From bfe7ad5be77a6a8925a7ab1628452c8942222102 Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Tue, 10 Apr 2018 11:09:52 -0400 Subject: target/arm: avoid integer overflow in next_page PC check If the PC is in the last page of the address space, next_page_start overflows to 0. Fix it. Reviewed-by: Richard Henderson Cc: Peter Maydell Signed-off-by: Emilio G. Cota Signed-off-by: Richard Henderson --- target/arm/translate.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'target/arm/translate.c') diff --git a/target/arm/translate.c b/target/arm/translate.c index ad208867a7..0f6629f745 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -9930,7 +9930,7 @@ static bool thumb_insn_is_16bit(DisasContext *s, uint32_t insn) return false; } - if ((insn >> 11) == 0x1e && (s->pc < s->next_page_start - 3)) { + if ((insn >> 11) == 0x1e && s->pc - s->page_start < TARGET_PAGE_SIZE - 3) { /* 0b1111_0xxx_xxxx_xxxx : BL/BLX prefix, and the suffix * is not on the next page; we merge this into a 32-bit * insn. @@ -12301,8 +12301,7 @@ static int arm_tr_init_disas_context(DisasContextBase *dcbase, dc->is_ldex = false; dc->ss_same_el = false; /* Can't be true since EL_d must be AArch64 */ - dc->next_page_start = - (dc->base.pc_first & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE; + dc->page_start = dc->base.pc_first & TARGET_PAGE_MASK; /* If architectural single step active, limit to 1. */ if (is_singlestepping(dc)) { @@ -12312,7 +12311,7 @@ static int arm_tr_init_disas_context(DisasContextBase *dcbase, /* ARM is a fixed-length ISA. Bound the number of insns to execute to those left on the page. */ if (!dc->thumb) { - int bound = (dc->next_page_start - dc->base.pc_first) / 4; + int bound = -(dc->base.pc_first | TARGET_PAGE_MASK) / 4; max_insns = MIN(max_insns, bound); } @@ -12584,8 +12583,8 @@ static void thumb_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu) * but isn't very efficient). */ if (dc->base.is_jmp == DISAS_NEXT - && (dc->pc >= dc->next_page_start - || (dc->pc >= dc->next_page_start - 3 + && (dc->pc - dc->page_start >= TARGET_PAGE_SIZE + || (dc->pc - dc->page_start >= TARGET_PAGE_SIZE - 3 && insn_crosses_page(env, dc)))) { dc->base.is_jmp = DISAS_TOO_MANY; } -- cgit v1.2.1 From b542683d77b4f56cef0221b267c341616d87bce9 Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Mon, 19 Feb 2018 20:51:58 -0500 Subject: translator: merge max_insns into DisasContextBase MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit While at it, use int for both num_insns and max_insns to make sure we have same-type comparisons. Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Michael Clark Signed-off-by: Emilio G. Cota Signed-off-by: Richard Henderson --- target/arm/translate.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'target/arm/translate.c') diff --git a/target/arm/translate.c b/target/arm/translate.c index 0f6629f745..731cf327a1 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -12243,8 +12243,7 @@ static bool insn_crosses_page(CPUARMState *env, DisasContext *s) return !thumb_insn_is_16bit(s, insn); } -static int arm_tr_init_disas_context(DisasContextBase *dcbase, - CPUState *cs, int max_insns) +static void arm_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) { DisasContext *dc = container_of(dcbase, DisasContext, base); CPUARMState *env = cs->env_ptr; @@ -12305,14 +12304,14 @@ static int arm_tr_init_disas_context(DisasContextBase *dcbase, /* If architectural single step active, limit to 1. */ if (is_singlestepping(dc)) { - max_insns = 1; + dc->base.max_insns = 1; } /* ARM is a fixed-length ISA. Bound the number of insns to execute to those left on the page. */ if (!dc->thumb) { int bound = -(dc->base.pc_first | TARGET_PAGE_MASK) / 4; - max_insns = MIN(max_insns, bound); + dc->base.max_insns = MIN(dc->base.max_insns, bound); } cpu_F0s = tcg_temp_new_i32(); @@ -12323,8 +12322,6 @@ static int arm_tr_init_disas_context(DisasContextBase *dcbase, cpu_V1 = cpu_F1d; /* FIXME: cpu_M0 can probably be the same as cpu_V0. */ cpu_M0 = tcg_temp_new_i64(); - - return max_insns; } static void arm_tr_tb_start(DisasContextBase *dcbase, CPUState *cpu) -- cgit v1.2.1