From 77077a83006c3c9bdca496727f1735a3c5c5355d Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Fri, 6 Oct 2017 16:46:47 +0100 Subject: arm: Fix SMC reporting to EL2 when QEMU provides PSCI This properly forwards SMC events to EL2 when PSCI is provided by QEMU itself and, thus, ARM_FEATURE_EL3 is off. Found and tested with the Jailhouse hypervisor. Solution based on suggestions by Peter Maydell. Signed-off-by: Jan Kiszka Message-id: 4f243068-aaea-776f-d18f-f9e05e7be9cd@siemens.com Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- target/arm/helper.c | 9 ++++++++- target/arm/op_helper.c | 27 +++++++++++++++++---------- 2 files changed, 25 insertions(+), 11 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index 8be78ea2f8..0b9c9fded6 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -3717,7 +3717,14 @@ static void hcr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) if (arm_feature(env, ARM_FEATURE_EL3)) { valid_mask &= ~HCR_HCD; - } else { + } else if (cpu->psci_conduit != QEMU_PSCI_CONDUIT_SMC) { + /* Architecturally HCR.TSC is RES0 if EL3 is not implemented. + * However, if we're using the SMC PSCI conduit then QEMU is + * effectively acting like EL3 firmware and so the guest at + * EL2 should retain the ability to prevent EL1 from being + * able to make SMC calls into the ersatz firmware, so in + * that case HCR.TSC should be read/write. + */ valid_mask &= ~HCR_TSC; } diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c index 6a60464ab9..3914145709 100644 --- a/target/arm/op_helper.c +++ b/target/arm/op_helper.c @@ -953,22 +953,29 @@ void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome) */ bool undef = arm_feature(env, ARM_FEATURE_AARCH64) ? smd : smd && !secure; - if (arm_is_psci_call(cpu, EXCP_SMC)) { - /* If PSCI is enabled and this looks like a valid PSCI call then - * that overrides the architecturally mandated SMC behaviour. + if (!arm_feature(env, ARM_FEATURE_EL3) && + cpu->psci_conduit != QEMU_PSCI_CONDUIT_SMC) { + /* If we have no EL3 then SMC always UNDEFs and can't be + * trapped to EL2. PSCI-via-SMC is a sort of ersatz EL3 + * firmware within QEMU, and we want an EL2 guest to be able + * to forbid its EL1 from making PSCI calls into QEMU's + * "firmware" via HCR.TSC, so for these purposes treat + * PSCI-via-SMC as implying an EL3. */ - return; - } - - if (!arm_feature(env, ARM_FEATURE_EL3)) { - /* If we have no EL3 then SMC always UNDEFs */ undef = true; } else if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) { - /* In NS EL1, HCR controlled routing to EL2 has priority over SMD. */ + /* In NS EL1, HCR controlled routing to EL2 has priority over SMD. + * We also want an EL2 guest to be able to forbid its EL1 from + * making PSCI calls into QEMU's "firmware" via HCR.TSC. + */ raise_exception(env, EXCP_HYP_TRAP, syndrome, 2); } - if (undef) { + /* If PSCI is enabled and this looks like a valid PSCI call then + * suppress the UNDEF -- we'll catch the SMC exception and + * implement the PSCI call behaviour there. + */ + if (undef && !arm_is_psci_call(cpu, EXCP_SMC)) { raise_exception(env, EXCP_UDEF, syn_uncategorized(), exception_target_el(env)); } -- cgit v1.2.3 From 8573378e62d19e25a2434e23462ec99ef4d065ac Mon Sep 17 00:00:00 2001 From: Michael Olbrich Date: Fri, 6 Oct 2017 16:46:47 +0100 Subject: hw/sd: fix out-of-bounds check for multi block reads The current code checks if the next block exceeds the size of the card. This generates an error while reading the last block of the card. Do the out-of-bounds check when starting to read a new block to fix this. This issue became visible with increased error checking in Linux 4.13. Cc: qemu-stable@nongnu.org Signed-off-by: Michael Olbrich Reviewed-by: Alistair Francis Message-id: 20170916091611.10241-1-m.olbrich@pengutronix.de Signed-off-by: Peter Maydell --- hw/sd/sd.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/hw/sd/sd.c b/hw/sd/sd.c index ba47bff4db..35347a5bbc 100644 --- a/hw/sd/sd.c +++ b/hw/sd/sd.c @@ -1797,8 +1797,13 @@ uint8_t sd_read_data(SDState *sd) break; case 18: /* CMD18: READ_MULTIPLE_BLOCK */ - if (sd->data_offset == 0) + if (sd->data_offset == 0) { + if (sd->data_start + io_len > sd->size) { + sd->card_status |= ADDRESS_ERROR; + return 0x00; + } BLK_READ_BLOCK(sd->data_start, io_len); + } ret = sd->data[sd->data_offset ++]; if (sd->data_offset >= io_len) { @@ -1812,11 +1817,6 @@ uint8_t sd_read_data(SDState *sd) break; } } - - if (sd->data_start + io_len > sd->size) { - sd->card_status |= ADDRESS_ERROR; - break; - } } break; -- cgit v1.2.3 From d858914435a13982c3ea981bb24dee958b2ca7c4 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Fri, 6 Oct 2017 16:46:47 +0100 Subject: hw/arm/xlnx-zynqmp: Mark the "xlnx, zynqmp" device with user_creatable = false The device uses serial_hds in its realize function and thus can't be used twice. Apart from that, the comma in its name makes it quite hard to use for the user anyway, since a comma is normally used to separate the device name from its properties when using the "-device" parameter or the "device_add" HMP command. Signed-off-by: Thomas Huth Reviewed-by: Alistair Francis Message-id: 1506441116-16627-1-git-send-email-thuth@redhat.com Signed-off-by: Peter Maydell --- hw/arm/xlnx-zynqmp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/arm/xlnx-zynqmp.c b/hw/arm/xlnx-zynqmp.c index 2b27daf51d..d4b6560194 100644 --- a/hw/arm/xlnx-zynqmp.c +++ b/hw/arm/xlnx-zynqmp.c @@ -440,6 +440,8 @@ static void xlnx_zynqmp_class_init(ObjectClass *oc, void *data) dc->props = xlnx_zynqmp_props; dc->realize = xlnx_zynqmp_realize; + /* Reason: Uses serial_hds in realize function, thus can't be used twice */ + dc->user_creatable = false; } static const TypeInfo xlnx_zynqmp_type_info = { -- cgit v1.2.3 From 8ff26a3344b6e6d1eeb00b4043232a5bdbc0ebf9 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:47 +0100 Subject: nvic: Clear the vector arrays and prigroup on reset MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Reset for devices does not include an automatic clear of the device state (unlike CPU state, where most of the state structure is cleared to zero). Add some missing initialization of NVIC state that meant that the device was left in the wrong state if the guest did a warm reset. (In particular, since we were resetting the computed state like s->exception_prio but not all the state it was computed from like s->vectors[x].active, the NVIC wound up in an inconsistent state that could later trigger assertion failures.) Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Message-id: 1506092407-26985-2-git-send-email-peter.maydell@linaro.org --- hw/intc/armv7m_nvic.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index d90d8d0784..bc7b66d9cc 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -1782,6 +1782,11 @@ static void armv7m_nvic_reset(DeviceState *dev) int resetprio; NVICState *s = NVIC(dev); + memset(s->vectors, 0, sizeof(s->vectors)); + memset(s->sec_vectors, 0, sizeof(s->sec_vectors)); + s->prigroup[M_REG_NS] = 0; + s->prigroup[M_REG_S] = 0; + s->vectors[ARMV7M_EXCP_NMI].enabled = 1; /* MEM, BUS, and USAGE are enabled through * the System Handler Control register -- cgit v1.2.3 From 5b5223997c04b769bb362767cecb5f7ec382c5f0 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:47 +0100 Subject: target/arm: Don't switch to target stack early in v7M exception return MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently our M profile exception return code switches to the target stack pointer relatively early in the process, before it tries to pop the exception frame off the stack. This is awkward for v8M for two reasons: * in v8M the process vs main stack pointer is not selected purely by the value of CONTROL.SPSEL, so updating SPSEL and relying on that to switch to the right stack pointer won't work * the stack we should be reading the stack frame from and the stack we will eventually switch to might not be the same if the guest is doing strange things Change our exception return code to use a 'frame pointer' to read the exception frame rather than assuming that we can switch the live stack pointer this early. