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| author | Chris Wright <chrisw@sous-sol.org> | 2007-06-01 00:46:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-06-01 08:18:28 -0700 |
| commit | 0939c17c7bcf1c838bea4445b80a6966809a438f (patch) | |
| tree | 3d93789babaab344aa9c6840e267ffe34caadc6c /arch | |
| parent | 24faa9eef876d39e0826a36f31ae0e8b0eeb9835 (diff) | |
| download | lwn-0939c17c7bcf1c838bea4445b80a6966809a438f.tar.gz lwn-0939c17c7bcf1c838bea4445b80a6966809a438f.zip | |
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/i386/oprofile/nmi_int.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/i386/oprofile/nmi_int.c b/arch/i386/oprofile/nmi_int.c index a7c0783b269a..11b7a51566a8 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); |