* [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-08-30 20:01 ` Alexei Starovoitov
` (2 more replies)
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 2/8] bpf: Be conservative during verification for invalid kfunc calls Kumar Kartikeya Dwivedi
` (6 subsequent siblings)
7 siblings, 3 replies; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
This change adds support on the kernel side to allow for BPF programs to
call kernel module functions. Userspace will prepare an array of module
BTF fds that is passed in during BPF_PROG_LOAD. In the kernel, the
module BTF array is placed in the auxilliary struct for bpf_prog.
The verifier then uses insn->off to index into this table. insn->off is
used by subtracting one from it, as userspace has to set the index of
array in insn->off incremented by 1. This lets us denote vmlinux btf by
insn->off == 0, and the prog->aux->kfunc_btf_tab[insn->off - 1] for
module BTFs.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
include/linux/bpf.h | 1 +
include/linux/filter.h | 9 ++++
include/uapi/linux/bpf.h | 3 +-
kernel/bpf/core.c | 14 ++++++
kernel/bpf/syscall.c | 55 +++++++++++++++++++++-
kernel/bpf/verifier.c | 85 ++++++++++++++++++++++++++--------
tools/include/uapi/linux/bpf.h | 3 +-
7 files changed, 147 insertions(+), 23 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f4c16f19f83e..39f59e5f3a26 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -874,6 +874,7 @@ struct bpf_prog_aux {
void *jit_data; /* JIT specific data. arch dependent */
struct bpf_jit_poke_descriptor *poke_tab;
struct bpf_kfunc_desc_tab *kfunc_tab;
+ struct bpf_kfunc_btf_tab *kfunc_btf_tab;
u32 size_poke_tab;
struct bpf_ksym ksym;
const struct bpf_prog_ops *ops;
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 7d248941ecea..46451891633d 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -592,6 +592,15 @@ struct bpf_prog {
struct bpf_insn insnsi[];
};
+#define MAX_KFUNC_DESCS 256
+/* There can only be at most MAX_KFUNC_DESCS module BTFs for kernel module
+ * function calls.
+ */
+struct bpf_kfunc_btf_tab {
+ u32 nr_btfs;
+ struct btf_mod_pair btfs[];
+};
+
struct sk_filter {
refcount_t refcnt;
struct rcu_head rcu;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 791f31dd0abe..4cbb2082a553 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1334,8 +1334,9 @@ union bpf_attr {
/* or valid module BTF object fd or 0 to attach to vmlinux */
__u32 attach_btf_obj_fd;
};
- __u32 :32; /* pad */
+ __u32 kfunc_btf_fds_cnt; /* reuse hole for count of BTF fds below */
__aligned_u64 fd_array; /* array of FDs */
+ __aligned_u64 kfunc_btf_fds; /* array of BTF FDs for module kfunc support */
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 9f4636d021b1..73ba6d862df3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2249,12 +2249,26 @@ static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
kfree(aux->used_btfs);
}
+static void bpf_free_kfunc_btf_tab(struct bpf_prog_aux *aux)
+{
+ struct bpf_kfunc_btf_tab *tab = aux->kfunc_btf_tab;
+
+ if (tab) {
+ while (tab->nr_btfs--) {
+ module_put(tab->btfs[tab->nr_btfs].module);
+ btf_put(tab->btfs[tab->nr_btfs].btf);
+ }
+ kfree(tab);
+ }
+}
+
static void bpf_prog_free_deferred(struct work_struct *work)
{
struct bpf_prog_aux *aux;
int i;
aux = container_of(work, struct bpf_prog_aux, work);
+ bpf_free_kfunc_btf_tab(aux);
bpf_free_used_maps(aux);
bpf_free_used_btfs(aux);
if (bpf_prog_is_dev_bound(aux))
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4e50c0bfdb7d..bbbd664b2872 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2156,16 +2156,16 @@ static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
}
/* last field in 'union bpf_attr' used by this command */
-#define BPF_PROG_LOAD_LAST_FIELD fd_array
+#define BPF_PROG_LOAD_LAST_FIELD kfunc_btf_fds
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;
char license[128];
bool is_gpl;
+ int err;
if (CHECK_ATTR(BPF_PROG_LOAD))
return -EINVAL;
@@ -2204,6 +2204,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
return -EPERM;
if (is_perfmon_prog_type(type) && !perfmon_capable())
return -EPERM;
+ if (attr->kfunc_btf_fds_cnt > MAX_KFUNC_DESCS)
+ return -E2BIG;
/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
* or btf, we need to check which one it is
@@ -2254,6 +2256,55 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
return -ENOMEM;
}
+ if (attr->kfunc_btf_fds_cnt) {
+ struct bpf_kfunc_btf_tab *tab;
+ int fds[MAX_KFUNC_DESCS], i;
+ bpfptr_t kfunc_btf_fds;
+ u32 kfunc_btf_size, n;
+
+ kfunc_btf_size = min_t(u32, MAX_KFUNC_DESCS, attr->kfunc_btf_fds_cnt);
+ kfunc_btf_fds = make_bpfptr(attr->kfunc_btf_fds, uattr.is_kernel);
+
+ err = -EFAULT;
+ if (copy_from_bpfptr(fds, kfunc_btf_fds, kfunc_btf_size * sizeof(int)))
+ goto free_prog;
+
+ err = -ENOMEM;
+
+ n = kfunc_btf_size;
+ kfunc_btf_size *= sizeof(prog->aux->kfunc_btf_tab->btfs[0]);
+ kfunc_btf_size += sizeof(*prog->aux->kfunc_btf_tab);
+ prog->aux->kfunc_btf_tab = kzalloc(kfunc_btf_size, GFP_KERNEL);
+ if (!prog->aux->kfunc_btf_tab)
+ goto free_prog;
+
+ tab = prog->aux->kfunc_btf_tab;
+ for (i = 0; i < n; i++) {
+ struct btf_mod_pair *p;
+ struct btf *mod_btf;
+
+ mod_btf = btf_get_by_fd(fds[i]);
+ if (IS_ERR(mod_btf)) {
+ err = PTR_ERR(mod_btf);
+ goto free_prog;
+ }
+ if (!btf_is_module(mod_btf)) {
+ err = -EINVAL;
+ btf_put(mod_btf);
+ goto free_prog;
+ }
+
+ p = &tab->btfs[tab->nr_btfs];
+ p->module = btf_try_get_module(mod_btf);
+ if (!p->module) {
+ btf_put(mod_btf);
+ goto free_prog;
+ }
+ p->btf = mod_btf;
+ tab->nr_btfs++;
+ }
+ }
+
prog->expected_attach_type = attr->expected_attach_type;
prog->aux->attach_btf = attach_btf;
prog->aux->attach_btf_id = attr->attach_btf_id;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 206c221453cf..de0670a8b1df 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1632,7 +1632,6 @@ struct bpf_kfunc_desc {
s32 imm;
};
-#define MAX_KFUNC_DESCS 256
struct bpf_kfunc_desc_tab {
struct bpf_kfunc_desc descs[MAX_KFUNC_DESCS];
u32 nr_descs;
@@ -1660,13 +1659,45 @@ find_kfunc_desc(const struct bpf_prog *prog, u32 func_id)
sizeof(tab->descs[0]), kfunc_desc_cmp_by_id);
}
-static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id)
+static struct btf *find_kfunc_desc_btf(struct bpf_verifier_env *env,
+ u32 func_id, s16 offset)
+{
+ struct bpf_kfunc_btf_tab *btf_tab;
+
+ btf_tab = env->prog->aux->kfunc_btf_tab;
+ /* offset can be MAX_KFUNC_DESCS, since index into the array is offset - 1,
+ * as we reserve offset == 0 for btf_vmlinux
+ */
+ if (offset < 0 || offset > MAX_KFUNC_DESCS) {
+ verbose(env, "offset %d is incorrect for kernel function call\n", (int)offset);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (offset) {
+ if (!btf_tab) {
+ verbose(env,
+ "offset %d for kfunc call but no kernel module BTFs passed\n",
+ (int)offset);
+ return ERR_PTR(-EINVAL);
+ } else if (offset > btf_tab->nr_btfs) {
+ verbose(env,
+ "offset %d incorrect for module BTF array with %u descriptors\n",
+ (int)offset, btf_tab->nr_btfs);
+ return ERR_PTR(-EINVAL);
+ }
+ return btf_tab->btfs[offset - 1].btf;
+ }
+ return btf_vmlinux ?: ERR_PTR(-ENOENT);
+}
+
+static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, s16 offset)
{
const struct btf_type *func, *func_proto;
struct bpf_kfunc_desc_tab *tab;
struct bpf_prog_aux *prog_aux;
struct bpf_kfunc_desc *desc;
const char *func_name;
+ struct btf *desc_btf;
unsigned long addr;
int err;
@@ -1699,6 +1730,12 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id)
prog_aux->kfunc_tab = tab;
}
+ desc_btf = find_kfunc_desc_btf(env, func_id, offset);
+ if (IS_ERR(desc_btf)) {
+ verbose(env, "failed to find BTF for kernel function\n");
+ return PTR_ERR(desc_btf);
+ }
+
if (find_kfunc_desc(env->prog, func_id))
return 0;
@@ -1707,20 +1744,20 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id)
return -E2BIG;
}
- func = btf_type_by_id(btf_vmlinux, func_id);
+ func = btf_type_by_id(desc_btf, func_id);
if (!func || !btf_type_is_func(func)) {
verbose(env, "kernel btf_id %u is not a function\n",
func_id);
return -EINVAL;
}
- func_proto = btf_type_by_id(btf_vmlinux, func->type);
+ func_proto = btf_type_by_id(desc_btf, func->type);
if (!func_proto || !btf_type_is_func_proto(func_proto)) {
verbose(env, "kernel function btf_id %u does not have a valid func_proto\n",
func_id);
return -EINVAL;
}
- func_name = btf_name_by_offset(btf_vmlinux, func->name_off);
+ func_name = btf_name_by_offset(desc_btf, func->name_off);
addr = kallsyms_lookup_name(func_name);
