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-rw-r--r--kernel/bpf/arena.c16
-rw-r--r--kernel/bpf/ringbuf.c31
-rw-r--r--kernel/bpf/verifier.c61
3 files changed, 97 insertions, 11 deletions
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index 583ee4fe48ef..e52b3ad231b9 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -212,6 +212,7 @@ static u64 arena_map_mem_usage(const struct bpf_map *map)
struct vma_list {
struct vm_area_struct *vma;
struct list_head head;
+ atomic_t mmap_count;
};
static int remember_vma(struct bpf_arena *arena, struct vm_area_struct *vma)
@@ -221,20 +222,30 @@ static int remember_vma(struct bpf_arena *arena, struct vm_area_struct *vma)
vml = kmalloc(sizeof(*vml), GFP_KERNEL);
if (!vml)
return -ENOMEM;
+ atomic_set(&vml->mmap_count, 1);
vma->vm_private_data = vml;
vml->vma = vma;
list_add(&vml->head, &arena->vma_list);
return 0;
}
+static void arena_vm_open(struct vm_area_struct *vma)
+{
+ struct vma_list *vml = vma->vm_private_data;
+
+ atomic_inc(&vml->mmap_count);
+}
+
static void arena_vm_close(struct vm_area_struct *vma)
{
struct bpf_map *map = vma->vm_file->private_data;
struct bpf_arena *arena = container_of(map, struct bpf_arena, map);
- struct vma_list *vml;
+ struct vma_list *vml = vma->vm_private_data;
+ if (!atomic_dec_and_test(&vml->mmap_count))
+ return;
guard(mutex)(&arena->lock);
- vml = vma->vm_private_data;
+ /* update link list under lock */
list_del(&vml->head);
vma->vm_private_data = NULL;
kfree(vml);
@@ -287,6 +298,7 @@ out:
}
static const struct vm_operations_struct arena_vm_ops = {
+ .open = arena_vm_open,
.close = arena_vm_close,
.fault = arena_vm_fault,
};
diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c
index 0ee653a936ea..e20b90c36131 100644
--- a/kernel/bpf/ringbuf.c
+++ b/kernel/bpf/ringbuf.c
@@ -51,7 +51,8 @@ struct bpf_ringbuf {
* This prevents a user-space application from modifying the
* position and ruining in-kernel tracking. The permissions of the
* pages depend on who is producing samples: user-space or the
- * kernel.
+ * kernel. Note that the pending counter is placed in the same
+ * page as the producer, so that it shares the same cache line.
*
* Kernel-producer
* ---------------
@@ -70,6 +71,7 @@ struct bpf_ringbuf {
*/
unsigned long consumer_pos __aligned(PAGE_SIZE);
unsigned long producer_pos __aligned(PAGE_SIZE);
+ unsigned long pending_pos;
char data[] __aligned(PAGE_SIZE);
};
@@ -179,6 +181,7 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
rb->mask = data_sz - 1;
rb->consumer_pos = 0;
rb->producer_pos = 0;
+ rb->pending_pos = 0;
return rb;
}
@@ -404,9 +407,9 @@ bpf_ringbuf_restore_from_rec(struct bpf_ringbuf_hdr *hdr)
static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)
{
- unsigned long cons_pos, prod_pos, new_prod_pos, flags;
- u32 len, pg_off;
+ unsigned long cons_pos, prod_pos, new_prod_pos, pend_pos, flags;
struct bpf_ringbuf_hdr *hdr;
+ u32 len, pg_off, tmp_size, hdr_len;
if (unlikely(size > RINGBUF_MAX_RECORD_SZ))
return NULL;
@@ -424,13 +427,29 @@ static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)
spin_lock_irqsave(&rb->spinlock, flags);
}
+ pend_pos = rb->pending_pos;
prod_pos = rb->producer_pos;
new_prod_pos = prod_pos + len;
- /* check for out of ringbuf space by ensuring producer position
- * doesn't advance more than (ringbuf_size - 1) ahead
+ while (pend_pos < prod_pos) {
+ hdr = (void *)rb->data + (pend_pos & rb->mask);
+ hdr_len = READ_ONCE(hdr->len);
+ if (hdr_len & BPF_RINGBUF_BUSY_BIT)
+ break;
+ tmp_size = hdr_len & ~BPF_RINGBUF_DISCARD_BIT;
+ tmp_size = round_up(tmp_size + BPF_RINGBUF_HDR_SZ, 8);
+ pend_pos += tmp_size;
+ }
+ rb->pending_pos = pend_pos;
+
+ /* check for out of ringbuf space:
+ * - by ensuring producer position doesn't advance more than
+ * (ringbuf_size - 1) ahead
+ * - by ensuring oldest not yet committed record until newest
+ * record does not span more than (ringbuf_size - 1)
*/