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-3-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 130 +++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 98 insertions(+), 32 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index 0b9c9fded6..7548d4c6ec 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6047,16 +6047,6 @@ static void v7m_push(CPUARMState *env, uint32_t val) stl_phys(cs->as, env->regs[13], val); } -static uint32_t v7m_pop(CPUARMState *env) -{ - CPUState *cs = CPU(arm_env_get_cpu(env)); - uint32_t val; - - val = ldl_phys(cs->as, env->regs[13]); - env->regs[13] += 4; - return val; -} - /* Return true if we're using the process stack pointer (not the MSP) */ static bool v7m_using_psp(CPUARMState *env) { @@ -6148,6 +6138,43 @@ void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest) env->regs[15] = dest & ~1; } +static uint32_t *get_v7m_sp_ptr(CPUARMState *env, bool secure, bool threadmode, + bool spsel) +{ + /* Return a pointer to the location where we currently store the + * stack pointer for the requested security state and thread mode. + * This pointer will become invalid if the CPU state is updated + * such that the stack pointers are switched around (eg changing + * the SPSEL control bit). + * Compare the v8M ARM ARM pseudocode LookUpSP_with_security_mode(). + * Unlike that pseudocode, we require the caller to pass us in the + * SPSEL control bit value; this is because we also use this + * function in handling of pushing of the callee-saves registers + * part of the v8M stack frame (pseudocode PushCalleeStack()), + * and in the tailchain codepath the SPSEL bit comes from the exception + * return magic LR value from the previous exception. The pseudocode + * opencodes the stack-selection in PushCalleeStack(), but we prefer + * to make this utility function generic enough to do the job. + */ + bool want_psp = threadmode && spsel; + + if (secure == env->v7m.secure) { + /* Currently switch_v7m_sp switches SP as it updates SPSEL, + * so the SP we want is always in regs[13]. + * When we decouple SPSEL from the actually selected SP + * we need to check want_psp against v7m_using_psp() + * to see whether we need regs[13] or v7m.other_sp. + */ + return &env->regs[13]; + } else { + if (want_psp) { + return &env->v7m.other_ss_psp; + } else { + return &env->v7m.other_ss_msp; + } + } +} + static uint32_t arm_v7m_load_vector(ARMCPU *cpu) { CPUState *cs = CPU(cpu); @@ -6219,6 +6246,7 @@ static void v7m_push_stack(ARMCPU *cpu) static void do_v7m_exception_exit(ARMCPU *cpu) { CPUARMState *env = &cpu->env; + CPUState *cs = CPU(cpu); uint32_t excret; uint32_t xpsr; bool ufault = false; @@ -6226,6 +6254,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) bool return_to_handler = false; bool rettobase = false; bool exc_secure = false; + bool return_to_secure; /* We can only get here from an EXCP_EXCEPTION_EXIT, and * gen_bx_excret() enforces the architectural rule @@ -6293,6 +6322,9 @@ static void do_v7m_exception_exit(ARMCPU *cpu) g_assert_not_reached(); } + return_to_secure = arm_feature(env, ARM_FEATURE_M_SECURITY) && + (excret & R_V7M_EXCRET_S_MASK); + switch (excret & 0xf) { case 1: /* Return to Handler */ return_to_handler = true; @@ -6322,32 +6354,66 @@ static void do_v7m_exception_exit(ARMCPU *cpu) return; } - /* Switch to the target stack. */ + /* Set CONTROL.SPSEL from excret.SPSEL. For QEMU this currently + * causes us to switch the active SP, but we will change this + * later to not do that so we can support v8M. + */ switch_v7m_sp(env, return_to_sp_process); - /* Pop registers. */ - env->regs[0] = v7m_pop(env); - env->regs[1] = v7m_pop(env); - env->regs[2] = v7m_pop(env); - env->regs[3] = v7m_pop(env); - env->regs[12] = v7m_pop(env); - env->regs[14] = v7m_pop(env); - env->regs[15] = v7m_pop(env); - if (env->regs[15] & 1) { - qemu_log_mask(LOG_GUEST_ERROR, - "M profile return from interrupt with misaligned " - "PC is UNPREDICTABLE\n"); - /* Actual hardware seems to ignore the lsbit, and there are several - * RTOSes out there which incorrectly assume the r15 in the stack - * frame should be a Thumb-style "lsbit indicates ARM/Thumb" value. + + { + /* The stack pointer we should be reading the exception frame from + * depends on bits in the magic exception return type value (and + * for v8M isn't necessarily the stack pointer we will eventually + * end up resuming execution with). Get a pointer to the location + * in the CPU state struct where the SP we need is currently being + * stored; we will use and modify it in place. + * We use this limited C variable scope so we don't accidentally + * use 'frame_sp_p' after we do something that makes it invalid. + */ + uint32_t *frame_sp_p = get_v7m_sp_ptr(env, + return_to_secure, + !return_to_handler, + return_to_sp_process); + uint32_t frameptr = *frame_sp_p; + + /* Pop registers. TODO: make these accesses use the correct + * attributes and address space (S/NS, priv/unpriv) and handle + * memory transaction failures. */ - env->regs[15] &= ~1U; + env->regs[0] = ldl_phys(cs->as, frameptr); + env->regs[1] = ldl_phys(cs->as, frameptr + 0x4); + env->regs[2] = ldl_phys(cs->as, frameptr + 0x8); + env->regs[3] = ldl_phys(cs->as, frameptr + 0xc); + env->regs[12] = ldl_phys(cs->as, frameptr + 0x10); + env->regs[14] = ldl_phys(cs->as, frameptr + 0x14); + env->regs[15] = ldl_phys(cs->as, frameptr + 0x18); + if (env->regs[15] & 1) { + qemu_log_mask(LOG_GUEST_ERROR, + "M profile return from interrupt with misaligned " + "PC is UNPREDICTABLE\n"); + /* Actual hardware seems to ignore the lsbit, and there are several + * RTOSes out there which incorrectly assume the r15 in the stack + * frame should be a Thumb-style "lsbit indicates ARM/Thumb" value. + */ + env->regs[15] &= ~1U; + } + xpsr = ldl_phys(cs->as, frameptr + 0x1c); + + /* Commit to consuming the stack frame */ + frameptr += 0x20; + /* Undo stack alignment (the SPREALIGN bit indicates that the original + * pre-exception SP was not 8-aligned and we added a padding word to + * align it, so we undo this by ORing in the bit that increases it + * from the current 8-aligned value to the 8-unaligned value. (Adding 4 + * would work too but a logical OR is how the pseudocode specifies it.) + */ + if (xpsr & XPSR_SPREALIGN) { + frameptr |= 4; + } + *frame_sp_p = frameptr; } - xpsr = v7m_pop(env); + /* This xpsr_write() will invalidate frame_sp_p as it may switch stack */ xpsr_write(env, xpsr, ~XPSR_SPREALIGN); - /* Undo stack alignment. */ - if (xpsr & XPSR_SPREALIGN) { - env->regs[13] |= 4; - } /* The restored xPSR exception field will be zero if we're * resuming in Thread mode. If that doesn't match what the -- cgit v1.2.3 From de2db7ec894f11931932ca78cd14a8d2b1389d5b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:47 +0100 Subject: target/arm: Prepare for CONTROL.SPSEL being nonzero in Handler mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In the v7M architecture, there is an invariant that if the CPU is in Handler mode then the CONTROL.SPSEL bit cannot be nonzero. This in turn means that the current stack pointer is always indicated by CONTROL.SPSEL, even though Handler mode always uses the Main stack pointer. In v8M, this invariant is removed, and CONTROL.SPSEL may now be nonzero in Handler mode (though Handler mode still always uses the Main stack pointer). In preparation for this change, change how we handle this bit: rename switch_v7m_sp() to the now more accurate write_v7m_control_spsel(), and make it check both the handler mode state and the SPSEL bit. Note that this implicitly changes the point at which we switch active SP on exception exit from before we pop the exception frame to after it. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-4-git-send-email-peter.maydell@linaro.org --- hw/intc/armv7m_nvic.c | 2 +- target/arm/cpu.h | 8 ++++++- target/arm/helper.c | 65 ++++++++++++++++++++++++++++++++++----------------- 3 files changed, 51 insertions(+), 24 deletions(-) diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index bc7b66d9cc..a1041c205e 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -616,7 +616,7 @@ bool armv7m_nvic_acknowledge_irq(void *opaque) vec->active = 1; vec->pending = 0; - env->v7m.exception = s->vectpending; + write_v7m_exception(env, s->vectpending); nvic_irq_update(s); diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 8afceca873..ad6eff498b 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -991,6 +991,11 @@ void pmccntr_sync(CPUARMState *env); #define PSTATE_MODE_EL1t 4 #define PSTATE_MODE_EL0t 0 +/* Write a new value to v7m.exception, thus transitioning into or out + * of Handler mode; this may result in a change of active stack pointer. + */ +void write_v7m_exception(CPUARMState *env, uint32_t new_exc); + /* Map EL and handler into a PSTATE_MODE. */ static inline unsigned int aarch64_pstate_mode(unsigned int el, bool handler) { @@ -1071,7 +1076,8 @@ static inline void xpsr_write(CPUARMState *env, uint32_t val, uint32_t mask) env->condexec_bits |= (val >> 8) & 0xfc; } if (mask & XPSR_EXCP) { - env->v7m.exception = val & XPSR_EXCP; + /* Note that this only happens on exception exit */ + write_v7m_exception(env, val & XPSR_EXCP); } } diff --git a/target/arm/helper.c b/target/arm/helper.c index 7548d4c6ec..36173e21a7 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6059,21 +6059,44 @@ static bool v7m_using_psp(CPUARMState *env) env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK; } -/* Switch to V7M main or process stack pointer. */ -static void switch_v7m_sp(CPUARMState *env, bool new_spsel) +/* Write to v7M CONTROL.SPSEL bit. This may change the current + * stack pointer between Main and Process stack pointers. + */ +static void write_v7m_control_spsel(CPUARMState *env, bool new_spsel) { uint32_t tmp; - uint32_t old_control = env->v7m.control[env->v7m.secure]; - bool old_spsel = old_control & R_V7M_CONTROL_SPSEL_MASK; + bool new_is_psp, old_is_psp = v7m_using_psp(env); + + env->v7m.control[env->v7m.secure] = + deposit32(env->v7m.control[env->v7m.secure], + R_V7M_CONTROL_SPSEL_SHIFT, + R_V7M_CONTROL_SPSEL_LENGTH, new_spsel); + + new_is_psp = v7m_using_psp(env); - if (old_spsel != new_spsel) { + if (old_is_psp != new_is_psp) { tmp = env->v7m.other_sp; env->v7m.other_sp = env->regs[13]; env->regs[13] = tmp; + } +} + +void write_v7m_exception(CPUARMState *env, uint32_t new_exc) +{ + /* Write a new value to v7m.exception, thus transitioning into or out + * of Handler mode; this may result in a change of active stack pointer. + */ + bool new_is_psp, old_is_psp = v7m_using_psp(env); + uint32_t tmp; - env->v7m.control[env->v7m.secure] = deposit32(old_control, - R_V7M_CONTROL_SPSEL_SHIFT, - R_V7M_CONTROL_SPSEL_LENGTH, new_spsel); + env->v7m.exception = new_exc; + + new_is_psp = v7m_using_psp(env); + + if (old_is_psp != new_is_psp) { + tmp = env->v7m.other_sp; + env->v7m.other_sp = env->regs[13]; + env->regs[13] = tmp; } } @@ -6159,13 +6182,11 @@ static uint32_t *get_v7m_sp_ptr(CPUARMState *env, bool secure, bool threadmode, bool want_psp = threadmode && spsel; if (secure == env->v7m.secure) { - /* Currently switch_v7m_sp switches SP as it updates SPSEL, - * so the SP we want is always in regs[13]. - * When we decouple SPSEL from the actually selected SP - * we need to check want_psp against v7m_using_psp() - * to see whether we need regs[13] or v7m.other_sp. - */ - return &env->regs[13]; + if (want_psp == v7m_using_psp(env)) { + return &env->regs[13]; + } else { + return &env->v7m.other_sp; + } } else { if (want_psp) { return &env->v7m.other_ss_psp; @@ -6208,7 +6229,7 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr) uint32_t addr; armv7m_nvic_acknowledge_irq(env->nvic); - switch_v7m_sp(env, 0); + write_v7m_control_spsel(env, 0); arm_clear_exclusive(env); /* Clear IT bits */ env->condexec_bits = 0; @@ -6354,11 +6375,11 @@ static void do_v7m_exception_exit(ARMCPU *cpu) return; } - /* Set CONTROL.SPSEL from excret.SPSEL. For QEMU this currently - * causes us to switch the active SP, but we will change this - * later to not do that so we can support v8M. + /* Set CONTROL.SPSEL from excret.SPSEL. Since we're still in + * Handler mode (and will be until we write the new XPSR.Interrupt + * field) this does not switch around the current stack pointer. */ - switch_v7m_sp(env, return_to_sp_process); + write_v7m_control_spsel(env, return_to_sp_process); { /* The stack pointer we should be reading the exception frame from @@ -9173,11 +9194,11 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val) case 20: /* CONTROL */ /* Writing to the SPSEL bit only has an effect if we are in * thread mode; other bits can be updated by any privileged code. - * switch_v7m_sp() deals with updating the SPSEL bit in + * write_v7m_control_spsel() deals with updating the SPSEL bit in * env->v7m.control, so we only need update the others. */ if (!arm_v7m_is_handler_mode(env)) { - switch_v7m_sp(env, (val & R_V7M_CONTROL_SPSEL_MASK) != 0); + write_v7m_control_spsel(env, (val & R_V7M_CONTROL_SPSEL_MASK) != 0); } env->v7m.control[env->v7m.secure] &= ~R_V7M_CONTROL_NPRIV_MASK; env->v7m.control[env->v7m.secure] |= val & R_V7M_CONTROL_NPRIV_MASK; -- cgit v1.2.3 From 3919e60b6efd9a86a0e6ba637aa584222855ac3a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:47 +0100 Subject: target/arm: Restore security state on exception return Now that we can handle the CONTROL.SPSEL bit not necessarily being in sync with the current stack pointer, we can restore the correct security state on exception return. This happens before we start to read registers off the stack frame, but after we have taken possible usage faults for bad exception return magic values and updated CONTROL.SPSEL. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-5-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/target/arm/helper.c b/target/arm/helper.c index 36173e21a7..b82fc9f163 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6381,6 +6381,8 @@ static void do_v7m_exception_exit(ARMCPU *cpu) */ write_v7m_control_spsel(env, return_to_sp_process); + switch_v7m_security_state(env, return_to_secure); + { /* The stack pointer we should be reading the exception frame from * depends on bits in the magic exception return type value (and -- cgit v1.2.3 From 3f0cddeee1f266d43c956581f3050058360a810d Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Restore SPSEL to correct CONTROL register on exception return On exception return for v8M, the SPSEL bit in the EXC_RETURN magic value should be restored to the SPSEL bit in the CONTROL register banked specified by the EXC_RETURN.ES bit. Add write_v7m_control_spsel_for_secstate() which behaves like write_v7m_control_spsel() but allows the caller to specify which CONTROL bank to use, reimplement write_v7m_control_spsel() in terms of it, and use it in exception return. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-6-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 40 +++++++++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 13 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index b82fc9f163..1bab86cfd2 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6059,28 +6059,42 @@ static bool v7m_using_psp(CPUARMState *env) env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK; } -/* Write to v7M CONTROL.SPSEL bit. This may change the current - * stack pointer between Main and Process stack pointers. +/* Write to v7M CONTROL.SPSEL bit for the specified security bank. + * This may change the current stack pointer between Main and Process + * stack pointers if it is done for the CONTROL register for the current + * security state. */ -static void write_v7m_control_spsel(CPUARMState *env, bool new_spsel) +static void write_v7m_control_spsel_for_secstate(CPUARMState *env, + bool new_spsel, + bool secstate) { - uint32_t tmp; - bool new_is_psp, old_is_psp = v7m_using_psp(env); + bool old_is_psp = v7m_using_psp(env); - env->v7m.control[env->v7m.secure] = - deposit32(env->v7m.control[env->v7m.secure], + env->v7m.control[secstate] = + deposit32(env->v7m.control[secstate], R_V7M_CONTROL_SPSEL_SHIFT, R_V7M_CONTROL_SPSEL_LENGTH, new_spsel); - new_is_psp = v7m_using_psp(env); + if (secstate == env->v7m.secure) { + bool new_is_psp = v7m_using_psp(env); + uint32_t tmp; - if (old_is_psp != new_is_psp) { - tmp = env->v7m.other_sp; - env->v7m.other_sp = env->regs[13]; - env->regs[13] = tmp; + if (old_is_psp != new_is_psp) { + tmp = env->v7m.other_sp; + env->v7m.other_sp = env->regs[13]; + env->regs[13] = tmp; + } } } +/* Write to v7M CONTROL.SPSEL bit. This may change the current + * stack pointer between Main and Process stack pointers. + */ +static void write_v7m_control_spsel(CPUARMState *env, bool new_spsel) +{ + write_v7m_control_spsel_for_secstate(env, new_spsel, env->v7m.secure); +} + void write_v7m_exception(CPUARMState *env, uint32_t new_exc) { /* Write a new value to v7m.exception, thus transitioning into or out @@ -6379,7 +6393,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) * Handler mode (and will be until we write the new XPSR.Interrupt * field) this does not switch around the current stack pointer. */ - write_v7m_control_spsel(env, return_to_sp_process); + write_v7m_control_spsel_for_secstate(env, return_to_sp_process, exc_secure); switch_v7m_security_state(env, return_to_secure); -- cgit v1.2.3 From 224e0c300a0098fb577a03bd29d774d0769f632a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Check for xPSR mismatch usage faults earlier for v8M ARM v8M specifies that the INVPC usage fault for mismatched xPSR exception field and handler mode bit should be checked before updating the PSR and SP, so that the fault is taken with the existing stack frame rather than by pushing a new one. Perform this check in the right place for v8M. Since v7M specifies in its pseudocode that this usage fault check should happen later, we have to retain the original code for that check rather than being able to merge the two. (The distinction is architecturally visible but only in very obscure corner cases like attempting an invalid exception return with an exception frame in read only memory.) Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-7-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index 1bab86cfd2..bee0f5ddb6 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6436,6 +6436,29 @@ static void do_v7m_exception_exit(ARMCPU *cpu) } xpsr = ldl_phys(cs->as, frameptr + 0x1c); + if (arm_feature(env, ARM_FEATURE_V8)) { + /* For v8M we have to check whether the xPSR exception field + * matches the EXCRET value for return to handler/thread + * before we commit to changing the SP and xPSR. + */ + bool will_be_handler = (xpsr & XPSR_EXCP) != 0; + if (return_to_handler != will_be_handler) { + /* Take an INVPC UsageFault on the current stack. + * By this point we will have switched to the security state + * for the background state, so this UsageFault will target + * that state. + */ + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, + env->v7m.secure); + env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; + v7m_exception_taken(cpu, excret); + qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing " + "stackframe: failed exception return integrity " + "check\n"); + return; + } + } + /* Commit to consuming the stack frame */ frameptr += 0x20; /* Undo stack alignment (the SPREALIGN bit indicates that the original @@ -6455,12 +6478,13 @@ static void do_v7m_exception_exit(ARMCPU *cpu) /* The restored xPSR exception field will be zero if we're * resuming in Thread mode. If that doesn't match what the * exception return excret specified then this is a UsageFault. + * v7M requires we make this check here; v8M did it earlier. */ if (return_to_handler != arm_v7m_is_handler_mode(env)) { - /* Take an INVPC UsageFault by pushing the stack again. - * TODO: the v8M version of this code should target the - * background state for this exception. + /* Take an INVPC UsageFault by pushing the stack again; + * we know we're v7M so this is never a Secure UsageFault. */ + assert(!arm_feature(env, ARM_FEATURE_V8)); armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, false); env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; v7m_push_stack(cpu); -- cgit v1.2.3 From cb484f9a6e790205e69d9a444c3e353a3a1cfd84 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Warn about restoring to unaligned stack MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Attempting to do an exception return with an exception frame that is not 8-aligned is UNPREDICTABLE in v8M; warn about this. (It is not UNPREDICTABLE in v7M, and our implementation can handle the merely-4-aligned case fine, so we don't need to do anything except warn.) Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-8-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/target/arm/helper.c b/target/arm/helper.c index bee0f5ddb6..bb57be73bf 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6413,6 +6413,13 @@ static void do_v7m_exception_exit(ARMCPU *cpu) return_to_sp_process); uint32_t frameptr = *frame_sp_p; + if (!QEMU_IS_ALIGNED(frameptr, 8) && + arm_feature(env, ARM_FEATURE_V8)) { + qemu_log_mask(LOG_GUEST_ERROR, + "M profile exception return with non-8-aligned SP " + "for destination state is UNPREDICTABLE\n"); + } + /* Pop registers. TODO: make these accesses use the correct * attributes and address space (S/NS, priv/unpriv) and handle * memory transaction failures. -- cgit v1.2.3 From 4e4259d3c574a8e89c3af27bcb84bc19a442efb1 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Don't warn about exception return with PC low bit set for v8M MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In the v8M architecture, return from an exception to a PC which has bit 0 set is not UNPREDICTABLE; it is defined that bit 0 is discarded [R_HRJH]. Restrict our complaint about this to v7M. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-9-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index bb57be73bf..c7cf24ccb9 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6431,16 +6431,24 @@ static void do_v7m_exception_exit(ARMCPU *cpu) env->regs[12] = ldl_phys(cs->as, frameptr + 0x10); env->regs[14] = ldl_phys(cs->as, frameptr + 0x14); env->regs[15] = ldl_phys(cs->as, frameptr + 0x18); + + /* Returning from an exception with a PC with bit 0 set is defined + * behaviour on v8M (bit 0 is ignored), but for v7M it was specified + * to be UNPREDICTABLE. In practice actual v7M hardware seems to ignore + * the lsbit, and there are several RTOSes out there which incorrectly + * assume the r15 in the stack frame should be a Thumb-style "lsbit + * indicates ARM/Thumb" value, so ignore the bit on v7M as well, but + * complain about the badly behaved guest. + */ if (env->regs[15] & 1) { - qemu_log_mask(LOG_GUEST_ERROR, - "M profile return from interrupt with misaligned " - "PC is UNPREDICTABLE\n"); - /* Actual hardware seems to ignore the lsbit, and there are several - * RTOSes out there which incorrectly assume the r15 in the stack - * frame should be a Thumb-style "lsbit indicates ARM/Thumb" value. - */ env->regs[15] &= ~1U; + if (!arm_feature(env, ARM_FEATURE_V8)) { + qemu_log_mask(LOG_GUEST_ERROR, + "M profile return from interrupt with misaligned " + "PC is UNPREDICTABLE on v7M\n"); + } } + xpsr = ldl_phys(cs->as, frameptr + 0x1c); if (arm_feature(env, ARM_FEATURE_V8)) { -- cgit v1.2.3 From bed079da04dd9e0e249b9bc22bca8dce58b67f40 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Add new-in-v8M SFSR and SFAR Add the new M profile Secure Fault Status Register and Secure Fault Address Register. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-10-git-send-email-peter.maydell@linaro.org --- hw/intc/armv7m_nvic.c | 34 ++++++++++++++++++++++++++++++++++ target/arm/cpu.h | 12 ++++++++++++ target/arm/machine.c | 2 ++ 3 files changed, 48 insertions(+) diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index a1041c205e..deea6379c2 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -1017,6 +1017,22 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset, MemTxAttrs attrs) goto bad_offset; } return cpu->env.pmsav8.mair1[attrs.secure]; + case 0xde4: /* SFSR */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return 0; + } + return cpu->env.v7m.sfsr; + case 0xde8: /* SFAR */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return 0; + } + return cpu->env.v7m.sfar; default: bad_offset: qemu_log_mask(LOG_GUEST_ERROR, "NVIC: Bad read offset 0x%x\n", offset); @@ -1368,6 +1384,24 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value, * only affect cacheability, and we don't implement caching. */ break; + case 0xde4: /* SFSR */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return; + } + cpu->env.v7m.sfsr &= ~value; /* W1C */ + break; + case 0xde8: /* SFAR */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return; + } + cpu->env.v7m.sfsr = value; + break; case 0xf00: /* Software Triggered Interrupt Register */ { int excnum = (value & 0x1ff) + NVIC_FIRST_IRQ; diff --git a/target/arm/cpu.h b/target/arm/cpu.h index ad6eff498b..9e3a16dad5 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -443,8 +443,10 @@ typedef struct CPUARMState { uint32_t cfsr[M_REG_NUM_BANKS]; /* Configurable Fault Status */ uint32_t hfsr; /* HardFault Status */ uint32_t dfsr; /* Debug Fault Status Register */ + uint32_t sfsr; /* Secure Fault Status Register */ uint32_t mmfar[M_REG_NUM_BANKS]; /* MemManage Fault Address */ uint32_t bfar; /* BusFault Address */ + uint32_t sfar; /* Secure Fault Address Register */ unsigned mpu_ctrl[M_REG_NUM_BANKS]; /* MPU_CTRL */ int exception; uint32_t primask[M_REG_NUM_BANKS]; @@ -1260,6 +1262,16 @@ FIELD(V7M_DFSR, DWTTRAP, 2, 1) FIELD(V7M_DFSR, VCATCH, 3, 1) FIELD(V7M_DFSR, EXTERNAL, 4, 1) +/* V7M SFSR bits */ +FIELD(V7M_SFSR, INVEP, 0, 1) +FIELD(V7M_SFSR, INVIS, 1, 1) +FIELD(V7M_SFSR, INVER, 2, 1) +FIELD(V7M_SFSR, AUVIOL, 3, 1) +FIELD(V7M_SFSR, INVTRAN, 4, 1) +FIELD(V7M_SFSR, LSPERR, 5, 1) +FIELD(V7M_SFSR, SFARVALID, 6, 1) +FIELD(V7M_SFSR, LSERR, 7, 1) + /* v7M MPU_CTRL bits */ FIELD(V7M_MPU_CTRL, ENABLE, 0, 1) FIELD(V7M_MPU_CTRL, HFNMIENA, 1, 1) diff --git a/target/arm/machine.c b/target/arm/machine.c index 29df7ac87d..a0d7ed8dc6 100644 --- a/target/arm/machine.c +++ b/target/arm/machine.c @@ -276,6 +276,8 @@ static const VMStateDescription vmstate_m_security = { VMSTATE_UINT32(env.v7m.ccr[M_REG_S], ARMCPU), VMSTATE_UINT32(env.v7m.mmfar[M_REG_S], ARMCPU), VMSTATE_UINT32(env.v7m.cfsr[M_REG_S], ARMCPU), + VMSTATE_UINT32(env.v7m.sfsr, ARMCPU), + VMSTATE_UINT32(env.v7m.sfar, ARMCPU), VMSTATE_END_OF_LIST() } }; -- cgit v1.2.3 From bfb2eb52788b9605ef2fc9bc72683d4299117fde Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Update excret sanity checks for v8M In v8M, more bits are defined in the exception-return magic values; update the code that checks these so we accept the v8M values when the CPU permits them. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-11-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 73 ++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 58 insertions(+), 15 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index c7cf24ccb9..4aa32d0a0e 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6285,8 +6285,9 @@ static void do_v7m_exception_exit(ARMCPU *cpu) uint32_t excret; uint32_t xpsr; bool ufault = false; - bool return_to_sp_process = false; - bool return_to_handler = false; + bool sfault = false; + bool return_to_sp_process; + bool return_to_handler; bool rettobase = false; bool exc_secure = false; bool return_to_secure; @@ -6320,6 +6321,19 @@ static void do_v7m_exception_exit(ARMCPU *cpu) excret); } + if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { + /* EXC_RETURN.ES validation check (R_SMFL). We must do this before + * we pick which FAULTMASK to clear. + */ + if (!env->v7m.secure && + ((excret & R_V7M_EXCRET_ES_MASK) || + !