powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers
This is a rewrite so that we don't assume we are using the DABR throughout the
code. We now use the arch_hw_breakpoint to store the breakpoint in a generic
manner in the thread_struct, rather than storing the raw DABR value.
The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from
userspace. We keep this functionality, so that future changes (like the POWER8
DAWR), will still fake the DABR to userspace.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c
index 8c21658..c0244e7 100644
--- a/arch/powerpc/kernel/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace32.c
@@ -252,6 +252,9 @@
}
case PTRACE_GET_DEBUGREG: {
+#ifndef CONFIG_PPC_ADV_DEBUG_REGS
+ unsigned long dabr_fake;
+#endif
ret = -EINVAL;
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
@@ -259,7 +262,10 @@
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
ret = put_user(child->thread.dac1, (u32 __user *)data);
#else
- ret = put_user(child->thread.dabr, (u32 __user *)data);
+ dabr_fake = (
+ (child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
+ (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
+ ret = put_user(dabr_fake, (u32 __user *)data);
#endif
break;
}