1. 28 5月, 2013 1 次提交
  2. 22 5月, 2013 1 次提交
    • M
      m68k: implement futex.h to support userspace robust futexes and PI mutexes · e4f2dfbb
      Mikael Pettersson 提交于
      Linux/M68K currently doesn't support robust futexes or PI mutexes.
      The problem is that the futex code needs to perform certain ops
      (cmpxchg, set, add, or, andn, xor) atomically on user-space
      addresses, and M68K's lack of a futex.h causes those operations
      to be unsupported and disabled.
      
      This patch adds that support, but only for uniprocessor machines,
      which is adequate for M68K.  For UP it's enough to disable preemption
      to ensure mutual exclusion (futexes don't need to care about other
      hardware agents), and the mandatory pagefault_disable() does just that.
      
      This patch is closely based on the one I co-wrote for UP ARM back
      in August 2008.  The main change is that this patch uses the C
      get_user/put_user accessors instead of inline assembly code with
      exception table fixups.
      
      For non-MMU machines the new futex.h simply redirects to the generic
      futex.h, so there is no functional change for them.
      
      Tested on aranym with the glibc-2.17 test suite: no regressions, and
      a number of mutex/condvar test cases went from failing to succeeding
      (tst-mutexpi{5,5a,6,9}, tst-cond2[45], tst-robust[1-9], tst-robustpi[1-8]).
      Also tested with glibc-2.18 HEAD and a local glibc patch to enable PI
      mutexes: no regressions.
      Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
      Acked-by: NAndreas Schwab <schwab@linux-m68k.org>
      [geert: Added removal of ""generic-y += futex.h"]
      Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
      e4f2dfbb
  3. 01 5月, 2013 1 次提交
    • T
      dump_stack: consolidate dump_stack() implementations and unify their behaviors · 196779b9
      Tejun Heo 提交于
      Both dump_stack() and show_stack() are currently implemented by each
      architecture.  show_stack(NULL, NULL) dumps the backtrace for the
      current task as does dump_stack().  On some archs, dump_stack() prints
      extra information - pid, utsname and so on - in addition to the
      backtrace while the two are identical on other archs.
      
      The usages in arch-independent code of the two functions indicate
      show_stack(NULL, NULL) should print out bare backtrace while
      dump_stack() is used for debugging purposes when something went wrong,
      so it does make sense to print additional information on the task which
      triggered dump_stack().
      
      There's no reason to require archs to implement two separate but mostly
      identical functions.  It leads to unnecessary subtle information.
      
      This patch expands the dummy fallback dump_stack() implementation in
      lib/dump_stack.c such that it prints out debug information (taken from
      x86) and invokes show_stack(NULL, NULL) and drops arch-specific
      dump_stack() implementations in all archs except blackfin.  Blackfin's
      dump_stack() does something wonky that I don't understand.
      
      Debug information can be printed separately by calling
      dump_stack_print_info() so that arch-specific dump_stack()
      implementation can still emit the same debug information.  This is used
      in blackfin.
      
      This patch brings the following behavior changes.
      
      * On some archs, an extra level in backtrace for show_stack() could be
        printed.  This is because the top frame was determined in
        dump_stack() on those archs while generic dump_stack() can't do that
        reliably.  It can be compensated by inlining dump_stack() but not
        sure whether that'd be necessary.
      
      * Most archs didn't use to print debug info on dump_stack().  They do
        now.
      
      An example WARN dump follows.
      
       WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
       Hardware name: empty
       Modules linked in:
       CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
        0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
        ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
        0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
       Call Trace:
        [<ffffffff81c614dc>] dump_stack+0x19/0x1b
        [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
        [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
        [<ffffffff8234a071>] init_workqueues+0x35/0x505
        ...
      
      v2: CPU number added to the generic debug info as requested by s390
          folks and dropped the s390 specific dump_stack().  This loses %ksp
          from the debug message which the maintainers think isn't important
          enough to keep the s390-specific dump_stack() implementation.
      
          dump_stack_print_info() is moved to kernel/printk.c from
          lib/dump_stack.c.  Because linkage is per objecct file,
          dump_stack_print_info() living in the same lib file as generic
          dump_stack() means that archs which implement custom dump_stack()
          - at this point, only blackfin - can't use dump_stack_print_info()
          as that will bring in the generic version of dump_stack() too.  v1
          The v1 patch broke build on blackfin due to this issue.  The build
          breakage was reported by Fengguang Wu.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NDavid S. Miller <davem@davemloft.net>
      Acked-by: NVineet Gupta <vgupta@synopsys.com>
      Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
      Acked-by: NVineet Gupta <vgupta@synopsys.com>
      Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>	[s390 bits]
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      196779b9
  4. 30 4月, 2013 1 次提交
  5. 29 4月, 2013 9 次提交
  6. 17 4月, 2013 10 次提交
  7. 16 4月, 2013 1 次提交
  8. 09 4月, 2013 1 次提交
  9. 08 4月, 2013 1 次提交
  10. 05 4月, 2013 1 次提交
  11. 21 3月, 2013 1 次提交
  12. 13 3月, 2013 1 次提交
  13. 06 3月, 2013 1 次提交
  14. 04 3月, 2013 5 次提交
  15. 28 2月, 2013 1 次提交
  16. 26 2月, 2013 1 次提交
  17. 14 2月, 2013 1 次提交
    • A
      burying unused conditionals · d64008a8
      Al Viro 提交于
      __ARCH_WANT_SYS_RT_SIGACTION,
      __ARCH_WANT_SYS_RT_SIGSUSPEND,
      __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND,
      __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL - not used anymore
      CONFIG_GENERIC_{SIGALTSTACK,COMPAT_RT_SIG{ACTION,QUEUEINFO,PENDING,PROCMASK}} -
      can be assumed always set.
      d64008a8
  18. 09 2月, 2013 1 次提交
  19. 06 2月, 2013 1 次提交
    • G
      m68knommu: fix trap on execing /bin/init · e95c3f7a
      Greg Ungerer 提交于
      As of commit fea82210 ("m68k: switch to saner kernel_execve() semantics")
      the non-mmu m68k targets have trapped on booting. The execing of /bin/init
      causes the exec path to try and return through a 0x0 return address - thus
      trapping or otherwise hanging or crashing.
      
      The problem isn't in the exec path as such though, but rather in the
      m68knommu start_thread() macro. It is trying to clear the a6 register that
      it assumes is part of a struct switch_stack below the thread registers on
      our stack. But that is not what the stack frames look like when this is run.
      So it ends up corrupting our call stack and zeroing out a function return
      address that is sitting there.
      
      The clearing of a6 was introduced many years ago in commit 7bf9a37d
      ("m68knommu: force stack alignment on ColdFire"). It used to work because
      the kernel init exec code path had a short cut back to the exception return
      code, and it didn't need to return through the calls on the stack.
      Signed-off-by: NGreg Ungerer <gerg@uclinux.org>
      e95c3f7a