When fall-through warnings was enabled by default, d93512ef0f0e
("Makefile: Globally enable fall-through warning"), we could see the
following warnings was starting to show up. However, this was originally
introduced in commit 6ee33c2712fc ("ARM: hw_breakpoint: correct and
simplify alignment fixup code"). Commit d968d2b801d8 ("ARM: 7497/1:
hw_breakpoint: allow single-byte watchpoints on all addresses") was
written with the intent to allow single-byte watchpoints on all
addresses but forgot to move 'case 1:' down below 'case 2:'.

../arch/arm/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’:
../arch/arm/kernel/hw_breakpoint.c:609:7: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
    if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
       ^
../arch/arm/kernel/hw_breakpoint.c:611:3: note: here
   case 3:
   ^~~~
../arch/arm/kernel/hw_breakpoint.c:613:7: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
    if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
       ^
../arch/arm/kernel/hw_breakpoint.c:615:3: note: here
   default:
   ^~~~~~~

Rework so 'case 1:' are next to 'case 3:' and also add '/* Fall through
*/' so that the compiler doesn't warn about fall-through.

Cc: [email protected] # v3.16
Fixes: 6ee33c2712fc ("ARM: hw_breakpoint: correct and simplify alignment fixup 
code")
Signed-off-by: Anders Roxell <[email protected]>
---
 arch/arm/kernel/hw_breakpoint.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index af8b8e15f589..c14d506969ba 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -603,15 +603,17 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
        case 0:
                /* Aligned */
                break;
-       case 1:
        case 2:
                /* Allow halfword watchpoints and breakpoints. */
                if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
                        break;
+               /* Fall through */
+       case 1:
        case 3:
                /* Allow single byte watchpoint. */
                if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
                        break;
+               /* Fall through */
        default:
                ret = -EINVAL;
                goto out;
-- 
2.20.1

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