powerpc: Extended ptrace interface
powerpc: Extended ptrace interface
From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Based on patches originally written by Torez Smith.
Add a new extended ptrace interface so that user-space has a single
interface for powerpc, without having to know the specific layout
of the debug registers.
Implement:
PPC_PTRACE_GETHWDEBUGINFO
PPC_PTRACE_SETHWDEBUG
PPC_PTRACE_DELHWDEBUG
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Acked-by: David Gibson <dwg@au1.ibm.com>
Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Sergio Durigan Junior <sergiodj@br.ibm.com>
Cc: Thiago Jung Bauermann <bauerman@br.ibm.com>
Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 292c814..8847bd6 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -835,6 +835,52 @@
user_disable_single_step(child);
}
+static long ppc_set_hwdebug(struct task_struct *child,
+ struct ppc_hw_breakpoint *bp_info)
+{
+ /*
+ * We currently support one data breakpoint
+ */
+ if (((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0) ||
+ ((bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0) ||
+ (bp_info->trigger_type != PPC_BREAKPOINT_TRIGGER_WRITE) ||
+ (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) ||
+ (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE))
+ return -EINVAL;
+
+ if (child->thread.dabr)
+ return -ENOSPC;
+
+ if ((unsigned long)bp_info->addr >= TASK_SIZE)
+ return -EIO;
+
+ child->thread.dabr = (unsigned long)bp_info->addr;
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+ child->thread.dbcr0 = DBCR0_IDM;
+ if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
+ child->thread.dbcr0 |= DBSR_DAC1R;
+ if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
+ child->thread.dbcr0 |= DBSR_DAC1W;
+ child->thread.regs->msr |= MSR_DE;
+#endif
+ return 1;
+}
+
+static long ppc_del_hwdebug(struct task_struct *child, long addr, long data)
+{
+ if (data != 1)
+ return -EINVAL;
+ if (child->thread.dabr == 0)
+ return -ENOENT;
+
+ child->thread.dabr = 0;
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+ child->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM);
+ child->thread.regs->msr &= ~MSR_DE;
+#endif
+ return 0;
+}
+
/*
* Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
* we mark them as obsolete now, they will be removed in a future version
@@ -928,6 +974,50 @@
break;
}
+ case PPC_PTRACE_GETHWDBGINFO: {
+ struct ppc_debug_info dbginfo;
+
+ dbginfo.version = 1;
+ dbginfo.num_instruction_bps = 0;
+ dbginfo.num_data_bps = 1;
+ dbginfo.num_condition_regs = 0;
+#ifdef CONFIG_PPC64
+ dbginfo.data_bp_alignment = 8;
+#else
+ dbginfo.data_bp_alignment = 4;
+#endif
+ dbginfo.sizeof_condition = 0;
+ dbginfo.features = 0;
+
+ if (!access_ok(VERIFY_WRITE, data,
+ sizeof(struct ppc_debug_info)))
+ return -EFAULT;
+ ret = __copy_to_user((struct ppc_debug_info __user *)data,
+ &dbginfo, sizeof(struct ppc_debug_info)) ?
+ -EFAULT : 0;
+ break;
+ }
+
+ case PPC_PTRACE_SETHWDEBUG: {
+ struct ppc_hw_breakpoint bp_info;
+
+ if (!access_ok(VERIFY_READ, data,
+ sizeof(struct ppc_hw_breakpoint)))
+ return -EFAULT;
+ ret = __copy_from_user(&bp_info,
+ (struct ppc_hw_breakpoint __user *)data,
+ sizeof(struct ppc_hw_breakpoint)) ?
+ -EFAULT : 0;
+ if (!ret)
+ ret = ppc_set_hwdebug(child, &bp_info);
+ break;
+ }
+
+ case PPC_PTRACE_DELHWDEBUG: {
+ ret = ppc_del_hwdebug(child, addr, data);
+ break;
+ }
+
case PTRACE_GET_DEBUGREG: {
ret = -EINVAL;
/* We only support one DABR and no IABRS at the moment */