[PATCH bpf-next 0/2] drm, bpf: User drm_mm in bpf

[PATCH bpf-next 0/2] drm, bpf: User drm_mm in bpf

[Alexei Starovoitov]

From: Alexei Starovoitov <ast@kernel.org>

Hi DRM folks,

we'd like to start using drm_mm in bpf arena.
The drm_mm logic fits particularly well to bpf use case.
See individual patches.

objdump -h lib/drm_mm.o 
.text         000012c7

So no vmlinux size concerns.

Alexei Starovoitov (2):
  drm, bpf: Move drm_mm.c to lib to be used by bpf arena
  bpf: Switch bpf arena to use drm_mm instead of maple_tree

 MAINTAINERS                       |  1 +
 drivers/gpu/drm/Makefile          |  1 -
 drivers/gpu/drm/drm_print.c       | 39 ++++++++++++++++++
 kernel/bpf/arena.c                | 67 ++++++++++++++++++++++++-------
 lib/Makefile                      |  2 +
 {drivers/gpu/drm => lib}/drm_mm.c | 40 +-----------------
 6 files changed, 95 insertions(+), 55 deletions(-)
 rename {drivers/gpu/drm => lib}/drm_mm.c (96%)

-- 
2.43.5

[PATCH bpf-next 1/2] drm, bpf: Move drm_mm.c to lib to be used by bpf arena

[Alexei Starovoitov]

From: Alexei Starovoitov <ast@kernel.org>

Move drm_mm.c to lib. The next commit will use drm_mm to manage
memory regions in bpf arena. Move drm_mm_print to
drivers/gpu/drm/drm_print.c, since it's not a core functionality
of drm_mm and it depeneds on drm_printer while drm_mm is
generic and usuable as-is by other subsystems.
Also add __maybe_unused to suppress compiler warnings.
Update MAINTAINERS file as well.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 MAINTAINERS                       |  1 +
 drivers/gpu/drm/Makefile          |  1 -
 drivers/gpu/drm/drm_print.c       | 39 ++++++++++++++++++++++++++++++
 lib/Makefile                      |  1 +
 {drivers/gpu/drm => lib}/drm_mm.c | 40 +------------------------------
 5 files changed, 42 insertions(+), 40 deletions(-)
 rename {drivers/gpu/drm => lib}/drm_mm.c (96%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 6880a8fac74c..1bfaa335fae7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7504,6 +7504,7 @@ F:	drivers/gpu/vga/
 F:	include/drm/drm
 F:	include/linux/vga*
 F:	include/uapi/drm/
+F:	lib/drm_mm.c
 X:	drivers/gpu/drm/amd/
 X:	drivers/gpu/drm/armada/
 X:	drivers/gpu/drm/etnaviv/
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 784229d4504d..e35d5de2b9f0 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -59,7 +59,6 @@ drm-y := \
 	drm_ioctl.o \
 	drm_lease.o \
 	drm_managed.o \
-	drm_mm.o \
 	drm_mode_config.o \
 	drm_mode_object.o \
 	drm_modes.o \
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index 0081190201a7..2a8a5e0d691e 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -34,6 +34,7 @@
 #include <drm/drm.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_print.h>
+#include <drm/drm_mm.h>
 
 /*
  * __drm_debug: Enable debug output.
@@ -267,6 +268,44 @@ void drm_printf(struct drm_printer *p, const char *f, ...)
 }
 EXPORT_SYMBOL(drm_printf);
 
