From b101957a5871ec616e18a8a6f0330d0e06a05754 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Mon, 24 Jun 2013 15:47:22 +1000 Subject: powerpc/hw_brk: Fix setting of length for exact mode breakpoints 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(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 98c2fc198712..64f7bd5b1b0f 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -1449,7 +1449,9 @@ static long ppc_set_hwdebug(struct task_struct *child, */ 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; } -- cgit v1.2.2