From bbb83c9908a0395449bbfcf12e1cba568bb10709 Mon Sep 17 00:00:00 2001 From: Liang Yan Date: Fri, 7 Feb 2020 14:04:21 +0000 Subject: [PATCH 13/22] target/arm/monitor: query-cpu-model-expansion crashed qemu when using machine type none Commit e19afd566781 mentioned that target-arm only supports queryable cpu models 'max', 'host', and the current type when KVM is in use. The logic works well until using machine type none. For machine type none, cpu_type will be null if cpu option is not set by command line, strlen(cpu_type) will terminate process. So We add a check above it. This won't affect i386 and s390x since they do not use current_cpu. Signed-off-by: Liang Yan Message-id: 20200203134251.12986-1-lyan@suse.com Reviewed-by: Andrew Jones Tested-by: Andrew Jones Signed-off-by: Peter Maydell --- target/arm/monitor.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/target/arm/monitor.c b/target/arm/monitor.c index 560970de7f..e2b1d117a4 100644 --- a/target/arm/monitor.c +++ b/target/arm/monitor.c @@ -131,17 +131,20 @@ CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type, } if (kvm_enabled()) { - const char *cpu_type = current_machine->cpu_type; - int len = strlen(cpu_type) - strlen(ARM_CPU_TYPE_SUFFIX); bool supported = false; if (!strcmp(model->name, "host") || !strcmp(model->name, "max")) { /* These are kvmarm's recommended cpu types */ supported = true; - } else if (strlen(model->name) == len && - !strncmp(model->name, cpu_type, len)) { - /* KVM is enabled and we're using this type, so it works. */ - supported = true; + } else if (current_machine->cpu_type) { + const char *cpu_type = current_machine->cpu_type; + int len = strlen(cpu_type) - strlen(ARM_CPU_TYPE_SUFFIX); + + if (strlen(model->name) == len && + !strncmp(model->name, cpu_type, len)) { + /* KVM is enabled and we're using this type, so it works. */ + supported = true; + } } if (!supported) { error_setg(errp, "We cannot guarantee the CPU type '%s' works " -- 2.18.4