2022-06-04 02:48:51

by patrick wang

Subject: [PATCH v2 4/4] mm: kmemleak: kmemleak_*_phys() set address type and check PA when scan

The kmemleak_*_phys() functions call next level interface
by setting address type to physical. And the physical address
of objects will be checked for its boundary when scan instead
of in kmemleak_*_phys().

Suggested-by: Catalin Marinas <[email protected]>
Signed-off-by: Patrick Wang <[email protected]>
---
mm/kmemleak.c | 37 +++++++++++++++++++++++++++++--------
1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 246a70b7218f..62d1ad8f8a44 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1156,8 +1156,12 @@ EXPORT_SYMBOL(kmemleak_no_scan);
void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count,
gfp_t gfp)
{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_alloc(__va(phys), size, min_count, gfp);
+ pr_debug("%s(0x%pa, %zu, %d)\n", __func__, &phys, size, min_count);
+
+ if (kmemleak_enabled && !min_count)
+ /* create object with OBJECT_PHYS flag */
+ create_object((unsigned long)phys, size, min_count,
+ gfp, true);
}
EXPORT_SYMBOL(kmemleak_alloc_phys);

@@ -1170,8 +1174,10 @@ EXPORT_SYMBOL(kmemleak_alloc_phys);
*/
void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size)
{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_free_part(__va(phys), size);
+ pr_debug("%s(0x%pa)\n", __func__, &phys);
+
+ if (kmemleak_enabled)
+ delete_object_part((unsigned long)phys, size, true);
}
EXPORT_SYMBOL(kmemleak_free_part_phys);

@@ -1182,8 +1188,10 @@ EXPORT_SYMBOL(kmemleak_free_part_phys);
*/
void __ref kmemleak_not_leak_phys(phys_addr_t phys)
{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_not_leak(__va(phys));
+ pr_debug("%s(0x%pa)\n", __func__, &phys);
+
+ if (kmemleak_enabled)
+ make_gray_object((unsigned long)phys, true);
}
EXPORT_SYMBOL(kmemleak_not_leak_phys);

@@ -1194,8 +1202,10 @@ EXPORT_SYMBOL(kmemleak_not_leak_phys);
*/
void __ref kmemleak_ignore_phys(phys_addr_t phys)
{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_ignore(__va(phys));
+ pr_debug("%s(0x%pa)\n", __func__, &phys);
+
+ if (kmemleak_enabled)
+ make_black_object((unsigned long)phys, true);
}
EXPORT_SYMBOL(kmemleak_ignore_phys);

@@ -1468,6 +1478,17 @@ static void kmemleak_scan(void)
dump_object_info(object);
}
#endif
+
+ /* ignore objects outside lowmem (paint them black) */
+ if ((object->flags & OBJECT_PHYS) &&
+ !(object->flags & OBJECT_NO_SCAN)) {
+ unsigned long phys = object->pointer;
+
+ if (PHYS_PFN(phys) < min_low_pfn ||
+ PHYS_PFN(phys + object->size) >= max_low_pfn)
+ __paint_it(object, KMEMLEAK_BLACK);
+ }
+
/* reset the reference count (whiten the object) */
object->count = 0;
if (color_gray(object) && get_object(object))
--
2.25.1

2022-06-06 15:46:31

by Catalin Marinas

Subject: Re: [PATCH v2 4/4] mm: kmemleak: kmemleak_*_phys() set address type and check PA when scan

On Fri, Jun 03, 2022 at 11:54:15AM +0800, Patrick Wang wrote:
> diff --git a/mm/kmemleak.c b/mm/kmemleak.c
> index 246a70b7218f..62d1ad8f8a44 100644
> --- a/mm/kmemleak.c
> +++ b/mm/kmemleak.c
> @@ -1156,8 +1156,12 @@ EXPORT_SYMBOL(kmemleak_no_scan);
> void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count,
> gfp_t gfp)
> {
> - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
> - kmemleak_alloc(__va(phys), size, min_count, gfp);
> + pr_debug("%s(0x%pa, %zu, %d)\n", __func__, &phys, size, min_count);
> +
> + if (kmemleak_enabled && !min_count)
> + /* create object with OBJECT_PHYS flag */
> + create_object((unsigned long)phys, size, min_count,
> + gfp, true);
> }

With an early patch, just drop min_count altogether from this API,
assume 0.

