Messages in this thread Patch in this message | | | Date | Sat, 8 Sep 2012 19:06:23 +0200 | From | Oleg Nesterov <> | Subject | [PATCH 8/7] uprobes: Fix arch_uprobe_disable_step() && UTASK_SSTEP_TRAPPED interaction |
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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> --- 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
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