Avoid sign extension in packed-switch.

This code (at least in the ARM version) is trying to assign to r0 and r1
from C by returning a 64-bit result. The mistaken use of signed integers
for pointers can lead to sign extension if the JIT code cache is at a
sufficiently high address.

Bug: 6799823
Bug: 6703991

(cherry-pick from 2d0c1c2dbe44458ebb199c47ce1047f266db5349.)

Change-Id: I79e72228b60e195272d11899ac69bb4a76b7402f

1 files changed, 7 insertions, 7 deletions

diff --git a/vm/compiler/codegen/arm/CodegenDriver.cpp b/vm/compiler/codegen/arm/CodegenDriver.cpp
index d96aa6561..78809dc74 100644
--- a/vm/compiler/codegen/arm/CodegenDriver.cpp
+++ b/vm/compiler/codegen/arm/CodegenDriver.cpp
@@ -2789,16 +2789,16 @@ static bool handleFmt23x(CompilationUnit *cUnit, MIR *mir)
  * chaining cell for case default [8 bytes]
  * noChain exit
  */
-static s8 findPackedSwitchIndex(const u2* switchData, int testVal, int pc)
+static u8 findPackedSwitchIndex(const u2* switchData, int testVal, uintptr_t pc)
 {
     int size;
     int firstKey;
     const int *entries;
     int index;
     int jumpIndex;
-    int caseDPCOffset = 0;
+    uintptr_t caseDPCOffset = 0;
     /* In Thumb mode pc is 4 ahead of the "mov r2, pc" instruction */
-    int chainingPC = (pc + 4) & ~3;
+    uintptr_t chainingPC = (pc + 4) & ~3;
 
     /*
      * Packed switch data format:
@@ -2837,16 +2837,16 @@ static s8 findPackedSwitchIndex(const u2* switchData, int testVal, int pc)
     }
 
     chainingPC += jumpIndex * CHAIN_CELL_NORMAL_SIZE;
-    return (((s8) caseDPCOffset) << 32) | (u8) chainingPC;
+    return (((u8) caseDPCOffset) << 32) | (u8) chainingPC;
 }
 
 /* See comments for findPackedSwitchIndex */
-static s8 findSparseSwitchIndex(const u2* switchData, int testVal, int pc)
+static u8 findSparseSwitchIndex(const u2* switchData, int testVal, uintptr_t pc)
 {
     int size;
     const int *keys;
     const int *entries;
-    int chainingPC = (pc + 4) & ~3;
+    uintptr_t chainingPC = (pc + 4) & ~3;
     int i;
 
     /*
@@ -2888,7 +2888,7 @@ static s8 findSparseSwitchIndex(const u2* switchData, int testVal, int pc)
             int jumpIndex = (i < MAX_CHAINED_SWITCH_CASES) ?
                            i : MAX_CHAINED_SWITCH_CASES + 1;
             chainingPC += jumpIndex * CHAIN_CELL_NORMAL_SIZE;
-            return (((s8) entries[i]) << 32) | (u8) chainingPC;
+            return (((u8) entries[i]) << 32) | (u8) chainingPC;
         } else if (k > testVal) {
             break;
         }