> EXPORT_SYMBOL(kmemleak_alloc_phys);
>
> @@ -1170,8 +1174,10 @@ EXPORT_SYMBOL(kmemleak_alloc_phys);
> */
> void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size)
> {
> - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
> - kmemleak_free_part(__va(phys), size);
> + pr_debug("%s(0x%pa)\n", __func__, &phys);
> +
> + if (kmemleak_enabled)
> + delete_object_part((unsigned long)phys, size, true);
> }
> EXPORT_SYMBOL(kmemleak_free_part_phys);
>
> @@ -1182,8 +1188,10 @@ EXPORT_SYMBOL(kmemleak_free_part_phys);
> */
> void __ref kmemleak_not_leak_phys(phys_addr_t phys)
> {
> - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
> - kmemleak_not_leak(__va(phys));
> + pr_debug("%s(0x%pa)\n", __func__, &phys);
> +
> + if (kmemleak_enabled)
> + make_gray_object((unsigned long)phys, true);
> }
> EXPORT_SYMBOL(kmemleak_not_leak_phys);

This function doesn't have any callers, so please remove it.

> @@ -1194,8 +1202,10 @@ EXPORT_SYMBOL(kmemleak_not_leak_phys);
> */
> void __ref kmemleak_ignore_phys(phys_addr_t phys)
> {
> - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
> - kmemleak_ignore(__va(phys));
> + pr_debug("%s(0x%pa)\n", __func__, &phys);
> +
> + if (kmemleak_enabled)
> + make_black_object((unsigned long)phys, true);
> }
> EXPORT_SYMBOL(kmemleak_ignore_phys);

Ah, that's still in use and we do need make_black_object(), contrary to
what I commented on a previous patch. We can still avoid changing
make_gray_object().

(we could replace the kmemleak_ignore_phys() calls
kmemleak_free_part_phys() but that's not in line with what we do for the
virtual objects)

> @@ -1468,6 +1478,17 @@ static void kmemleak_scan(void)
> dump_object_info(object);
> }
> #endif
> +
> + /* ignore objects outside lowmem (paint them black) */
> + if ((object->flags & OBJECT_PHYS) &&
> + !(object->flags & OBJECT_NO_SCAN)) {
> + unsigned long phys = object->pointer;
> +
> + if (PHYS_PFN(phys) < min_low_pfn ||
> + PHYS_PFN(phys + object->size) >= max_low_pfn)
> + __paint_it(object, KMEMLEAK_BLACK);
> + }
> +
> /* reset the reference count (whiten the object) */
> object->count = 0;
> if (color_gray(object) && get_object(object))

This looks fine.

--
Catalin

2022-06-08 02:19:15

by patrick wang

Subject: Re: [PATCH v2 4/4] mm: kmemleak: kmemleak_*_phys() set address type and check PA when scan

On 2022/6/6 23:29, Catalin Marinas wrote:
> On Fri, Jun 03, 2022 at 11:54:15AM +0800, Patrick Wang wrote:
>> diff --git a/mm/kmemleak.c b/mm/kmemleak.c
>> index 246a70b7218f..62d1ad8f8a44 100644
>> --- a/mm/kmemleak.c
>> +++ b/mm/kmemleak.c
>> @@ -1156,8 +1156,12 @@ EXPORT_SYMBOL(kmemleak_no_scan);
>> void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count,
>> gfp_t gfp)
>> {
>> - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
>> - kmemleak_alloc(__va(phys), size, min_count, gfp);
>> + pr_debug("%s(0x%pa, %zu, %d)\n", __func__, &phys, size, min_count);
>> +
>> + if (kmemleak_enabled && !min_count)
>> + /* create object with OBJECT_PHYS flag */
>> + create_object((unsigned long)phys, size, min_count,
>> + gfp, true);
>> }
>
> With an early patch, just drop min_count altogether from this API,
> assume 0.

Will do.

>
>> EXPORT_SYMBOL(kmemleak_alloc_phys);
>>
>> @@ -1170,8 +1174,10 @@ EXPORT_SYMBOL(kmemleak_alloc_phys);
>> */
>> void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size)
>> {
>> - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
>> - kmemleak_free_part(__va(phys), size);
>> + pr_debug("%s(0x%pa)\n", __func__, &phys);
>> +
>> + if (kmemleak_enabled)
>> + delete_object_part((unsigned long)phys, size, true);
>> }
>> EXPORT_SYMBOL(kmemleak_free_part_phys);
>>
>> @@ -1182,8 +1188,10 @@ EXPORT_SYMBOL(kmemleak_free_part_phys);
>> */
>> void __ref kmemleak_not_leak_phys(phys_addr_t phys)
>> {
>> - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
>> - kmemleak_not_leak(__va(phys));
>> + pr_debug("%s(0x%pa)\n", __func__, &phys);
>> +
>> + if (kmemleak_enabled)
>> + make_gray_object((unsigned long)phys, true);
>> }
>> EXPORT_SYMBOL(kmemleak_not_leak_phys);
>
> This function doesn't have any callers, so please remove it.

Will do.

Thanks,
Patrick