uprobes/x86: Fix arch_uprobe_disable_step() && UTASK_SSTEP_TRAPPED interaction (d6a00b35) · Commits · 戴 / test

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>

arch/x86/kernel/uprobes.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -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 (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;
		}
		}

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