diff options
| author | Pierre Gondois <pierre.gondois@arm.com> | 2022-11-16 10:49:58 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-23 20:03:51 +0100 |
| commit | 2613cc29c5723881ca603b1a3b50f0107010d5d6 (patch) | |
| tree | 863e79e87e2381123a4a0b0f4e97d65135480bea | |
| parent | 9dc5f12f95e00fb0e0500ea4a8da0c0f29e718cb (diff) | |
cacheinfo: Remove of_node_put() for fw_token
fw_token is used for DT/ACPI systems to identify CPUs sharing caches.
For DT based systems, fw_token is set to a pointer to a DT node.
commit 3da72e18371c ("cacheinfo: Decrement refcount in
cache_setup_of_node()")
doesn't increment the refcount of fw_token anymore in
cache_setup_of_node(). fw_token is indeed used as a token and not
as a (struct device_node*), so no reference to fw_token should be
kept.
However, [1] is triggered when hotplugging a CPU multiple times
since cache_shared_cpu_map_remove() decrements the refcount to
fw_token at each CPU unplugging, eventually reaching 0.
Remove of_node_put() for fw_token in cache_shared_cpu_map_remove().
[1]
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 4 PID: 32 at lib/refcount.c:22 refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
Modules linked in:
CPU: 4 PID: 32 Comm: cpuhp/4 Tainted: G W 6.1.0-rc1-14091-g9fdf2ca7b9c8 #76
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Oct 31 2022
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
lr : refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
[...]
Call trace:
[...]
of_node_release (drivers/of/dynamic.c:335)
kobject_put (lib/kobject.c:677 lib/kobject.c:704 ./include/linux/kref.h:65 lib/kobject.c:721)
of_node_put (drivers/of/dynamic.c:49)
free_cache_attributes.part.0 (drivers/base/cacheinfo.c:712)
cacheinfo_cpu_pre_down (drivers/base/cacheinfo.c:718)
cpuhp_invoke_callback (kernel/cpu.c:247 (discriminator 4))
cpuhp_thread_fun (kernel/cpu.c:785)
smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3))
kthread (kernel/kthread.c:376)
ret_from_fork (arch/arm64/kernel/entry.S:861)
---[ end trace 0000000000000000 ]---
Fixes: 3da72e18371c ("cacheinfo: Decrement refcount in cache_setup_of_node()")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Link: https://lore.kernel.org/r/20221116094958.2141072-1-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/base/cacheinfo.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 04317cde800c..950b22cdb5f7 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -317,8 +317,6 @@ static void cache_shared_cpu_map_remove(unsigned int cpu) cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); } - if (of_have_populated_dt()) - of_node_put(this_leaf->fw_token); } } |