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| author | Borislav Petkov <bp@suse.de> | 2015-08-08 10:46:02 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-09-17 15:06:54 +0200 |
| commit | 2110d70c5e58326a10e93cfefdc0b3686e2ada12 (patch) | |
| tree | b0a272279c817b91ba3bf8e632dfcc930e9d6d2c | |
| parent | Linux 4.3-rc1 (diff) | |
| download | linux-2110d70c5e58326a10e93cfefdc0b3686e2ada12.tar.xz linux-2110d70c5e58326a10e93cfefdc0b3686e2ada12.zip | |
cpu/cacheinfo: Fix teardown path
Philip Müller reported a hang when booting 32-bit 4.1 kernel on an AMD
box. A fragment of the splat was enough to pinpoint the issue:
task: f58e0000 ti: f58e8000 task.ti: f58e800
EIP: 0060:[<c135a903>] EFLAGS: 00010206 CPU: 0
EIP is at free_cache_attributes+0x83/0xd0
EAX: 00000001 EBX: f589d46c ECX: 00000090 EDX: 360c2000
ESI: 00000000 EDI: c1724a80 EBP: f58e9ec0 ESP: f58e9ea0
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: 000000ac CR3: 01731000 CR4: 000006d0
cache_shared_cpu_map_setup() did check sibling CPUs cacheinfo descriptor
while the respective teardown path cache_shared_cpu_map_remove() didn't.
Fix that.
>From tglx's version: to be on the safe side, move the cacheinfo
descriptor check to free_cache_attributes(), thus cleaning up the
hotplug path a little and making this even more robust.
Reported-and-tested-by: Philip Müller <philm@manjaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: <stable@vger.kernel.org> # 4.1
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: manjaro-dev@manjaro.org
Cc: Philip Müller <philm@manjaro.org>
Link: https://lkml.kernel.org/r/55B47BB8.6080202@manjaro.org
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/base/cacheinfo.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 764280a91776..e9fd32e91668 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -148,7 +148,11 @@ static void cache_shared_cpu_map_remove(unsigned int cpu) if (sibling == cpu) /* skip itself */ continue; + sib_cpu_ci = get_cpu_cacheinfo(sibling); + if (!sib_cpu_ci->info_list) + continue; + sib_leaf = sib_cpu_ci->info_list + index; cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); @@ -159,6 +163,9 @@ static void cache_shared_cpu_map_remove(unsigned int cpu) static void free_cache_attributes(unsigned int cpu) { + if (!per_cpu_cacheinfo(cpu)) + return; + cache_shared_cpu_map_remove(cpu); kfree(per_cpu_cacheinfo(cpu)); @@ -514,8 +521,7 @@ static int cacheinfo_cpu_callback(struct notifier_block *nfb, break; case CPU_DEAD: cache_remove_dev(cpu); - if (per_cpu_cacheinfo(cpu)) - free_cache_attributes(cpu); + free_cache_attributes(cpu); break; } return notifier_from_errno(rc); |