From 6e3895edd5ca6fc875e27b3f1fbc2f9a2a0d42d7 Mon Sep 17 00:00:00 2001

From: Jon Masters <jcm@redhat.com>

Date: Mon, 16 May 2016 15:40:24 -0400

Subject: [[RHEL7.3 TEST PATCH]] mozjs17: support 48-bit VA limits in tagged

 pointers on AArch64

The 64-bit ARM Architecture (AArch64) provides certain bits of

high order VA (Virtual Address) space for tagged pointers, but

these are limited to above 48 bits. mozjs has can existing

assumption that it can use everything above 47 bits itself.

This is needed to support a 48-bit VA kernel on RHEL(SA)7.

The patch is from Zheng Xu <zheng.xu@linaro.org>

Signed-off-by: Jon Masters <jcm@redhat.com>

---

 ...64-support-tagged-pointers-48bit-va-limit.patch | 118 +++++++++++++++++++++

 1 file changed, 118 insertions(+)

 create mode 100644 mozjs17-aarch64-support-tagged-pointers-48bit-va-limit.patch

diff -urNp mozjs17.0.0_orig/js/src/jsval.h mozjs17.0.0/js/src/jsval.h

--- mozjs17.0.0_orig/js/src/jsval.h	2016-05-16 15:33:42.400203358 -0400

+++ mozjs17.0.0/js/src/jsval.h	2016-05-16 15:31:21.350657048 -0400

@@ -35,7 +35,7 @@ JS_BEGIN_EXTERN_C

 #endif

 #if JS_BITS_PER_WORD == 64

-# define JSVAL_TAG_SHIFT 47

+# define JSVAL_TAG_SHIFT 48

 #endif

 /*

@@ -94,7 +94,8 @@ JS_STATIC_ASSERT(sizeof(JSValueTag) == 4

 /* Remember to propagate changes to the C defines below. */

 JS_ENUM_HEADER(JSValueTag, uint32_t)

 {

-    JSVAL_TAG_MAX_DOUBLE           = 0x1FFF0,

+    JSVAL_TAG_DUMMY                = 0xFFFFFFFF,  /* Make sure the enums cannot fit 16-bits. */

+    JSVAL_TAG_MAX_DOUBLE           = 0xFFF8,

     JSVAL_TAG_INT32                = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_INT32,

     JSVAL_TAG_UNDEFINED            = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_UNDEFINED,

     JSVAL_TAG_STRING               = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_STRING,

@@ -150,7 +151,7 @@ typedef uint32_t JSValueTag;

 #elif JS_BITS_PER_WORD == 64

 typedef uint32_t JSValueTag;

-#define JSVAL_TAG_MAX_DOUBLE         ((uint32_t)(0x1FFF0))

+#define JSVAL_TAG_MAX_DOUBLE         ((uint32_t)(0xFFF8))

 #define JSVAL_TAG_INT32              (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_INT32)

 #define JSVAL_TAG_UNDEFINED          (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_UNDEFINED)

 #define JSVAL_TAG_STRING             (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_STRING)

@@ -188,8 +189,8 @@ typedef uint64_t JSValueShiftedTag;

 #elif JS_BITS_PER_WORD == 64

-#define JSVAL_PAYLOAD_MASK           0x00007FFFFFFFFFFFLL

-#define JSVAL_TAG_MASK               0xFFFF800000000000LL

+#define JSVAL_PAYLOAD_MASK           0x0000FFFFFFFFFFFFLL

+#define JSVAL_TAG_MASK               0xFFFF000000000000LL

 #define JSVAL_TYPE_TO_TAG(type)      ((JSValueTag)(JSVAL_TAG_MAX_DOUBLE | (type)))

 #define JSVAL_TYPE_TO_SHIFTED_TAG(type) (((uint64_t)JSVAL_TYPE_TO_TAG(type)) << JSVAL_TAG_SHIFT)

@@ -251,8 +252,8 @@ typedef union jsval_layout

 #if (!defined(_WIN64) && defined(__cplusplus))

     /* MSVC does not pack these correctly :-( */

     struct {

-        uint64_t           payload47 : 47;

-        JSValueTag         tag : 17;

+        uint64_t           payload48 : 48;

+        JSValueTag         tag : 16;

     } debugView;

