From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Neuling , Edjunior Barbosa Machado , Benjamin Herrenschmidt Subject: [ 001/103] powerpc/hw_brk: Fix setting of length for exact mode breakpoints Date: Tue, 23 Jul 2013 15:25:12 -0700 Message-Id: <20130723220418.740673542@linuxfoundation.org> In-Reply-To: <20130723220418.532514378@linuxfoundation.org> References: <20130723220418.532514378@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Neuling commit b0b0aa9c7faf94e92320eabd8a1786c7747e40a8 upstream. The smallest match region for both the DABR and DAWR is 8 bytes, so the kernel needs to filter matches when users want to look at regions smaller than this. Currently we set the length of PPC_BREAKPOINT_MODE_EXACT breakpoints to 8. This is wrong as in exact mode we should only match on 1 address, hence the length should be 1. This ensures that the kernel will filter out any exact mode hardware breakpoint matches on any addresses other than the requested one. Signed-off-by: Michael Neuling Reported-by: Edjunior Barbosa Machado Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/ptrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -1449,7 +1449,9 @@ static long ppc_set_hwdebug(struct task_ */ if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE) { len = bp_info->addr2 - bp_info->addr; - } else if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) { + } else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT) + len = 1; + else { ptrace_put_breakpoints(child); return -EINVAL; }