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bpf: Simplify freeing logic in linfo and jited_linfo

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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: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015130.1544323-1-kafai@fb.com
This commit is contained in:
Martin KaFai Lau 2021-03-24 18:51:30 -07:00 committed by Alexei Starovoitov
parent 36e7985160
commit e16301fbe1
4 changed files with 17 additions and 28 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
include/linux/filter.h
View file

@ -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);

29
kernel/bpf/core.c
View file

@ -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)

3
kernel/bpf/syscall.c
View file

@ -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);

4
kernel/bpf/verifier.c
View file

@ -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;
}