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Commit 7df737e9 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

bpf: remove global variables 



Move three global variables protected by bpf_verifier_lock into
'struct bpf_verifier_env' to allow parallel verification.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 3b880244

include/linux/bpf_verifier.h

+5 −0
Original line number Diff line number Diff line
@@ -295,6 +295,11 @@ struct bpf_verifier_env { 
	const struct bpf_line_info *prev_linfo;

	struct bpf_verifier_log log;

	struct bpf_subprog_info subprog_info[BPF_MAX_SUBPROGS + 1];

	struct {

		int *insn_state;

		int *insn_stack;

		int cur_stack;

	} cfg;

	u32 subprog_cnt;

	/* number of instructions analyzed by the verifier */

	u32 insn_processed;

kernel/bpf/verifier.c

+13 −12
Original line number Diff line number Diff line
@@ -5369,10 +5369,6 @@ enum { 


#define STATE_LIST_MARK ((struct bpf_verifier_state_list *) -1L)



static int *insn_stack;	/* stack of insns to process */

static int cur_stack;	/* current stack index */

static int *insn_state;



/* t, w, e - match pseudo-code above:

 * t - index of current instruction

 * w - next instruction
@@ -5380,6 +5376,9 @@ static int *insn_state; 
 */

static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)

{

	int *insn_stack = env->cfg.insn_stack;

	int *insn_state = env->cfg.insn_state;



	if (e == FALLTHROUGH && insn_state[t] >= (DISCOVERED | FALLTHROUGH))

		return 0;
@@ -5400,9 +5399,9 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env) 
		/* tree-edge */

		insn_state[t] = DISCOVERED | e;

		insn_state[w] = DISCOVERED;

		if (cur_stack >= env->prog->len)

		if (env->cfg.cur_stack >= env->prog->len)

			return -E2BIG;

		insn_stack[cur_stack++] = w;

		insn_stack[env->cfg.cur_stack++] = w;

		return 1;

	} else if ((insn_state[w] & 0xF0) == DISCOVERED) {

		verbose_linfo(env, t, "%d: ", t);
@@ -5426,14 +5425,15 @@ static int check_cfg(struct bpf_verifier_env *env) 
{

	struct bpf_insn *insns = env->prog->insnsi;

	int insn_cnt = env->prog->len;

	int *insn_stack, *insn_state;

	int ret = 0;

	int i, t;



	insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);

	insn_state = env->cfg.insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);

	if (!insn_state)

		return -ENOMEM;



	insn_stack = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);

	insn_stack = env->cfg.insn_stack = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);

	if (!insn_stack) {

		kvfree(insn_state);

		return -ENOMEM;
@@ -5441,12 +5441,12 @@ static int check_cfg(struct bpf_verifier_env *env) 


	insn_state[0] = DISCOVERED; /* mark 1st insn as discovered */

	insn_stack[0] = 0; /* 0 is the first instruction */

	cur_stack = 1;

	env->cfg.cur_stack = 1;



peek_stack:

	if (cur_stack == 0)

	if (env->cfg.cur_stack == 0)

		goto check_state;

	t = insn_stack[cur_stack - 1];

	t = insn_stack[env->cfg.cur_stack - 1];



	if (BPF_CLASS(insns[t].code) == BPF_JMP ||

	    BPF_CLASS(insns[t].code) == BPF_JMP32) {
@@ -5515,7 +5515,7 @@ static int check_cfg(struct bpf_verifier_env *env) 


mark_explored:

	insn_state[t] = EXPLORED;

	if (cur_stack-- <= 0) {

	if (env->cfg.cur_stack-- <= 0) {

		verbose(env, "pop stack internal bug\n");

		ret = -EFAULT;

		goto err_free;
@@ -5535,6 +5535,7 @@ static int check_cfg(struct bpf_verifier_env *env) 
err_free:

	kvfree(insn_state);

	kvfree(insn_stack);

	env->cfg.insn_state = env->cfg.insn_stack = NULL;

	return ret;

}