Commit 734db377 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: kprobes: Fix up race against probe point removal. 



Handle a corner case where another CPU or debugger removes the probe
point from underneath us.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 247bc6d2

arch/sh/kernel/kprobes.c

+11 −0
Original line number Diff line number Diff line
@@ -252,6 +252,17 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) 
	p = get_kprobe(addr);

	if (!p) {

		/* Not one of ours: let kernel handle it */

		if (*(kprobe_opcode_t *)addr != BREAKPOINT_INSTRUCTION) {

			/*

			 * The breakpoint instruction was removed right

			 * after we hit it. Another cpu has removed

			 * either a probepoint or a debugger breakpoint

			 * at this address. In either case, no further

			 * handling of this interrupt is appropriate.

			 */

			ret = 1;

		}



		goto no_kprobe;

	}