+static u64 drm_mm_dump_hole(struct drm_printer *p, const struct drm_mm_node *entry)
+{
+	u64 start, size;
+
+	size = entry->hole_size;
+	if (size) {
+		start = drm_mm_hole_node_start(entry);
+		drm_printf(p, "%#018llx-%#018llx: %llu: free\n",
+			   start, start + size, size);
+	}
+
+	return size;
+}
+/**
+ * drm_mm_print - print allocator state
+ * @mm: drm_mm allocator to print
+ * @p: DRM printer to use
+ */
+void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p)
+{
+	const struct drm_mm_node *entry;
+	u64 total_used = 0, total_free = 0, total = 0;
+
+	total_free += drm_mm_dump_hole(p, &mm->head_node);
+
+	drm_mm_for_each_node(entry, mm) {
+		drm_printf(p, "%#018llx-%#018llx: %llu: used\n", entry->start,
+			   entry->start + entry->size, entry->size);
+		total_used += entry->size;
+		total_free += drm_mm_dump_hole(p, entry);
+	}
+	total = total_free + total_used;
+
+	drm_printf(p, "total: %llu, used %llu free %llu\n", total,
+		   total_used, total_free);
+}
+EXPORT_SYMBOL(drm_mm_print);
+
 /**
  * drm_print_bits - print bits to a &drm_printer stream
  *
diff --git a/lib/Makefile b/lib/Makefile
index 773adf88af41..605aa25b71ab 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o
 obj-y += kstrtox.o
 obj-$(CONFIG_FIND_BIT_BENCHMARK) += find_bit_benchmark.o
 obj-$(CONFIG_TEST_BPF) += test_bpf.o
+obj-$(CONFIG_DRM) += drm_mm.o
 test_dhry-objs := dhry_1.o dhry_2.o dhry_run.o
 obj-$(CONFIG_TEST_DHRY) += test_dhry.o
 obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
diff --git a/drivers/gpu/drm/drm_mm.c b/lib/drm_mm.c
similarity index 96%
rename from drivers/gpu/drm/drm_mm.c
rename to lib/drm_mm.c
index 5ace481c1901..45ea9864ed2e 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/lib/drm_mm.c
@@ -151,7 +151,7 @@ static void show_leaks(struct drm_mm *mm) { }
 
 INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
 		     u64, __subtree_last,
-		     START, LAST, static inline, drm_mm_interval_tree)
+		     START, LAST, static inline __maybe_unused, drm_mm_interval_tree)
 
 struct drm_mm_node *
 __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last)
@@ -966,41 +966,3 @@ void drm_mm_takedown(struct drm_mm *mm)
 		show_leaks(mm);
 }
 EXPORT_SYMBOL(drm_mm_takedown);
-
-static u64 drm_mm_dump_hole(struct drm_printer *p, const struct drm_mm_node *entry)
-{
-	u64 start, size;
-
-	size = entry->hole_size;
-	if (size) {
-		start = drm_mm_hole_node_start(entry);
-		drm_printf(p, "%#018llx-%#018llx: %llu: free\n",
-			   start, start + size, size);
-	}
-
-	return size;
-}
-/**
- * drm_mm_print - print allocator state
- * @mm: drm_mm allocator to print
- * @p: DRM printer to use
- */
-void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p)
-{
-	const struct drm_mm_node *entry;
-	u64 total_used = 0, total_free = 0, total = 0;
-
-	total_free += drm_mm_dump_hole(p, &mm->head_node);
-
-	drm_mm_for_each_node(entry, mm) {
-		drm_printf(p, "%#018llx-%#018llx: %llu: used\n", entry->start,
-			   entry->start + entry->size, entry->size);
-		total_used += entry->size;
-		total_free += drm_mm_dump_hole(p, entry);
-	}
-	total = total_free + total_used;
-
-	drm_printf(p, "total: %llu, used %llu free %llu\n", total,
-		   total_used, total_free);
-}
-EXPORT_SYMBOL(drm_mm_print);
-- 
2.43.5

[PATCH bpf-next 2/2] bpf: Switch bpf arena to use drm_mm instead of maple_tree

[Alexei Starovoitov]

From: Alexei Starovoitov <ast@kernel.org>

bpf arena is moving towards non-sleepable allocations in tracing
context while maple_tree does kmalloc/kfree deep inside. Hence switch
bpf arena to drm_mm algorithm that works with externally provided
drm_mm_node-s. This patch kmalloc/kfree-s drm_mm_node-s, but the next
patch will switch to bpf_mem_alloc and preallocated drm_mm_node-s.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/arena.c | 67 +++++++++++++++++++++++++++++++++++-----------
 lib/Makefile       |  1 +
 2 files changed, 53 insertions(+), 15 deletions(-)

diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index e52b3ad231b9..ef1de26020f2 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -6,6 +6,7 @@
 #include <linux/btf_ids.h>
 #include <linux/vmalloc.h>
 #include <linux/pagemap.h>
+#include <drm/drm_mm.h>
 
 /*
  * bpf_arena is a sparsely populated shared memory region between bpf program and
@@ -45,7 +46,7 @@ struct bpf_arena {
 	u64 user_vm_start;
 	u64 user_vm_end;
 	struct vm_struct *kern_vm;
-	struct maple_tree mt;
+	struct drm_mm mm;
 	struct list_head vma_list;
 	struct mutex lock;
 };
@@ -132,7 +133,7 @@ static struct bpf_map *arena_map_alloc(union bpf_attr *attr)
 
