Commit 588fbd61 authored by Oleg Nesterov's avatar Oleg Nesterov
Browse files

uprobes/x86: Introduce uprobe_xol_ops->abort() and default_abort_op() 



arch_uprobe_abort_xol() calls handle_riprel_post_xol() even if
auprobe->ops != default_xol_ops. This is fine correctness wise, only
default_pre_xol_op() can set UPROBE_FIX_RIP_AX|UPROBE_FIX_RIP_CX and
otherwise handle_riprel_post_xol() is nop.

But this doesn't look clean and this doesn't allow us to move ->fixups
into the union in arch_uprobe. Move this handle_riprel_post_xol() call
into the new default_abort_op() hook and change arch_uprobe_abort_xol()
accordingly.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Reviewed-by: default avatarJim Keniston <jkenisto@us.ibm.com>
parent dd91016d

arch/x86/kernel/uprobes.c

+11 −3
Original line number Diff line number Diff line
@@ -394,6 +394,7 @@ struct uprobe_xol_ops { 
	bool	(*emulate)(struct arch_uprobe *, struct pt_regs *);

	int	(*pre_xol)(struct arch_uprobe *, struct pt_regs *);

	int	(*post_xol)(struct arch_uprobe *, struct pt_regs *);

	void	(*abort)(struct arch_uprobe *, struct pt_regs *);

};



static inline int sizeof_long(void)
@@ -444,9 +445,15 @@ static int default_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs 
	return 0;

}



static void default_abort_op(struct arch_uprobe *auprobe, struct pt_regs *regs)

{

	handle_riprel_post_xol(auprobe, regs, NULL);

}



static struct uprobe_xol_ops default_xol_ops = {

	.pre_xol  = default_pre_xol_op,

	.post_xol = default_post_xol_op,

	.abort	  = default_abort_op,

};



static bool branch_is_call(struct arch_uprobe *auprobe)
@@ -820,10 +827,11 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) 
{

	struct uprobe_task *utask = current->utask;



	current->thread.trap_nr = utask->autask.saved_trap_nr;

	handle_riprel_post_xol(auprobe, regs, NULL);

	instruction_pointer_set(regs, utask->vaddr);

	if (auprobe->ops->abort)

		auprobe->ops->abort(auprobe, regs);



	current->thread.trap_nr = utask->autask.saved_trap_nr;

	regs->ip = utask->vaddr;

	/* clear TF if it was set by us in arch_uprobe_pre_xol() */

	if (!utask->autask.saved_tf)

		regs->flags &= ~X86_EFLAGS_TF;

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