Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / hw_breakpoint.c

diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index bba85c8f80373937ef9fe746e1a2ed4fc39f58ee..367a954f9937979c574a805bab2e3cbad706d202 100644 (file)
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -24,10 +24,12 @@
 #include <linux/cpu_pm.h>
 #include <linux/errno.h>
 #include <linux/hw_breakpoint.h>
+#include <linux/kprobes.h>
 #include <linux/perf_event.h>
 #include <linux/ptrace.h>
 #include <linux/smp.h>
 
+#include <asm/compat.h>
 #include <asm/current.h>
 #include <asm/debug-monitors.h>
 #include <asm/hw_breakpoint.h>
@@ -126,6 +128,7 @@ static u64 read_wb_reg(int reg, int n)
 
        return val;
 }
+NOKPROBE_SYMBOL(read_wb_reg);
 
 static void write_wb_reg(int reg, int n, u64 val)
 {
@@ -139,6 +142,7 @@ static void write_wb_reg(int reg, int n, u64 val)
        }
        isb();
 }
+NOKPROBE_SYMBOL(write_wb_reg);
 
 /*
  * Convert a breakpoint privilege level to the corresponding exception
@@ -156,6 +160,7 @@ static enum dbg_active_el debug_exception_level(int privilege)
                return -EINVAL;
        }
 }
+NOKPROBE_SYMBOL(debug_exception_level);
 
 enum hw_breakpoint_ops {
        HW_BREAKPOINT_INSTALL,
@@ -163,6 +168,20 @@ enum hw_breakpoint_ops {
        HW_BREAKPOINT_RESTORE
 };
 
+static int is_compat_bp(struct perf_event *bp)
+{
+       struct task_struct *tsk = bp->hw.target;
+
+       /*
+        * tsk can be NULL for per-cpu (non-ptrace) breakpoints.
+        * In this case, use the native interface, since we don't have
+        * the notion of a "compat CPU" and could end up relying on
+        * deprecated behaviour if we use unaligned watchpoints in
+        * AArch64 state.
+        */
+       return tsk && is_compat_thread(task_thread_info(tsk));
+}
+
 /**
  * hw_breakpoint_slot_setup - Find and setup a perf slot according to
  *                           operations
@@ -420,7 +439,7 @@ static int arch_build_bp_info(struct perf_event *bp)
         * Watchpoints can be of length 1, 2, 4 or 8 bytes.
         */
        if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
-               if (is_compat_task()) {
+               if (is_compat_bp(bp)) {
                        if (info->ctrl.len != ARM_BREAKPOINT_LEN_2 &&
                            info->ctrl.len != ARM_BREAKPOINT_LEN_4)
                                return -EINVAL;
@@ -477,7 +496,7 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
         * AArch32 tasks expect some simple alignment fixups, so emulate
         * that here.
         */
-       if (is_compat_task()) {
+       if (is_compat_bp(bp)) {
                if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
                        alignment_mask = 0x7;
                else
@@ -560,6 +579,7 @@ static void toggle_bp_registers(int reg, enum dbg_active_el el, int enable)
                write_wb_reg(reg, i, ctrl);
        }
 }
+NOKPROBE_SYMBOL(toggle_bp_registers);
 
 /*
  * Debug exception handlers.
@@ -639,6 +659,7 @@ unlock:
 
        return 0;
 }
+NOKPROBE_SYMBOL(breakpoint_handler);
 
 static int watchpoint_handler(unsigned long addr, unsigned int esr,
                              struct pt_regs *regs)
@@ -741,6 +762,7 @@ unlock:
 
        return 0;
 }
+NOKPROBE_SYMBOL(watchpoint_handler);
 
 /*
  * Handle single-step exception.
@@ -798,6 +820,7 @@ int reinstall_suspended_bps(struct pt_regs *regs)
 
        return !handled_exception;
 }
+NOKPROBE_SYMBOL(reinstall_suspended_bps);
 
 /*
  * Context-switcher for restoring suspended breakpoints.