[PATCH 12/14] bpf: Allow no charge for bpf prog

[Yafang Shao <laoar.shao@xxxxxxxxx>]

Allow not to charge memory used by bpf progs. This includes the memory
used by bpf progs itself, auxxiliary data, statistics and bpf line info.

Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
 kernel/bpf/core.c    | 12 ++++++++++--
 kernel/bpf/syscall.c |  6 ++++--
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 0f68b8203c18..7aa750e8bd7d 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -144,12 +144,17 @@ EXPORT_SYMBOL_GPL(bpf_prog_alloc);
 
 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
 {
+	gfp_t gfp_flags = GFP_KERNEL | __GFP_NOWARN;
+
 	if (!prog->aux->nr_linfo || !prog->jit_requested)
 		return 0;
 
+	if (!prog->aux->no_charge)
+		gfp_flags |= __GFP_ACCOUNT;
+
 	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
 					  sizeof(*prog->aux->jited_linfo),
-					  GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
+					  gfp_flags);
 	if (!prog->aux->jited_linfo)
 		return -ENOMEM;
 
@@ -224,7 +229,7 @@ void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 				  gfp_t gfp_extra_flags)
 {
-	gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
+	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
 	struct bpf_prog *fp;
 	u32 pages;
 
@@ -233,6 +238,9 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 	if (pages <= fp_old->pages)
 		return fp_old;
 
+	if (!fp_old->aux->no_charge)
+		gfp_flags |= __GFP_ACCOUNT;
+
 	fp = __vmalloc(size, gfp_flags);
 	if (fp) {
 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index fdfbb4d0d5e0..e386b549fafc 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2218,9 +2218,10 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
 	enum bpf_prog_type type = attr->prog_type;
 	struct bpf_prog *prog, *dst_prog = NULL;
 	struct btf *attach_btf = NULL;
-	int err;
+	gfp_t gfp_flags = GFP_USER;
 	char license[128];
 	bool is_gpl;
+	int err;
 
 	if (CHECK_ATTR(BPF_PROG_LOAD))
 		return -EINVAL;
@@ -2305,7 +2306,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
 	}
 
 	/* plain bpf_prog allocation */
-	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER | __GFP_ACCOUNT);
+	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt),
+				prog_flags_no_charge(gfp_flags, attr));
 	if (!prog) {
 		if (dst_prog)
 			bpf_prog_put(dst_prog);
-- 
2.17.1