if (!addr) {
verbose(env, "cannot find address for kernel function %s\n",
@@ -1731,7 +1768,7 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id)
desc = &tab->descs[tab->nr_descs++];
desc->func_id = func_id;
desc->imm = BPF_CAST_CALL(addr) - __bpf_call_base;
- err = btf_distill_func_proto(&env->log, btf_vmlinux,
+ err = btf_distill_func_proto(&env->log, desc_btf,
func_proto, func_name,
&desc->func_model);
if (!err)
@@ -1815,7 +1852,7 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env)
} else if (bpf_pseudo_call(insn)) {
ret = add_subprog(env, i + insn->imm + 1);
} else {
- ret = add_kfunc_call(env, insn->imm);
+ ret = add_kfunc_call(env, insn->imm, insn->off);
}
if (ret < 0)
@@ -2152,12 +2189,17 @@ static int get_prev_insn_idx(struct bpf_verifier_state *st, int i,
static const char *disasm_kfunc_name(void *data, const struct bpf_insn *insn)
{
const struct btf_type *func;
+ struct btf *desc_btf;
if (insn->src_reg != BPF_PSEUDO_KFUNC_CALL)
return NULL;
- func = btf_type_by_id(btf_vmlinux, insn->imm);
- return btf_name_by_offset(btf_vmlinux, func->name_off);
+ desc_btf = find_kfunc_desc_btf(data, insn->imm, insn->off);
+ if (IS_ERR(desc_btf))
+ return "<error>";
+
+ func = btf_type_by_id(desc_btf, insn->imm);
+ return btf_name_by_offset(desc_btf, func->name_off);
}
/* For given verifier state backtrack_insn() is called from the last insn to
@@ -6482,12 +6524,17 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
const char *func_name, *ptr_type_name;
u32 i, nargs, func_id, ptr_type_id;
const struct btf_param *args;
+ struct btf *desc_btf;
int err;
+ desc_btf = find_kfunc_desc_btf(env, insn->imm, insn->off);
+ if (IS_ERR(desc_btf))
+ return PTR_ERR(desc_btf);
+
func_id = insn->imm;
- func = btf_type_by_id(btf_vmlinux, func_id);
- func_name = btf_name_by_offset(btf_vmlinux, func->name_off);
- func_proto = btf_type_by_id(btf_vmlinux, func->type);
+ func = btf_type_by_id(desc_btf, func_id);
+ func_name = btf_name_by_offset(desc_btf, func->name_off);
+ func_proto = btf_type_by_id(desc_btf, func->type);
if (!env->ops->check_kfunc_call ||
!env->ops->check_kfunc_call(func_id)) {
@@ -6497,7 +6544,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
}
/* Check the arguments */
- err = btf_check_kfunc_arg_match(env, btf_vmlinux, func_id, regs);
+ err = btf_check_kfunc_arg_match(env, desc_btf, func_id, regs);
if (err)
return err;
@@ -6505,15 +6552,15 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
mark_reg_not_init(env, regs, caller_saved[i]);
/* Check return type */
- t = btf_type_skip_modifiers(btf_vmlinux, func_proto->type, NULL);
+ t = btf_type_skip_modifiers(desc_btf, func_proto->type, NULL);
if (btf_type_is_scalar(t)) {
mark_reg_unknown(env, regs, BPF_REG_0);
mark_btf_func_reg_size(env, BPF_REG_0, t->size);
} else if (btf_type_is_ptr(t)) {
- ptr_type = btf_type_skip_modifiers(btf_vmlinux, t->type,
+ ptr_type = btf_type_skip_modifiers(desc_btf, t->type,
&ptr_type_id);
if (!btf_type_is_struct(ptr_type)) {
- ptr_type_name = btf_name_by_offset(btf_vmlinux,
+ ptr_type_name = btf_name_by_offset(desc_btf,
ptr_type->name_off);
verbose(env, "kernel function %s returns pointer type %s %s is not supported\n",
func_name, btf_type_str(ptr_type),
@@ -6521,7 +6568,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
return -EINVAL;
}
mark_reg_known_zero(env, regs, BPF_REG_0);
- regs[BPF_REG_0].btf = btf_vmlinux;
+ regs[BPF_REG_0].btf = desc_btf;
regs[BPF_REG_0].type = PTR_TO_BTF_ID;
regs[BPF_REG_0].btf_id = ptr_type_id;
mark_btf_func_reg_size(env, BPF_REG_0, sizeof(void *));
@@ -6532,7 +6579,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
for (i = 0; i < nargs; i++) {
u32 regno = i + 1;
- t = btf_type_skip_modifiers(btf_vmlinux, args[i].type, NULL);
+ t = btf_type_skip_modifiers(desc_btf, args[i].type, NULL);
if (btf_type_is_ptr(t))
mark_btf_func_reg_size(env, regno, sizeof(void *));
else
@@ -11070,7 +11117,6 @@ static int do_check(struct bpf_verifier_env *env)
env->jmps_processed++;
if (opcode == BPF_CALL) {
if (BPF_SRC(insn->code) != BPF_K ||
- insn->off != 0 ||
(insn->src_reg != BPF_REG_0 &&
insn->src_reg != BPF_PSEUDO_CALL &&
insn->src_reg != BPF_PSEUDO_KFUNC_CALL) ||
@@ -12425,6 +12471,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
func[i]->aux->stack_depth = env->subprog_info[i].stack_depth;
func[i]->jit_requested = 1;
func[i]->aux->kfunc_tab = prog->aux->kfunc_tab;
+ func[i]->aux->kfunc_btf_tab = prog->aux->kfunc_btf_tab;
func[i]->aux->linfo = prog->aux->linfo;
func[i]->aux->nr_linfo = prog->aux->nr_linfo;
func[i]->aux->jited_linfo = prog->aux->jited_linfo;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 791f31dd0abe..4cbb2082a553 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1334,8 +1334,9 @@ union bpf_attr {
/* or valid module BTF object fd or 0 to attach to vmlinux */
__u32 attach_btf_obj_fd;
};
- __u32 :32; /* pad */
+ __u32 kfunc_btf_fds_cnt; /* reuse hole for count of BTF fds below */
__aligned_u64 fd_array; /* array of FDs */
+ __aligned_u64 kfunc_btf_fds; /* array of BTF FDs for module kfunc support */
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls Kumar Kartikeya Dwivedi
@ 2021-08-30 20:01 ` Alexei Starovoitov
2021-08-30 20:03 ` kernel test robot
2021-08-30 22:19 ` kernel test robot
2 siblings, 0 replies; 20+ messages in thread
From: Alexei Starovoitov @ 2021-08-30 20:01 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi
Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
On Mon, Aug 30, 2021 at 11:04:17PM +0530, Kumar Kartikeya Dwivedi wrote:
> This change adds support on the kernel side to allow for BPF programs to
> call kernel module functions. Userspace will prepare an array of module
> BTF fds that is passed in during BPF_PROG_LOAD. In the kernel, the
> module BTF array is placed in the auxilliary struct for bpf_prog.
>
> The verifier then uses insn->off to index into this table. insn->off is
> used by subtracting one from it, as userspace has to set the index of
> array in insn->off incremented by 1. This lets us denote vmlinux btf by
> insn->off == 0, and the prog->aux->kfunc_btf_tab[insn->off - 1] for
> module BTFs.
>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
> include/linux/bpf.h | 1 +
> include/linux/filter.h | 9 ++++
> include/uapi/linux/bpf.h | 3 +-
> kernel/bpf/core.c | 14 ++++++
> kernel/bpf/syscall.c | 55 +++++++++++++++++++++-
> kernel/bpf/verifier.c | 85 ++++++++++++++++++++++++++--------
> tools/include/uapi/linux/bpf.h | 3 +-
> 7 files changed, 147 insertions(+), 23 deletions(-)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index f4c16f19f83e..39f59e5f3a26 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -874,6 +874,7 @@ struct bpf_prog_aux {
> void *jit_data; /* JIT specific data. arch dependent */
> struct bpf_jit_poke_descriptor *poke_tab;
> struct bpf_kfunc_desc_tab *kfunc_tab;
> + struct bpf_kfunc_btf_tab *kfunc_btf_tab;
> u32 size_poke_tab;
> struct bpf_ksym ksym;
> const struct bpf_prog_ops *ops;
> diff --git a/include/linux/filter.h b/include/linux/filter.h
> index 7d248941ecea..46451891633d 100644
> --- a/include/linux/filter.h
> +++ b/include/linux/filter.h
> @@ -592,6 +592,15 @@ struct bpf_prog {
> struct bpf_insn insnsi[];
> };
>
> +#define MAX_KFUNC_DESCS 256
> +/* There can only be at most MAX_KFUNC_DESCS module BTFs for kernel module
> + * function calls.
> + */
> +struct bpf_kfunc_btf_tab {
> + u32 nr_btfs;
> + struct btf_mod_pair btfs[];
> +};
> +
> struct sk_filter {
> refcount_t refcnt;
> struct rcu_head rcu;
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 791f31dd0abe..4cbb2082a553 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -1334,8 +1334,9 @@ union bpf_attr {
> /* or valid module BTF object fd or 0 to attach to vmlinux */
> __u32 attach_btf_obj_fd;
> };
> - __u32 :32; /* pad */
> + __u32 kfunc_btf_fds_cnt; /* reuse hole for count of BTF fds below */
No need for size.
> __aligned_u64 fd_array; /* array of FDs */
> + __aligned_u64 kfunc_btf_fds; /* array of BTF FDs for module kfunc support */
Just reuse fd_array. No need for another array of FDs.
> + tab = prog->aux->kfunc_btf_tab;
> + for (i = 0; i < n; i++) {
> + struct btf_mod_pair *p;
> + struct btf *mod_btf;
> +
> + mod_btf = btf_get_by_fd(fds[i]);
> + if (IS_ERR(mod_btf)) {
> + err = PTR_ERR(mod_btf);
> + goto free_prog;
> + }
> + if (!btf_is_module(mod_btf)) {
> + err = -EINVAL;
> + btf_put(mod_btf);
> + goto free_prog;
> + }
just do that dynamically like access to fd_array is handled in other places.
no need to preload.
