From f80741d107673f162e3b097fc76a1590036cc9d1 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Alex=20Benn=C3=A9e?= Date: Thu, 12 Dec 2019 11:47:34 +0000 Subject: [PATCH] target/arm: ensure we use current exception state after SCR update MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit A write to the SCR can change the effective EL by droppping the system from secure to non-secure mode. However if we use a cached current_el from before the change we'll rebuild the flags incorrectly. To fix this we introduce the ARM_CP_NEWEL CP flag to indicate the new EL should be used when recomputing the flags. Signed-off-by: Alex Bennée Tested-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 20191212114734.6962-1-alex.bennee@linaro.org Cc: Richard Henderson Message-Id: <20191209143723.6368-1-alex.bennee@linaro.org> Cc: qemu-stable@nongnu.org Signed-off-by: Peter Maydell --- target/arm/cpu.h | 8 ++++++-- target/arm/helper.c | 14 +++++++++++++- target/arm/helper.h | 1 + target/arm/translate.c | 6 +++++- 4 files changed, 25 insertions(+), 4 deletions(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 4106e4ae59..5f70e9e043 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2238,6 +2238,9 @@ static inline uint64_t cpreg_to_kvm_id(uint32_t cpregid) * RAISES_EXC is for when the read or write hook might raise an exception; * the generated code will synchronize the CPU state before calling the hook * so that it is safe for the hook to call raise_exception(). + * NEWEL is for writes to registers that might change the exception + * level - typically on older ARM chips. For those cases we need to + * re-read the new el when recomputing the translation flags. */ #define ARM_CP_SPECIAL 0x0001 #define ARM_CP_CONST 0x0002 @@ -2257,10 +2260,11 @@ static inline uint64_t cpreg_to_kvm_id(uint32_t cpregid) #define ARM_CP_SVE 0x2000 #define ARM_CP_NO_GDB 0x4000 #define ARM_CP_RAISES_EXC 0x8000 +#define ARM_CP_NEWEL 0x10000 /* Used only as a terminator for ARMCPRegInfo lists */ -#define ARM_CP_SENTINEL 0xffff +#define ARM_CP_SENTINEL 0xfffff /* Mask of only the flag bits in a type field */ -#define ARM_CP_FLAG_MASK 0xf0ff +#define ARM_CP_FLAG_MASK 0x1f0ff /* Valid values for ARMCPRegInfo state field, indicating which of * the AArch32 and AArch64 execution states this register is visible in. diff --git a/target/arm/helper.c b/target/arm/helper.c index 3a93844a3b..5074b5f69c 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -5133,7 +5133,7 @@ static const ARMCPRegInfo el3_cp_reginfo[] = { .opc0 = 3, .opc1 = 6, .crn = 1, .crm = 1, .opc2 = 0, .access = PL3_RW, .fieldoffset = offsetof(CPUARMState, cp15.scr_el3), .resetvalue = 0, .writefn = scr_write }, - { .name = "SCR", .type = ARM_CP_ALIAS, + { .name = "SCR", .type = ARM_CP_ALIAS | ARM_CP_NEWEL, .cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 0, .access = PL1_RW, .accessfn = access_trap_aa32s_el1, .fieldoffset = offsetoflow32(CPUARMState, cp15.scr_el3), @@ -11472,6 +11472,18 @@ void HELPER(rebuild_hflags_m32)(CPUARMState *env, int el) env->hflags = rebuild_hflags_m32(env, fp_el, mmu_idx); } +/* + * If we have triggered a EL state change we can't rely on the + * translator having passed it too us, we need to recompute. + */ +void HELPER(rebuild_hflags_a32_newel)(CPUARMState *env) +{ + int el = arm_current_el(env); + int fp_el = fp_exception_el(env, el); + ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el); + env->hflags = rebuild_hflags_a32(env, fp_el, mmu_idx); +} + void HELPER(rebuild_hflags_a32)(CPUARMState *env, int el) { int fp_el = fp_exception_el(env, el); diff --git a/target/arm/helper.h b/target/arm/helper.h index 7ce5169afb..aa3d8cd08f 100644 --- a/target/arm/helper.h +++ b/target/arm/helper.h @@ -91,6 +91,7 @@ DEF_HELPER_2(get_user_reg, i32, env, i32) DEF_HELPER_3(set_user_reg, void, env, i32, i32) DEF_HELPER_FLAGS_2(rebuild_hflags_m32, TCG_CALL_NO_RWG, void, env, int) +DEF_HELPER_FLAGS_1(rebuild_hflags_a32_newel, TCG_CALL_NO_RWG, void, env) DEF_HELPER_FLAGS_2(rebuild_hflags_a32, TCG_CALL_NO_RWG, void, env, int) DEF_HELPER_FLAGS_2(rebuild_hflags_a64, TCG_CALL_NO_RWG, void, env, int) diff --git a/target/arm/translate.c b/target/arm/translate.c index f162be8434..2b6c1f91bf 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -7083,7 +7083,11 @@ static int disas_coproc_insn(DisasContext *s, uint32_t insn) if (arm_dc_feature(s, ARM_FEATURE_M)) { gen_helper_rebuild_hflags_m32(cpu_env, tcg_el); } else { - gen_helper_rebuild_hflags_a32(cpu_env, tcg_el); + if (ri->type & ARM_CP_NEWEL) { + gen_helper_rebuild_hflags_a32_newel(cpu_env); + } else { + gen_helper_rebuild_hflags_a32(cpu_env, tcg_el); + } } tcg_temp_free_i32(tcg_el); /* -- 2.11.4.GIT