- if (new_prod_pos - cons_pos > rb->mask) {
+ if (new_prod_pos - cons_pos > rb->mask ||
+ new_prod_pos - pend_pos > rb->mask) {
spin_unlock_irqrestore(&rb->spinlock, flags);
return NULL;
}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c955f98c9a2b..fcecaba8668d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6236,6 +6236,7 @@ static void set_sext32_default_val(struct bpf_reg_state *reg, int size)
}
reg->u32_min_value = 0;
reg->u32_max_value = U32_MAX;
+ reg->var_off = tnum_subreg(tnum_unknown);
}
static void coerce_subreg_to_size_sx(struct bpf_reg_state *reg, int size)
@@ -6280,6 +6281,7 @@ static void coerce_subreg_to_size_sx(struct bpf_reg_state *reg, int size)
reg->s32_max_value = s32_max;
reg->u32_min_value = (u32)s32_min;
reg->u32_max_value = (u32)s32_max;
+ reg->var_off = tnum_subreg(tnum_range(s32_min, s32_max));
return;
}
@@ -12719,6 +12721,16 @@ static bool signed_add32_overflows(s32 a, s32 b)
return res < a;
}
+static bool signed_add16_overflows(s16 a, s16 b)
+{
+ /* Do the add in u16, where overflow is well-defined */
+ s16 res = (s16)((u16)a + (u16)b);
+
+ if (b < 0)
+ return res > a;
+ return res < a;
+}
+
static bool signed_sub_overflows(s64 a, s64 b)
{
/* Do the sub in u64, where overflow is well-defined */
@@ -17448,11 +17460,11 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
goto skip_inf_loop_check;
}
if (is_may_goto_insn_at(env, insn_idx)) {
- if (states_equal(env, &sl->state, cur, RANGE_WITHIN)) {
+ if (sl->state.may_goto_depth != cur->may_goto_depth &&
+ states_equal(env, &sl->state, cur, RANGE_WITHIN)) {
update_loop_entry(cur, &sl->state);
goto hit;
}
- goto skip_inf_loop_check;
}
if (calls_callback(env, insn_idx)) {
if (states_equal(env, &sl->state, cur, RANGE_WITHIN))
@@ -18730,6 +18742,39 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of
return new_prog;
}
+/*
+ * For all jmp insns in a given 'prog' that point to 'tgt_idx' insn adjust the
+ * jump offset by 'delta'.
+ */
+static int adjust_jmp_off(struct bpf_prog *prog, u32 tgt_idx, u32 delta)
+{
+ struct bpf_insn *insn = prog->insnsi;
+ u32 insn_cnt = prog->len, i;
+
+ for (i = 0; i < insn_cnt; i++, insn++) {
+ u8 code = insn->code;
+
+ if ((BPF_CLASS(code) != BPF_JMP && BPF_CLASS(code) != BPF_JMP32) ||
+ BPF_OP(code) == BPF_CALL || BPF_OP(code) == BPF_EXIT)
+ continue;
+
+ if (insn->code == (BPF_JMP32 | BPF_JA)) {
+ if (i + 1 + insn->imm != tgt_idx)
+ continue;
+ if (signed_add32_overflows(insn->imm, delta))
+ return -ERANGE;
+ insn->imm += delta;
+ } else {
+ if (i + 1 + insn->off != tgt_idx)
+ continue;
+ if (signed_add16_overflows(insn->imm, delta))
+ return -ERANGE;
+ insn->off += delta;
+ }
+ }
+ return 0;
+}
+
static int adjust_subprog_starts_after_remove(struct bpf_verifier_env *env,
u32 off, u32 cnt)
{
@@ -20004,7 +20049,10 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
stack_depth_extra = 8;
insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_AX, BPF_REG_10, stack_off);
- insn_buf[1] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_AX, 0, insn->off + 2);
+ if (insn->off >= 0)
+ insn_buf[1] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_AX, 0, insn->off + 2);
+ else
+ insn_buf[1] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_AX, 0, insn->off - 1);
insn_buf[2] = BPF_ALU64_IMM(BPF_SUB, BPF_REG_AX, 1);
insn_buf[3] = BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_AX, stack_off);
cnt = 4;
@@ -20546,6 +20594,13 @@ next_insn:
if (!new_prog)
return -ENOMEM;
env->prog = prog = new_prog;
+ /*
+ * If may_goto is a first insn of a prog there could be a jmp
+ * insn that points to it, hence adjust all such jmps to point
+ * to insn after BPF_ST that inits may_goto count.
+ * Adjustment will succeed because bpf_patch_insn_data() didn't fail.
+ */
+ WARN_ON(adjust_jmp_off(env->prog, subprog_start, 1));
}
/* Since poke tab is now finalized, publish aux to tracker. */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-29 18:35:35 +0000