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls Kumar Kartikeya Dwivedi
2021-08-30 20:01 ` Alexei Starovoitov
@ 2021-08-30 20:03 ` kernel test robot
2021-08-30 22:19 ` kernel test robot
2 siblings, 0 replies; 20+ messages in thread
From: kernel test robot @ 2021-08-30 20:03 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 23156 bytes --]
Hi Kumar,
[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on bpf-next/master]
url: https://github.com/0day-ci/linux/commits/Kumar-Kartikeya-Dwivedi/Support-kernel-module-function-calls-from-eBPF/20210831-013531
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: arc-allyesconfig (attached as .config)
compiler: arceb-elf-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/e868250a992dc2f10616aa6e2882072bb42bb1c5
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Kumar-Kartikeya-Dwivedi/Support-kernel-module-function-calls-from-eBPF/20210831-013531
git checkout e868250a992dc2f10616aa6e2882072bb42bb1c5
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from include/linux/perf_event.h:25,
from include/linux/trace_events.h:10,
from include/trace/syscall.h:7,
from include/linux/syscalls.h:87,
from kernel/bpf/syscall.c:9:
arch/arc/include/asm/perf_event.h:126:27: warning: 'arc_pmu_cache_map' defined but not used [-Wunused-const-variable=]
126 | static const unsigned int arc_pmu_cache_map[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
| ^~~~~~~~~~~~~~~~~
arch/arc/include/asm/perf_event.h:91:27: warning: 'arc_pmu_ev_hw_map' defined but not used [-Wunused-const-variable=]
91 | static const char * const arc_pmu_ev_hw_map[] = {
| ^~~~~~~~~~~~~~~~~
kernel/bpf/syscall.c: In function 'bpf_prog_load':
>> kernel/bpf/syscall.c:2402:1: warning: the frame size of 1164 bytes is larger than 1024 bytes [-Wframe-larger-than=]
2402 | }
| ^
vim +2402 kernel/bpf/syscall.c
09756af46893c1 Alexei Starovoitov 2014-09-26 2160
af2ac3e13e4575 Alexei Starovoitov 2021-05-13 2161 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
09756af46893c1 Alexei Starovoitov 2014-09-26 2162 {
09756af46893c1 Alexei Starovoitov 2014-09-26 2163 enum bpf_prog_type type = attr->prog_type;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2164 struct bpf_prog *prog, *dst_prog = NULL;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2165 struct btf *attach_btf = NULL;
09756af46893c1 Alexei Starovoitov 2014-09-26 2166 char license[128];
09756af46893c1 Alexei Starovoitov 2014-09-26 2167 bool is_gpl;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2168 int err;
09756af46893c1 Alexei Starovoitov 2014-09-26 2169
09756af46893c1 Alexei Starovoitov 2014-09-26 2170 if (CHECK_ATTR(BPF_PROG_LOAD))
09756af46893c1 Alexei Starovoitov 2014-09-26 2171 return -EINVAL;
09756af46893c1 Alexei Starovoitov 2014-09-26 2172
c240eff63a1cf1 Jiong Wang 2019-05-24 2173 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
c240eff63a1cf1 Jiong Wang 2019-05-24 2174 BPF_F_ANY_ALIGNMENT |
10d274e880eb20 Alexei Starovoitov 2019-08-22 2175 BPF_F_TEST_STATE_FREQ |
1e6c62a8821557 Alexei Starovoitov 2020-08-27 2176 BPF_F_SLEEPABLE |
c240eff63a1cf1 Jiong Wang 2019-05-24 2177 BPF_F_TEST_RND_HI32))
e07b98d9bffe41 David S. Miller 2017-05-10 2178 return -EINVAL;
e07b98d9bffe41 David S. Miller 2017-05-10 2179
e9ee9efc0d1765 David Miller 2018-11-30 2180 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
e9ee9efc0d1765 David Miller 2018-11-30 2181 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2c78ee898d8f10 Alexei Starovoitov 2020-05-13 2182 !bpf_capable())
e9ee9efc0d1765 David Miller 2018-11-30 2183 return -EPERM;
e9ee9efc0d1765 David Miller 2018-11-30 2184
09756af46893c1 Alexei Starovoitov 2014-09-26 2185 /* copy eBPF program license from user space */
af2ac3e13e4575 Alexei Starovoitov 2021-05-13 2186 if (strncpy_from_bpfptr(license,
af2ac3e13e4575 Alexei Starovoitov 2021-05-13 2187 make_bpfptr(attr->license, uattr.is_kernel),
09756af46893c1 Alexei Starovoitov 2014-09-26 2188 sizeof(license) - 1) < 0)
09756af46893c1 Alexei Starovoitov 2014-09-26 2189 return -EFAULT;
09756af46893c1 Alexei Starovoitov 2014-09-26 2190 license[sizeof(license) - 1] = 0;
09756af46893c1 Alexei Starovoitov 2014-09-26 2191
09756af46893c1 Alexei Starovoitov 2014-09-26 2192 /* eBPF programs must be GPL compatible to use GPL-ed functions */
09756af46893c1 Alexei Starovoitov 2014-09-26 2193 is_gpl = license_is_gpl_compatible(license);
09756af46893c1 Alexei Starovoitov 2014-09-26 2194
c04c0d2b968ac4 Alexei Starovoitov 2019-04-01 2195 if (attr->insn_cnt == 0 ||
2c78ee898d8f10 Alexei Starovoitov 2020-05-13 2196 attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
ef0915cacd04c9 Daniel Borkmann 2016-12-07 2197 return -E2BIG;
80b7d81912d807 Chenbo Feng 2017-05-31 2198 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
80b7d81912d807 Chenbo Feng 2017-05-31 2199 type != BPF_PROG_TYPE_CGROUP_SKB &&
2c78ee898d8f10 Alexei Starovoitov 2020-05-13 2200 !bpf_capable())
2c78ee898d8f10 Alexei Starovoitov 2020-05-13 2201 return -EPERM;
2c78ee898d8f10 Alexei Starovoitov 2020-05-13 2202
b338cb921e6739 Maciej Żenczykowski 2020-06-20 2203 if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
2c78ee898d8f10 Alexei Starovoitov 2020-05-13 2204 return -EPERM;
2c78ee898d8f10 Alexei Starovoitov 2020-05-13 2205 if (is_perfmon_prog_type(type) && !perfmon_capable())
1be7f75d1668d6 Alexei Starovoitov 2015-10-07 2206 return -EPERM;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2207 if (attr->kfunc_btf_fds_cnt > MAX_KFUNC_DESCS)
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2208 return -E2BIG;
1be7f75d1668d6 Alexei Starovoitov 2015-10-07 2209
290248a5b7d829 Andrii Nakryiko 2020-12-03 2210 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
290248a5b7d829 Andrii Nakryiko 2020-12-03 2211 * or btf, we need to check which one it is
290248a5b7d829 Andrii Nakryiko 2020-12-03 2212 */
290248a5b7d829 Andrii Nakryiko 2020-12-03 2213 if (attr->attach_prog_fd) {
290248a5b7d829 Andrii Nakryiko 2020-12-03 2214 dst_prog = bpf_prog_get(attr->attach_prog_fd);
290248a5b7d829 Andrii Nakryiko 2020-12-03 2215 if (IS_ERR(dst_prog)) {
290248a5b7d829 Andrii Nakryiko 2020-12-03 2216 dst_prog = NULL;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2217 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
290248a5b7d829 Andrii Nakryiko 2020-12-03 2218 if (IS_ERR(attach_btf))
290248a5b7d829 Andrii Nakryiko 2020-12-03 2219 return -EINVAL;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2220 if (!btf_is_kernel(attach_btf)) {
8bdd8e275ede97 Andrii Nakryiko 2020-12-07 2221 /* attaching through specifying bpf_prog's BTF
8bdd8e275ede97 Andrii Nakryiko 2020-12-07 2222 * objects directly might be supported eventually
8bdd8e275ede97 Andrii Nakryiko 2020-12-07 2223 */
290248a5b7d829 Andrii Nakryiko 2020-12-03 2224 btf_put(attach_btf);
8bdd8e275ede97 Andrii Nakryiko 2020-12-07 2225 return -ENOTSUPP;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2226 }
290248a5b7d829 Andrii Nakryiko 2020-12-03 2227 }
290248a5b7d829 Andrii Nakryiko 2020-12-03 2228 } else if (attr->attach_btf_id) {
290248a5b7d829 Andrii Nakryiko 2020-12-03 2229 /* fall back to vmlinux BTF, if BTF type ID is specified */
290248a5b7d829 Andrii Nakryiko 2020-12-03 2230 attach_btf = bpf_get_btf_vmlinux();
290248a5b7d829 Andrii Nakryiko 2020-12-03 2231 if (IS_ERR(attach_btf))
290248a5b7d829 Andrii Nakryiko 2020-12-03 2232 return PTR_ERR(attach_btf);
290248a5b7d829 Andrii Nakryiko 2020-12-03 2233 if (!attach_btf)
290248a5b7d829 Andrii Nakryiko 2020-12-03 2234 return -EINVAL;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2235 btf_get(attach_btf);
290248a5b7d829 Andrii Nakryiko 2020-12-03 2236 }
290248a5b7d829 Andrii Nakryiko 2020-12-03 2237
aac3fc320d9404 Andrey Ignatov 2018-03-30 2238 bpf_prog_load_fixup_attach_type(attr);
ccfe29eb29c2ed Alexei Starovoitov 2019-10-15 2239 if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
290248a5b7d829 Andrii Nakryiko 2020-12-03 2240 attach_btf, attr->attach_btf_id,
290248a5b7d829 Andrii Nakryiko 2020-12-03 2241 dst_prog)) {
290248a5b7d829 Andrii Nakryiko 2020-12-03 2242 if (dst_prog)
290248a5b7d829 Andrii Nakryiko 2020-12-03 2243 bpf_prog_put(dst_prog);
290248a5b7d829 Andrii Nakryiko 2020-12-03 2244 if (attach_btf)
290248a5b7d829 Andrii Nakryiko 2020-12-03 2245 btf_put(attach_btf);
5e43f899b03a34 Andrey Ignatov 2018-03-30 2246 return -EINVAL;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2247 }
5e43f899b03a34 Andrey Ignatov 2018-03-30 2248
09756af46893c1 Alexei Starovoitov 2014-09-26 2249 /* plain bpf_prog allocation */
09756af46893c1 Alexei Starovoitov 2014-09-26 2250 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
290248a5b7d829 Andrii Nakryiko 2020-12-03 2251 if (!prog) {
290248a5b7d829 Andrii Nakryiko 2020-12-03 2252 if (dst_prog)
290248a5b7d829 Andrii Nakryiko 2020-12-03 2253 bpf_prog_put(dst_prog);
290248a5b7d829 Andrii Nakryiko 2020-12-03 2254 if (attach_btf)
290248a5b7d829 Andrii Nakryiko 2020-12-03 2255 btf_put(attach_btf);
09756af46893c1 Alexei Starovoitov 2014-09-26 2256 return -ENOMEM;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2257 }
09756af46893c1 Alexei Starovoitov 2014-09-26 2258
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2259 if (attr->kfunc_btf_fds_cnt) {
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2260 struct bpf_kfunc_btf_tab *tab;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2261 int fds[MAX_KFUNC_DESCS], i;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2262 bpfptr_t kfunc_btf_fds;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2263 u32 kfunc_btf_size, n;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2264
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2265 kfunc_btf_size = min_t(u32, MAX_KFUNC_DESCS, attr->kfunc_btf_fds_cnt);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2266 kfunc_btf_fds = make_bpfptr(attr->kfunc_btf_fds, uattr.is_kernel);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2267
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2268 err = -EFAULT;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2269 if (copy_from_bpfptr(fds, kfunc_btf_fds, kfunc_btf_size * sizeof(int)))
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2270 goto free_prog;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2271
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2272 err = -ENOMEM;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2273
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2274 n = kfunc_btf_size;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2275 kfunc_btf_size *= sizeof(prog->aux->kfunc_btf_tab->btfs[0]);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2276 kfunc_btf_size += sizeof(*prog->aux->kfunc_btf_tab);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2277 prog->aux->kfunc_btf_tab = kzalloc(kfunc_btf_size, GFP_KERNEL);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2278 if (!prog->aux->kfunc_btf_tab)
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2279 goto free_prog;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2280
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2281 tab = prog->aux->kfunc_btf_tab;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2282 for (i = 0; i < n; i++) {
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2283 struct btf_mod_pair *p;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2284 struct btf *mod_btf;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2285
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2286 mod_btf = btf_get_by_fd(fds[i]);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2287 if (IS_ERR(mod_btf)) {
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2288 err = PTR_ERR(mod_btf);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2289 goto free_prog;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2290 }
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2291 if (!btf_is_module(mod_btf)) {
