_RELOCATABLE=y.
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      b160544c
    • Paul Mackerras's avatar
      powerpc: Work around ld bug in older binutils · 2a4b9c5a
      Paul Mackerras authored
      Commit 549e8152 ("powerpc: Make the
      64-bit kernel as a position-independent executable") added lines to
      vmlinux.lds.S to add the extra sections needed to implement a
      relocatable kernel.  However, those lines seem to trigger a bug in
      older versions of GNU ld (such as 2.16.1) when building a
      non-relocatable kernel.  Since ld 2.16.1 is still a popular choice for
      cross-toolchains, this adds an #ifdef to vmlinux.lds.S so the added
      lines are only included when building a relocatable kernel.
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      2a4b9c5a
    • Milton Miller's avatar
      powerpc/ppc64/kdump: Better flag for running relocatable · 8b8b0cc1
      Milton Miller authored
      The __kdump_flag ABI is overly constraining for future development.
      
      As of 2.6.27, the kernel entry point has 4 constraints:  Offset 0 is
      the starting point for the master (boot) cpu (entered with r3 pointing
      to the device tree structure), offset 0x60 is code for the slave cpus
      (entered with r3 set to their device tree physical id), offset 0x20 is
      used by the iseries hypervisor, and secondary cpus must be well behaved
      when the first 256 bytes are copied to address 0.
      
      Placing the __kdump_flag at 0x18 is bad because:
      
      - It was taking the last 8 bytes before the iseries hypervisor data.
      - It was 8 bytes for a boolean flag
      - It had no way of identifying that the flag was present
      - It does leave any room for the master to add any additional code
        before branching, which hurts debug.
      - It will be unnecessarily hard for 32 bit code to be common (8 bytes)
      
      Now that we have eliminated the use of __kdump_flag in favor of
      the standard is_kdump_kernel(), this flag only controls run without
      relocating the kernel to PHYSICAL_START (0), so rename it __run_at_load.
      
      Move the flag to 0x5c, 1 word before the secondary cpu entry point at
      0x60.  Initialize it with "run0" to say it will run at 0 unless it is
      set to 1.  It only exists if we are relocatable.
      Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      8b8b0cc1
    • Milton Miller's avatar
      powerpc: Use is_kdump_kernel() · 62a8bd6c
      Milton Miller authored
      linux/crash_dump.h defines is_kdump_kernel() to be used by code that
      needs to know if the previous kernel crashed instead of a (clean) boot
      or reboot.
      
      This updates the just added powerpc code to use it.  This is needed
      for the next commit, which will remove __kdump_flag.
      Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      62a8bd6c
    • Milton Miller's avatar
      powerpc: Kexec exit should not use magic numbers · 1767c8f3
      Milton Miller authored
      Commit 54622f10 ("powerpc: Support for
      relocatable kdump kernel") added a magic flag value in a register to
      tell purgatory that it should be a panic kernel.  This part is wrong
      and is reverted by this commit.
      
      The kernel gets a list of memory blocks and a entry point from user space.
      Its job is to copy the blocks into place and then branch to the designated
      entry point (after turning "off" the mmu).
      
      The user space tool inserts a trampoline, called purgatory, that runs
      before the user supplied code.   Its job is to establish the entry
      environment for the new kernel or other application based on the contents
      of memory.  The purgatory code is compiled and embedded in the tool,
      where it is later patched using the elf symbol table using elf symbols.
      
      Since the tool knows it is creating a purgatory that will run after a
      kernel crash, it should just patch purgatory (or the kernel directly)
      if something needs to happen.
      Signed-off-by: default avatarMilton Miller <miltonm@bga.com>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      1767c8f3
    • Paul Mackerras's avatar
  2. 30 Oct, 2008 2 commits
  3. 28 Oct, 2008 4 commits
  4. 26 Oct, 2008 21 commits
  5. 24 Oct, 2008 6 commits