From 95f875654ae8b433b50a2bc7858e34af957cbaa4 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 15 Jun 2018 14:57:13 +0100 Subject: arm: Don't crash if user tries to use a Cortex-M CPU without an NVIC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Cortex-M CPU and its NVIC are two intimately intertwined parts of the same hardware; it is not possible to use one without the other. Unfortunately a lot of our board models don't do any sanity checking on the CPU type the user asks for, so a command line like qemu-system-arm -M versatilepb -cpu cortex-m3 will create an M3 without an NVIC, and coredump immediately. In the other direction, trying a non-M-profile CPU in an M-profile board won't blow up, but doesn't do anything useful either: qemu-system-arm -M lm3s6965evb -cpu arm926 Add some checking in the NVIC and CPU realize functions that the user isn't trying to use an NVIC without an M-profile CPU or an M-profile CPU without an NVIC, so we can produce a helpful error message rather than a core dump. Fixes: https://bugs.launchpad.net/qemu/+bug/1766896 Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Message-id: 20180601160355.15393-1-peter.maydell@linaro.org --- target/arm/cpu.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'target/arm/cpu.c') diff --git a/target/arm/cpu.c b/target/arm/cpu.c index ab047b9402..e1de45e904 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -767,6 +767,24 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp) return; } +#ifndef CONFIG_USER_ONLY + /* The NVIC and M-profile CPU are two halves of a single piece of + * hardware; trying to use one without the other is a command line + * error and will result in segfaults if not caught here. + */ + if (arm_feature(env, ARM_FEATURE_M)) { + if (!env->nvic) { + error_setg(errp, "This board cannot be used with Cortex-M CPUs"); + return; + } + } else { + if (env->nvic) { + error_setg(errp, "This board can only be used with Cortex-M CPUs"); + return; + } + } +#endif + cpu_exec_realizefn(cs, &local_err); if (local_err != NULL) { error_propagate(errp, local_err); -- cgit 1.4.1