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2292 err = -EINVAL;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2293 btf_put(mod_btf);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2294 goto free_prog;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2295 }
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2296
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2297 p = &tab->btfs[tab->nr_btfs];
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2298 p->module = btf_try_get_module(mod_btf);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2299 if (!p->module) {
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2300 btf_put(mod_btf);
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2301 goto free_prog;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2302 }
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2303 p->btf = mod_btf;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2304 tab->nr_btfs++;
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2305 }
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2306 }
e868250a992dc2 Kumar Kartikeya Dwivedi 2021-08-30 2307
5e43f899b03a34 Andrey Ignatov 2018-03-30 2308 prog->expected_attach_type = attr->expected_attach_type;
290248a5b7d829 Andrii Nakryiko 2020-12-03 2309 prog->aux->attach_btf = attach_btf;
ccfe29eb29c2ed Alexei Starovoitov 2019-10-15 2310 prog->aux->attach_btf_id = attr->attach_btf_id;
3aac1ead5eb6b7 Toke Høiland-Jørgensen 2020-09-29 2311 prog->aux->dst_prog = dst_prog;
9a18eedb145d08 Jakub Kicinski 2017-12-27 2312 prog->aux->offload_requested = !!attr->prog_ifindex;
1e6c62a8821557 Alexei Starovoitov 2020-08-27 2313 prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
9a18eedb145d08 Jakub Kicinski 2017-12-27 2314
afdb09c720b62b Chenbo Feng 2017-10-18 2315 err = security_bpf_prog_alloc(prog->aux);
aaac3ba95e4c8b Alexei Starovoitov 2015-10-07 2316 if (err)
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2317 goto free_prog;
afdb09c720b62b Chenbo Feng 2017-10-18 2318
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2319 prog->aux->user = get_current_user();
09756af46893c1 Alexei Starovoitov 2014-09-26 2320 prog->len = attr->insn_cnt;
09756af46893c1 Alexei Starovoitov 2014-09-26 2321
09756af46893c1 Alexei Starovoitov 2014-09-26 2322 err = -EFAULT;
af2ac3e13e4575 Alexei Starovoitov 2021-05-13 2323 if (copy_from_bpfptr(prog->insns,
af2ac3e13e4575 Alexei Starovoitov 2021-05-13 2324 make_bpfptr(attr->insns, uattr.is_kernel),
aafe6ae9cee32d Daniel Borkmann 2016-12-18 2325 bpf_prog_insn_size(prog)) != 0)
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2326 goto free_prog_sec;
09756af46893c1 Alexei Starovoitov 2014-09-26 2327
09756af46893c1 Alexei Starovoitov 2014-09-26 2328 prog->orig_prog = NULL;
a91263d520246b Daniel Borkmann 2015-09-30 2329 prog->jited = 0;
09756af46893c1 Alexei Starovoitov 2014-09-26 2330
85192dbf4de087 Andrii Nakryiko 2019-11-17 2331 atomic64_set(&prog->aux->refcnt, 1);
a91263d520246b Daniel Borkmann 2015-09-30 2332 prog->gpl_compatible = is_gpl ? 1 : 0;
09756af46893c1 Alexei Starovoitov 2014-09-26 2333
9a18eedb145d08 Jakub Kicinski 2017-12-27 2334 if (bpf_prog_is_dev_bound(prog->aux)) {
ab3f0063c48c26 Jakub Kicinski 2017-11-03 2335 err = bpf_prog_offload_init(prog, attr);
ab3f0063c48c26 Jakub Kicinski 2017-11-03 2336 if (err)
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2337 goto free_prog_sec;
ab3f0063c48c26 Jakub Kicinski 2017-11-03 2338 }
ab3f0063c48c26 Jakub Kicinski 2017-11-03 2339
09756af46893c1 Alexei Starovoitov 2014-09-26 2340 /* find program type: socket_filter vs tracing_filter */
09756af46893c1 Alexei Starovoitov 2014-09-26 2341 err = find_prog_type(type, prog);
09756af46893c1 Alexei Starovoitov 2014-09-26 2342 if (err < 0)
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2343 goto free_prog_sec;
09756af46893c1 Alexei Starovoitov 2014-09-26 2344
9285ec4c8b61d4 Jason A. Donenfeld 2019-06-21 2345 prog->aux->load_time = ktime_get_boottime_ns();
8e7ae2518f5265 Martin KaFai Lau 2020-03-13 2346 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
8e7ae2518f5265 Martin KaFai Lau 2020-03-13 2347 sizeof(attr->prog_name));
8e7ae2518f5265 Martin KaFai Lau 2020-03-13 2348 if (err < 0)
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2349 goto free_prog_sec;
cb4d2b3f03d8ee Martin KaFai Lau 2017-09-27 2350
09756af46893c1 Alexei Starovoitov 2014-09-26 2351 /* run eBPF verifier */
838e96904ff3fc Yonghong Song 2018-11-19 2352 err = bpf_check(&prog, attr, uattr);
09756af46893c1 Alexei Starovoitov 2014-09-26 2353 if (err < 0)
09756af46893c1 Alexei Starovoitov 2014-09-26 2354 goto free_used_maps;
09756af46893c1 Alexei Starovoitov 2014-09-26 2355
d1c55ab5e41fcd Daniel Borkmann 2016-05-13 2356 prog = bpf_prog_select_runtime(prog, &err);
04fd61ab36ec06 Alexei Starovoitov 2015-05-19 2357 if (err < 0)
04fd61ab36ec06 Alexei Starovoitov 2015-05-19 2358 goto free_used_maps;
09756af46893c1 Alexei Starovoitov 2014-09-26 2359
dc4bb0e2356149 Martin KaFai Lau 2017-06-05 2360 err = bpf_prog_alloc_id(prog);
dc4bb0e2356149 Martin KaFai Lau 2017-06-05 2361 if (err)
dc4bb0e2356149 Martin KaFai Lau 2017-06-05 2362 goto free_used_maps;
dc4bb0e2356149 Martin KaFai Lau 2017-06-05 2363
c751798aa224fa Daniel Borkmann 2019-08-23 2364 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
c751798aa224fa Daniel Borkmann 2019-08-23 2365 * effectively publicly exposed. However, retrieving via
c751798aa224fa Daniel Borkmann 2019-08-23 2366 * bpf_prog_get_fd_by_id() will take another reference,
c751798aa224fa Daniel Borkmann 2019-08-23 2367 * therefore it cannot be gone underneath us.
c751798aa224fa Daniel Borkmann 2019-08-23 2368 *
c751798aa224fa Daniel Borkmann 2019-08-23 2369 * Only for the time /after/ successful bpf_prog_new_fd()
c751798aa224fa Daniel Borkmann 2019-08-23 2370 * and before returning to userspace, we might just hold
c751798aa224fa Daniel Borkmann 2019-08-23 2371 * one reference and any parallel close on that fd could
c751798aa224fa Daniel Borkmann 2019-08-23 2372 * rip everything out. Hence, below notifications must
c751798aa224fa Daniel Borkmann 2019-08-23 2373 * happen before bpf_prog_new_fd().
c751798aa224fa Daniel Borkmann 2019-08-23 2374 *
c751798aa224fa Daniel Borkmann 2019-08-23 2375 * Also, any failure handling from this point onwards must
c751798aa224fa Daniel Borkmann 2019-08-23 2376 * be using bpf_prog_put() given the program is exposed.
b16d9aa4c2b90a Martin KaFai Lau 2017-06-05 2377 */
74451e66d516c5 Daniel Borkmann 2017-02-16 2378 bpf_prog_kallsyms_add(prog);
6ee52e2a3fe4ea Song Liu 2019-01-17 2379 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
bae141f54be83b Daniel Borkmann 2019-12-06 2380 bpf_audit_prog(prog, BPF_AUDIT_LOAD);
c751798aa224fa Daniel Borkmann 2019-08-23 2381
c751798aa224fa Daniel Borkmann 2019-08-23 2382 err = bpf_prog_new_fd(prog);
c751798aa224fa Daniel Borkmann 2019-08-23 2383 if (err < 0)
c751798aa224fa Daniel Borkmann 2019-08-23 2384 bpf_prog_put(prog);
09756af46893c1 Alexei Starovoitov 2014-09-26 2385 return err;
09756af46893c1 Alexei Starovoitov 2014-09-26 2386
09756af46893c1 Alexei Starovoitov 2014-09-26 2387 free_used_maps:
cd7455f1013ef9 Daniel Borkmann 2019-10-22 2388 /* In case we have subprogs, we need to wait for a grace
cd7455f1013ef9 Daniel Borkmann 2019-10-22 2389 * period before we can tear down JIT memory since symbols
cd7455f1013ef9 Daniel Borkmann 2019-10-22 2390 * are already exposed under kallsyms.
cd7455f1013ef9 Daniel Borkmann 2019-10-22 2391 */
cd7455f1013ef9 Daniel Borkmann 2019-10-22 2392 __bpf_prog_put_noref(prog, prog->aux->func_cnt);
cd7455f1013ef9 Daniel Borkmann 2019-10-22 2393 return err;
afdb09c720b62b Chenbo Feng 2017-10-18 2394 free_prog_sec:
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2395 free_uid(prog->aux->user);
afdb09c720b62b Chenbo Feng 2017-10-18 2396 security_bpf_prog_free(prog->aux);
3ac1f01b43b6e2 Roman Gushchin 2020-12-01 2397 free_prog:
22dc4a0f5ed11b Andrii Nakryiko 2020-12-03 2398 if (prog->aux->attach_btf)
22dc4a0f5ed11b Andrii Nakryiko 2020-12-03 2399 btf_put(prog->aux->attach_btf);
09756af46893c1 Alexei Starovoitov 2014-09-26 2400 bpf_prog_free(prog);
09756af46893c1 Alexei Starovoitov 2014-09-26 2401 return err;
09756af46893c1 Alexei Starovoitov 2014-09-26 @2402 }
09756af46893c1 Alexei Starovoitov 2014-09-26 2403
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 68479 bytes --]
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls Kumar Kartikeya Dwivedi
2021-08-30 20:01 ` Alexei Starovoitov
2021-08-30 20:03 ` kernel test robot
@ 2021-08-30 22:19 ` kernel test robot
2 siblings, 0 replies; 20+ messages in thread
From: kernel test robot @ 2021-08-30 22:19 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 1419 bytes --]
Hi Kumar,
[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on bpf-next/master]
url: https://github.com/0day-ci/linux/commits/Kumar-Kartikeya-Dwivedi/Support-kernel-module-function-calls-from-eBPF/20210831-013531
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: um-x86_64_defconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/e868250a992dc2f10616aa6e2882072bb42bb1c5
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Kumar-Kartikeya-Dwivedi/Support-kernel-module-function-calls-from-eBPF/20210831-013531
git checkout e868250a992dc2f10616aa6e2882072bb42bb1c5
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=um SUBARCH=x86_64 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
/usr/bin/ld: kernel/bpf/core.o: in function `bpf_prog_free_deferred':
>> core.c:(.text+0x7b0): undefined reference to `btf_put'
collect2: error: ld returned 1 exit status
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 9615 bytes --]
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH bpf-next RFC v1 2/8] bpf: Be conservative during verification for invalid kfunc calls
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls Kumar Kartikeya Dwivedi
` (5 subsequent siblings)
7 siblings, 0 replies; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
This change modifies the BPF verifier to only return error for invalid
kfunc calls specially marked by userspace (with insn->imm == 0) after
the verifier has eliminated dead instructions. This can be handled in
the fixup stage, and skip processing during add and check stages.
If such an invalid call is dropped, the fixup stage will not encounter
insn->imm as 0, otherwise it bails out and returns an error.
This can be used by userspace to use branches to call old and new kfunc
helpers across kernel versions by setting the rodata map value before
loading the BPF program, enhancing runtime portability. The next patch
introduces libbpf support for this.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
kernel/bpf/verifier.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index de0670a8b1df..9904b9a96b04 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1730,6 +1730,15 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, s16 offset)
prog_aux->kfunc_tab = tab;
}
+ /* btf_idr allocates IDs from 1, so func_id == 0 is always invalid, but
+ * instead of returning an error, be conservative and wait until the
+ * code elimination pass before returning error, so that invalid calls
+ * that get pruned out can be in BPF programs loaded from userspace.
+ * It is also required that offset be 0.
+ */
+ if (!func_id && !offset)
+ return 0;
+
desc_btf = find_kfunc_desc_btf(env, func_id, offset);
if (IS_ERR(desc_btf)) {
verbose(env, "failed to find BTF for kernel function\n");
@@ -6527,6 +6536,10 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
struct btf *desc_btf;
int err;
+ /* skip for now, but return error when we find this in fixup_kfunc_call */
+ if (!insn->imm)
+ return 0;
+
desc_btf = find_kfunc_desc_btf(env, insn->imm, insn->off);
if (IS_ERR(desc_btf))
return PTR_ERR(desc_btf);
@@ -12658,6 +12671,11 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env,
{
const struct bpf_kfunc_desc *desc;
+ if (!insn->imm) {
+ verbose(env, "invalid kernel function call not eliminated in verifier pass\n");
+ return -EINVAL;
+ }
+
/* insn->imm has the btf func_id. Replace it with
* an address (relative to __bpf_base_call).
