[PATCH v3] lib/test_rhashtable: Make test_insert_dup() allocate its hash table dynamically

From: Bart Van Assche
Date: Wed Jan 30 2019 - 13:43:05 EST


The test_insert_dup() function from lib/test_rhashtable.c passes a
pointer to a stack object to rhltable_init(). Allocate the hash table
dynamically to avoid that the following is reported with object
debugging enabled:

ODEBUG: object (ptrval) is on stack (ptrval), but NOT annotated.
WARNING: CPU: 0 PID: 1 at lib/debugobjects.c:368 __debug_object_init+0x312/0x480
Modules linked in:
EIP: __debug_object_init+0x312/0x480
Call Trace:
? debug_object_init+0x1a/0x20
? __init_work+0x16/0x30
? rhashtable_init+0x1e1/0x460
? sched_clock_cpu+0x57/0xe0
? rhltable_init+0xb/0x20
? test_insert_dup+0x32/0x20f
? trace_hardirqs_on+0x38/0xf0
? ida_dump+0x10/0x10
? jhash+0x130/0x130
? my_hashfn+0x30/0x30
? test_rht_init+0x6aa/0xab4
? ida_dump+0x10/0x10
? test_rhltable+0xc5c/0xc5c
? do_one_initcall+0x67/0x28e
? trace_hardirqs_off+0x22/0xe0
? restore_all_kernel+0xf/0x70
? trace_hardirqs_on_thunk+0xc/0x10
? restore_all_kernel+0xf/0x70
? kernel_init_freeable+0x142/0x213
? rest_init+0x230/0x230
? kernel_init+0x10/0x110
? schedule_tail_wrapper+0x9/0xc
? ret_from_fork+0x19/0x24

Cc: Thomas Graf <tgraf@xxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---

Changes compared to v2: fixed build error.

Changes compared to v1: instead of modifying rhashtable_init(), modify its
caller.

lib/test_rhashtable.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
index 6a8ac7626797..e52f8cafe227 100644
--- a/lib/test_rhashtable.c
+++ b/lib/test_rhashtable.c
@@ -541,38 +541,45 @@ static unsigned int __init print_ht(struct rhltable *rhlt)
static int __init test_insert_dup(struct test_obj_rhl *rhl_test_objects,
int cnt, bool slow)
{
- struct rhltable rhlt;
+ struct rhltable *rhlt;
unsigned int i, ret;
const char *key;
int err = 0;

- err = rhltable_init(&rhlt, &test_rht_params_dup);
- if (WARN_ON(err))
+ rhlt = kmalloc(sizeof(*rhlt), GFP_KERNEL);
+ if (WARN_ON(!rhlt))
+ return -EINVAL;
+
+ err = rhltable_init(rhlt, &test_rht_params_dup);
+ if (WARN_ON(err)) {
+ kfree(rhlt);
return err;
+ }

for (i = 0; i < cnt; i++) {
rhl_test_objects[i].value.tid = i;
- key = rht_obj(&rhlt.ht, &rhl_test_objects[i].list_node.rhead);
+ key = rht_obj(&rhlt->ht, &rhl_test_objects[i].list_node.rhead);
key += test_rht_params_dup.key_offset;

if (slow) {
- err = PTR_ERR(rhashtable_insert_slow(&rhlt.ht, key,
+ err = PTR_ERR(rhashtable_insert_slow(&rhlt->ht, key,
&rhl_test_objects[i].list_node.rhead));
if (err == -EAGAIN)
err = 0;
} else
- err = rhltable_insert(&rhlt,
+ err = rhltable_insert(rhlt,
&rhl_test_objects[i].list_node,
test_rht_params_dup);
if (WARN(err, "error %d on element %d/%d (%s)\n", err, i, cnt, slow? "slow" : "fast"))
goto skip_print;
}

- ret = print_ht(&rhlt);
+ ret = print_ht(rhlt);
WARN(ret != cnt, "missing rhltable elements (%d != %d, %s)\n", ret, cnt, slow? "slow" : "fast");

skip_print:
- rhltable_destroy(&rhlt);
+ rhltable_destroy(rhlt);
+ kfree(rhlt);

return 0;
}
--
2.20.1.495.gaa96b0ce6b-goog