From b97f2bcf142440f86fa80d7a4a3e231fbcf26d5f Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Mon, 1 Aug 2016 08:12:17 +0200 Subject: [PATCH 77/99] exec: Don't use cpu_index to detect if cpu_exec_init()'s been called RH-Author: Igor Mammedov Message-id: <1470039143-24450-73-git-send-email-imammedo@redhat.com> Patchwork-id: 71688 O-Subject: [RHEV-7.3 qemu-kvm-rhev PATCH 72/78] exec: Don't use cpu_index to detect if cpu_exec_init()'s been called Bugzilla: 1087672 RH-Acked-by: Marcel Apfelbaum RH-Acked-by: David Gibson RH-Acked-by: Eduardo Habkost 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 (cherry picked from commit 8b1b835035fda831b405c1947210efcf758a7ca8) Signed-off-by: Miroslav Rezanina --- exec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/exec.c b/exec.c index f453f88..79db83d 100644 --- a/exec.c +++ b/exec.c @@ -640,13 +640,14 @@ 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(); -- 1.8.3.1