*/
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 2/8] bpf: Be conservative during verification for invalid kfunc calls Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-09-01 0:55 ` Andrii Nakryiko
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 4/8] libbpf: Resolve invalid kfunc calls with imm = 0, off = 0 Kumar Kartikeya Dwivedi
` (4 subsequent siblings)
7 siblings, 1 reply; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
tools/lib/bpf/bpf.c | 3 ++
tools/lib/bpf/libbpf.c | 71 +++++++++++++++++++++++++++++++--
tools/lib/bpf/libbpf_internal.h | 2 +
3 files changed, 73 insertions(+), 3 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 2401fad090c5..df2d1ceba146 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -265,6 +265,9 @@ int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr)
attr.line_info_cnt = load_attr->line_info_cnt;
attr.line_info = ptr_to_u64(load_attr->line_info);
+ attr.kfunc_btf_fds = ptr_to_u64(load_attr->kfunc_btf_fds);
+ attr.kfunc_btf_fds_cnt = load_attr->kfunc_btf_fds_cnt;
+
if (load_attr->name)
memcpy(attr.prog_name, load_attr->name,
min(strlen(load_attr->name), (size_t)BPF_OBJ_NAME_LEN - 1));
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 88d8825fc6f6..c4677ef97caa 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -419,6 +419,12 @@ struct extern_desc {
/* local btf_id of the ksym extern's type. */
__u32 type_id;
+ /* offset to be patched in for insn->off,
+ * this is 0 for btf_vmlinux, and index + 1
+ * for module BTF, where index is BTF index in
+ * obj->kfunc_btf_fds.fds array
+ */
+ __u32 offset;
} ksym;
};
};
@@ -515,6 +521,13 @@ struct bpf_object {
void *priv;
bpf_object_clear_priv_t clear_priv;
+ struct {
+ struct hashmap *map;
+ int *fds;
+ size_t cap_cnt;
+ __u32 n_fds;
+ } kfunc_btf_fds;
+
char path[];
};
#define obj_elf_valid(o) ((o)->efile.elf)
@@ -5327,6 +5340,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
ext = &obj->externs[relo->sym_off];
insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
insn[0].imm = ext->ksym.kernel_btf_id;
+ insn[0].off = ext->ksym.offset;
break;
case RELO_SUBPROG_ADDR:
if (insn[0].src_reg != BPF_PSEUDO_FUNC) {
@@ -6122,6 +6136,11 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
load_attr.log_level = prog->log_level;
load_attr.prog_flags = prog->prog_flags;
+ if (prog->obj->kfunc_btf_fds.n_fds) {
+ load_attr.kfunc_btf_fds = prog->obj->kfunc_btf_fds.fds;
+ load_attr.kfunc_btf_fds_cnt = prog->obj->kfunc_btf_fds.n_fds;
+ }
+
if (prog->obj->gen_loader) {
bpf_gen__prog_load(prog->obj->gen_loader, &load_attr,
prog - prog->obj->programs);
@@ -6723,9 +6742,49 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
}
if (kern_btf != obj->btf_vmlinux) {
- pr_warn("extern (func ksym) '%s': function in kernel module is not supported\n",
- ext->name);
- return -ENOTSUP;
+ size_t index;
+ void *value;
+
+ /* Lazy initialize btf->fd index map */
+ if (!obj->kfunc_btf_fds.map) {
+ obj->kfunc_btf_fds.map = hashmap__new(bpf_core_hash_fn, bpf_core_equal_fn,
+ NULL);
+ if (!obj->kfunc_btf_fds.map)
+ return -ENOMEM;
+
+ obj->kfunc_btf_fds.fds = calloc(8, sizeof(*obj->kfunc_btf_fds.fds));
+ if (!obj->kfunc_btf_fds.fds) {
+ hashmap__free(obj->kfunc_btf_fds.map);
+ return -ENOMEM;
+ }
+ obj->kfunc_btf_fds.cap_cnt = 8;
+ }
+
+ if (!hashmap__find(obj->kfunc_btf_fds.map, kern_btf, &value)) {
+ size_t *cap_cnt = &obj->kfunc_btf_fds.cap_cnt;
+ /* Not found, insert BTF fd into slot, and grab next
+ * index from the fd array.
+ */
+ ret = libbpf_ensure_mem((void **)&obj->kfunc_btf_fds.fds,
+ cap_cnt, sizeof(int), obj->kfunc_btf_fds.n_fds + 1);
+ if (ret)
+ return ret;
+ index = obj->kfunc_btf_fds.n_fds++;
+ obj->kfunc_btf_fds.fds[index] = kern_btf_fd;
+ value = (void *)index;
+ ret = hashmap__add(obj->kfunc_btf_fds.map, kern_btf, &value);
+ if (ret)
+ return ret;
+
+ } else {
+ index = (size_t)value;
+ }
+ /* index starts from 0, so shift offset by 1 as offset == 0 is reserved
+ * for btf_vmlinux in the kernel
+ */
+ ext->ksym.offset = index + 1;
+ } else {
+ ext->ksym.offset = 0;
}
kern_func = btf__type_by_id(kern_btf, kfunc_id);
@@ -6901,6 +6960,12 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
err = bpf_gen__finish(obj->gen_loader);
}
+ /* clean up kfunc_btf */
+ hashmap__free(obj->kfunc_btf_fds.map);
+ obj->kfunc_btf_fds.map = NULL;
+ zfree(&obj->kfunc_btf_fds.fds);
+ obj->kfunc_btf_fds.cap_cnt = obj->kfunc_btf_fds.n_fds = 0;
+
/* clean up module BTFs */
for (i = 0; i < obj->btf_module_cnt; i++) {
close(obj->btf_modules[i].fd);
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 533b0211f40a..701719d9caaf 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -276,6 +276,8 @@ struct bpf_prog_load_params {
__u32 log_level;
char *log_buf;
size_t log_buf_sz;
+ int *kfunc_btf_fds;
+ __u32 kfunc_btf_fds_cnt;
};
int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr);
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls Kumar Kartikeya Dwivedi
@ 2021-09-01 0:55 ` Andrii Nakryiko
2021-09-01 2:27 ` Kumar Kartikeya Dwivedi
0 siblings, 1 reply; 20+ messages in thread
From: Andrii Nakryiko @ 2021-09-01 0:55 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi
Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen,
Networking
On Mon, Aug 30, 2021 at 10:34 AM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>
-ENOCOMMITMESSAGE?
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
> tools/lib/bpf/bpf.c | 3 ++
> tools/lib/bpf/libbpf.c | 71 +++++++++++++++++++++++++++++++--
> tools/lib/bpf/libbpf_internal.h | 2 +
> 3 files changed, 73 insertions(+), 3 deletions(-)
>
[...]
> @@ -515,6 +521,13 @@ struct bpf_object {
> void *priv;
> bpf_object_clear_priv_t clear_priv;
>
> + struct {
> + struct hashmap *map;
> + int *fds;
> + size_t cap_cnt;
> + __u32 n_fds;
> + } kfunc_btf_fds;
> +
> char path[];
> };
> #define obj_elf_valid(o) ((o)->efile.elf)
> @@ -5327,6 +5340,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
> ext = &obj->externs[relo->sym_off];
> insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
> insn[0].imm = ext->ksym.kernel_btf_id;
> + insn[0].off = ext->ksym.offset;
Just a few lines above we use insn[1].imm =
ext->ksym.kernel_btf_obj_fd; for EXT_KSYM (for variables). Why are you
inventing a new form if we already have a pretty consistent pattern?
> break;
> case RELO_SUBPROG_ADDR:
> if (insn[0].src_reg != BPF_PSEUDO_FUNC) {
[...]
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls
2021-09-01 0:55 ` Andrii Nakryiko
@ 2021-09-01 2:27 ` Kumar Kartikeya Dwivedi
2021-09-01 2:59 ` Alexei Starovoitov
0 siblings, 1 reply; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-09-01 2:27 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen,
Networking
On Wed, Sep 01, 2021 at 06:25:14AM IST, Andrii Nakryiko wrote:
> On Mon, Aug 30, 2021 at 10:34 AM Kumar Kartikeya Dwivedi
> <memxor@gmail.com> wrote:
> >
>
> -ENOCOMMITMESSAGE?
>
> > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> > ---
> > tools/lib/bpf/bpf.c | 3 ++
> > tools/lib/bpf/libbpf.c | 71 +++++++++++++++++++++++++++++++--
> > tools/lib/bpf/libbpf_internal.h | 2 +
> > 3 files changed, 73 insertions(+), 3 deletions(-)
> >
>
> [...]
>
> > @@ -515,6 +521,13 @@ struct bpf_object {
> > void *priv;
> > bpf_object_clear_priv_t clear_priv;
> >
> > + struct {
> > + struct hashmap *map;
> > + int *fds;
> > + size_t cap_cnt;
> > + __u32 n_fds;
> > + } kfunc_btf_fds;
> > +
> > char path[];
> > };
> > #define obj_elf_valid(o) ((o)->efile.elf)
> > @@ -5327,6 +5340,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
> > ext = &obj->externs[relo->sym_off];
> > insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
> > insn[0].imm = ext->ksym.kernel_btf_id;
> > + insn[0].off = ext->ksym.offset;
>
> Just a few lines above we use insn[1].imm =
> ext->ksym.kernel_btf_obj_fd; for EXT_KSYM (for variables). Why are you
> inventing a new form if we already have a pretty consistent pattern?
>
That makes sense. This is all new to me, so I went with what was described in
e6ac2450d6de (bpf: Support bpf program calling kernel function), but I'll rework
it to encode the btf fd like that in the next spin. It also makes the everything
far simpler.
> > break;
> > case RELO_SUBPROG_ADDR:
> > if (insn[0].src_reg != BPF_PSEUDO_FUNC) {
>
> [...]
--
Kartikeya
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls
2021-09-01 2:27 ` Kumar Kartikeya Dwivedi
@ 2021-09-01 2:59 ` Alexei Starovoitov
2021-09-01 3:38 ` Andrii Nakryiko
0 siblings, 1 reply; 20+ messages in thread
From: Alexei Starovoitov @ 2021-09-01 2:59 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi
Cc: Andrii Nakryiko, bpf, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen,
Networking
On Tue, Aug 31, 2021 at 7:27 PM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
> > > @@ -5327,6 +5340,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
> > > ext = &obj->externs[relo->sym_off];
> > > insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
> > > insn[0].imm = ext->ksym.kernel_btf_id;
> > > + insn[0].off = ext->ksym.offset;
> >
> > Just a few lines above we use insn[1].imm =
> > ext->ksym.kernel_btf_obj_fd; for EXT_KSYM (for variables). Why are you
> > inventing a new form if we already have a pretty consistent pattern?
> >
>
> That makes sense. This is all new to me, so I went with what was described in
> e6ac2450d6de (bpf: Support bpf program calling kernel function), but I'll rework
> it to encode the btf fd like that in the next spin. It also makes the everything
> far simpler.
Hmm. kfunc call is a call insn. There is no imm[1].
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls
2021-09-01 2:59 ` Alexei Starovoitov
@ 2021-09-01 3:38 ` Andrii Nakryiko
0 siblings, 0 replies; 20+ messages in thread
From: Andrii Nakryiko @ 2021-09-01 3:38 UTC (permalink / raw)
To: Alexei Starovoitov
Cc: Kumar Kartikeya Dwivedi, bpf, Alexei Starovoitov,
Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu,
Yonghong Song, Jesper Dangaard Brouer,
Toke Høiland-Jørgensen, Networking
On Tue, Aug 31, 2021 at 7:59 PM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Tue, Aug 31, 2021 at 7:27 PM Kumar Kartikeya Dwivedi
> <memxor@gmail.com> wrote:
> > > > @@ -5327,6 +5340,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
> > > > ext = &obj->externs[relo->sym_off];
> > > > insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
> > > > insn[0].imm = ext->ksym.kernel_btf_id;
> > > > + insn[0].off = ext->ksym.offset;
> > >
> > > Just a few lines above we use insn[1].imm =
> > > ext->ksym.kernel_btf_obj_fd; for EXT_KSYM (for variables). Why are you
> > > inventing a new form if we already have a pretty consistent pattern?
> > >
> >
> > That makes sense. This is all new to me, so I went with what was described in
> > e6ac2450d6de (bpf: Support bpf program calling kernel function), but I'll rework
> > it to encode the btf fd like that in the next spin. It also makes the everything
> > far simpler.