 #endif

     struct {

@@ -295,8 +296,8 @@ typedef union jsval_layout

 {

     uint64_t asBits;

     struct {

-        JSValueTag         tag : 17;

-        uint64_t           payload47 : 47;

+        JSValueTag         tag : 16;

+        uint64_t           payload48 : 48;

     } debugView;

     struct {

         uint32_t           padding;

@@ -788,7 +789,7 @@ JSVAL_SAME_TYPE_IMPL(jsval_layout lhs, j

 {

     uint64_t lbits = lhs.asBits, rbits = rhs.asBits;

     return (lbits <= JSVAL_SHIFTED_TAG_MAX_DOUBLE && rbits <= JSVAL_SHIFTED_TAG_MAX_DOUBLE) ||

-           (((lbits ^ rbits) & 0xFFFF800000000000LL) == 0);

+           (((lbits ^ rbits) & 0xFFFF000000000000LL) == 0);

 }

 static JS_ALWAYS_INLINE jsval_layout

@@ -810,7 +811,7 @@ JSVAL_TO_PRIVATE_UINT32_IMPL(jsval_layou

 static JS_ALWAYS_INLINE JSValueType

 JSVAL_EXTRACT_NON_DOUBLE_TYPE_IMPL(jsval_layout l)

 {

-   uint64_t type = (l.asBits >> JSVAL_TAG_SHIFT) & 0xF;

+   uint64_t type = (l.asBits >> JSVAL_TAG_SHIFT) & 0x7;

    JS_ASSERT(type > JSVAL_TYPE_DOUBLE);

    return (JSValueType)type;

 }

diff -urNp mozjs17.0.0_orig/js/src/methodjit/MethodJIT.cpp mozjs17.0.0/js/src/methodjit/MethodJIT.cpp

--- mozjs17.0.0_orig/js/src/methodjit/MethodJIT.cpp	2013-02-11 17:33:23.000000000 -0500

+++ mozjs17.0.0/js/src/methodjit/MethodJIT.cpp	2016-05-16 15:36:35.044096031 -0400

@@ -238,8 +238,8 @@ JS_STATIC_ASSERT(offsetof(VMFrame, saved

 JS_STATIC_ASSERT(offsetof(VMFrame, scratch) == 0x18);

 JS_STATIC_ASSERT(VMFrame::offsetOfFp == 0x38);

-JS_STATIC_ASSERT(JSVAL_TAG_MASK == 0xFFFF800000000000LL);

-JS_STATIC_ASSERT(JSVAL_PAYLOAD_MASK == 0x00007FFFFFFFFFFFLL);

+JS_STATIC_ASSERT(JSVAL_TAG_MASK == 0xFFFF000000000000LL);

+JS_STATIC_ASSERT(JSVAL_PAYLOAD_MASK == 0x0000FFFFFFFFFFFFLL);

 asm (

 ".text\n"

@@ -266,8 +266,8 @@ SYMBOL_STRING(JaegerTrampoline) ":"

     CFI(".cfi_offset rbx, -56"           "\n")

     /* Load mask registers. */

-    "movq $0xFFFF800000000000, %r13"     "\n"

-    "movq $0x00007FFFFFFFFFFF, %r14"     "\n"

+    "movq $0xFFFF000000000000, %r13"     "\n"

+    "movq $0x0000FFFFFFFFFFFF, %r14"     "\n"

     /* Build the JIT frame.

      * rdi = cx

@@ -947,8 +947,8 @@ extern "C" {

 JS_STATIC_ASSERT(offsetof(VMFrame, savedRBX) == 0x68);

 JS_STATIC_ASSERT(offsetof(VMFrame, scratch) == 0x18);

 JS_STATIC_ASSERT(VMFrame::offsetOfFp == 0x38);

-JS_STATIC_ASSERT(JSVAL_TAG_MASK == 0xFFFF800000000000LL);

-JS_STATIC_ASSERT(JSVAL_PAYLOAD_MASK == 0x00007FFFFFFFFFFFLL);

+JS_STATIC_ASSERT(JSVAL_TAG_MASK == 0xFFFF000000000000LL);

+JS_STATIC_ASSERT(JSVAL_PAYLOAD_MASK == 0x0000FFFFFFFFFFFFLL);

 #endif                   /* _WIN64 */

-- 

2.5.5