From 43fabd30e2f411e8d70ff347902a7c8ed308233e Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 30 Nov 2018 13:01:57 -0800 Subject: [PATCH] tcg/arm: Return false on failure from patch_reloc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This does require an extra two checks within the slow paths to replace the assert that we're moving. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- 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); -- GitLab