From: Igor Mammedov Date: Mon, 25 Jul 2016 09:59:20 +0000 (+0200) Subject: exec: Don't use cpu_index to detect if cpu_exec_init()'s been called X-Git-Tag: v2.7.0-rc1~8^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8b1b835035fda831b405c1947210efcf758a7ca8;p=thirdparty%2Fqemu.git exec: Don't use cpu_index to detect if cpu_exec_init()'s been called Instead use QTAIL's tqe_prev field to detect if cpu's been placed in list by cpu_exec_init() which is always set if QTAIL element is in list. Fixes SIGSEGV on failure path in case cpu_index is assigned by board and cpu.relalize() fails before cpu_exec_init() is called. In follow up patches, cpu_index will be assigned by boards that support cpu hot(un)plug and need stable cpu_index that doesn't depend on order cpus are created/removed. Signed-off-by: Igor Mammedov Reported-by: David Gibson Reviewed-by: David Gibson Signed-off-by: Eduardo Habkost --- diff --git a/exec.c b/exec.c index 2f57c624a5b..ae45a707b64 100644 --- a/exec.c +++ b/exec.c @@ -643,13 +643,14 @@ void cpu_exec_exit(CPUState *cpu) CPUClass *cc = CPU_GET_CLASS(cpu); cpu_list_lock(); - if (cpu->cpu_index == -1) { - /* cpu_index was never allocated by this @cpu or was already freed. */ + if (cpu->node.tqe_prev == NULL) { + /* there is nothing to undo since cpu_exec_init() hasn't been called */ cpu_list_unlock(); return; } QTAILQ_REMOVE(&cpus, cpu, node); + cpu->node.tqe_prev = NULL; cpu_release_index(cpu); cpu->cpu_index = -1; cpu_list_unlock();