1 files changed, 17 insertions, 28 deletions

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 3d5fb509bdeb..7114ba220fd4 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -126,6 +126,8 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
         *dr7 |= encode_dr7(i, info->len, info->type);
 
         set_debugreg(*dr7, 7);
+        if (info->mask)
+                set_dr_addr_mask(info->mask, i);
 
         return 0;
 }
@@ -161,29 +163,8 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
         *dr7 &= ~__encode_dr7(i, info->len, info->type);
 
         set_debugreg(*dr7, 7);
-}
-
-static int get_hbp_len(u8 hbp_len)
-{
-        unsigned int len_in_bytes = 0;
-
-        switch (hbp_len) {
-        case X86_BREAKPOINT_LEN_1:
-                len_in_bytes = 1;
-                break;
-        case X86_BREAKPOINT_LEN_2:
-                len_in_bytes = 2;
-                break;
-        case X86_BREAKPOINT_LEN_4:
-                len_in_bytes = 4;
-                break;
-#ifdef CONFIG_X86_64
-        case X86_BREAKPOINT_LEN_8:
-                len_in_bytes = 8;
-                break;
-#endif
-        }
-        return len_in_bytes;
+        if (info->mask)
+                set_dr_addr_mask(0, i);
 }
 
 /*
@@ -196,7 +177,7 @@ int arch_check_bp_in_kernelspace(struct perf_event *bp)
         struct arch_hw_breakpoint *info = counter_arch_bp(bp);
 
         va = info->address;
-        len = get_hbp_len(info->len);
+        len = bp->attr.bp_len;
 
         return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
 }
@@ -277,6 +258,8 @@ static int arch_build_bp_info(struct perf_event *bp)
         }
 
         /* Len */
+        info->mask = 0;
+
         switch (bp->attr.bp_len) {
         case HW_BREAKPOINT_LEN_1:
                 info->len = X86_BREAKPOINT_LEN_1;
@@ -293,11 +276,17 @@ static int arch_build_bp_info(struct perf_event *bp)
                 break;
 #endif
         default:
-                return -EINVAL;
+                if (!is_power_of_2(bp->attr.bp_len))
+                        return -EINVAL;
+                if (!cpu_has_bpext)
+                        return -EOPNOTSUPP;
+                info->mask = bp->attr.bp_len - 1;
+                info->len = X86_BREAKPOINT_LEN_1;
         }
 
         return 0;
 }
+
 /*
  * Validate the arch-specific HW Breakpoint register settings
  */
@@ -312,11 +301,11 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
         if (ret)
                 return ret;
 
-        ret = -EINVAL;
-
         switch (info->len) {
         case X86_BREAKPOINT_LEN_1:
                 align = 0;
+                if (info->mask)
+                        align = info->mask;
                 break;
         case X86_BREAKPOINT_LEN_2:
                 align = 1;
@@ -330,7 +319,7 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
                 break;
 #endif
         default:
-                return ret;
+                WARN_ON_ONCE(1);
         }
 
         /*