| Message ID | 1372052843-19109-1-git-send-email-mikey@neuling.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | b0b0aa9c7faf94e92320eabd8a1786c7747e40a8 |
| Headers | show |
On 06/24/2013 11:17 AM, Michael Neuling wrote: > 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 <mikey@neuling.org> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 98c2fc1..64f7bd5 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; }
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 <mikey@neuling.org> Reported-by: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com> Cc: stable@vger.kernel.org --- arch/powerpc/kernel/ptrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)