x86: fix oprofile double free
Chuck reports that the recent fix from Andi to oprofile
6c977aad03a18019015035958c65b6729cd0574c introduces a double free. Each
cpu's cpu_msrs is setup to point to cpu 0's, which causes free_msrs to free
cpu 0's pointers for_each_possible_cpu. Rather than copy the pointers, do
a deep copy instead.
[acme@redhat.com: allocate_msrs() was using for_each_online_cpu()]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dave Jones <davej@redhat.com>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/i386/oprofile/nmi_int.c b/arch/i386/oprofile/nmi_int.c
index a7c0783..11b7a51 100644
--- a/arch/i386/oprofile/nmi_int.c
+++ b/arch/i386/oprofile/nmi_int.c
@@ -154,7 +154,7 @@
size_t counters_size = sizeof(struct op_msr) * model->num_counters;
int i;
- for_each_online_cpu(i) {
+ for_each_possible_cpu(i) {
cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
if (!cpu_msrs[i].counters) {
success = 0;
@@ -211,8 +211,14 @@
/* Assume saved/restored counters are the same on all CPUs */
model->fill_in_addresses(&cpu_msrs[0]);
for_each_possible_cpu (cpu) {
- if (cpu != 0)
- cpu_msrs[cpu] = cpu_msrs[0];
+ if (cpu != 0) {
+ memcpy(cpu_msrs[cpu].counters, cpu_msrs[0].counters,
+ sizeof(struct op_msr) * model->num_counters);
+
+ memcpy(cpu_msrs[cpu].controls, cpu_msrs[0].controls,
+ sizeof(struct op_msr) * model->num_controls);
+ }
+
}
on_each_cpu(nmi_save_registers, NULL, 0, 1);
on_each_cpu(nmi_cpu_setup, NULL, 0, 1);