lkml.org 
[lkml]   [2012]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 8/7] uprobes: Fix arch_uprobe_disable_step() && UTASK_SSTEP_TRAPPED interaction
* Oleg Nesterov <oleg@redhat.com> [2012-09-08 19:06:23]:

> arch_uprobe_disable_step() should also take UTASK_SSTEP_TRAPPED into
> account. In this case the probed insn was not executed, we need to
> clear X86_EFLAGS_TF if it was set by us and that is all.
>
> Again, this code will look more clean when we move it into
> arch_uprobe_post_xol() and arch_uprobe_abort_xol().
>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>



Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

note:
I also think this should be merged into 6/7 patch if possible

--
thanks and regards
Srikar

> ---
> arch/x86/kernel/uprobes.c | 14 ++++++++++----
> 1 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
> index 7e993d1..9538f00 100644
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -706,14 +706,20 @@ void arch_uprobe_disable_step(struct arch_uprobe *auprobe)
> {
> struct task_struct *task = current;
> struct arch_uprobe_task *autask = &task->utask->autask;
> + bool trapped = (task->utask->state == UTASK_SSTEP_TRAPPED);
> struct pt_regs *regs = task_pt_regs(task);
> /*
> * The state of TIF_BLOCKSTEP was not saved so we can get an extra
> * SIGTRAP if we do not clear TF. We need to examine the opcode to
> * make it right.
> */
> - if (autask->saved_tf)
> - send_sig(SIGTRAP, task, 0);
> - else if (!(auprobe->fixups & UPROBE_FIX_SETF))
> - regs->flags &= ~X86_EFLAGS_TF;
> + if (unlikely(trapped)) {
> + if (!autask->saved_tf)
> + regs->flags &= ~X86_EFLAGS_TF;
> + } else {
> + if (autask->saved_tf)
> + send_sig(SIGTRAP, task, 0);
> + else if (!(auprobe->fixups & UPROBE_FIX_SETF))
> + regs->flags &= ~X86_EFLAGS_TF;
> + }
> }
> --
> 1.5.5.1
>
>



\
 
 \ /
  Last update: 2012-09-12 15:21    [W:0.104 / U:6.788 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site