(excret & R_V7M_EXCRET_DCRS_MASK))) { + sfault = 1; + /* For all other purposes, treat ES as 0 (R_HXSR) */ + excret &= ~R_V7M_EXCRET_ES_MASK; + } + } + if (env->v7m.exception != ARMV7M_EXCP_NMI) { /* Auto-clear FAULTMASK on return from other than NMI. * If the security extension is implemented then this only @@ -6357,24 +6371,53 @@ static void do_v7m_exception_exit(ARMCPU *cpu) g_assert_not_reached(); } + return_to_handler = !(excret & R_V7M_EXCRET_MODE_MASK); + return_to_sp_process = excret & R_V7M_EXCRET_SPSEL_MASK; return_to_secure = arm_feature(env, ARM_FEATURE_M_SECURITY) && (excret & R_V7M_EXCRET_S_MASK); - switch (excret & 0xf) { - case 1: /* Return to Handler */ - return_to_handler = true; - break; - case 13: /* Return to Thread using Process stack */ - return_to_sp_process = true; - /* fall through */ - case 9: /* Return to Thread using Main stack */ - if (!rettobase && - !(env->v7m.ccr[env->v7m.secure] & R_V7M_CCR_NONBASETHRDENA_MASK)) { + if (arm_feature(env, ARM_FEATURE_V8)) { + if (!arm_feature(env, ARM_FEATURE_M_SECURITY)) { + /* UNPREDICTABLE if S == 1 or DCRS == 0 or ES == 1 (R_XLCP); + * we choose to take the UsageFault. + */ + if ((excret & R_V7M_EXCRET_S_MASK) || + (excret & R_V7M_EXCRET_ES_MASK) || + !(excret & R_V7M_EXCRET_DCRS_MASK)) { + ufault = true; + } + } + if (excret & R_V7M_EXCRET_RES0_MASK) { ufault = true; } - break; - default: - ufault = true; + } else { + /* For v7M we only recognize certain combinations of the low bits */ + switch (excret & 0xf) { + case 1: /* Return to Handler */ + break; + case 13: /* Return to Thread using Process stack */ + case 9: /* Return to Thread using Main stack */ + /* We only need to check NONBASETHRDENA for v7M, because in + * v8M this bit does not exist (it is RES1). + */ + if (!rettobase && + !(env->v7m.ccr[env->v7m.secure] & + R_V7M_CCR_NONBASETHRDENA_MASK)) { + ufault = true; + } + break; + default: + ufault = true; + } + } + + if (sfault) { + env->v7m.sfsr |= R_V7M_SFSR_INVER_MASK; + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + v7m_exception_taken(cpu, excret); + qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " + "stackframe: failed EXC_RETURN.ES validity check\n"); + return; } if (ufault) { -- cgit v1.2.3 From 907bedb3f3ce134c149599bd9cb61856d811b8ca Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Add support for restoring v8M additional state context For v8M, exceptions from Secure to Non-Secure state will save callee-saved registers to the exception frame as well as the caller-saved registers. Add support for unstacking these registers in exception exit when necessary. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-12-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/target/arm/helper.c b/target/arm/helper.c index 4aa32d0a0e..f93a2143da 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6463,6 +6463,36 @@ static void do_v7m_exception_exit(ARMCPU *cpu) "for destination state is UNPREDICTABLE\n"); } + /* Do we need to pop callee-saved registers? */ + if (return_to_secure && + ((excret & R_V7M_EXCRET_ES_MASK) == 0 || + (excret & R_V7M_EXCRET_DCRS_MASK) == 0)) { + uint32_t expected_sig = 0xfefa125b; + uint32_t actual_sig = ldl_phys(cs->as, frameptr); + + if (expected_sig != actual_sig) { + /* Take a SecureFault on the current stack */ + env->v7m.sfsr |= R_V7M_SFSR_INVIS_MASK; + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + v7m_exception_taken(cpu, excret); + qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " + "stackframe: failed exception return integrity " + "signature check\n"); + return; + } + + env->regs[4] = ldl_phys(cs->as, frameptr + 0x8); + env->regs[5] = ldl_phys(cs->as, frameptr + 0xc); + env->regs[6] = ldl_phys(cs->as, frameptr + 0x10); + env->regs[7] = ldl_phys(cs->as, frameptr + 0x14); + env->regs[8] = ldl_phys(cs->as, frameptr + 0x18); + env->regs[9] = ldl_phys(cs->as, frameptr + 0x1c); + env->regs[10] = ldl_phys(cs->as, frameptr + 0x20); + env->regs[11] = ldl_phys(cs->as, frameptr + 0x24); + + frameptr += 0x28; + } + /* Pop registers. TODO: make these accesses use the correct * attributes and address space (S/NS, priv/unpriv) and handle * memory transaction failures. -- cgit v1.2.3 From d3392718e1fcf0859fb7c0774a8e946bacb8419c Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:49 +0100 Subject: target/arm: Add v8M support to exception entry code Add support for v8M and in particular the security extension to the exception entry code. This requires changes to: * calculation of the exception-return magic LR value * push the callee-saves registers in certain cases * clear registers when taking non-secure exceptions to avoid leaking information from the interrupted secure code * switch to the correct security state on entry * use the vector table for the security state we're targeting Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-13-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 165 +++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 145 insertions(+), 20 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index f93a2143da..707dbb7444 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6210,12 +6210,12 @@ static uint32_t *get_v7m_sp_ptr(CPUARMState *env, bool secure, bool threadmode, } } -static uint32_t arm_v7m_load_vector(ARMCPU *cpu) +static uint32_t arm_v7m_load_vector(ARMCPU *cpu, bool targets_secure) { CPUState *cs = CPU(cpu); CPUARMState *env = &cpu->env; MemTxResult result; - hwaddr vec = env->v7m.vecbase[env->v7m.secure] + env->v7m.exception * 4; + hwaddr vec = env->v7m.vecbase[targets_secure] + env->v7m.exception * 4; uint32_t addr; addr = address_space_ldl(cs->as, vec, @@ -6227,13 +6227,48 @@ static uint32_t arm_v7m_load_vector(ARMCPU *cpu) * Since we don't model Lockup, we just report this guest error * via cpu_abort(). */ - cpu_abort(cs, "Failed to read from exception vector table " - "entry %08x\n", (unsigned)vec); + cpu_abort(cs, "Failed to read from %s exception vector table " + "entry %08x\n", targets_secure ? "secure" : "nonsecure", + (unsigned)vec); } return addr; } -static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr) +static void v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain) +{ + /* For v8M, push the callee-saves register part of the stack frame. + * Compare the v8M pseudocode PushCalleeStack(). + * In the tailchaining case this may not be the current stack. + */ + CPUARMState *env = &cpu->env; + CPUState *cs = CPU(cpu); + uint32_t *frame_sp_p; + uint32_t frameptr; + + if (dotailchain) { + frame_sp_p = get_v7m_sp_ptr(env, true, + lr & R_V7M_EXCRET_MODE_MASK, + lr & R_V7M_EXCRET_SPSEL_MASK); + } else { + frame_sp_p = &env->regs[13]; + } + + frameptr = *frame_sp_p - 0x28; + + stl_phys(cs->as, frameptr, 0xfefa125b); + stl_phys(cs->as, frameptr + 0x8, env->regs[4]); + stl_phys(cs->as, frameptr + 0xc, env->regs[5]); + stl_phys(cs->as, frameptr + 0x10, env->regs[6]); + stl_phys(cs->as, frameptr + 0x14, env->regs[7]); + stl_phys(cs->as, frameptr + 0x18, env->regs[8]); + stl_phys(cs->as, frameptr + 0x1c, env->regs[9]); + stl_phys(cs->as, frameptr + 0x20, env->regs[10]); + stl_phys(cs->as, frameptr + 0x24, env->regs[11]); + + *frame_sp_p = frameptr; +} + +static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain) { /* Do the "take the exception" parts of exception entry, * but not the pushing of state to the stack. This is @@ -6241,14 +6276,84 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr) */ CPUARMState *env = &cpu->env; uint32_t addr; + bool targets_secure; + + targets_secure = armv7m_nvic_acknowledge_irq(env->nvic); - armv7m_nvic_acknowledge_irq(env->nvic); + if (arm_feature(env, ARM_FEATURE_V8)) { + if (arm_feature(env, ARM_FEATURE_M_SECURITY) && + (lr & R_V7M_EXCRET_S_MASK)) { + /* The background code (the owner of the registers in the + * exception frame) is Secure. This means it may either already + * have or now needs to push callee-saves registers. + */ + if (targets_secure) { + if (dotailchain && !(lr & R_V7M_EXCRET_ES_MASK)) { + /* We took an exception from Secure to NonSecure + * (which means the callee-saved registers got stacked) + * and are now tailchaining to a Secure exception. + * Clear DCRS so eventual return from this Secure + * exception unstacks the callee-saved registers. + */ + lr &= ~R_V7M_EXCRET_DCRS_MASK; + } + } else { + /* We're going to a non-secure exception; push the + * callee-saves registers to the stack now, if they're + * not already saved. + */ + if (lr & R_V7M_EXCRET_DCRS_MASK && + !