>
> Hmm. kfunc call is a call insn. There is no imm[1].
Doh, right :( Never mind, we'll need to use fd_array for this.
Either way, I don't think hashmap use is warranted here to find a BTF
slot. Let's just do linear search, it's not like we are going to have
thousands of module BTFs used by any single BPF program, right?
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH bpf-next RFC v1 4/8] libbpf: Resolve invalid kfunc calls with imm = 0, off = 0
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
` (2 preceding siblings ...)
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-09-01 0:35 ` Andrii Nakryiko
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 5/8] tools: Allow specifying base BTF file in resolve_btfids Kumar Kartikeya Dwivedi
` (3 subsequent siblings)
7 siblings, 1 reply; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
Preserve these calls as it allows verifier to succeed in loading the
program if they are determined to be unreachable after dead code
elimination during program load. If not, the verifier will fail at
runtime.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
tools/lib/bpf/libbpf.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index c4677ef97caa..9df90098f111 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6736,9 +6736,14 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
kfunc_id = find_ksym_btf_id(obj, ext->name, BTF_KIND_FUNC,
&kern_btf, &kern_btf_fd);
if (kfunc_id < 0) {
- pr_warn("extern (func ksym) '%s': not found in kernel BTF\n",
+ pr_warn("extern (func ksym) '%s': not found in kernel BTF, encoding btf_id as 0\n",
ext->name);
- return kfunc_id;
+ /* keep invalid kfuncs, so that verifier can load the program if
+ * they get removed during DCE pass in the verifier.
+ * The encoding must be insn->imm = 0, insn->off = 0.
+ */
+ kfunc_id = kern_btf_fd = 0;
+ goto resolve;
}
if (kern_btf != obj->btf_vmlinux) {
@@ -6798,11 +6803,18 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
return -EINVAL;
}
+resolve:
ext->is_set = true;
ext->ksym.kernel_btf_obj_fd = kern_btf_fd;
ext->ksym.kernel_btf_id = kfunc_id;
- pr_debug("extern (func ksym) '%s': resolved to kernel [%d]\n",
- ext->name, kfunc_id);
+ if (kfunc_id) {
+ pr_debug("extern (func ksym) '%s': resolved to kernel [%d]\n",
+ ext->name, kfunc_id);
+ } else {
+ ext->ksym.offset = 0;
+ pr_debug("extern (func ksym) '%s': added special invalid kfunc with imm = 0\n",
+ ext->name);
+ }
return 0;
}
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 4/8] libbpf: Resolve invalid kfunc calls with imm = 0, off = 0
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 4/8] libbpf: Resolve invalid kfunc calls with imm = 0, off = 0 Kumar Kartikeya Dwivedi
@ 2021-09-01 0:35 ` Andrii Nakryiko
0 siblings, 0 replies; 20+ messages in thread
From: Andrii Nakryiko @ 2021-09-01 0:35 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi
Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen,
Networking
On Mon, Aug 30, 2021 at 10:34 AM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>
> Preserve these calls as it allows verifier to succeed in loading the
> program if they are determined to be unreachable after dead code
> elimination during program load. If not, the verifier will fail at
> runtime.
>
This should be controlled by whether extern for func is weak or not,
just like we do for variables (see
bpf_object__resolve_ksym_var_btf_id()).
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
> tools/lib/bpf/libbpf.c | 20 ++++++++++++++++----
> 1 file changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index c4677ef97caa..9df90098f111 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -6736,9 +6736,14 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
> kfunc_id = find_ksym_btf_id(obj, ext->name, BTF_KIND_FUNC,
> &kern_btf, &kern_btf_fd);
> if (kfunc_id < 0) {
> - pr_warn("extern (func ksym) '%s': not found in kernel BTF\n",
> + pr_warn("extern (func ksym) '%s': not found in kernel BTF, encoding btf_id as 0\n",
> ext->name);
> - return kfunc_id;
> + /* keep invalid kfuncs, so that verifier can load the program if
> + * they get removed during DCE pass in the verifier.
> + * The encoding must be insn->imm = 0, insn->off = 0.
> + */
> + kfunc_id = kern_btf_fd = 0;
> + goto resolve;
> }
>
> if (kern_btf != obj->btf_vmlinux) {
> @@ -6798,11 +6803,18 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
> return -EINVAL;
> }
>
> +resolve:
> ext->is_set = true;
> ext->ksym.kernel_btf_obj_fd = kern_btf_fd;
> ext->ksym.kernel_btf_id = kfunc_id;
> - pr_debug("extern (func ksym) '%s': resolved to kernel [%d]\n",
> - ext->name, kfunc_id);
> + if (kfunc_id) {
> + pr_debug("extern (func ksym) '%s': resolved to kernel [%d]\n",
> + ext->name, kfunc_id);
> + } else {
> + ext->ksym.offset = 0;
> + pr_debug("extern (func ksym) '%s': added special invalid kfunc with imm = 0\n",
> + ext->name);
> + }
>
> return 0;
> }
> --
> 2.33.0
>
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH bpf-next RFC v1 5/8] tools: Allow specifying base BTF file in resolve_btfids
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
` (3 preceding siblings ...)
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 4/8] libbpf: Resolve invalid kfunc calls with imm = 0, off = 0 Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 6/8] bpf: btf: Introduce helpers for dynamic BTF set registration Kumar Kartikeya Dwivedi
` (2 subsequent siblings)
7 siblings, 0 replies; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
This commits allows specifying the base BTF for resolving btf id
lists/sets during link time in the resolve_btfids tool. The base BTF is
set to NULL if no path is passed. This allows resolving BTF ids for
module kernel objects.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
tools/bpf/resolve_btfids/main.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index de6365b53c9c..206e1120082f 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -89,6 +89,7 @@ struct btf_id {
struct object {
const char *path;
const char *btf;
+ const char *base_btf_path;
struct {
int fd;
@@ -477,16 +478,27 @@ static int symbols_resolve(struct object *obj)
int nr_structs = obj->nr_structs;
int nr_unions = obj->nr_unions;
int nr_funcs = obj->nr_funcs;
+ struct btf *base_btf = NULL;
int err, type_id;
struct btf *btf;
__u32 nr_types;
- btf = btf__parse(obj->btf ?: obj->path, NULL);
+ if (obj->base_btf_path) {
+ base_btf = btf__parse(obj->base_btf_path, NULL);
+ err = libbpf_get_error(base_btf);
+ if (err) {
+ pr_err("FAILED: load base BTF from %s: %s\n",
+ obj->base_btf_path, strerror(-err));
+ return -1;
+ }
+ }
+
+ btf = btf__parse_split(obj->btf ?: obj->path, base_btf);
err = libbpf_get_error(btf);
if (err) {
pr_err("FAILED: load BTF from %s: %s\n",
obj->btf ?: obj->path, strerror(-err));
- return -1;
+ goto out;
}
err = -1;
@@ -545,6 +557,7 @@ static int symbols_resolve(struct object *obj)
err = 0;
out:
+ btf__free(base_btf);
btf__free(btf);
return err;
}
@@ -697,6 +710,8 @@ int main(int argc, const char **argv)
"BTF data"),
OPT_BOOLEAN(0, "no-fail", &no_fail,
"do not fail if " BTF_IDS_SECTION " section is not found"),
+ OPT_STRING('s', "base-btf", &obj.base_btf_path, "file",
+ "path of file providing base BTF data"),
OPT_END()
};
int err = -1;
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH bpf-next RFC v1 6/8] bpf: btf: Introduce helpers for dynamic BTF set registration
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
` (4 preceding siblings ...)
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 5/8] tools: Allow specifying base BTF file in resolve_btfids Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 8/8] bpf, selftests: Add basic test for module kfunc call Kumar Kartikeya Dwivedi
7 siblings, 0 replies; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
This adds macros that generate BTF set registration APIs and
check_kfunc_call callback. These require a type, which namespaces each
BTF set. This is in preparation to allow for nf_conntrack registering
unstable helpers it wants to expose to XDP and SCHED_CLS programs in
subsequent patches.
With in kernel sets, the way this is supposed to work is, in kernel
callback looks up within the in-kernel kfunc whitelist, and then defers
to the dynamic BTF set lookup if it doesn't find the BTF id. If there is
no in-kernel BTF id set, this callback can be directly used.
Also fix includes for btf.h and bpfptr.h so that they can included in
isolation. This is in preparation for their usage in tcp_bbr, tcp_cubic
and tcp_dctcp modules in the next patch.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
include/linux/bpfptr.h | 1 +
include/linux/btf.h | 15 +++++++++++++++
kernel/bpf/btf.c | 34 ++++++++++++++++++++++++++++++++++
3 files changed, 50 insertions(+)
diff --git a/include/linux/bpfptr.h b/include/linux/bpfptr.h
index 546e27fc6d46..46e1757d06a3 100644
--- a/include/linux/bpfptr.h
+++ b/include/linux/bpfptr.h
@@ -3,6 +3,7 @@
#ifndef _LINUX_BPFPTR_H
#define _LINUX_BPFPTR_H
+#include <linux/mm.h>
#include <linux/sockptr.h>
typedef sockptr_t bpfptr_t;
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 214fde93214b..d024b0eb43f9 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -5,6 +5,7 @@
#define _LINUX_BTF_H 1
#include <linux/types.h>
+#include <linux/bpfptr.h>
#include <uapi/linux/btf.h>
#include <uapi/linux/bpf.h>
@@ -238,4 +239,18 @@ static inline const char *btf_name_by_offset(const struct btf *btf,
}
#endif
+struct kfunc_btf_set {
+ struct list_head list;
+ struct btf_id_set *set;
+};
+
+/* Register set of BTF ids */
+#define DECLARE_KFUNC_BTF_SET_REG(type) \
+ void register_##type##_kfunc_btf_set(struct kfunc_btf_set *s); \
+ bool __bpf_check_##type##_kfunc_call(u32 kfunc_id); \
+ void unregister_##type##_kfunc_btf_set(struct kfunc_btf_set *s)
+
+#define DEFINE_KFUNC_BTF_SET(set, name) \
+ struct kfunc_btf_set name = { LIST_HEAD_INIT(name.list), (set) }
+
#endif
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index dfe61df4f974..35873495761d 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6215,3 +6215,37 @@ const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = {
};
BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct)
+
+/* Typesafe helpers to register BTF ID sets for modules */
+#define DEFINE_KFUNC_BTF_SET_REG(type) \
+ static DEFINE_MUTEX(type##_kfunc_btf_set_mutex); \
+ static LIST_HEAD(type##_kfunc_btf_set_list); \
+ void register_##type##_kfunc_btf_set(struct kfunc_btf_set *s) \
+ { \
+ mutex_lock(&type##_kfunc_btf_set_mutex); \
+ list_add(&s->list, &type##_kfunc_btf_set_list); \
+ mutex_unlock(&type##_kfunc_btf_set_mutex); \
+ } \
+ EXPORT_SYMBOL_GPL(register_##type##_kfunc_btf_set); \
+ bool __bpf_check_##type##_kfunc_call(u32 kfunc_id) \
+ { \
+ struct kfunc_btf_set *s; \
+ mutex_lock(&type##_kfunc_btf_set_mutex); \
+ list_for_each_entry(s, &type##_kfunc_btf_set_list, list) { \
+ if (btf_id_set_contains(s->set, kfunc_id)) { \
+ mutex_unlock(&type##_kfunc_btf_set_mutex); \
+ return true; \
+ } \
+ } \
+ mutex_unlock(&type##_kfunc_btf_set_mutex); \
+ return false; \
+ } \
+ void unregister_##type##_kfunc_btf_set(struct kfunc_btf_set *s) \
+ { \
+ if (!s) \
+ return; \
+ mutex_lock(&type##_kfunc_btf_set_mutex); \
+ list_del_init(&s->list); \
+ mutex_unlock(&type##_kfunc_btf_set_mutex); \
+ } \
+ EXPORT_SYMBOL_GPL(unregister_##type##_kfunc_btf_set)
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
` (5 preceding siblings ...)
