* [PATCH v2 0/2] mm: fix the names of general cma and hugetlb cma
@ 2020-06-16 22:31 Barry Song
2020-06-16 22:31 ` [PATCH v2 1/2] mm: cma: fix the name of CMA areas Barry Song
2020-06-16 22:31 ` [PATCH v2 2/2] mm: hugetlb: fix the name of hugetlb CMA Barry Song
0 siblings, 2 replies; 3+ messages in thread
From: Barry Song @ 2020-06-16 22:31 UTC (permalink / raw)
To: akpm, mike.kravetz; +Cc: linux-mm, linux-kernel, linuxarm, Barry Song
the current code of CMA can only work when users pass a const string as name
parameter. we need to fix the way to handle names in CMA.
On the other hand, to avoid name conflicts after enabling CMA_DEBUGFS, each
hugetlb should get a different CMA name.
-v2:
add acked-by and reviewed-by
rebase to 5.8-rc1
Barry Song (2):
mm: cma: fix the name of CMA areas
mm: hugetlb: fix the name of hugetlb CMA
mm/cma.c | 13 ++++++-------
mm/cma.h | 4 +++-
mm/hugetlb.c | 4 +++-
3 files changed, 12 insertions(+), 9 deletions(-)
--
2.23.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v2 1/2] mm: cma: fix the name of CMA areas
2020-06-16 22:31 [PATCH v2 0/2] mm: fix the names of general cma and hugetlb cma Barry Song
@ 2020-06-16 22:31 ` Barry Song
2020-06-16 22:31 ` [PATCH v2 2/2] mm: hugetlb: fix the name of hugetlb CMA Barry Song
1 sibling, 0 replies; 3+ messages in thread
From: Barry Song @ 2020-06-16 22:31 UTC (permalink / raw)
To: akpm, mike.kravetz
Cc: linux-mm, linux-kernel, linuxarm, Barry Song, Roman Gushchin
if users give a name saved in stack, the current code will generate magic
pointer.
if users don't give a name(NULL), kasprintf() will always return NULL as
we are at the early stage. that means cma_init_reserved_mem() will return
-ENOMEM if users set name parameter as NULL.
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
---
-v2:
rebase to 5.8-rc1
add acked-by and reviewed-by
mm/cma.c | 13 ++++++-------
mm/cma.h | 4 +++-
2 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/mm/cma.c b/mm/cma.c
index 0463ad2ce06b..b24151fa2101 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -202,13 +202,12 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
* subsystems (like slab allocator) are available.
*/
cma = &cma_areas[cma_area_count];
- if (name) {
- cma->name = name;
- } else {
- cma->name = kasprintf(GFP_KERNEL, "cma%d\n", cma_area_count);
- if (!cma->name)
- return -ENOMEM;
- }
+
+ if (name)
+ snprintf(cma->name, CMA_MAX_NAME, name);
+ else
+ snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count);
+
cma->base_pfn = PFN_DOWN(base);
cma->count = size >> PAGE_SHIFT;
cma->order_per_bit = order_per_bit;
diff --git a/mm/cma.h b/mm/cma.h
index 33c0b517733c..27d3f0e9f68f 100644
--- a/mm/cma.h
+++ b/mm/cma.h
@@ -2,6 +2,8 @@
#ifndef __MM_CMA_H__
#define __MM_CMA_H__
+#define CMA_MAX_NAME 64
+
struct cma {
unsigned long base_pfn;
unsigned long count;
@@ -12,7 +14,7 @@ struct cma {
struct hlist_head mem_head;
spinlock_t mem_head_lock;
#endif
- const char *name;
+ char name[CMA_MAX_NAME];
};
extern struct cma cma_areas[MAX_CMA_AREAS];
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 2/2] mm: hugetlb: fix the name of hugetlb CMA
2020-06-16 22:31 [PATCH v2 0/2] mm: fix the names of general cma and hugetlb cma Barry Song
2020-06-16 22:31 ` [PATCH v2 1/2] mm: cma: fix the name of CMA areas Barry Song
@ 2020-06-16 22:31 ` Barry Song
1 sibling, 0 replies; 3+ messages in thread
From: Barry Song @ 2020-06-16 22:31 UTC (permalink / raw)
To: akpm, mike.kravetz
Cc: linux-mm, linux-kernel, linuxarm, Barry Song, Roman Gushchin
once we enable CMA_DEBUGFS, we will get the below errors:
directory 'cma-hugetlb' with parent 'cma' already present
we should have different names for different CMA areas.
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
---
-v2:
rebase to 5.8-rc1
add acked-by and reviewed-by
mm/hugetlb.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 57ece74e3aae..d54bb7e35005 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5692,12 +5692,14 @@ void __init hugetlb_cma_reserve(int order)
reserved = 0;
for_each_node_state(nid, N_ONLINE) {
int res;
+ char name[20];
size = min(per_node, hugetlb_cma_size - reserved);
size = round_up(size, PAGE_SIZE << order);
+ snprintf(name, 20, "hugetlb%d", nid);
res = cma_declare_contiguous_nid(0, size, 0, PAGE_SIZE << order,
- 0, false, "hugetlb",
+ 0, false, name,
&hugetlb_cma[nid], nid);
if (res) {
pr_warn("hugetlb_cma: reservation failed: err %d, node %d",
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
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