Merge remote-tracking branch 'ubifs/linux-next'

[karo-tx-linux.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..b45c95d34b8323e74992e0a4a56e6da0e1257c60 100644 (file)
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -28,6 +28,7 @@
 #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>
@@ -163,6 +164,20 @@ 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 +435,7 @@ 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 +492,7 @@ 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