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 6/8] bpf: btf: Introduce helpers for dynamic BTF set registration Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-08-31 0:16 ` kernel test robot
2021-09-01 0:48 ` Andrii Nakryiko
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 8/8] bpf, selftests: Add basic test for module kfunc call Kumar Kartikeya Dwivedi
7 siblings, 2 replies; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
This commit moves BTF ID lookup into the newly added registration
helper, in a way that the bbr, cubic, and dctcp implementation set up
their sets in the bpf_tcp_ca kfunc_btf_set list, while the ones not
dependent on modules are looked up from the wrapper function.
This lifts the restriction for them to be compiled as built in objects,
and can be loaded as modules if required. Also modify link-vmlinux.sh to
resolve_btfids in TCP congestion control modules if the config option is
set, using the base BTF support added in the previous commit.
See following commits for background on use of:
CONFIG_X86 ifdef:
569c484f9995 (bpf: Limit static tcp-cc functions in the .BTF_ids list to x86)
CONFIG_DYNAMIC_FTRACE ifdef:
7aae231ac93b (bpf: tcp: Limit calling some tcp cc functions to CONFIG_DYNAMIC_FTRACE)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
include/linux/btf.h | 2 ++
kernel/bpf/btf.c | 2 ++
net/ipv4/bpf_tcp_ca.c | 34 +++-------------------------------
net/ipv4/tcp_bbr.c | 28 +++++++++++++++++++++++++++-
net/ipv4/tcp_cubic.c | 26 +++++++++++++++++++++++++-
net/ipv4/tcp_dctcp.c | 26 +++++++++++++++++++++++++-
scripts/Makefile.modfinal | 1 +
7 files changed, 85 insertions(+), 34 deletions(-)
diff --git a/include/linux/btf.h b/include/linux/btf.h
index d024b0eb43f9..8c0f29ed2af9 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -253,4 +253,6 @@ struct kfunc_btf_set {
#define DEFINE_KFUNC_BTF_SET(set, name) \
struct kfunc_btf_set name = { LIST_HEAD_INIT(name.list), (set) }
+DECLARE_KFUNC_BTF_SET_REG(bpf_tcp_ca);
+
#endif
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 35873495761d..cc12470a55f9 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6249,3 +6249,5 @@ BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct)
mutex_unlock(&type##_kfunc_btf_set_mutex); \
} \
EXPORT_SYMBOL_GPL(unregister_##type##_kfunc_btf_set)
+
+DEFINE_KFUNC_BTF_SET_REG(bpf_tcp_ca);
diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c
index 0dcee9df1326..804f2f912fe9 100644
--- a/net/ipv4/bpf_tcp_ca.c
+++ b/net/ipv4/bpf_tcp_ca.c
@@ -223,41 +223,13 @@ BTF_ID(func, tcp_reno_cong_avoid)
BTF_ID(func, tcp_reno_undo_cwnd)
BTF_ID(func, tcp_slow_start)
BTF_ID(func, tcp_cong_avoid_ai)
-#ifdef CONFIG_X86
-#ifdef CONFIG_DYNAMIC_FTRACE
-#if IS_BUILTIN(CONFIG_TCP_CONG_CUBIC)
-BTF_ID(func, cubictcp_init)
-BTF_ID(func, cubictcp_recalc_ssthresh)
-BTF_ID(func, cubictcp_cong_avoid)
-BTF_ID(func, cubictcp_state)
-BTF_ID(func, cubictcp_cwnd_event)
-BTF_ID(func, cubictcp_acked)
-#endif
-#if IS_BUILTIN(CONFIG_TCP_CONG_DCTCP)
-BTF_ID(func, dctcp_init)
-BTF_ID(func, dctcp_update_alpha)
-BTF_ID(func, dctcp_cwnd_event)
-BTF_ID(func, dctcp_ssthresh)
-BTF_ID(func, dctcp_cwnd_undo)
-BTF_ID(func, dctcp_state)
-#endif
-#if IS_BUILTIN(CONFIG_TCP_CONG_BBR)
-BTF_ID(func, bbr_init)
-BTF_ID(func, bbr_main)
-BTF_ID(func, bbr_sndbuf_expand)
-BTF_ID(func, bbr_undo_cwnd)
-BTF_ID(func, bbr_cwnd_event)
-BTF_ID(func, bbr_ssthresh)
-BTF_ID(func, bbr_min_tso_segs)
-BTF_ID(func, bbr_set_state)
-#endif
-#endif /* CONFIG_DYNAMIC_FTRACE */
-#endif /* CONFIG_X86 */
BTF_SET_END(bpf_tcp_ca_kfunc_ids)
static bool bpf_tcp_ca_check_kfunc_call(u32 kfunc_btf_id)
{
- return btf_id_set_contains(&bpf_tcp_ca_kfunc_ids, kfunc_btf_id);
+ if (btf_id_set_contains(&bpf_tcp_ca_kfunc_ids, kfunc_btf_id))
+ return true;
+ return __bpf_check_bpf_tcp_ca_kfunc_call(kfunc_btf_id);
}
static const struct bpf_verifier_ops bpf_tcp_ca_verifier_ops = {
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 6274462b86b4..1fea15dd0e05 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -56,6 +56,8 @@
* otherwise TCP stack falls back to an internal pacing using one high
* resolution timer per TCP socket and may use more resources.
*/
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
#include <linux/module.h>
#include <net/tcp.h>
#include <linux/inet_diag.h>
@@ -1152,14 +1154,38 @@ static struct tcp_congestion_ops tcp_bbr_cong_ops __read_mostly = {
.set_state = bbr_set_state,
};
+BTF_SET_START(tcp_bbr_kfunc_ids)
+#ifdef CONFIG_X86
+#ifdef CONFIG_DYNAMIC_FTRACE
+BTF_ID(func, bbr_init)
+BTF_ID(func, bbr_main)
+BTF_ID(func, bbr_sndbuf_expand)
+BTF_ID(func, bbr_undo_cwnd)
+BTF_ID(func, bbr_cwnd_event)
+BTF_ID(func, bbr_ssthresh)
+BTF_ID(func, bbr_min_tso_segs)
+BTF_ID(func, bbr_set_state)
+#endif
+#endif
+BTF_SET_END(tcp_bbr_kfunc_ids)
+
+static DEFINE_KFUNC_BTF_SET(&tcp_bbr_kfunc_ids, tcp_bbr_kfunc_btf_set);
+
static int __init bbr_register(void)
{
+ int ret;
+
BUILD_BUG_ON(sizeof(struct bbr) > ICSK_CA_PRIV_SIZE);
- return tcp_register_congestion_control(&tcp_bbr_cong_ops);
+ ret = tcp_register_congestion_control(&tcp_bbr_cong_ops);
+ if (ret)
+ return ret;
+ register_bpf_tcp_ca_kfunc_btf_set(&tcp_bbr_kfunc_btf_set);
+ return 0;
}
static void __exit bbr_unregister(void)
{
+ unregister_bpf_tcp_ca_kfunc_btf_set(&tcp_bbr_kfunc_btf_set);
tcp_unregister_congestion_control(&tcp_bbr_cong_ops);
}
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 4a30deaa9a37..5b36b9442797 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -25,6 +25,8 @@
*/
#include <linux/mm.h>
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
#include <linux/module.h>
#include <linux/math64.h>
#include <net/tcp.h>
@@ -482,8 +484,25 @@ static struct tcp_congestion_ops cubictcp __read_mostly = {
.name = "cubic",
};
+BTF_SET_START(tcp_cubic_kfunc_ids)
+#ifdef CONFIG_X86
+#ifdef CONFIG_DYNAMIC_FTRACE
+BTF_ID(func, cubictcp_init)
+BTF_ID(func, cubictcp_recalc_ssthresh)
+BTF_ID(func, cubictcp_cong_avoid)
+BTF_ID(func, cubictcp_state)
+BTF_ID(func, cubictcp_cwnd_event)
+BTF_ID(func, cubictcp_acked)
+#endif
+#endif
+BTF_SET_END(tcp_cubic_kfunc_ids)
+
+static DEFINE_KFUNC_BTF_SET(&tcp_cubic_kfunc_ids, tcp_cubic_kfunc_btf_set);
+
static int __init cubictcp_register(void)
{
+ int ret;
+
BUILD_BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE);
/* Precompute a bunch of the scaling factors that are used per-packet
@@ -514,11 +533,16 @@ static int __init cubictcp_register(void)
/* divide by bic_scale and by constant Srtt (100ms) */
do_div(cube_factor, bic_scale * 10);
- return tcp_register_congestion_control(&cubictcp);
+ ret = tcp_register_congestion_control(&cubictcp);
+ if (ret)
+ return ret;
+ register_bpf_tcp_ca_kfunc_btf_set(&tcp_cubic_kfunc_btf_set);
+ return 0;
}
static void __exit cubictcp_unregister(void)
{
+ unregister_bpf_tcp_ca_kfunc_btf_set(&tcp_cubic_kfunc_btf_set);
tcp_unregister_congestion_control(&cubictcp);
}
diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c
index 79f705450c16..efc47b4c7a11 100644
--- a/net/ipv4/tcp_dctcp.c
+++ b/net/ipv4/tcp_dctcp.c
@@ -36,6 +36,8 @@
* Glenn Judd <glenn.judd@morganstanley.com>
*/
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <net/tcp.h>
@@ -236,14 +238,36 @@ static struct tcp_congestion_ops dctcp_reno __read_mostly = {
.name = "dctcp-reno",
};
+BTF_SET_START(tcp_dctcp_kfunc_ids)
+#ifdef CONFIG_X86
+#ifdef CONFIG_DYNAMIC_FTRACE
+BTF_ID(func, dctcp_init)
+BTF_ID(func, dctcp_update_alpha)
+BTF_ID(func, dctcp_cwnd_event)
+BTF_ID(func, dctcp_ssthresh)
+BTF_ID(func, dctcp_cwnd_undo)
+BTF_ID(func, dctcp_state)
+#endif
+#endif
+BTF_SET_END(tcp_dctcp_kfunc_ids)
+
+static DEFINE_KFUNC_BTF_SET(&tcp_dctcp_kfunc_ids, tcp_dctcp_kfunc_btf_set);
+
static int __init dctcp_register(void)
{
+ int ret;
+
BUILD_BUG_ON(sizeof(struct dctcp) > ICSK_CA_PRIV_SIZE);
- return tcp_register_congestion_control(&dctcp);
+ ret = tcp_register_congestion_control(&dctcp);
+ if (ret)
+ return ret;
+ register_bpf_tcp_ca_kfunc_btf_set(&tcp_dctcp_kfunc_btf_set);
+ return 0;
}
static void __exit dctcp_unregister(void)
{
+ unregister_bpf_tcp_ca_kfunc_btf_set(&tcp_dctcp_kfunc_btf_set);
tcp_unregister_congestion_control(&dctcp);
}
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 5e9b8057fb24..0755d4b8b74a 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -58,6 +58,7 @@ quiet_cmd_btf_ko = BTF [M] $@
cmd_btf_ko = \
if [ -f vmlinux ]; then \
LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J --btf_base vmlinux $@; \
+ $(RESOLVE_BTFIDS) --no-fail -s vmlinux $@; \
else \
printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
fi;
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules Kumar Kartikeya Dwivedi
@ 2021-08-31 0:16 ` kernel test robot
2021-09-01 0:48 ` Andrii Nakryiko
1 sibling, 0 replies; 20+ messages in thread
From: kernel test robot @ 2021-08-31 0:16 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 1754 bytes --]
Hi Kumar,
[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on bpf-next/master]
url: https://github.com/0day-ci/linux/commits/Kumar-Kartikeya-Dwivedi/Support-kernel-module-function-calls-from-eBPF/20210831-013531
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: um-x86_64_defconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/5bc18bc51d4d66d55910a9829c2a6b0a5a6b61ea
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Kumar-Kartikeya-Dwivedi/Support-kernel-module-function-calls-from-eBPF/20210831-013531
git checkout 5bc18bc51d4d66d55910a9829c2a6b0a5a6b61ea
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=um SUBARCH=x86_64 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
/usr/bin/ld: net/ipv4/tcp_cubic.o: in function `cubictcp_unregister':
>> tcp_cubic.c:(.exit.text+0xd): undefined reference to `unregister_bpf_tcp_ca_kfunc_btf_set'
/usr/bin/ld: net/ipv4/tcp_cubic.o: in function `cubictcp_register':
>> tcp_cubic.c:(.init.text+0x8e): undefined reference to `register_bpf_tcp_ca_kfunc_btf_set'
/usr/bin/ld: kernel/bpf/core.o: in function `bpf_prog_free_deferred':
core.c:(.text+0x7b0): undefined reference to `btf_put'
collect2: error: ld returned 1 exit status
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 9615 bytes --]
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules Kumar Kartikeya Dwivedi
2021-08-31 0:16 ` kernel test robot
@ 2021-09-01 0:48 ` Andrii Nakryiko
1 sibling, 0 replies; 20+ messages in thread
From: Andrii Nakryiko @ 2021-09-01 0:48 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi
Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen,
Networking
On Mon, Aug 30, 2021 at 10:34 AM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>
> This commit moves BTF ID lookup into the newly added registration
> helper, in a way that the bbr, cubic, and dctcp implementation set up
> their sets in the bpf_tcp_ca kfunc_btf_set list, while the ones not
> dependent on modules are looked up from the wrapper function.
