diff mbox series

[v3,14/16] tcg/arm: Return false on failure from patch_reloc

Message ID 20181130215221.20554-15-richard.henderson@linaro.org
State Superseded
Headers show
Series tcg: Assorted cleanups | expand

Commit Message

Richard Henderson Nov. 30, 2018, 9:52 p.m. UTC
This does require an extra two checks within the slow paths
to replace the assert that we're moving.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 tcg/arm/tcg-target.inc.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

-- 
2.17.2

Comments

Alex Bennée Dec. 3, 2018, 10:43 a.m. UTC | #1
Richard Henderson <richard.henderson@linaro.org> writes:

> This does require an extra two checks within the slow paths

> to replace the assert that we're moving.

>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


Reviewed-by: Alex Bennée <alex.bennee@linaro.org>


> ---

>  tcg/arm/tcg-target.inc.c | 22 ++++++++++++++++------

>  1 file changed, 16 insertions(+), 6 deletions(-)

>

> diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c

> index deefa20fbf..49f57d655e 100644

> --- a/tcg/arm/tcg-target.inc.c

> +++ b/tcg/arm/tcg-target.inc.c

> @@ -187,10 +187,14 @@ static const uint8_t tcg_cond_to_arm_cond[] = {

>      [TCG_COND_GTU] = COND_HI,

>  };

>

> -static inline void reloc_pc24(tcg_insn_unit *code_ptr, tcg_insn_unit *target)

> +static inline bool reloc_pc24(tcg_insn_unit *code_ptr, tcg_insn_unit *target)

>  {

>      ptrdiff_t offset = (tcg_ptr_byte_diff(target, code_ptr) - 8) >> 2;

> -    *code_ptr = (*code_ptr & ~0xffffff) | (offset & 0xffffff);

> +    if (offset == sextract32(offset, 0, 24)) {

> +        *code_ptr = (*code_ptr & ~0xffffff) | (offset & 0xffffff);

> +        return true;

> +    }

> +    return false;

>  }

>

>  static bool patch_reloc(tcg_insn_unit *code_ptr, int type,

> @@ -199,7 +203,7 @@ static bool patch_reloc(tcg_insn_unit *code_ptr, int type,

>      tcg_debug_assert(addend == 0);

>

>      if (type == R_ARM_PC24) {

> -        reloc_pc24(code_ptr, (tcg_insn_unit *)value);

> +        return reloc_pc24(code_ptr, (tcg_insn_unit *)value);

>      } else if (type == R_ARM_PC13) {

>          intptr_t diff = value - (uintptr_t)(code_ptr + 2);

>          tcg_insn_unit insn = *code_ptr;

> @@ -213,7 +217,11 @@ static bool patch_reloc(tcg_insn_unit *code_ptr, int type,

>          } else {

>              int rd = extract32(insn, 12, 4);

>              int rt = rd == TCG_REG_PC ? TCG_REG_TMP : rd;

> -            assert(diff >= 0x1000 && diff < 0x100000);

> +

> +            if (diff < 0x1000 || diff >= 0x100000) {

> +                return false;

> +            }

> +

>              /* add rt, pc, #high */

>              *code_ptr++ = ((insn & 0xf0000000) | (1 << 25) | ARITH_ADD

>                             | (TCG_REG_PC << 16) | (rt << 12)

> @@ -1372,7 +1380,8 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)

>      TCGMemOp opc = get_memop(oi);

>      void *func;

>

> -    reloc_pc24(lb->label_ptr[0], s->code_ptr);

> +    bool ok = reloc_pc24(lb->label_ptr[0], s->code_ptr);

> +    tcg_debug_assert(ok);

>

>      argreg = tcg_out_arg_reg32(s, TCG_REG_R0, TCG_AREG0);

>      if (TARGET_LONG_BITS == 64) {

> @@ -1432,7 +1441,8 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)

>      TCGMemOpIdx oi = lb->oi;

>      TCGMemOp opc = get_memop(oi);

>

> -    reloc_pc24(lb->label_ptr[0], s->code_ptr);

> +    bool ok = reloc_pc24(lb->label_ptr[0], s->code_ptr);

> +    tcg_debug_assert(ok);

>

>      argreg = TCG_REG_R0;

>      argreg = tcg_out_arg_reg32(s, argreg, TCG_AREG0);



--
Alex Bennée
diff mbox series

Patch

diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c
index deefa20fbf..49f57d655e 100644
--- a/tcg/arm/tcg-target.inc.c
+++ b/tcg/arm/tcg-target.inc.c
@@ -187,10 +187,14 @@  static const uint8_t tcg_cond_to_arm_cond[] = {
     [TCG_COND_GTU] = COND_HI,
 };
 
-static inline void reloc_pc24(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
+static inline bool reloc_pc24(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
 {
     ptrdiff_t offset = (tcg_ptr_byte_diff(target, code_ptr) - 8) >> 2;
-    *code_ptr = (*code_ptr & ~0xffffff) | (offset & 0xffffff);
+    if (offset == sextract32(offset, 0, 24)) {
+        *code_ptr = (*code_ptr & ~0xffffff) | (offset & 0xffffff);
+        return true;
+    }
+    return false;
 }
 
 static bool patch_reloc(tcg_insn_unit *code_ptr, int type,
@@ -199,7 +203,7 @@  static bool patch_reloc(tcg_insn_unit *code_ptr, int type,
     tcg_debug_assert(addend == 0);
 
     if (type == R_ARM_PC24) {
-        reloc_pc24(code_ptr, (tcg_insn_unit *)value);
+        return reloc_pc24(code_ptr, (tcg_insn_unit *)value);
     } else if (type == R_ARM_PC13) {
         intptr_t diff = value - (uintptr_t)(code_ptr + 2);
         tcg_insn_unit insn = *code_ptr;
@@ -213,7 +217,11 @@  static bool patch_reloc(tcg_insn_unit *code_ptr, int type,
         } else {
             int rd = extract32(insn, 12, 4);
             int rt = rd == TCG_REG_PC ? TCG_REG_TMP : rd;
-            assert(diff >= 0x1000 && diff < 0x100000);
+
+            if (diff < 0x1000 || diff >= 0x100000) {
+                return false;
+            }
+
             /* add rt, pc, #high */
             *code_ptr++ = ((insn & 0xf0000000) | (1 << 25) | ARITH_ADD
                            | (TCG_REG_PC << 16) | (rt << 12)
@@ -1372,7 +1380,8 @@  static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     TCGMemOp opc = get_memop(oi);
     void *func;
 
-    reloc_pc24(lb->label_ptr[0], s->code_ptr);
+    bool ok = reloc_pc24(lb->label_ptr[0], s->code_ptr);
+    tcg_debug_assert(ok);
 
     argreg = tcg_out_arg_reg32(s, TCG_REG_R0, TCG_AREG0);
     if (TARGET_LONG_BITS == 64) {
@@ -1432,7 +1441,8 @@  static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     TCGMemOpIdx oi = lb->oi;
     TCGMemOp opc = get_memop(oi);
 
-    reloc_pc24(lb->label_ptr[0], s->code_ptr);
+    bool ok = reloc_pc24(lb->label_ptr[0], s->code_ptr);
+    tcg_debug_assert(ok);
 
     argreg = TCG_REG_R0;
     argreg = tcg_out_arg_reg32(s, argreg, TCG_AREG0);