Commit e16301fb authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: Simplify freeing logic in linfo and jited_linfo 



This patch simplifies the linfo freeing logic by combining
"bpf_prog_free_jited_linfo()" and "bpf_prog_free_unused_jited_linfo()"
into the new "bpf_prog_jit_attempt_done()".
It is a prep work for the kernel function call support.  In a later
patch, freeing the kernel function call descriptors will also
be done in the "bpf_prog_jit_attempt_done()".

"bpf_prog_free_linfo()" is removed since it is only called by
"__bpf_prog_put_noref()".  The kvfree() are directly called
instead.

It also takes this chance to s/kcalloc/kvcalloc/ for the jited_linfo
allocation.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015130.1544323-1-kafai@fb.com
parent 36e79851

include/linux/filter.h

+1 −2
Original line number Diff line number Diff line
@@ -877,8 +877,7 @@ void bpf_prog_free_linfo(struct bpf_prog *prog); 
void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,

			       const u32 *insn_to_jit_off);

int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog);

void bpf_prog_free_jited_linfo(struct bpf_prog *prog);

void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog);

void bpf_prog_jit_attempt_done(struct bpf_prog *prog);



struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);

struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags);

kernel/bpf/core.c

+12 −23
Original line number Diff line number Diff line
@@ -143,7 +143,7 @@ int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) 
	if (!prog->aux->nr_linfo || !prog->jit_requested)

		return 0;



	prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,

	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,

					  sizeof(*prog->aux->jited_linfo),

					  GFP_KERNEL_ACCOUNT | __GFP_NOWARN);

	if (!prog->aux->jited_linfo)
@@ -152,16 +152,13 @@ int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) 
	return 0;

}



void bpf_prog_free_jited_linfo(struct bpf_prog *prog)

void bpf_prog_jit_attempt_done(struct bpf_prog *prog)

{

	kfree(prog->aux->jited_linfo);

	if (prog->aux->jited_linfo &&

	    (!prog->jited || !prog->aux->jited_linfo[0])) {

		kvfree(prog->aux->jited_linfo);

		prog->aux->jited_linfo = NULL;

	}



void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)

{

	if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])

		bpf_prog_free_jited_linfo(prog);

}



/* The jit engine is responsible to provide an array
@@ -217,12 +214,6 @@ void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, 
			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];

}



void bpf_prog_free_linfo(struct bpf_prog *prog)

{

	bpf_prog_free_jited_linfo(prog);

	kvfree(prog->aux->linfo);

}



struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,

				  gfp_t gfp_extra_flags)

{
@@ -1866,15 +1857,13 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) 
			return fp;



		fp = bpf_int_jit_compile(fp);

		if (!fp->jited) {

			bpf_prog_free_jited_linfo(fp);

		bpf_prog_jit_attempt_done(fp);

#ifdef CONFIG_BPF_JIT_ALWAYS_ON

		if (!fp->jited) {

			*err = -ENOTSUPP;

			return fp;

#endif

		} else {

			bpf_prog_free_unused_jited_linfo(fp);

		}

#endif

	} else {

		*err = bpf_prog_offload_compile(fp);

		if (*err)

kernel/bpf/syscall.c

+2 −1
Original line number Diff line number Diff line
@@ -1694,7 +1694,8 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 
{

	bpf_prog_kallsyms_del_all(prog);

	btf_put(prog->aux->btf);

	bpf_prog_free_linfo(prog);

	kvfree(prog->aux->jited_linfo);

	kvfree(prog->aux->linfo);

	if (prog->aux->attach_btf)

		btf_put(prog->aux->attach_btf);

kernel/bpf/verifier.c

+2 −2
Original line number Diff line number Diff line
@@ -11741,7 +11741,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) 
	prog->bpf_func = func[0]->bpf_func;

	prog->aux->func = func;

	prog->aux->func_cnt = env->subprog_cnt;

	bpf_prog_free_unused_jited_linfo(prog);

	bpf_prog_jit_attempt_done(prog);

	return 0;

out_free:

	for (i = 0; i < env->subprog_cnt; i++) {
@@ -11764,7 +11764,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) 
		insn->off = 0;

		insn->imm = env->insn_aux_data[i].call_imm;

	}

	bpf_prog_free_jited_linfo(prog);

	bpf_prog_jit_attempt_done(prog);

	return err;

}