From nobody Tue Feb 10 12:43:04 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=linaro.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 153849849127517.61102188991788; Tue, 2 Oct 2018 09:41:31 -0700 (PDT) Received: from localhost ([::1]:44744 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g7Njm-0002xu-3C for importer@patchew.org; Tue, 02 Oct 2018 12:41:30 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34779) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g7Nea-0006cO-So for qemu-devel@nongnu.org; Tue, 02 Oct 2018 12:36:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g7NeZ-00053a-Ih for qemu-devel@nongnu.org; Tue, 02 Oct 2018 12:36:08 -0400 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:51546) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g7NeV-0004yW-IQ; Tue, 02 Oct 2018 12:36:03 -0400 Received: from pm215 by orth.archaic.org.uk with local (Exim 4.89) (envelope-from ) id 1g7NeR-0007GU-W0; Tue, 02 Oct 2018 17:35:59 +0100 From: Peter Maydell To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Date: Tue, 2 Oct 2018 17:35:44 +0100 Message-Id: <20181002163556.10279-2-peter.maydell@linaro.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181002163556.10279-1-peter.maydell@linaro.org> References: <20181002163556.10279-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2001:8b0:1d0::2 Subject: [Qemu-devel] [PATCH 01/13] target/arm: Define new TBFLAG for v8M stack checking X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: patches@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" The Arm v8M architecture includes hardware stack limit checking. When certain instructions update the stack pointer, if the new value of SP is below the limit set in the associated limit register then an exception is taken. Add a TB flag that tracks whether the limit-checking code needs to be emitted. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daud=C3=A9 Reviewed-by: Richard Henderson --- target/arm/cpu.h | 7 +++++++ target/arm/translate.h | 1 + target/arm/helper.c | 10 ++++++++++ target/arm/translate.c | 1 + 4 files changed, 19 insertions(+) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 65c0fa0a659..d2c1d005ed7 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1336,8 +1336,10 @@ FIELD(V7M_CCR, UNALIGN_TRP, 3, 1) FIELD(V7M_CCR, DIV_0_TRP, 4, 1) FIELD(V7M_CCR, BFHFNMIGN, 8, 1) FIELD(V7M_CCR, STKALIGN, 9, 1) +FIELD(V7M_CCR, STKOFHFNMIGN, 10, 1) FIELD(V7M_CCR, DC, 16, 1) FIELD(V7M_CCR, IC, 17, 1) +FIELD(V7M_CCR, BP, 18, 1) =20 /* V7M SCR bits */ FIELD(V7M_SCR, SLEEPONEXIT, 1, 1) @@ -2842,6 +2844,9 @@ static inline bool arm_cpu_data_is_big_endian(CPUARMS= tate *env) /* For M profile only, Handler (ie not Thread) mode */ #define ARM_TBFLAG_HANDLER_SHIFT 21 #define ARM_TBFLAG_HANDLER_MASK (1 << ARM_TBFLAG_HANDLER_SHIFT) +/* For M profile only, whether we should generate stack-limit checks */ +#define ARM_TBFLAG_STACKCHECK_SHIFT 22 +#define ARM_TBFLAG_STACKCHECK_MASK (1 << ARM_TBFLAG_STACKCHECK_SHIFT) =20 /* Bit usage when in AArch64 state */ #define ARM_TBFLAG_TBI0_SHIFT 0 /* TBI0 for EL0/1 or TBI for EL2/3 = */ @@ -2884,6 +2889,8 @@ static inline bool arm_cpu_data_is_big_endian(CPUARMS= tate *env) (((F) & ARM_TBFLAG_BE_DATA_MASK) >> ARM_TBFLAG_BE_DATA_SHIFT) #define ARM_TBFLAG_HANDLER(F) \ (((F) & ARM_TBFLAG_HANDLER_MASK) >> ARM_TBFLAG_HANDLER_SHIFT) +#define ARM_TBFLAG_STACKCHECK(F) \ + (((F) & ARM_TBFLAG_STACKCHECK_MASK) >> ARM_TBFLAG_STACKCHECK_SHIFT) #define ARM_TBFLAG_TBI0(F) \ (((F) & ARM_TBFLAG_TBI0_MASK) >> ARM_TBFLAG_TBI0_SHIFT) #define ARM_TBFLAG_TBI1(F) \ diff --git a/target/arm/translate.h b/target/arm/translate.h index 45f04244be8..c1b65f3efb0 100644 --- a/target/arm/translate.h +++ b/target/arm/translate.h @@ -38,6 +38,7 @@ typedef struct DisasContext { int vec_stride; bool v7m_handler_mode; bool v8m_secure; /* true if v8M and we're in Secure mode */ + bool v8m_stackcheck; /* true if we need to perform v8M stack limit che= cks */ /* Immediate value in AArch32 SVC insn; must be set if is_jmp =3D=3D D= ISAS_SWI * so that top level loop can generate correct syndrome information. */ diff --git a/target/arm/helper.c b/target/arm/helper.c index 5e721a65272..6ed8631dbee 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -12667,6 +12667,16 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target= _ulong *pc, flags |=3D ARM_TBFLAG_HANDLER_MASK; } =20 + /* v8M always applies stack limit checks unless CCR.STKOFHFNMIGN is + * suppressing them because the requested execution priority is less t= han 0. + */ + if (arm_feature(env, ARM_FEATURE_V8) && + arm_feature(env, ARM_FEATURE_M) && + !((mmu_idx & ARM_MMU_IDX_M_NEGPRI) && + (env->v7m.ccr[env->v7m.secure] & R_V7M_CCR_STKOFHFNMIGN_MASK))) { + flags |=3D ARM_TBFLAG_STACKCHECK_MASK; + } + *pflags =3D flags; *cs_base =3D 0; } diff --git a/target/arm/translate.c b/target/arm/translate.c index c6a5d2ac444..751d5811cee 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -12451,6 +12451,7 @@ static void arm_tr_init_disas_context(DisasContextB= ase *dcbase, CPUState *cs) dc->v7m_handler_mode =3D ARM_TBFLAG_HANDLER(dc->base.tb->flags); dc->v8m_secure =3D arm_feature(env, ARM_FEATURE_M_SECURITY) && regime_is_secure(env, dc->mmu_idx); + dc->v8m_stackcheck =3D ARM_TBFLAG_STACKCHECK(dc->base.tb->flags); dc->cp_regs =3D cpu->cp_regs; dc->features =3D env->features; =20 --=20 2.19.0