Depending on the setting of CONFIG_X86_32_LAZY_GS, gs may be saved in
the thread_struct or in pt_regs. Use the task_user_gs() accessor to
checkpoint gs appropriately for both cases. This solves post-restart
program crashes when CONFIG_X86_32_LAZY_GS=n.
Tested-by: Serge Hallyn <serue@xxxxxxxxxx>
Signed-off-by: Nathan Lynch <ntl@xxxxxxxxx>
---
arch/x86/kernel/checkpoint_32.c | 8 +-------
1 files changed, 1 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/checkpoint_32.c b/arch/x86/kernel/checkpoint_32.c
index 32cde34..c4ce450 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;
@@ -108,15 +107,10 @@ void save_cpu_regs(struct ckpt_hdr_cpu *h, struct task_struct *t)
h->ds = encode_segment(regs->ds);
h->es = encode_segment(regs->es);
- /*
- * for checkpoint in process context (from within a container)
- * the GS segment register should be saved from the hardware;
- * otherwise it is already saved on the thread structure
- */
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);
--
1.6.6.1
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