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authorChris Wright <chrisw@sous-sol.org>2007-06-01 00:46:39 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-06-01 08:18:28 -0700
commit0939c17c7bcf1c838bea4445b80a6966809a438f (patch)
tree3d93789babaab344aa9c6840e267ffe34caadc6c
parent24faa9eef876d39e0826a36f31ae0e8b0eeb9835 (diff)
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>
-rw-r--r--arch/i386/oprofile/nmi_int.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/i386/oprofile/nmi_int.c b/arch/i386/oprofile/nmi_int.c
index a7c0783b269..11b7a51566a 100644
--- a/arch/i386/oprofile/nmi_int.c
+++ b/arch/i386/oprofile/nmi_int.c
@@ -154,7 +154,7 @@ static int allocate_msrs(void)
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 @@ static int nmi_setup(void)
/* 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);