diff options
| -rw-r--r-- | target/arm/cpu.c | 11 | ||||
| -rw-r--r-- | target/arm/helper.c | 47 |
2 files changed, 55 insertions, 3 deletions
diff --git a/target/arm/cpu.c b/target/arm/cpu.c index adf84f9686..822efa5b2c 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -1694,6 +1694,17 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp) return; } +#ifdef CONFIG_USER_ONLY + /* + * User mode relies on IC IVAU instructions to catch modification of + * dual-mapped code. + * + * Clear CTR_EL0.DIC to ensure that software that honors these flags uses + * IC IVAU even if the emulated processor does not normally require it. + */ + cpu->ctr = FIELD_DP64(cpu->ctr, CTR_EL0, DIC, 0); +#endif + if (arm_feature(env, ARM_FEATURE_AARCH64) && cpu->has_vfp != cpu->has_neon) { /* diff --git a/target/arm/helper.c b/target/arm/helper.c index a0b84efab5..8e836aaee1 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -5234,6 +5234,36 @@ static void mdcr_el2_write(CPUARMState *env, const ARMCPRegInfo *ri, } } +#ifdef CONFIG_USER_ONLY +/* + * `IC IVAU` is handled to improve compatibility with JITs that dual-map their + * code to get around W^X restrictions, where one region is writable and the + * other is executable. + * + * Since the executable region is never written to we cannot detect code + * changes when running in user mode, and rely on the emulated JIT telling us + * that the code has changed by executing this instruction. + */ +static void ic_ivau_write(CPUARMState *env, const ARMCPRegInfo *ri, + uint64_t value) +{ + uint64_t icache_line_mask, start_address, end_address; + const ARMCPU *cpu; + + cpu = env_archcpu(env); + + icache_line_mask = (4 << extract32(cpu->ctr, 0, 4)) - 1; + start_address = value & ~icache_line_mask; + end_address = value | icache_line_mask; + + mmap_lock(); + + tb_invalidate_phys_range(start_address, end_address); + + mmap_unlock(); +} +#endif + static const ARMCPRegInfo v8_cp_reginfo[] = { /* * Minimal set of EL0-visible registers. This will need to be expanded @@ -5273,7 +5303,10 @@ static const ARMCPRegInfo v8_cp_reginfo[] = { { .name = "CURRENTEL", .state = ARM_CP_STATE_AA64, .opc0 = 3, .opc1 = 0, .opc2 = 2, .crn = 4, .crm = 2, .access = PL1_R, .type = ARM_CP_CURRENTEL }, - /* Cache ops: all NOPs since we don't emulate caches */ + /* + * Instruction cache ops. All of these except `IC IVAU` NOP because we + * don't emulate caches. + */ { .name = "IC_IALLUIS", .state = ARM_CP_STATE_AA64, .opc0 = 1, .opc1 = 0, .crn = 7, .crm = 1, .opc2 = 0, .access = PL1_W, .type = ARM_CP_NOP, @@ -5286,9 +5319,17 @@ static const ARMCPRegInfo v8_cp_reginfo[] = { .accessfn = access_tocu }, { .name = "IC_IVAU", .state = ARM_CP_STATE_AA64, .opc0 = 1, .opc1 = 3, .crn = 7, .crm = 5, .opc2 = 1, - .access = PL0_W, .type = ARM_CP_NOP, + .access = PL0_W, .fgt = FGT_ICIVAU, - .accessfn = access_tocu }, + .accessfn = access_tocu, +#ifdef CONFIG_USER_ONLY + .type = ARM_CP_NO_RAW, + .writefn = ic_ivau_write +#else + .type = ARM_CP_NOP +#endif + }, + /* Cache ops: all NOPs since we don't emulate caches */ { .name = "DC_IVAC", .state = ARM_CP_STATE_AA64, .opc0 = 1, .opc1 = 0, .crn = 7, .crm = 6, .opc2 = 1, .access = PL1_W, .accessfn = aa64_cacheop_poc_access, |