From c7c3c4da432ddb543d4b0a9abbb245f11b26afd0 Mon Sep 17 00:00:00 2001

From: Mike Pall <mike>

Date: Wed, 7 Jun 2017 19:36:46 +0200

Subject: [PATCH 04/72] MIPS: Fix handling of spare long-range jump slots.

Contributed by Djordje Kovacevic and Stefan Pejic.

---

 src/lj_asm_mips.h | 9 +++++----

 src/lj_jit.h      | 6 ++++++

 src/lj_mcode.c    | 6 ------

 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/lj_asm_mips.h b/src/lj_asm_mips.h

index d0a1ca5..7631190 100644

--- a/src/lj_asm_mips.h

+++ b/src/lj_asm_mips.h

@@ -65,10 +65,9 @@ static Reg ra_alloc2(ASMState *as, IRIns *ir, RegSet allow)

 static void asm_sparejump_setup(ASMState *as)

 {

   MCode *mxp = as->mcbot;

-  /* Assumes sizeof(MCLink) == 8. */

-  if (((uintptr_t)mxp & (LJ_PAGESIZE-1)) == 8) {

+  if (((uintptr_t)mxp & (LJ_PAGESIZE-1)) == sizeof(MCLink)) {

     lua_assert(MIPSI_NOP == 0);

-    memset(mxp+2, 0, MIPS_SPAREJUMP*8);

+    memset(mxp, 0, MIPS_SPAREJUMP*2*sizeof(MCode));

     mxp += MIPS_SPAREJUMP*2;

     lua_assert(mxp < as->mctop);

     lj_mcode_sync(as->mcbot, mxp);

@@ -1947,7 +1946,9 @@ void lj_asm_patchexit(jit_State *J, GCtrace *T, ExitNo exitno, MCode *target)

 	  if (!cstart) cstart = p-1;

 	} else {  /* Branch out of range. Use spare jump slot in mcarea. */

 	  int i;

-	  for (i = 2; i < 2+MIPS_SPAREJUMP*2; i += 2) {

+	  for (i = (int)(sizeof(MCLink)/sizeof(MCode));

+	       i < (int)(sizeof(MCLink)/sizeof(MCode)+MIPS_SPAREJUMP*2);

+	       i += 2) {

 	    if (mcarea[i] == tjump) {

 	      delta = mcarea+i - p;

 	      goto patchbranch;

diff --git a/src/lj_jit.h b/src/lj_jit.h

index a2e8fd9..3f38d28 100644

--- a/src/lj_jit.h

+++ b/src/lj_jit.h

@@ -155,6 +155,12 @@ typedef uint8_t MCode;

 typedef uint32_t MCode;

 #endif

+/* Linked list of MCode areas. */

+typedef struct MCLink {

+  MCode *next;		/* Next area. */

+  size_t size;		/* Size of current area. */

+} MCLink;

+

 /* Stack snapshot header. */

 typedef struct SnapShot {

   uint16_t mapofs;	/* Offset into snapshot map. */

diff --git a/src/lj_mcode.c b/src/lj_mcode.c

index f0a1f69..5ea89f6 100644

--- a/src/lj_mcode.c

+++ b/src/lj_mcode.c

@@ -272,12 +272,6 @@ static void *mcode_alloc(jit_State *J, size_t sz)

 /* -- MCode area management ----------------------------------------------- */

-/* Linked list of MCode areas. */

-typedef struct MCLink {

-  MCode *next;		/* Next area. */

-  size_t size;		/* Size of current area. */

-} MCLink;

-

 /* Allocate a new MCode area. */

 static void mcode_allocarea(jit_State *J)

 {

-- 

2.20.1