While running gdb on cyclictest on v3.2-rc2-rt3 I got the following error
[root@starship ~]# [11887.443716] BUG: sleeping function called from invalid con
text at /home/jkacur/linux-rt/kernel/rtmutex.c:645
[11887.443720] in_atomic(): 1, irqs_disabled(): 0, pid: 4859, name: cyclictest
[11887.443723] no locks held by cyclictest/4859.
[11887.443726] Pid: 4859, comm: cyclictest Not tainted 3.2.0-rc2-rt3-debug-expr+
#1
[11887.443728] Call Trace:
[11887.443737] [<ffffffff81035543>] __might_sleep+0x185/0x18d
[11887.443743] [<ffffffff8107c3ed>] rt_spin_lock_fastlock.clone.0+0x24/0x31
[11887.443749] [<ffffffff813fba9b>] rt_spin_lock+0x16/0x40
[11887.443754] [<ffffffff81053eee>] force_sig_info+0x3d/0xeb
[11887.443758] [<ffffffff81053fb2>] force_sig+0x16/0x18
[11887.443761] [<ffffffff813fd0a1>] do_trap+0xef/0x130
[11887.443766] [<ffffffff81076525>] ? trace_hardirqs_on_caller+0x12a/0x161
[11887.443771] [<ffffffff813fd16f>] do_int3+0x8d/0x9a
[11887.443774] [<ffffffff813fc9e7>] int3+0x27/0x40
I found that there is a patch for this in v2.6.33.9-rt31 that I forward-ported
to v3.2-rc2-rt3
I believe that Thomas Gleixner is the original author, but I'm not sure.
Thomas - can you provide your signed-off-by if you are the author?
Forward-ported from v2.6.33.9-rt31 to v3.2-rc2-rt3
Signed-off-by: John Kacur <jkacur@xxxxxxxxxx>
---
arch/x86/kernel/traps.c | 24 +++++++++++++-----------
1 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a8e3eb8..3654390 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -87,9 +87,10 @@ static inline void conditional_sti(struct pt_regs *regs)
local_irq_enable();
}
-static inline void preempt_conditional_sti(struct pt_regs *regs)
+static inline void preempt_conditional_sti(struct pt_regs *regs, int stack)
{
- inc_preempt_count();
+ if (stack)
+ inc_preempt_count();
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
}
@@ -100,11 +101,12 @@ static inline void conditional_cli(struct pt_regs *regs)
local_irq_disable();
}
-static inline void preempt_conditional_cli(struct pt_regs *regs)
+static inline void preempt_conditional_cli(struct pt_regs *regs, int stack)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_disable();
- dec_preempt_count();
+ if (stack)
+ dec_preempt_count();
}
static void __kprobes
@@ -222,9 +224,9 @@ dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
12, SIGBUS) == NOTIFY_STOP)
return;
- preempt_conditional_sti(regs);
+ preempt_conditional_sti(regs, STACKFAULT_STACK);
do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
- preempt_conditional_cli(regs);
+ preempt_conditional_cli(regs, STACKFAULT_STACK);
}
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
@@ -316,9 +318,9 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
return;
#endif
- preempt_conditional_sti(regs);
+ preempt_conditional_sti(regs, DEBUG_STACK);
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
- preempt_conditional_cli(regs);
+ preempt_conditional_cli(regs, DEBUG_STACK);
}
#ifdef CONFIG_X86_64
@@ -412,12 +414,12 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
return;
/* It's safe to allow irq's after DR6 has been saved */
- preempt_conditional_sti(regs);
+ preempt_conditional_sti(regs, DEBUG_STACK);
if (regs->flags & X86_VM_MASK) {
handle_vm86_trap((struct kernel_vm86_regs *) regs,
error_code, 1);
- preempt_conditional_cli(regs);
+ preempt_conditional_cli(regs, DEBUG_STACK);
return;
}
@@ -436,7 +438,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
si_code = get_si_code(tsk->thread.debugreg6);
if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
send_sigtrap(tsk, regs, error_code, si_code);
- preempt_conditional_cli(regs);
+ preempt_conditional_cli(regs, DEBUG_STACK);
return;
}
--
1.7.2.3
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