 	INIT_LIST_HEAD(&arena->vma_list);
 	bpf_map_init_from_attr(&arena->map, attr);
-	mt_init_flags(&arena->mt, MT_FLAGS_ALLOC_RANGE);
+	drm_mm_init(&arena->mm, 0, attr->max_entries);
 	mutex_init(&arena->lock);
 
 	return &arena->map;
@@ -164,6 +165,7 @@ static int existing_page_cb(pte_t *ptep, unsigned long addr, void *data)
 static void arena_map_free(struct bpf_map *map)
 {
 	struct bpf_arena *arena = container_of(map, struct bpf_arena, map);
+	struct drm_mm_node *node, *next;
 
 	/*
 	 * Check that user vma-s are not around when bpf map is freed.
@@ -183,7 +185,11 @@ static void arena_map_free(struct bpf_map *map)
 	apply_to_existing_page_range(&init_mm, bpf_arena_get_kern_vm_start(arena),
 				     KERN_VM_SZ - GUARD_SZ, existing_page_cb, NULL);
 	free_vm_area(arena->kern_vm);
-	mtree_destroy(&arena->mt);
+	drm_mm_for_each_node_safe(node, next, &arena->mm) {
+		drm_mm_remove_node(node);
+		kfree(node);
+	}
+	drm_mm_takedown(&arena->mm);
 	bpf_map_area_free(arena);
 }
 
@@ -257,6 +263,7 @@ static vm_fault_t arena_vm_fault(struct vm_fault *vmf)
 {
 	struct bpf_map *map = vmf->vma->vm_file->private_data;
 	struct bpf_arena *arena = container_of(map, struct bpf_arena, map);
+	struct drm_mm_node *node;
 	struct page *page;
 	long kbase, kaddr;
 	int ret;
@@ -274,20 +281,30 @@ static vm_fault_t arena_vm_fault(struct vm_fault *vmf)
 		/* User space requested to segfault when page is not allocated by bpf prog */
 		return VM_FAULT_SIGSEGV;
 
-	ret = mtree_insert(&arena->mt, vmf->pgoff, MT_ENTRY, GFP_KERNEL);
-	if (ret)
+	node = kzalloc(sizeof(*node), GFP_KERNEL);
+	if (!node)
+		return VM_FAULT_SIGSEGV;
+
+	node->start = vmf->pgoff;
+	node->size = 1;
+	ret = drm_mm_reserve_node(&arena->mm, node);
+	if (ret) {
+		kfree(node);
 		return VM_FAULT_SIGSEGV;
+	}
 
 	/* Account into memcg of the process that created bpf_arena */
 	ret = bpf_map_alloc_pages(map, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, 1, &page);
 	if (ret) {
-		mtree_erase(&arena->mt, vmf->pgoff);
+		drm_mm_remove_node(node);
+		kfree(node);
 		return VM_FAULT_SIGSEGV;
 	}
 
 	ret = vm_area_map_pages(arena->kern_vm, kaddr, kaddr + PAGE_SIZE, &page);
 	if (ret) {
-		mtree_erase(&arena->mt, vmf->pgoff);
+		drm_mm_remove_node(node);
+		kfree(node);
 		__free_page(page);
 		return VM_FAULT_SIGSEGV;
 	}
@@ -420,6 +437,7 @@ static long arena_alloc_pages(struct bpf_arena *arena, long uaddr, long page_cnt
 	/* user_vm_end/start are fixed before bpf prog runs */
 	long page_cnt_max = (arena->user_vm_end - arena->user_vm_start) >> PAGE_SHIFT;
 	u64 kern_vm_start = bpf_arena_get_kern_vm_start(arena);
+	struct drm_mm_node *node;
 	struct page **pages;
 	long pgoff = 0;
 	u32 uaddr32;
@@ -442,14 +460,21 @@ static long arena_alloc_pages(struct bpf_arena *arena, long uaddr, long page_cnt
 	if (!pages)
 		return 0;
 
+	node = kzalloc(sizeof(*node), GFP_KERNEL);
+	if (!node) {
+		kvfree(pages);
+		return 0;
+	}
 	guard(mutex)(&arena->lock);
 
