[Qemu-devel] [PULL 2/2] kvm-all: Use 'tmpcpu' instead of 'cpu' in sub-looping to avoid 'cpu' be NULL

[Paolo Bonzini <pbonzini@redhat.com>]

From: Chen Gang <gang.chen.5i5j@gmail.com>

If kvm_arch_remove_sw_breakpoint() in CPU_FOREACH() always be fail, it
will let 'cpu' NULL. And the next kvm_arch_remove_sw_breakpoint() in
QTAILQ_FOREACH_SAFE() will get NULL parameter for 'cpu'.

And kvm_arch_remove_sw_breakpoint() can assumes 'cpu' must never be NULL,
so need define additional temporary variable for 'cpu' to avoid the case.

Cc: qemu-stable@nongnu.org
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 kvm-all.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 3ae30ee..1402f4f 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -2077,12 +2077,13 @@ void kvm_remove_all_breakpoints(CPUState *cpu)
 {
     struct kvm_sw_breakpoint *bp, *next;
     KVMState *s = cpu->kvm_state;
+    CPUState *tmpcpu;
 
     QTAILQ_FOREACH_SAFE(bp, &s->kvm_sw_breakpoints, entry, next) {
         if (kvm_arch_remove_sw_breakpoint(cpu, bp) != 0) {
             /* Try harder to find a CPU that currently sees the breakpoint. */
-            CPU_FOREACH(cpu) {
-                if (kvm_arch_remove_sw_breakpoint(cpu, bp) == 0) {
+            CPU_FOREACH(tmpcpu) {
+                if (kvm_arch_remove_sw_breakpoint(tmpcpu, bp) == 0) {
                     break;
                 }
             }
-- 
1.8.3.1