From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Leo Yan <leo.yan@arm.com>, Mike Leach <mike.leach@linaro.org>,
James Clark <james.clark@linaro.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
Mao Jinlong <quic_jinlmao@quicinc.com>
Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/8] coresight: Fix memory leak in coresight_alloc_device_name()
Date: Mon, 26 Jan 2026 15:48:28 +0000 [thread overview]
Message-ID: <062c51c2-082d-4771-83df-3e5bfa90927d@arm.com> (raw)
In-Reply-To: <20260126-arm_coresight_refactor_dev_register-v2-1-b5a3c0441c15@arm.com>
Hi Leo
On 26/01/2026 13:52, Leo Yan wrote:
> The memory leak detector reports:
>
> echo clear > /sys/kernel/debug/kmemleak
> modprobe coresight_funnel
> rmmod coresight_funnel
>
> # Scan memory leak and report it
> echo scan > /sys/kernel/debug/kmemleak
> cat /sys/kernel/debug/kmemleak
> unreferenced object 0xffff0008020c7200 (size 64):
> comm "modprobe", pid 410, jiffies 4295333721
> hex dump (first 32 bytes):
> d8 da fe 7e 09 00 ff ff e8 2e ff 7e 09 00 ff ff ...~.......~....
> b0 6c ff 7e 09 00 ff ff 30 83 00 7f 09 00 ff ff .l.~....0.......
> backtrace (crc 4116a690):
> kmemleak_alloc+0xd8/0xf8
> __kmalloc_node_track_caller_noprof+0x2c8/0x6f0
> krealloc_node_align_noprof+0x13c/0x2c8
> coresight_alloc_device_name+0xe4/0x158 [coresight]
> 0xffffd327ecef8394
> 0xffffd327ecef85ec
> amba_probe+0x118/0x1c8
> really_probe+0xc8/0x3f0
> __driver_probe_device+0x88/0x190
> driver_probe_device+0x44/0x120
> __driver_attach+0x100/0x238
> bus_for_each_dev+0x84/0xf0
> driver_attach+0x2c/0x40
> bus_add_driver+0x128/0x258
> driver_register+0x64/0x138
> __amba_driver_register+0x2c/0x48
>
> Change to use devm_krealloc_array() for allocation fwnode_list so that
> the device model can automatically release the memory when the module
> is unloaded.
>
> Fixes: 0f5f9b6ba9e1 ("coresight: Use platform agnostic names")
> Signed-off-by: Leo Yan <leo.yan@arm.com>
> ---
> drivers/hwtracing/coresight/coresight-core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index c660cf8adb1c7cafff8f85e501f056e4e151e372..ed304f292b7b02e89c59053d43f88fbf663cc993 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -1546,7 +1546,7 @@ char *coresight_alloc_device_name(struct coresight_dev_list *dict,
> if (idx < 0) {
> /* Make space for the new entry */
> idx = dict->nr_idx;
> - list = krealloc_array(dict->fwnode_list,
> + list = devm_krealloc_array(dev, dict->fwnode_list,
> idx + 1, sizeof(*dict->fwnode_list),
This is wrong. This would mean, the array gets released when the "dev"
goes away and thats not good. This is a per-driver list, not a
per-device list. Also, please remember that, we need to keep that node alive
when the device goes away, to make sure to allocate the same device name
when if/it comes back. May be, you could release the list and array,
when the "driver" goes away.
Kind regards
Suzuki
> GFP_KERNEL);
> if (ZERO_OR_NULL_PTR(list)) {
>
next prev parent reply other threads:[~2026-01-26 15:48 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-26 13:52 [PATCH v2 0/8] coresight: Fix device registration and unregistration Leo Yan
2026-01-26 13:52 ` [PATCH v2 1/8] coresight: Fix memory leak in coresight_alloc_device_name() Leo Yan
2026-01-26 15:48 ` Suzuki K Poulose [this message]
2026-01-26 16:18 ` Leo Yan
2026-01-26 13:52 ` [PATCH v2 2/8] coresight: Get parent device reference after sink ID map allocation Leo Yan
2026-01-26 13:52 ` [PATCH v2 3/8] coresight: Protect unregistration with mutex Leo Yan
2026-01-26 13:52 ` [PATCH v2 4/8] coresight: Refactor output connection sysfs link cleanup Leo Yan
2026-01-26 13:52 ` [PATCH v2 5/8] coresight: Refactor sysfs connection group cleanup Leo Yan
2026-01-26 13:52 ` [PATCH v2 6/8] coresight: Move sink validation into etm_perf_add_symlink_sink() Leo Yan
2026-01-26 13:52 ` [PATCH v2 7/8] coresight: Do not mix success path with failure handling Leo Yan
2026-01-26 13:52 ` [PATCH v2 8/8] coresight: Unify error handling in coresight_register() Leo Yan
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