-	if (uaddr)
-		ret = mtree_insert_range(&arena->mt, pgoff, pgoff + page_cnt - 1,
-					 MT_ENTRY, GFP_KERNEL);
-	else
-		ret = mtree_alloc_range(&arena->mt, &pgoff, MT_ENTRY,
-					page_cnt, 0, page_cnt_max - 1, GFP_KERNEL);
+	if (uaddr) {
+		node->start = pgoff;
+		node->size = page_cnt;
+		ret = drm_mm_reserve_node(&arena->mm, node);
+	} else {
+		ret = drm_mm_insert_node(&arena->mm, node, page_cnt);
+		pgoff = node->start;
+	}
 	if (ret)
 		goto out_free_pages;
 
@@ -476,7 +501,8 @@ static long arena_alloc_pages(struct bpf_arena *arena, long uaddr, long page_cnt
 	kvfree(pages);
 	return clear_lo32(arena->user_vm_start) + uaddr32;
 out:
-	mtree_erase(&arena->mt, pgoff);
+	drm_mm_remove_node(node);
+	kfree(node);
 out_free_pages:
 	kvfree(pages);
 	return 0;
@@ -499,6 +525,7 @@ static void zap_pages(struct bpf_arena *arena, long uaddr, long page_cnt)
 static void arena_free_pages(struct bpf_arena *arena, long uaddr, long page_cnt)
 {
 	u64 full_uaddr, uaddr_end;
+	struct drm_mm_node *node, *to_remove;
 	long kaddr, pgoff, i;
 	struct page *page;
 
@@ -516,7 +543,17 @@ static void arena_free_pages(struct bpf_arena *arena, long uaddr, long page_cnt)
 
 	pgoff = compute_pgoff(arena, uaddr);
 	/* clear range */
-	mtree_store_range(&arena->mt, pgoff, pgoff + page_cnt - 1, NULL, GFP_KERNEL);
+	for (;;) {
+		to_remove = NULL;
+		drm_mm_for_each_node_in_range(node, &arena->mm, pgoff, pgoff + page_cnt) {
+			to_remove = node;
+			break;
+		}
+		if (!to_remove)
+			break;
+		drm_mm_remove_node(to_remove);
+		kfree(to_remove);
+	}
 
 	if (page_cnt > 1)
 		/* bulk zap if multiple pages being freed */
diff --git a/lib/Makefile b/lib/Makefile
index 605aa25b71ab..d4787e6b0942 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o
 obj-y += kstrtox.o
 obj-$(CONFIG_FIND_BIT_BENCHMARK) += find_bit_benchmark.o
 obj-$(CONFIG_TEST_BPF) += test_bpf.o
+obj-$(CONFIG_BPF_SYSCALL) += drm_mm.o
 obj-$(CONFIG_DRM) += drm_mm.o
 test_dhry-objs := dhry_1.o dhry_2.o dhry_run.o
 obj-$(CONFIG_TEST_DHRY) += test_dhry.o
-- 
2.43.5

Re: [PATCH bpf-next 1/2] drm, bpf: Move drm_mm.c to lib to be used by bpf arena

[Kumar Kartikeya Dwivedi]

On Fri, 1 Nov 2024 at 18:55, Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> From: Alexei Starovoitov <ast@kernel.org>
>
> Move drm_mm.c to lib. The next commit will use drm_mm to manage
> memory regions in bpf arena. Move drm_mm_print to
> drivers/gpu/drm/drm_print.c, since it's not a core functionality
> of drm_mm and it depeneds on drm_printer while drm_mm is
> generic and usuable as-is by other subsystems.
> Also add __maybe_unused to suppress compiler warnings.
> Update MAINTAINERS file as well.
>
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
> ---

Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

Re: [PATCH bpf-next 2/2] bpf: Switch bpf arena to use drm_mm instead of maple_tree

[Kumar Kartikeya Dwivedi]

On Fri, 1 Nov 2024 at 18:55, Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> From: Alexei Starovoitov <ast@kernel.org>
>
> bpf arena is moving towards non-sleepable allocations in tracing
> context while maple_tree does kmalloc/kfree deep inside. Hence switch
> bpf arena to drm_mm algorithm that works with externally provided
> drm_mm_node-s. This patch kmalloc/kfree-s drm_mm_node-s, but the next
> patch will switch to bpf_mem_alloc and preallocated drm_mm_node-s.
>
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
> ---

Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

Re: [PATCH bpf-next 2/2] bpf: Switch bpf arena to use drm_mm instead of maple_tree

[kernel test robot]

Hi Alexei,

kernel test robot noticed the following build errors:

[auto build test ERROR on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Alexei-Starovoitov/drm-bpf-Move-drm_mm-c-to-lib-to-be-used-by-bpf-arena/20241102-075645
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20241101235453.63380-3-alexei.starovoitov%40gmail.com
patch subject: [PATCH bpf-next 2/2] bpf: Switch bpf arena to use drm_mm instead of maple_tree
config: i386-randconfig-003-20241104 (https://download.01.org/0day-ci/archive/20241105/202411051357.3XLBnPy3-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241105/202411051357.3XLBnPy3-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411051357.3XLBnPy3-lkp@intel.com/

All errors (new ones prefixed by >>):

   ld: lib/drm_mm.o: in function `show_leaks':
>> lib/drm_mm.c:135: undefined reference to `__drm_err'
>> ld: lib/drm_mm.c:129: undefined reference to `__drm_err'


vim +135 lib/drm_mm.c

5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  117  
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  118  static void show_leaks(struct drm_mm *mm)
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  119  {
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  120  	struct drm_mm_node *node;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  121  	char *buf;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  122  
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  123  	buf = kmalloc(BUFSZ, GFP_KERNEL);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  124  	if (!buf)
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  125  		return;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  126  
2bc98c86517b08 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-12-22  127  	list_for_each_entry(node, drm_mm_nodes(mm), node_list) {
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  128  		if (!node->stack) {
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31 @129  			DRM_ERROR("node [%08llx + %08llx]: unknown owner\n",
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  130  				  node->start, node->size);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  131  			continue;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  132  		}
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  133  
0f68d45ef41abb drivers/gpu/drm/drm_mm.c Imran Khan   2021-11-08  134  		stack_depot_snprint(node->stack, buf, BUFSZ, 0);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31 @135  		DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s",
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  136  			  node->start, node->size, buf);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  137  	}
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  138  
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  139  	kfree(buf);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  140  }
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  141  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH bpf-next 2/2] bpf: Switch bpf arena to use drm_mm instead of maple_tree

[kernel test robot]

Hi Alexei,

kernel test robot noticed the following build errors:

[auto build test ERROR on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Alexei-Starovoitov/drm-bpf-Move-drm_mm-c-to-lib-to-be-used-by-bpf-arena/20241102-075645
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20241101235453.63380-3-alexei.starovoitov%40gmail.com
patch subject: [PATCH bpf-next 2/2] bpf: Switch bpf arena to use drm_mm instead of maple_tree
config: sparc-randconfig-r061-20241105 (https://download.01.org/0day-ci/archive/20241105/202411052322.GENc72sg-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 14.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241105/202411052322.GENc72sg-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411052322.GENc72sg-lkp@intel.com/

All errors (new ones prefixed by >>):

   sparc64-linux-ld: lib/drm_mm.o: in function `drm_mm_takedown':
>> lib/drm_mm.c:135:(.text+0x470): undefined reference to `__drm_err'
>> sparc64-linux-ld: lib/drm_mm.c:129:(.text+0x4ac): undefined reference to `__drm_err'


vim +135 lib/drm_mm.c

5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  117  
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  118  static void show_leaks(struct drm_mm *mm)
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  119  {
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  120  	struct drm_mm_node *node;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  121  	char *buf;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  122  
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  123  	buf = kmalloc(BUFSZ, GFP_KERNEL);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  124  	if (!buf)
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  125  		return;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  126  
2bc98c86517b08 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-12-22  127  	list_for_each_entry(node, drm_mm_nodes(mm), node_list) {
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  128  		if (!node->stack) {
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31 @129  			DRM_ERROR("node [%08llx + %08llx]: unknown owner\n",
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  130  				  node->start, node->size);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  131  			continue;
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  132  		}
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  133  
0f68d45ef41abb drivers/gpu/drm/drm_mm.c Imran Khan   2021-11-08  134  		stack_depot_snprint(node->stack, buf, BUFSZ, 0);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31 @135  		DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s",
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  136  			  node->start, node->size, buf);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  137  	}
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  138  
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  139  	kfree(buf);
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  140  }
5705670d046342 drivers/gpu/drm/drm_mm.c Chris Wilson 2016-10-31  141  

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