[PATCH 2/2] samples: kmemleak: Print the raw pointers for debugging purposes

From: Catalin Marinas
Date: Thu Feb 06 2025 - 06:46:16 EST


The kmemleak-test.c module is meant to leak some pointers for debugging
the kmemleak detection, pointer information dumping. It's no use if it
prints the hashed values of such pointers.

Change the printk() format from %p to %px. While at it, also display the
raw __percpu pointer rather than this_cpu_ptr() since kmemleak now
tracks such pointers independently of the standard allocations.

Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
samples/kmemleak/kmemleak-test.c | 36 ++++++++++++++++----------------
1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/samples/kmemleak/kmemleak-test.c b/samples/kmemleak/kmemleak-test.c
index 544c36d51d56..8609812a37eb 100644
--- a/samples/kmemleak/kmemleak-test.c
+++ b/samples/kmemleak/kmemleak-test.c
@@ -40,25 +40,25 @@ static int kmemleak_test_init(void)
pr_info("Kmemleak testing\n");

/* make some orphan objects */
- pr_info("kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
- pr_info("kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
- pr_info("kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
- pr_info("kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
- pr_info("kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
- pr_info("kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
- pr_info("kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
- pr_info("kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
+ pr_info("kmalloc(32) = 0x%px\n", kmalloc(32, GFP_KERNEL));
+ pr_info("kmalloc(32) = 0x%px\n", kmalloc(32, GFP_KERNEL));
+ pr_info("kmalloc(1024) = 0x%px\n", kmalloc(1024, GFP_KERNEL));
+ pr_info("kmalloc(1024) = 0x%px\n", kmalloc(1024, GFP_KERNEL));
+ pr_info("kmalloc(2048) = 0x%px\n", kmalloc(2048, GFP_KERNEL));
+ pr_info("kmalloc(2048) = 0x%px\n", kmalloc(2048, GFP_KERNEL));
+ pr_info("kmalloc(4096) = 0x%px\n", kmalloc(4096, GFP_KERNEL));
+ pr_info("kmalloc(4096) = 0x%px\n", kmalloc(4096, GFP_KERNEL));
#ifndef CONFIG_MODULES
- pr_info("kmem_cache_alloc(files_cachep) = %p\n",
+ pr_info("kmem_cache_alloc(files_cachep) = 0x%px\n",
kmem_cache_alloc(files_cachep, GFP_KERNEL));
- pr_info("kmem_cache_alloc(files_cachep) = %p\n",
+ pr_info("kmem_cache_alloc(files_cachep) = 0x%px\n",
kmem_cache_alloc(files_cachep, GFP_KERNEL));
#endif
- pr_info("vmalloc(64) = %p\n", vmalloc(64));
- pr_info("vmalloc(64) = %p\n", vmalloc(64));
- pr_info("vmalloc(64) = %p\n", vmalloc(64));
- pr_info("vmalloc(64) = %p\n", vmalloc(64));
- pr_info("vmalloc(64) = %p\n", vmalloc(64));
+ pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
+ pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
+ pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
+ pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
+ pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));

/*
* Add elements to a list. They should only appear as orphan
@@ -66,7 +66,7 @@ static int kmemleak_test_init(void)
*/
for (i = 0; i < 10; i++) {
elem = kzalloc(sizeof(*elem), GFP_KERNEL);
- pr_info("kzalloc(sizeof(*elem)) = %p\n", elem);
+ pr_info("kzalloc(sizeof(*elem)) = 0x%px\n", elem);
if (!elem)
return -ENOMEM;
INIT_LIST_HEAD(&elem->list);
@@ -75,11 +75,11 @@ static int kmemleak_test_init(void)

for_each_possible_cpu(i) {
per_cpu(kmemleak_test_pointer, i) = kmalloc(129, GFP_KERNEL);
- pr_info("kmalloc(129) = %p\n",
+ pr_info("kmalloc(129) = 0x%px\n",
per_cpu(kmemleak_test_pointer, i));
}

- pr_info("__alloc_percpu(64, 4) = %p\n", __alloc_percpu(64, 4));
+ pr_info("__alloc_percpu(64, 4) = 0x%px\n", __alloc_percpu(64, 4));

return 0;
}