On 7/2/24 18:58, Suzuki K Poulose wrote:

Running perf with cs_etm on Juno triggers the following kmemleak warning !

:~# cat /sys/kernel/debug/kmemleak unreferenced object 0xffffff8806b6d720 (size 96): comm "perf", pid 562, jiffies 4297810960 hex dump (first 32 bytes): 38 d8 13 07 88 ff ff ff 00 d0 9e 85 c0 ff ff ff 8............... 00 10 00 88 c0 ff ff ff 00 f0 ff f7 ff 00 00 00 ................ backtrace (crc 1dbf6e00): [<ffffffc08107381c>] kmemleak_alloc+0xbc/0xd8 [<ffffffc0802f9798>] kmalloc_trace_noprof+0x220/0x2e8 [<ffffffc07bb71948>] tmc_alloc_sg_table+0x48/0x208 [coresight_tmc] [<ffffffc07bb71cbc>] tmc_etr_alloc_sg_buf+0xac/0x240 [coresight_tmc] [<ffffffc07bb72538>] tmc_alloc_etr_buf.constprop.0+0x1f0/0x260 [coresight_tmc] [<ffffffc07bb7280c>] alloc_etr_buf.constprop.0.isra.0+0x74/0xa8 [coresight_tmc] [<ffffffc07bb72950>] tmc_alloc_etr_buffer+0x110/0x260 [coresight_tmc] [<ffffffc07bb38afc>] etm_setup_aux+0x204/0x3b0 [coresight] [<ffffffc08025837c>] rb_alloc_aux+0x20c/0x318 [<ffffffc08024dd84>] perf_mmap+0x2e4/0x7a0 [<ffffffc0802cceb0>] mmap_region+0x3b0/0xa08 [<ffffffc0802cd8a8>] do_mmap+0x3a0/0x500 [<ffffffc080295328>] vm_mmap_pgoff+0x100/0x1d0 [<ffffffc0802cadf8>] ksys_mmap_pgoff+0xb8/0x110 [<ffffffc080020688>] __arm64_sys_mmap+0x38/0x58 [<ffffffc080028fc0>] invoke_syscall.constprop.0+0x58/0x100

This due to the fact that we do not free the "sg_table" itself while freeing up the SG table and data pages. Fix this by freeing the sg_table in tmc_free_sg_table().

Fixes: 99443ea19e8b ("coresight: Add generic TMC sg table framework") Cc: Mike Leach mike.leach@linaro.org Cc: James Clark james.clark@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com

LGTM

Reviewed-by: Anshuman Khandual anshuman.khandual@arm.com

---

drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index e75428fa1592..610ad51cda65 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -261,6 +261,7 @@ void tmc_free_sg_table(struct tmc_sg_table *sg_table) { tmc_free_table_pages(sg_table); tmc_free_data_pages(sg_table);

• kfree(sg_table);

} EXPORT_SYMBOL_GPL(tmc_free_sg_table); @@ -342,7 +343,6 @@ struct tmc_sg_table *tmc_alloc_sg_table(struct device *dev, rc = tmc_alloc_table_pages(sg_table); if (rc) { tmc_free_sg_table(sg_table);

• kfree(sg_table);
  

  return ERR_PTR(rc); }