From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <martin.lau@kernel.org>,
Dave Marchevsky <davemarchevsky@meta.com>,
Delyan Kratunov <delyank@meta.com>
Subject: [PATCH bpf-next v3 08/24] bpf: Refactor map->off_arr handling
Date: Thu, 3 Nov 2022 01:56:42 +0530 [thread overview]
Message-ID: <20221102202658.963008-9-memxor@gmail.com> (raw)
In-Reply-To: <20221102202658.963008-1-memxor@gmail.com>
Refactor map->off_arr handling into generic functions that can work on
their own without hardcoding map specific code. The btf_fields_offs
structure is now returned from btf_parse_field_offs, which can be reused
later for types in program BTF.
All functions like copy_map_value, zero_map_value call generic
underlying functions so that they can also be reused later for copying
to values allocated in programs which encode specific fields.
Later, some helper functions will also require access to this
btf_field_offs structure to be able to skip over special fields at
runtime.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
include/linux/bpf.h | 41 ++++++++++++++-----------
include/linux/btf.h | 1 +
kernel/bpf/btf.c | 55 +++++++++++++++++++++++++++++++++
kernel/bpf/syscall.c | 73 ++++++--------------------------------------
4 files changed, 89 insertions(+), 81 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 762e9a20c358..02967fbdf712 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -340,55 +340,62 @@ static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
}
/* copy everything but bpf_spin_lock, bpf_timer, and kptrs. There could be one of each. */
-static inline void __copy_map_value(struct bpf_map *map, void *dst, void *src, bool long_memcpy)
+static inline void bpf_obj_memcpy(struct btf_field_offs *foffs,
+ void *dst, void *src, u32 size,
+ bool long_memcpy)
{
u32 curr_off = 0;
int i;
- if (likely(!map->field_offs)) {
+ if (likely(!foffs)) {
if (long_memcpy)
- bpf_long_memcpy(dst, src, round_up(map->value_size, 8));
+ bpf_long_memcpy(dst, src, round_up(size, 8));
else
- memcpy(dst, src, map->value_size);
+ memcpy(dst, src, size);
return;
}
- for (i = 0; i < map->field_offs->cnt; i++) {
- u32 next_off = map->field_offs->field_off[i];
+ for (i = 0; i < foffs->cnt; i++) {
+ u32 next_off = foffs->field_off[i];
memcpy(dst + curr_off, src + curr_off, next_off - curr_off);
- curr_off += map->field_offs->field_sz[i];
+ curr_off += foffs->field_sz[i];
}
- memcpy(dst + curr_off, src + curr_off, map->value_size - curr_off);
+ memcpy(dst + curr_off, src + curr_off, size - curr_off);
}
static inline void copy_map_value(struct bpf_map *map, void *dst, void *src)
{
- __copy_map_value(map, dst, src, false);
+ bpf_obj_memcpy(map->field_offs, dst, src, map->value_size, false);
}
static inline void copy_map_value_long(struct bpf_map *map, void *dst, void *src)
{
- __copy_map_value(map, dst, src, true);
+ bpf_obj_memcpy(map->field_offs, dst, src, map->value_size, true);
}
-static inline void zero_map_value(struct bpf_map *map, void *dst)
+static inline void bpf_obj_memzero(struct btf_field_offs *foffs, void *dst, u32 size)
{
u32 curr_off = 0;
int i;
- if (likely(!map->field_offs)) {
- memset(dst, 0, map->value_size);
+ if (likely(!foffs)) {
+ memset(dst, 0, size);
return;
}
- for (i = 0; i < map->field_offs->cnt; i++) {
- u32 next_off = map->field_offs->field_off[i];
+ for (i = 0; i < foffs->cnt; i++) {
+ u32 next_off = foffs->field_off[i];
memset(dst + curr_off, 0, next_off - curr_off);
- curr_off += map->field_offs->field_sz[i];
+ curr_off += foffs->field_sz[i];
}
- memset(dst + curr_off, 0, map->value_size - curr_off);
+ memset(dst + curr_off, 0, size - curr_off);
+}
+
+static inline void zero_map_value(struct bpf_map *map, void *dst)
+{
+ bpf_obj_memzero(map->field_offs, dst, map->value_size);
}
