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/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index cbd759e..b451081 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -24,6 +24,12 @@
* 2 of the License, or (at your option) any later version.
*/
+#ifdef __KERNEL__
+#include <linux/types.h>
+#else
+#include <stdint.h>
+#endif
+
#ifndef __ASSEMBLY__
struct pt_regs {
@@ -294,4 +300,75 @@
#define PTRACE_SINGLEBLOCK 0x100 /* resume execution until next branch */
+#define PPC_PTRACE_GETHWDBGINFO 0x89
+#define PPC_PTRACE_SETHWDEBUG 0x88
+#define PPC_PTRACE_DELHWDEBUG 0x87
+
+#ifndef __ASSEMBLY__
+
+struct ppc_debug_info {
+ uint32_t version; /* Only version 1 exists to date */
+ uint32_t num_instruction_bps;
+ uint32_t num_data_bps;
+ uint32_t num_condition_regs;
+ uint32_t data_bp_alignment;
+ uint32_t sizeof_condition; /* size of the DVC register */
+ uint64_t features;
+};
+
+#endif /* __ASSEMBLY__ */
+
+/*
+ * features will have bits indication whether there is support for:
+ */
+#define PPC_DEBUG_FEATURE_INSN_BP_RANGE 0x0000000000000001
+#define PPC_DEBUG_FEATURE_INSN_BP_MASK 0x0000000000000002
+#define PPC_DEBUG_FEATURE_DATA_BP_RANGE 0x0000000000000004
+#define PPC_DEBUG_FEATURE_DATA_BP_MASK 0x0000000000000008
+
+#ifndef __ASSEMBLY__
+
+struct ppc_hw_breakpoint {
+ uint32_t version; /* currently, version must be 1 */
+ uint32_t trigger_type; /* only some combinations allowed */
+ uint32_t addr_mode; /* address match mode */
+ uint32_t condition_mode; /* break/watchpoint condition flags */
+ uint64_t addr; /* break/watchpoint address */
+ uint64_t addr2; /* range end or mask */
+ uint64_t condition_value; /* contents of the DVC register */
+};
+
+#endif /* __ASSEMBLY__ */
+
+/*
+ * Trigger Type
+ */
+#define PPC_BREAKPOINT_TRIGGER_EXECUTE 0x00000001
+#define PPC_BREAKPOINT_TRIGGER_READ 0x00000002
+#define PPC_BREAKPOINT_TRIGGER_WRITE 0x00000004
+#define PPC_BREAKPOINT_TRIGGER_RW \
+ (PPC_BREAKPOINT_TRIGGER_READ | PPC_BREAKPOINT_TRIGGER_WRITE)
+
+/*
+ * Address Mode
+ */
+#define PPC_BREAKPOINT_MODE_EXACT 0x00000000
+#define PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE 0x00000001
+#define PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE 0x00000002
+#define PPC_BREAKPOINT_MODE_MASK 0x00000003
+
+/*
+ * Condition Mode
+ */
+#define PPC_BREAKPOINT_CONDITION_MODE 0x00000003
+#define PPC_BREAKPOINT_CONDITION_NONE 0x00000000
+#define PPC_BREAKPOINT_CONDITION_AND 0x00000001
+#define PPC_BREAKPOINT_CONDITION_EXACT PPC_BREAKPOINT_CONDITION_AND
+#define PPC_BREAKPOINT_CONDITION_OR 0x00000002
+#define PPC_BREAKPOINT_CONDITION_AND_OR 0x00000003
+#define PPC_BREAKPOINT_CONDITION_BE_ALL 0x00ff0000
+#define PPC_BREAKPOINT_CONDITION_BE_SHIFT 16
+#define PPC_BREAKPOINT_CONDITION_BE(n) \
+ (1<<((n)+PPC_BREAKPOINT_CONDITION_BE_SHIFT))
+
#endif /* _ASM_POWERPC_PTRACE_H */
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 */