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: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
This commit is contained in:
Oleg Nesterov 2014-04-21 16:58:17 +02:00
parent dd91016dfc
commit 588fbd613c
1 changed files with 11 additions and 3 deletions

View File

@ -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;