void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 282006abd062..d80345fa566b 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -165,6 +165,7 @@ int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
int btf_find_timer(const struct btf *btf, const struct btf_type *t);
struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
u32 field_mask, u32 value_size);
+struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec);
bool btf_type_is_void(const struct btf_type *t);
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 33eb6828bd01..de8a93e70f5e 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3551,6 +3551,61 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type
return ERR_PTR(ret);
}
+static int btf_field_offs_cmp(const void *_a, const void *_b, const void *priv)
+{
+ const u32 a = *(const u32 *)_a;
+ const u32 b = *(const u32 *)_b;
+
+ if (a < b)
+ return -1;
+ else if (a > b)
+ return 1;
+ return 0;
+}
+
+static void btf_field_offs_swap(void *_a, void *_b, int size, const void *priv)
+{
+ struct btf_field_offs *foffs = (void *)priv;
+ u32 *off_base = foffs->field_off;
+ u32 *a = _a, *b = _b;
+ u8 *sz_a, *sz_b;
+
+ sz_a = foffs->field_sz + (a - off_base);
+ sz_b = foffs->field_sz + (b - off_base);
+
+ swap(*a, *b);
+ swap(*sz_a, *sz_b);
+}
+
+struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec)
+{
+ struct btf_field_offs *foffs;
+ u32 i, *off;
+ u8 *sz;
+
+ BUILD_BUG_ON(ARRAY_SIZE(foffs->field_off) != ARRAY_SIZE(foffs->field_sz));
+ if (IS_ERR_OR_NULL(rec) || WARN_ON_ONCE(rec->cnt > sizeof(foffs->field_off)))
+ return NULL;
+
+ foffs = kzalloc(sizeof(*foffs), GFP_KERNEL | __GFP_NOWARN);
+ if (!foffs)
+ return ERR_PTR(-ENOMEM);
+
+ off = &foffs->field_off[0];
+ sz = &foffs->field_sz[0];
+ for (i = 0; i < rec->cnt; i++) {
+ off[i] = rec->fields[i].offset;
+ sz[i] = btf_field_type_size(rec->fields[i].type);
+ }
+ foffs->cnt = rec->cnt;
+
+ if (foffs->cnt == 1)
+ return foffs;
+ sort_r(foffs->field_off, foffs->cnt, sizeof(foffs->field_off[0]),
+ btf_field_offs_cmp, btf_field_offs_swap, foffs);
+ return foffs;
+}
+
static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
u32 type_id, void *data, u8 bits_offset,
struct btf_show *show)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 73822d36aa56..85532d301124 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -943,66 +943,6 @@ int map_check_no_btf(const struct bpf_map *map,
return -ENOTSUPP;
}
-static int map_field_offs_cmp(const void *_a, const void *_b, const void *priv)
-{
- const u32 a = *(const u32 *)_a;
- const u32 b = *(const u32 *)_b;
-
- if (a < b)
- return -1;
- else if (a > b)
- return 1;
- return 0;
-}
-
-static void map_field_offs_swap(void *_a, void *_b, int size, const void *priv)
-{
- struct bpf_map *map = (struct bpf_map *)priv;
- u32 *off_base = map->field_offs->field_off;
- u32 *a = _a, *b = _b;
- u8 *sz_a, *sz_b;
-
- sz_a = map->field_offs->field_sz + (a - off_base);
- sz_b = map->field_offs->field_sz + (b - off_base);
-
- swap(*a, *b);
- swap(*sz_a, *sz_b);
-}
-
-static int bpf_map_alloc_off_arr(struct bpf_map *map)
-{
- bool has_fields = !IS_ERR_OR_NULL(map);
- struct btf_field_offs *fo;
- struct btf_record *rec;
- u32 i, *off;
- u8 *sz;
-
- if (!has_fields) {
- map->field_offs = NULL;
- return 0;
- }
-
- fo = kmalloc(sizeof(*map->field_offs), GFP_KERNEL | __GFP_NOWARN);
- if (!fo)
- return -ENOMEM;
- map->field_offs = fo;
-
- rec = map->record;
- off = &fo->field_off[fo->cnt];
- sz = &fo->field_sz[fo->cnt];
- for (i = 0; i < rec->cnt; i++) {
- *off++ = rec->fields[i].offset;
- *sz++ = btf_field_type_size(rec->fields[i].type);
- }
- fo->cnt = rec->cnt;
-
- if (fo->cnt == 1)
- return 0;
- sort_r(fo->field_off, fo->cnt, sizeof(fo->field_off[0]),
- map_field_offs_cmp, map_field_offs_swap, map);
- return 0;
-}
-
static int map_check_btf(struct bpf_map *map, const struct btf *btf,
u32 btf_key_id, u32 btf_value_id)
