[PATCH] coresight: Fix data argument to coresight_enable_helpers

[Carl Worth]

In the commit being fixed, coresight_enable_path() was changed to call
coresight_enable_helpers() with a final argument of 'path' rather than
'sink_data'. This was invalid, resulting in derefencing a pointer to
a 'struct coresight_path' as if it were a 'struct perf_output_handle'.

The compiler could not flag the error since there are several layers
of function calls treating the pointer as void*.

Fix to correctly pass the sink_data pointer as the final argument to
coresight_enable_helpers(), exactly as it was before the buggy commit.

Bug can be reproduced with:

$ perf record -e cs_etm//k -C 0-9 dd if=/dev/zero of=/dev/null

Showing an oops as follows:

[   88.696535] Unable to handle kernel paging request at virtual address 000f6e84934ed19e
...
[   88.911293] Call trace:
[   88.913728]  tmc_etr_get_buffer+0x30/0x80 [coresight_tmc] (P)
[   88.919463]  catu_enable_hw+0xbc/0x3d0 [coresight_catu]
[   88.924677]  catu_enable+0x70/0xe0 [coresight_catu]
[   88.929542]  coresight_enable_path+0xb0/0x258 [coresight]

Fixes: 080ee83cc361 ("Coresight: Change functions to accept the coresight_path")
Signed-off-by: Carl Worth <carl at os.amperecomputing.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 fa758cc21827..b1077d73c988 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -510,7 +510,7 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode,
 		type = csdev->type;
 
 		/* Enable all helpers adjacent to the path first */
-		ret = coresight_enable_helpers(csdev, mode, path);
+		ret = coresight_enable_helpers(csdev, mode, sink_data);
 		if (ret)
 			goto err_disable_path;
 		/*
-- 
2.39.5