>
> This lifts the restriction for them to be compiled as built in objects,
> and can be loaded as modules if required. Also modify link-vmlinux.sh to
> resolve_btfids in TCP congestion control modules if the config option is
> set, using the base BTF support added in the previous commit.
>
> See following commits for background on use of:
>
> CONFIG_X86 ifdef:
> 569c484f9995 (bpf: Limit static tcp-cc functions in the .BTF_ids list to x86)
>
> CONFIG_DYNAMIC_FTRACE ifdef:
> 7aae231ac93b (bpf: tcp: Limit calling some tcp cc functions to CONFIG_DYNAMIC_FTRACE)
>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
> include/linux/btf.h | 2 ++
> kernel/bpf/btf.c | 2 ++
> net/ipv4/bpf_tcp_ca.c | 34 +++-------------------------------
> net/ipv4/tcp_bbr.c | 28 +++++++++++++++++++++++++++-
> net/ipv4/tcp_cubic.c | 26 +++++++++++++++++++++++++-
> net/ipv4/tcp_dctcp.c | 26 +++++++++++++++++++++++++-
> scripts/Makefile.modfinal | 1 +
> 7 files changed, 85 insertions(+), 34 deletions(-)
>
[...]
> diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
> index 5e9b8057fb24..0755d4b8b74a 100644
> --- a/scripts/Makefile.modfinal
> +++ b/scripts/Makefile.modfinal
> @@ -58,6 +58,7 @@ quiet_cmd_btf_ko = BTF [M] $@
> cmd_btf_ko = \
> if [ -f vmlinux ]; then \
> LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J --btf_base vmlinux $@; \
> + $(RESOLVE_BTFIDS) --no-fail -s vmlinux $@; \
why is this --no-fail?
> else \
> printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
> fi;
> --
> 2.33.0
>
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH bpf-next RFC v1 8/8] bpf, selftests: Add basic test for module kfunc call
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
` (6 preceding siblings ...)
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules Kumar Kartikeya Dwivedi
@ 2021-08-30 17:34 ` Kumar Kartikeya Dwivedi
2021-08-30 20:07 ` Alexei Starovoitov
7 siblings, 1 reply; 20+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-08-30 17:34 UTC (permalink / raw)
To: bpf
Cc: Kumar Kartikeya Dwivedi, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
This has to drop light skeleton generation and instead use libbpf
skeleton support, as loader program does not support kfunc module calls,
yet. This also tests support for invalid kfunc calls we added in prior
changes, such that verifier handles invalid call as long as it is
removed by code elimination pass (before fixup_kfunc_call).
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
include/linux/btf.h | 1 +
kernel/bpf/btf.c | 1 +
kernel/trace/bpf_trace.c | 1 +
tools/testing/selftests/bpf/Makefile | 3 ++-
.../selftests/bpf/bpf_testmod/bpf_testmod.c | 23 ++++++++++++++++++-
.../selftests/bpf/prog_tests/ksyms_module.c | 10 ++++----
.../selftests/bpf/progs/test_ksyms_module.c | 9 ++++++++
7 files changed, 40 insertions(+), 8 deletions(-)
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 8c0f29ed2af9..6e704981c475 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -254,5 +254,6 @@ struct kfunc_btf_set {
struct kfunc_btf_set name = { LIST_HEAD_INIT(name.list), (set) }
DECLARE_KFUNC_BTF_SET_REG(bpf_tcp_ca);
+DECLARE_KFUNC_BTF_SET_REG(raw_tp);
#endif
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index cc12470a55f9..85a0c2737ea1 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6251,3 +6251,4 @@ BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct)
EXPORT_SYMBOL_GPL(unregister_##type##_kfunc_btf_set)
DEFINE_KFUNC_BTF_SET_REG(bpf_tcp_ca);
+DEFINE_KFUNC_BTF_SET_REG(raw_tp);
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 8e2eb950aa82..02fe14b5d005 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1599,6 +1599,7 @@ int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
.get_func_proto = raw_tp_prog_func_proto,
.is_valid_access = raw_tp_prog_is_valid_access,
+ .check_kfunc_call = __bpf_check_raw_tp_kfunc_call,
};
const struct bpf_prog_ops raw_tracepoint_prog_ops = {
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 866531c08e4f..1a4aa71e88f4 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -174,6 +174,7 @@ $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_tes
$(Q)$(RM) bpf_testmod/bpf_testmod.ko # force re-compilation
$(Q)$(MAKE) $(submake_extras) -C bpf_testmod
$(Q)cp bpf_testmod/bpf_testmod.ko $@
+ $(Q)$(RESOLVE_BTFIDS) -s ../../../../vmlinux bpf_testmod.ko
$(OUTPUT)/test_stub.o: test_stub.c $(BPFOBJ)
$(call msg,CC,,$@)
@@ -315,7 +316,7 @@ LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h \
linked_vars.skel.h linked_maps.skel.h
LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
- test_ksyms_module.c test_ringbuf.c atomics.c trace_printk.c
+ test_ringbuf.c atomics.c trace_printk.c
SKEL_BLACKLIST += $$(LSKELS)
test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 141d8da687d2..8242f2bb50b4 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -1,6 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <linux/error-injection.h>
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/percpu-defs.h>
@@ -13,6 +15,12 @@
DEFINE_PER_CPU(int, bpf_testmod_ksym_percpu) = 123;
+noinline void
+bpf_testmod_test_mod_kfunc(int i)
+{
+ pr_info("mod kfunc i=%d\n", i);
+}
+
noinline ssize_t
bpf_testmod_test_read(struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr,
@@ -55,13 +63,26 @@ static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = {
.write = bpf_testmod_test_write,
};
+BTF_SET_START(bpf_testmod_kfunc_ids)
+BTF_ID(func, bpf_testmod_test_mod_kfunc)
+BTF_SET_END(bpf_testmod_kfunc_ids)
+
+static DEFINE_KFUNC_BTF_SET(&bpf_testmod_kfunc_ids, bpf_testmod_kfunc_btf_set);
+
static int bpf_testmod_init(void)
{
- return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
+ int ret;
+
+ ret = sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
+ if (ret)
+ return ret;
+ register_raw_tp_kfunc_btf_set(&bpf_testmod_kfunc_btf_set);
+ return 0;
}
static void bpf_testmod_exit(void)
{
+ unregister_raw_tp_kfunc_btf_set(&bpf_testmod_kfunc_btf_set);
return sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
}
diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c
index 2cd5cded543f..d3b0adc2a495 100644
--- a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c
+++ b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c
@@ -4,21 +4,19 @@
#include <test_progs.h>
#include <bpf/libbpf.h>
#include <bpf/btf.h>
-#include "test_ksyms_module.lskel.h"
-
-static int duration;
+#include "test_ksyms_module.skel.h"
void test_ksyms_module(void)
{
- struct test_ksyms_module* skel;
+ struct test_ksyms_module *skel;
int err;
skel = test_ksyms_module__open_and_load();
- if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+ if (!ASSERT_OK_PTR(skel, "test_ksyms_module__open_and_load"))
return;
err = test_ksyms_module__attach(skel);
- if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+ if (!ASSERT_OK(err, "test_ksyms_module__attach"))
goto cleanup;
usleep(1);
diff --git a/tools/testing/selftests/bpf/progs/test_ksyms_module.c b/tools/testing/selftests/bpf/progs/test_ksyms_module.c
index d6a0b3086b90..81f8790cb99d 100644
--- a/tools/testing/selftests/bpf/progs/test_ksyms_module.c
+++ b/tools/testing/selftests/bpf/progs/test_ksyms_module.c
@@ -6,8 +6,11 @@
#include <bpf/bpf_helpers.h>
extern const int bpf_testmod_ksym_percpu __ksym;
+extern void bpf_testmod_test_mod_kfunc(int i) __ksym;
+extern void bpf_testmod_invalid_mod_kfunc(void) __ksym;
int out_mod_ksym_global = 0;
+const volatile int x = 0;
bool triggered = false;
SEC("raw_tp/sys_enter")
@@ -16,6 +19,12 @@ int handler(const void *ctx)
int *val;
__u32 cpu;
+ /* This should be preserved by clang, but DCE'd by verifier, and still
+ * allow loading the raw_tp prog
+ */
+ if (x)
+ bpf_testmod_invalid_mod_kfunc();
+ bpf_testmod_test_mod_kfunc(42);
val = (int *)bpf_this_cpu_ptr(&bpf_testmod_ksym_percpu);
out_mod_ksym_global = *val;
triggered = true;
--
2.33.0
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH bpf-next RFC v1 8/8] bpf, selftests: Add basic test for module kfunc call
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 8/8] bpf, selftests: Add basic test for module kfunc call Kumar Kartikeya Dwivedi
@ 2021-08-30 20:07 ` Alexei Starovoitov
0 siblings, 0 replies; 20+ messages in thread
From: Alexei Starovoitov @ 2021-08-30 20:07 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi
Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song,
Jesper Dangaard Brouer, Toke Høiland-Jørgensen, netdev
On Mon, Aug 30, 2021 at 11:04:24PM +0530, Kumar Kartikeya Dwivedi wrote:
> diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c
> index 2cd5cded543f..d3b0adc2a495 100644
> --- a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c
> +++ b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c
> @@ -4,21 +4,19 @@
> #include <test_progs.h>
> #include <bpf/libbpf.h>
> #include <bpf/btf.h>
> -#include "test_ksyms_module.lskel.h"
> -
> -static int duration;
> +#include "test_ksyms_module.skel.h"
bpf_btf_find_by_name_kind supports searching in modules,
so adding support for kfunc in modules to lskel shouldn't be hard to add.
^ permalink raw reply [flat|nested] 20+ messages in thread