{
@@ -1097,6 +1037,7 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
static int map_create(union bpf_attr *attr)
{
int numa_node = bpf_map_attr_numa_node(attr);
+ struct btf_field_offs *foffs;
struct bpf_map *map;
int f_flags;
int err;
@@ -1176,13 +1117,17 @@ static int map_create(union bpf_attr *attr)
attr->btf_vmlinux_value_type_id;
}
- err = bpf_map_alloc_off_arr(map);
- if (err)
+
+ foffs = btf_parse_field_offs(map->record);
+ if (IS_ERR(foffs)) {
+ err = PTR_ERR(foffs);
goto free_map;
+ }
+ map->field_offs = foffs;
err = security_bpf_map_alloc(map);
if (err)
- goto free_map_off_arr;
+ goto free_map_field_offs;
err = bpf_map_alloc_id(map);
if (err)
@@ -1206,7 +1151,7 @@ static int map_create(union bpf_attr *attr)
free_map_sec:
security_bpf_map_free(map);
-free_map_off_arr:
+free_map_field_offs:
kfree(map->field_offs);
free_map:
btf_put(map->btf);
--
2.38.1
next prev parent reply other threads:[~2022-11-02 20:27 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-02 20:26 [PATCH bpf-next v3 00/24] Local kptrs, BPF linked lists Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 01/24] bpf: Document UAPI details for special BPF types Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 02/24] bpf: Allow specifying volatile type modifier for kptrs Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 03/24] bpf: Clobber stack slot when writing over spilled PTR_TO_BTF_ID Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 04/24] bpf: Fix slot type check in check_stack_write_var_off Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 05/24] bpf: Drop reg_type_may_be_refcounted_or_null Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 06/24] bpf: Refactor kptr_off_tab into btf_record Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 07/24] bpf: Consolidate spin_lock, timer management " Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` Kumar Kartikeya Dwivedi [this message]
2022-11-02 20:26 ` [PATCH bpf-next v3 09/24] bpf: Support bpf_list_head in map values Kumar Kartikeya Dwivedi
2022-11-03 7:44 ` kernel test robot
2022-11-02 20:26 ` [PATCH bpf-next v3 10/24] bpf: Introduce local kptrs Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 11/24] bpf: Recognize bpf_{spin_lock,list_head,list_node} in " Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 12/24] bpf: Verify ownership relationships for user BTF types Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 13/24] bpf: Support locking bpf_spin_lock in local kptr Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 14/24] bpf: Allow locking bpf_spin_lock global variables Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 15/24] bpf: Rewrite kfunc argument handling Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 16/24] bpf: Drop kfunc bits from btf_check_func_arg_match Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 17/24] bpf: Support constant scalar arguments for kfuncs Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 18/24] bpf: Teach verifier about non-size constant arguments Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 19/24] bpf: Introduce bpf_obj_new Kumar Kartikeya Dwivedi
2022-11-02 22:58 ` kernel test robot
2022-11-03 0:29 ` kernel test robot
2022-11-02 20:26 ` [PATCH bpf-next v3 20/24] bpf: Introduce bpf_obj_drop Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 21/24] bpf: Permit NULL checking pointer with non-zero fixed offset Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 22/24] bpf: Introduce single ownership BPF linked list API Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 23/24] selftests/bpf: Add __contains macro to bpf_experimental.h Kumar Kartikeya Dwivedi
2022-11-02 20:26 ` [PATCH bpf-next v3 24/24] selftests/bpf: Add BPF linked list API tests Kumar Kartikeya Dwivedi
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