(dotailchain && (lr & R_V7M_EXCRET_ES_MASK))) { + v7m_push_callee_stack(cpu, lr, dotailchain); + } + lr |= R_V7M_EXCRET_DCRS_MASK; + } + } + + lr &= ~R_V7M_EXCRET_ES_MASK; + if (targets_secure || !arm_feature(env, ARM_FEATURE_M_SECURITY)) { + lr |= R_V7M_EXCRET_ES_MASK; + } + lr &= ~R_V7M_EXCRET_SPSEL_MASK; + if (env->v7m.control[targets_secure] & R_V7M_CONTROL_SPSEL_MASK) { + lr |= R_V7M_EXCRET_SPSEL_MASK; + } + + /* Clear registers if necessary to prevent non-secure exception + * code being able to see register values from secure code. + * Where register values become architecturally UNKNOWN we leave + * them with their previous values. + */ + if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { + if (!targets_secure) { + /* Always clear the caller-saved registers (they have been + * pushed to the stack earlier in v7m_push_stack()). + * Clear callee-saved registers if the background code is + * Secure (in which case these regs were saved in + * v7m_push_callee_stack()). + */ + int i; + + for (i = 0; i < 13; i++) { + /* r4..r11 are callee-saves, zero only if EXCRET.S == 1 */ + if (i < 4 || i > 11 || (lr & R_V7M_EXCRET_S_MASK)) { + env->regs[i] = 0; + } + } + /* Clear EAPSR */ + xpsr_write(env, 0, XPSR_NZCV | XPSR_Q | XPSR_GE | XPSR_IT); + } + } + } + + /* Switch to target security state -- must do this before writing SPSEL */ + switch_v7m_security_state(env, targets_secure); write_v7m_control_spsel(env, 0); arm_clear_exclusive(env); /* Clear IT bits */ env->condexec_bits = 0; env->regs[14] = lr; - addr = arm_v7m_load_vector(cpu); + addr = arm_v7m_load_vector(cpu, targets_secure); env->regs[15] = addr & 0xfffffffe; env->thumb = addr & 1; } @@ -6414,7 +6519,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) if (sfault) { env->v7m.sfsr |= R_V7M_SFSR_INVER_MASK; armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); - v7m_exception_taken(cpu, excret); + v7m_exception_taken(cpu, excret, true); qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " "stackframe: failed EXC_RETURN.ES validity check\n"); return; @@ -6426,7 +6531,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) */ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); - v7m_exception_taken(cpu, excret); + v7m_exception_taken(cpu, excret, true); qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing " "stackframe: failed exception return integrity check\n"); return; @@ -6474,7 +6579,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) /* Take a SecureFault on the current stack */ env->v7m.sfsr |= R_V7M_SFSR_INVIS_MASK; armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); - v7m_exception_taken(cpu, excret); + v7m_exception_taken(cpu, excret, true); qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " "stackframe: failed exception return integrity " "signature check\n"); @@ -6539,7 +6644,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; - v7m_exception_taken(cpu, excret); + v7m_exception_taken(cpu, excret, true); qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing " "stackframe: failed exception return integrity " "check\n"); @@ -6576,7 +6681,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, false); env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; v7m_push_stack(cpu); - v7m_exception_taken(cpu, excret); + v7m_exception_taken(cpu, excret, false); qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on new stackframe: " "failed exception return integrity check\n"); return; @@ -6720,20 +6825,40 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) return; /* Never happens. Keep compiler happy. */ } - lr = R_V7M_EXCRET_RES1_MASK | - R_V7M_EXCRET_S_MASK | - R_V7M_EXCRET_DCRS_MASK | - R_V7M_EXCRET_FTYPE_MASK | - R_V7M_EXCRET_ES_MASK; - if (env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK) { - lr |= R_V7M_EXCRET_SPSEL_MASK; + if (arm_feature(env, ARM_FEATURE_V8)) { + lr = R_V7M_EXCRET_RES1_MASK | + R_V7M_EXCRET_DCRS_MASK | + R_V7M_EXCRET_FTYPE_MASK; + /* The S bit indicates whether we should return to Secure + * or NonSecure (ie our current state). + * The ES bit indicates whether we're taking this exception + * to Secure or NonSecure (ie our target state). We set it + * later, in v7m_exception_taken(). + * The SPSEL bit is also set in v7m_exception_taken() for v8M. + * This corresponds to the ARM ARM pseudocode for v8M setting + * some LR bits in PushStack() and some in ExceptionTaken(); + * the distinction matters for the tailchain cases where we + * can take an exception without pushing the stack. + */ + if (env->v7m.secure) { + lr |= R_V7M_EXCRET_S_MASK; + } + } else { + lr = R_V7M_EXCRET_RES1_MASK | + R_V7M_EXCRET_S_MASK | + R_V7M_EXCRET_DCRS_MASK | + R_V7M_EXCRET_FTYPE_MASK | + R_V7M_EXCRET_ES_MASK; + if (env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK) { + lr |= R_V7M_EXCRET_SPSEL_MASK; + } } if (!arm_v7m_is_handler_mode(env)) { lr |= R_V7M_EXCRET_MODE_MASK; } v7m_push_stack(cpu); - v7m_exception_taken(cpu, lr); + v7m_exception_taken(cpu, lr, false); qemu_log_mask(CPU_LOG_INT, "... as %d\n", env->v7m.exception); } -- cgit v1.2.3 From 9901c576f6c02d43206e5faaf6e362ab7ea83246 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:49 +0100 Subject: nvic: Implement Security Attribution Unit registers Implement the register interface for the SAU: SAU_CTRL, SAU_TYPE, SAU_RNR, SAU_RBAR and SAU_RLAR. None of the actual behaviour is implemented here; registers just read back as written. When the CPU definition for Cortex-M33 is eventually added, its initfn will set cpu->sau_sregion, in the same way that we currently set cpu->pmsav7_dregion for the M3 and M4. Number of SAU regions is typically a configurable CPU parameter, but this patch doesn't provide a QEMU CPU property for it. We can easily add one when we have a board that requires it. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-14-git-send-email-peter.maydell@linaro.org --- hw/intc/armv7m_nvic.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++ target/arm/cpu.c | 27 ++++++++++++ target/arm/cpu.h | 10 +++++ target/arm/machine.c | 14 ++++++ 4 files changed, 167 insertions(+) diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index deea6379c2..bd1d5d3a0e 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -1017,6 +1017,60 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset, MemTxAttrs attrs) goto bad_offset; } return cpu->env.pmsav8.mair1[attrs.secure]; + case 0xdd0: /* SAU_CTRL */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return 0; + } + return cpu->env.sau.ctrl; + case 0xdd4: /* SAU_TYPE */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return 0; + } + return cpu->sau_sregion; + case 0xdd8: /* SAU_RNR */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return 0; + } + return cpu->env.sau.rnr; + case 0xddc: /* SAU_RBAR */ + { + int region = cpu->env.sau.rnr; + + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return 0; + } + if (region >= cpu->sau_sregion) { + return 0; + } + return cpu->env.sau.rbar[region]; + } + case 0xde0: /* SAU_RLAR */ + { + int region = cpu->env.sau.rnr; + + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return 0; + } + if (region >= cpu->sau_sregion) { + return 0; + } + return cpu->env.sau.rlar[region]; + } case 0xde4: /* SFSR */ if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { goto bad_offset; @@ -1384,6 +1438,68 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value, * only affect cacheability, and we don't implement caching. */ break; + case 0xdd0: /* SAU_CTRL */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return; + } + cpu->env.sau.ctrl = value & 3; + case 0xdd4: /* SAU_TYPE */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + break; + case 0xdd8: /* SAU_RNR */ + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return; + } + if (value >= cpu->sau_sregion) { + qemu_log_mask(LOG_GUEST_ERROR, "SAU region out of range %" + PRIu32 "/%" PRIu32 "\n", + value, cpu->sau_sregion); + } else { + cpu->env.sau.rnr = value; + } + break; + case 0xddc: /* SAU_RBAR */ + { + int region = cpu->env.sau.rnr; + + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return; + } + if (region >= cpu->sau_sregion) { + return; + } + cpu->env.sau.rbar[region] = value & ~0x1f; + tlb_flush(CPU(cpu)); + break; + } + case 0xde0: /* SAU_RLAR */ + { + int region = cpu->env.sau.rnr; + + if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { + goto bad_offset; + } + if (!attrs.secure) { + return; + } + if (region >= cpu->sau_sregion) { + return; + } + cpu->env.sau.rlar[region] = value & ~0x1c; + tlb_flush(CPU(cpu)); + break; + } case 0xde4: /* SFSR */ if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) { goto bad_offset; diff --git a/target/arm/cpu.c b/target/arm/cpu.c index 4300de66e2..f4f601f079 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -285,6 +285,18 @@ static void arm_cpu_reset(CPUState *s) env->pmsav8.mair1[M_REG_S] = 0; } + if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { + if (cpu->sau_sregion > 0) { + memset(env->sau.rbar, 0, sizeof(*env->sau.rbar) * cpu->sau_sregion); + memset(env->sau.rlar, 0, sizeof(*env->sau.rlar) * cpu->sau_sregion); + } + env->sau.rnr = 0; + /* SAU_CTRL reset value is IMPDEF; we choose 0, which is what + * the Cortex-M33 does. + */ + env->sau.ctrl = 0; + } + set_flush_to_zero(1, &env->vfp.standard_fp_status); set_flush_inputs_to_zero(1, &env->vfp.standard_fp_status); set_default_nan_mode(1, &env->vfp.standard_fp_status); @@ -873,6 +885,20 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp) } } + if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { + uint32_t nr = cpu->sau_sregion; + + if (nr > 0xff) { + error_setg(errp, "v8M SAU #regions invalid %" PRIu32, nr); + return; + } + + if (nr) { + env->sau.rbar = g_new0(uint32_t, nr); + env->sau.rlar = g_new0(uint32_t, nr); + } + } + if (arm_feature(env, ARM_FEATURE_EL3)) { set_feature(env, ARM_FEATURE_VBAR); } @@ -1141,6 +1167,7 @@ static void cortex_m4_initfn(Object *obj) cpu->midr = 0x410fc240; /* r0p0 */ cpu->pmsav7_dregion = 8; } + static void arm_v7m_class_init(ObjectClass *oc, void *data) { CPUClass *cc = CPU_CLASS(oc); diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 9e3a16dad5..441e584f1b 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -568,6 +568,14 @@ typedef struct CPUARMState { uint32_t mair1[M_REG_NUM_BANKS]; } pmsav8; + /* v8M SAU */ + struct { + uint32_t *rbar; + uint32_t *rlar; + uint32_t rnr; + uint32_t ctrl; + } sau; + void *nvic; const struct arm_boot_info *boot_info; /* Store GICv3CPUState to access from this struct */ @@ -663,6 +671,8 @@ struct ARMCPU { bool has_mpu; /* PMSAv7 MPU number of supported regions */ uint32_t pmsav7_dregion; + /* v8M SAU number of supported regions */ + uint32_t sau_sregion; /* PSCI conduit used to invoke PSCI methods * 0 - disabled, 1 - smc, 2 - hvc diff --git a/target/arm/machine.c b/target/arm/machine.c index a0d7ed8dc6..176274629c 100644 --- a/target/arm/machine.c +++ b/target/arm/machine.c @@ -242,6 +242,13 @@ static bool s_rnr_vmstate_validate(void *opaque, int version_id) return cpu->env.pmsav7.rnr[M_REG_S] < cpu->pmsav7_dregion; } +static bool sau_rnr_vmstate_validate(void *opaque, int version_id) +{ + ARMCPU *cpu = opaque; + + return cpu->env.sau.rnr < cpu->sau_sregion; +} + static bool m_security_needed(void *opaque) { ARMCPU *cpu = opaque; @@ -278,6 +285,13 @@ static const VMStateDescription vmstate_m_security = { VMSTATE_UINT32(env.v7m.cfsr[M_REG_S], ARMCPU), VMSTATE_UINT32(env.v7m.sfsr, ARMCPU), VMSTATE_UINT32(env.v7m.sfar, ARMCPU), + VMSTATE_VARRAY_UINT32(env.sau.rbar, ARMCPU, sau_sregion, 0, + vmstate_info_uint32, uint32_t), + VMSTATE_VARRAY_UINT32(env.sau.rlar, ARMCPU, sau_sregion, 0, + vmstate_info_uint32, uint32_t), + VMSTATE_UINT32(env.sau.rnr, ARMCPU), + VMSTATE_VALIDATE("SAU_RNR is valid", sau_rnr_vmstate_validate), + VMSTATE_UINT32(env.sau.ctrl, ARMCPU), VMSTATE_END_OF_LIST() } }; -- cgit v1.2.3 From 35337cc391245f251bfb9134f181c33e6375d6c1 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:49 +0100 Subject: target/arm: Implement security attribute lookups for memory accesses Implement the security attribute lookups for memory accesses in the get_phys_addr() functions, causing these to generate various kinds of SecureFault for bad accesses. The major subtlety in this code relates to handling of the case when the security attributes the SAU assigns to the address don't match the current security state of the CPU. In the ARM ARM pseudocode for validating instruction accesses, the security attributes of the address determine whether the Secure or NonSecure MPU state is used. At face value, handling this would require us to encode the relevant bits of state into mmu_idx for both S and NS at once, which would result in our needing 16 mmu indexes. Fortunately we don't actually need to do this because a mismatch between address attributes and CPU state means either: * some kind of fault (usually a SecureFault, but in theory perhaps a UserFault for unaligned access to Device memory) * execution of the SG instruction in NS state from a Secure & NonSecure code region The purpose of SG is simply to flip the CPU into Secure state, so we can handle it by emulating execution of that instruction directly in arm_v7m_cpu_do_interrupt(), which means we can treat all the mismatch cases as "throw an exception" and we don't need to encode the state of the other MPU bank into our mmu_idx values. This commit doesn't include the actual emulation of SG; it also doesn't include implementation of the IDAU, which is a per-board way to specify hard-coded memory attributes for addresses, which override the CPU-internal SAU if they specify a more secure setting than the SAU is programmed to. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1506092407-26985-15-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 182 ++++++++++++++++++++++++++++++++++++++++++++++++- target/arm/internals.h | 15 ++++ 2 files changed, 195 insertions(+), 2 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index 707dbb7444..1d689f00b3 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -31,6 +31,16 @@ static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address, target_ulong *page_size_ptr, uint32_t *fsr, ARMMMUFaultInfo *fi); +/* Security attributes for an address, as returned by v8m_security_lookup. */ +typedef struct V8M_SAttributes { + bool ns; + bool nsc; + uint8_t sregion; + bool srvalid; + uint8_t iregion; + bool irvalid; +} V8M_SAttributes; + /* Definitions for the PMCCNTR and PMCR registers */ #define PMCRD 0x8 #define PMCRC 0x4 @@ -6760,6 +6770,46 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) * raises the fault, in the A profile short-descriptor format. */ switch (env->exception.fsr & 0xf) { + case M_FAKE_FSR_NSC_EXEC: + /* Exception generated when we try to execute code at an address + * which is marked as Secure & Non-Secure Callable and the CPU + * is in the Non-Secure state. The only instruction which can + * be executed like this is SG (and that only if both halves of + * the SG instruction have the same security attributes.) + * Everything else must generate an INVEP SecureFault, so we + * emulate the SG instruction here. + * TODO: actually emulate SG. + */ + env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK; + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + qemu_log_mask(CPU_LOG_INT, + "...really SecureFault with SFSR.INVEP\n"); + break; + case M_FAKE_FSR_SFAULT: + /* Various flavours of SecureFault for attempts to execute or + * access data in the wrong security state. + */ + switch (cs->exception_index) { + case EXCP_PREFETCH_ABORT: + if (env->v7m.secure) { + env->v7m.sfsr |= R_V7M_SFSR_INVTRAN_MASK; + qemu_log_mask(CPU_LOG_INT, + "...really SecureFault with SFSR.INVTRAN\n"); + } else { + env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK; + qemu_log_mask(CPU_LOG_INT, + "...really SecureFault with SFSR.INVEP\n"); + } + break; + case EXCP_DATA_ABORT: + /* This must be an NS access to S memory */ + env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK; + qemu_log_mask(CPU_LOG_INT, + "...really SecureFault with SFSR.AUVIOL\n"); + break; + } + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + break; case 0x8: /* External Abort */ switch (cs->exception_index) { case EXCP_PREFETCH_ABORT: @@ -8846,9 +8896,89 @@ static bool get_phys_addr_pmsav7(CPUARMState *env, uint32_t address, return !(*prot & (1 << access_type)); } +static bool v8m_is_sau_exempt(CPUARMState *env, + uint32_t address, MMUAccessType access_type) +{ + /* The architecture specifies that certain address ranges are + * exempt from v8M SAU/IDAU checks. + */ + return + (access_type == MMU_INST_FETCH && m_is_system_region(env, address)) || + (address >= 0xe0000000 && address <= 0xe0002fff) || + (address >= 0xe000e000 && address <= 0xe000efff) || + (address >= 0xe002e000 && address <= 0xe002efff) || + (address >= 0xe0040000 && address <= 0xe0041fff) || + (address >= 0xe00ff000 && address <= 0xe00fffff); +} + +static void v8m_security_lookup(CPUARMState *env, uint32_t address, + MMUAccessType access_type, ARMMMUIdx mmu_idx, + V8M_SAttributes *sattrs) +{ + /* Look up the security attributes for this address. Compare the + * pseudocode SecurityCheck() function. + * We assume the caller has zero-initialized *sattrs. + */ + ARMCPU *cpu = arm_env_get_cpu(env); + int r; + + /* TODO: implement IDAU */ + + if (access_type == MMU_INST_FETCH && extract32(address, 28, 4) == 0xf) { + /* 0xf0000000..0xffffffff is always S for insn fetches */ + return; + } + + if (v8m_is_sau_exempt(env, address, access_type)) { + sattrs->ns = !regime_is_secure(env, mmu_idx); + return; + } + + switch (env->sau.ctrl & 3) { + case 0: /* SAU.ENABLE == 0, SAU.ALLNS == 0 */ + break; + case 2: /* SAU.ENABLE == 0, SAU.ALLNS == 1 */ + sattrs->ns = true; + break; + default: /* SAU.ENABLE == 1 */ + for (r = 0; r < cpu->sau_sregion; r++) { + if (env->sau.rlar[r] & 1) { + uint32_t base = env->sau.rbar[r] & ~0x1f; + uint32_t limit = env->sau.rlar[r] | 0x1f; + + if (base <= address && limit >= address) { + if (sattrs->srvalid) { + /* If we hit in more than one region then we must report + * as Secure, not NS-Callable, with no valid region + * number info. + */ + sattrs->ns = false; + sattrs->nsc = false; + sattrs->sregion = 0; + sattrs->srvalid = false; + break; + } else { + if (env->sau.rlar[r] & 2) { + sattrs->nsc = true; + } else { + sattrs->ns = true; + } + sattrs->srvalid = true; + sattrs->sregion = r; + } + } + } + } + + /* TODO when we support the IDAU then it may override the result here */ + break; + } +} + static bool get_phys_addr_pmsav8(CPUARMState *env, uint32_t address, MMUAccessType access_type, ARMMMUIdx mmu_idx, - hwaddr *phys_ptr, int *prot, uint32_t *fsr) + hwaddr *phys_ptr, MemTxAttrs *txattrs, + int *prot, uint32_t *fsr) { ARMCPU *cpu = arm_env_get_cpu(env); bool is_user = regime_is_user(env, mmu_idx); @@ -8856,10 +8986,58 @@ static bool get_phys_addr_pmsav8(CPUARMState *env, uint32_t address, int n; int matchregion = -1; bool hit = false; + V8M_SAttributes sattrs = {}; *phys_ptr = address; *prot = 0; + if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { + v8m_security_lookup(env, address, access_type, mmu_idx, &sattrs); + if (access_type == MMU_INST_FETCH) { + /* Instruction fetches always use the MMU bank and the + * transaction attribute determined by the fetch address, + * regardless of CPU state. This is painful for QEMU + * to handle, because it would mean we need to encode + * into the mmu_idx not just the (user, negpri) information + * for the current security state but also that for the + * other security state, which would balloon the number + * of mmu_idx values needed alarmingly. + * Fortunately we can avoid this because it's not actually + * possible to arbitrarily execute code from memory with + * the wrong security attribute: it will always generate + * an exception of some kind or another, apart from the + * special case of an NS CPU executing an SG instruction + * in S&NSC memory. So we always just fail the translation + * here and sort things out in the exception handler + * (including possibly emulating an SG instruction). + */ + if (sattrs.ns != !secure) { + *fsr = sattrs.nsc ? M_FAKE_FSR_NSC_EXEC : M_FAKE_FSR_SFAULT; + return true; + } + } else { + /* For data accesses we always use the MMU bank indicated + * by the current CPU state, but the security attributes + * might downgrade a secure access to nonsecure. + */ + if (sattrs.ns) { + txattrs->secure = false; + } else if (!secure) { + /* NS access to S memory must fault. + * Architecturally we should first check whether the + * MPU information for this address indicates that we + * are doing an unaligned access to Device memory, which + * should generate a UsageFault instead. QEMU does not + * currently check for that kind of unaligned access though. + * If we added it we would need to do so as a special case + * for M_FAKE_FSR_SFAULT in arm_v7m_cpu_do_interrupt(). + */ + *fsr = M_FAKE_FSR_SFAULT; + return true; + } + } + } + /* Unlike the ARM ARM pseudocode, we don't need to check whether this * was an exception vector read from the vector table (which is always * done using the default system address map), because those accesses @@ -9124,7 +9302,7 @@ static bool get_phys_addr(CPUARMState *env, target_ulong address, if (arm_feature(env, ARM_FEATURE_V8)) { /* PMSAv8 */ ret = get_phys_addr_pmsav8(env, address, access_type, mmu_idx, - phys_ptr, prot, fsr); + phys_ptr, attrs, prot, fsr); } else if (arm_feature(env, ARM_FEATURE_V7)) { /* PMSAv7 */ ret = get_phys_addr_pmsav7(env, address, access_type, mmu_idx, diff --git a/target/arm/internals.h b/target/arm/internals.h index 18be3702f2..fd9a7e8181 100644 --- a/target/arm/internals.h +++ b/target/arm/internals.h @@ -71,6 +71,21 @@ FIELD(V7M_EXCRET, DCRS, 5, 1) FIELD(V7M_EXCRET, S, 6, 1) FIELD(V7M_EXCRET, RES1, 7, 25) /* including the must-be-1 prefix */ +/* We use a few fake FSR values for internal purposes in M profile. + * M profile cores don't have A/R format FSRs, but currently our + * get_phys_addr() code assumes A/R profile and reports failures via + * an A/R format FSR value. We then translate that into the proper + * M profile exception and FSR status bit in arm_v7m_cpu_do_interrupt(). + * Mostly the FSR values we use for this are those defined for v7PMSA, + * since we share some of that codepath. A few kinds of fault are + * only for M profile and have no A/R equivalent, though, so we have + * to pick a value from the reserved range (which we never otherwise + * generate) to use for these. + * These values will never be visible to the guest. + */ +#define M_FAKE_FSR_NSC_EXEC 0xf /* NS executing in S&NSC memory */ +#define M_FAKE_FSR_SFAULT 0xe /* SecureFault INVTRAN, INVEP or AUVIOL */ + /* * For AArch64, map a given EL to an index in the banked_spsr array. * Note that this mapping and the AArch32 mapping defined in bank_number() -- cgit v1.2.3 From fe768788d29597ee56fc11ba2279d502c2617457 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:49 +0100 Subject: target/arm: Fix calculation of secure mm_idx values MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In cpu_mmu_index() we try to do this: if (env->v7m.secure) { mmu_idx += ARMMMUIdx_MSUser; } but it will give the wrong answer, because ARMMMUIdx_MSUser includes the 0x40 ARM_MMU_IDX_M field, and so does the mmu_idx we're adding to, and we'll end up with 0x8n rather than 0x4n. This error is then nullified by the call to arm_to_core_mmu_idx() which masks out the high part, but we're about to factor out the code that calculates the ARMMMUIdx values so it can be used without passing it through arm_to_core_mmu_idx(), so fix this bug first. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-16-git-send-email-peter.maydell@linaro.org --- target/arm/cpu.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 441e584f1b..70c1f85121 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2335,14 +2335,16 @@ static inline int cpu_mmu_index(CPUARMState *env, bool ifetch) int el = arm_current_el(env); if (arm_feature(env, ARM_FEATURE_M)) { - ARMMMUIdx mmu_idx = el == 0 ? ARMMMUIdx_MUser : ARMMMUIdx_MPriv; + ARMMMUIdx mmu_idx; - if (armv7m_nvic_neg_prio_requested(env->nvic, env->v7m.secure)) { - mmu_idx = ARMMMUIdx_MNegPri; + if (el == 0) { + mmu_idx = env->v7m.secure ? ARMMMUIdx_MSUser : ARMMMUIdx_MUser; + } else { + mmu_idx = env->v7m.secure ? ARMMMUIdx_MSPriv : ARMMMUIdx_MPriv; } - if (env->v7m.secure) { - mmu_idx += ARMMMUIdx_MSUser; + if (armv7m_nvic_neg_prio_requested(env->nvic, env->v7m.secure)) { + mmu_idx = env->v7m.secure ? ARMMMUIdx_MSNegPri : ARMMMUIdx_MNegPri; } return arm_to_core_mmu_idx(mmu_idx); -- cgit v1.2.3 From b81ac0eb6315e602b18439961e0538538e4aed4f Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:49 +0100 Subject: target/arm: Factor out "get mmuidx for specified security state" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit For the SG instruction and secure function return we are going to want to do memory accesses using the MMU index of the CPU in secure state, even though the CPU is currently in non-secure state. Write arm_v7m_mmu_idx_for_secstate() to do this job, and use it in cpu_mmu_index(). Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-17-git-send-email-peter.maydell@linaro.org --- target/arm/cpu.h | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 70c1f85121..89d49cdcb2 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2329,23 +2329,33 @@ static inline int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx) } } +/* Return the MMU index for a v7M CPU in the specified security state */ +static inline ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, + bool secstate) +{ + int el = arm_current_el(env); + ARMMMUIdx mmu_idx; + + if (el == 0) { + mmu_idx = secstate ? ARMMMUIdx_MSUser : ARMMMUIdx_MUser; + } else { + mmu_idx = secstate ? ARMMMUIdx_MSPriv : ARMMMUIdx_MPriv; + } + + if (armv7m_nvic_neg_prio_requested(env->nvic, secstate)) { + mmu_idx = secstate ? ARMMMUIdx_MSNegPri : ARMMMUIdx_MNegPri; + } + + return mmu_idx; +} + /* Determine the current mmu_idx to use for normal loads/stores */ static inline int cpu_mmu_index(CPUARMState *env, bool ifetch) { int el = arm_current_el(env); if (arm_feature(env, ARM_FEATURE_M)) { - ARMMMUIdx mmu_idx; - - if (el == 0) { - mmu_idx = env->v7m.secure ? ARMMMUIdx_MSUser : ARMMMUIdx_MUser; - } else { - mmu_idx = env->v7m.secure ? ARMMMUIdx_MSPriv : ARMMMUIdx_MPriv; - } - - if (armv7m_nvic_neg_prio_requested(env->nvic, env->v7m.secure)) { - mmu_idx = env->v7m.secure ? ARMMMUIdx_MSNegPri : ARMMMUIdx_MNegPri; - } + ARMMMUIdx mmu_idx = arm_v7m_mmu_idx_for_secstate(env, env->v7m.secure); return arm_to_core_mmu_idx(mmu_idx); } -- cgit v1.2.3 From 04829ce334bece78d4fa1d0fdbc8bc27dae9b242 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:49 +0100 Subject: nvic: Add missing code for writing SHCSR.HARDFAULTPENDED bit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When we added support for the new SHCSR bits in v8M in commit 437d59c17e9 the code to support writing to the new HARDFAULTPENDED bit was accidentally only added for non-secure writes; the secure banked version of the bit should also be writable. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-21-git-send-email-peter.maydell@linaro.org --- hw/intc/armv7m_nvic.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index bd1d5d3a0e..22d5e6e6af 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -1230,6 +1230,7 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value, s->sec_vectors[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0; s->sec_vectors[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0; + s->sec_vectors[ARMV7M_EXCP_HARD].pending = (value & (1 << 21)) != 0; /* SecureFault not banked, but RAZ/WI to NS */ s->vectors[ARMV7M_EXCP_SECURE].active = (value & (1 << 4)) != 0; s->vectors[ARMV7M_EXCP_SECURE].enabled = (value & (1 << 19)) != 0; -- cgit v1.2.3