Re: Linux Checkpoint-Restart - v19

[Nathan Lynch <ntl-e+AXbWqSrlAAvxtiuMwx3w@public.gmane.org>]

Hello-

On Tue, 2010-04-06 at 11:54 +0900, Jiro SEKIBA wrote:
> I tried checkpointing/restarting with this binary, but still get SEGV at the same point, 
> still get same gdb warning(Cannot find thread-local variables on this target)

I believe I have been experiencing a similar problem:

https://lists.linux-foundation.org/pipermail/containers/2010-April/024105.html

I may have found a fix.  Can you please test whether this kernel patch
makes the SEGVs after restart go away?


 arch/x86/kernel/checkpoint_32.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/checkpoint_32.c b/arch/x86/kernel/checkpoint_32.c
index 32cde34..d80c168 100644
--- a/arch/x86/kernel/checkpoint_32.c
+++ b/arch/x86/kernel/checkpoint_32.c
@@ -86,7 +86,6 @@ static unsigned short decode_segment(__u16 seg)
 
 void save_cpu_regs(struct ckpt_hdr_cpu *h, struct task_struct *t)
 {
-	struct thread_struct *thread = &t->thread;
 	struct pt_regs *regs = task_pt_regs(t);
 	unsigned long _gs;
 
@@ -116,7 +115,7 @@ void save_cpu_regs(struct ckpt_hdr_cpu *h, struct task_struct *t)
 	if (t == current)
 		_gs = get_user_gs(regs);
 	else
-		_gs = thread->gs;
+		_gs = task_user_gs(t);
 
 	h->fsindex = encode_segment(regs->fs);
 	h->gsindex = encode_segment(_gs);