From: Paul Mundt Date: Mon, 8 Sep 2008 09:15:55 +0000 (+0900) Subject: sh: kprobes: Fix up race against probe point removal. X-Git-Tag: v2.6.28-rc1~99^2~67 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=734db3770de03fbe9ae4e78519a7d1678189788c;p=linux-2.6-omap-h63xx.git 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: Paul Mundt --- diff --git a/arch/sh/kernel/kprobes.c b/arch/sh/kernel/kprobes.c index f0e1c78d0bf..a478ba78e75 100644 --- a/arch/sh/kernel/kprobes.c +++ b/arch/sh/kernel/kprobes.c @@ -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; }