uprobes: Change handle_swbp() to expose bp_vaddr to handler_chain()
Change handle_swbp() to set regs->ip = bp_vaddr in advance, this is
what consumer->handler() needs but uprobe_get_swbp_addr() is not
exported.
This also simplifies the code and makes it more consistent across
the supported architectures. handle_swbp() becomes the only caller
of uprobe_get_swbp_addr().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 04c104a..f1b8078 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1504,6 +1504,10 @@
}
return;
}
+
+ /* change it in advance for ->handler() and restart */
+ instruction_pointer_set(regs, bp_vaddr);
+
/*
* TODO: move copy_insn/etc into _register and remove this hack.
* After we hit the bp, _unregister + _register can install the
@@ -1511,14 +1515,14 @@
*/
smp_rmb(); /* pairs with wmb() in install_breakpoint() */
if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
- goto restart;
+ goto out;
utask = current->utask;
if (!utask) {
utask = add_utask();
/* Cannot allocate; re-execute the instruction. */
if (!utask)
- goto restart;
+ goto out;
}
handler_chain(uprobe, regs);
@@ -1531,12 +1535,7 @@
return;
}
-restart:
- /*
- * cannot singlestep; cannot skip instruction;
- * re-execute the instruction.
- */
- instruction_pointer_set(regs, bp_vaddr);
+ /* can_skip_sstep() succeeded, or restart if can't singlestep */
out:
put_uprobe(uprobe);
}
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index e668024..17d9b2b 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -492,7 +492,7 @@
return;
entry = ring_buffer_event_data(event);
- entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+ entry->ip = instruction_pointer(task_pt_regs(current));
data = (u8 *)&entry[1];
for (i = 0; i < tu->nr_args; i++)
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
@@ -667,7 +667,7 @@
if (!entry)
goto out;
- entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+ entry->ip = instruction_pointer(task_pt_regs(current));
data = (u8 *)&entry[1];
for (i = 0; i < tu->nr_args; i++)
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);