From: Calvin Owens <jcalvinowens@gmail.com>
To: Luis Chamberlain <mcgrof@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexei Starovoitov <ast@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Naveen N Rao <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
David S Miller <davem@davemloft.net>,
Thomas Gleixner <tglx@linutronix.de>
Cc: Calvin Owens <jcalvinowens@gmail.com>,
bpf@vger.kernel.org, linux-modules@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [RFC][PATCH 2/4] bpf: Allow BPF_JIT with CONFIG_MODULES=n
Date: Wed, 6 Mar 2024 12:05:09 -0800 [thread overview]
Message-ID: <afebd15dd032f908e46871bec5be438063ae7458.1709676663.git.jcalvinowens@gmail.com> (raw)
In-Reply-To: <cover.1709676663.git.jcalvinowens@gmail.com>
No BPF code has to change, except in struct_ops (for module refs).
This conflicts with bpf-next because of this (relevant) series:
https://lore.kernel.org/all/20240119225005.668602-1-thinker.li@gmail.com/
If something like this is merged down the road, it can go through
bpf-next at leisure once the module_alloc change is in: it's a one-way
dependency.
Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>
---
kernel/bpf/Kconfig | 2 +-
kernel/bpf/bpf_struct_ops.c | 28 ++++++++++++++++++++++++----
2 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig
index 6a906ff93006..77df483a8925 100644
--- a/kernel/bpf/Kconfig
+++ b/kernel/bpf/Kconfig
@@ -42,7 +42,7 @@ config BPF_JIT
bool "Enable BPF Just In Time compiler"
depends on BPF
depends on HAVE_CBPF_JIT || HAVE_EBPF_JIT
- depends on MODULES
+ select MODULE_ALLOC
help
BPF programs are normally handled by a BPF interpreter. This option
allows the kernel to generate native code when a program is loaded
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index 02068bd0e4d9..fbf08a1bb00c 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -108,11 +108,30 @@ const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
#endif
};
+#if IS_ENABLED(CONFIG_MODULES)
static const struct btf_type *module_type;
+static int bpf_struct_module_type_init(struct btf *btf)
+{
+ s32 module_id;
+
+ module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);
+ if (module_id < 0)
+ return 1;
+
+ module_type = btf_type_by_id(btf, module_id);
+ return 0;
+}
+#else
+static int bpf_struct_module_type_init(struct btf *btf)
+{
+ return 0;
+}
+#endif
+
void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
{
- s32 type_id, value_id, module_id;
+ s32 type_id, value_id;
const struct btf_member *member;
struct bpf_struct_ops *st_ops;
const struct btf_type *t;
@@ -125,12 +144,10 @@ void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
#include "bpf_struct_ops_types.h"
#undef BPF_STRUCT_OPS_TYPE
- module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);
- if (module_id < 0) {
+ if (bpf_struct_module_type_init(btf)) {
pr_warn("Cannot find struct module in btf_vmlinux\n");
return;
}
- module_type = btf_type_by_id(btf, module_id);
for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
st_ops = bpf_struct_ops[i];
@@ -433,12 +450,15 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
moff = __btf_member_bit_offset(t, member) / 8;
ptype = btf_type_resolve_ptr(btf_vmlinux, member->type, NULL);
+
+#if IS_ENABLED(CONFIG_MODULES)
if (ptype == module_type) {
if (*(void **)(udata + moff))
goto reset_unlock;
*(void **)(kdata + moff) = BPF_MODULE_OWNER;
continue;
}
+#endif
err = st_ops->init_member(t, member, kdata, udata);
if (err < 0)
--
2.43.0
next prev parent reply other threads:[~2024-03-06 20:05 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-06 20:05 [RFC][PATCH 0/4] Make bpf_jit and kprobes work with CONFIG_MODULES=n Calvin Owens
2024-03-06 20:05 ` [RFC][PATCH 1/4] module: mm: Make module_alloc() generally available Calvin Owens
2024-03-07 14:43 ` Christophe Leroy
2024-03-08 20:53 ` Calvin Owens
2024-03-08 2:16 ` Masami Hiramatsu
2024-03-08 20:43 ` Calvin Owens
2024-03-06 20:05 ` Calvin Owens [this message]
2024-03-07 22:09 ` [RFC][PATCH 2/4] bpf: Allow BPF_JIT with CONFIG_MODULES=n Christophe Leroy
2024-03-08 21:04 ` Calvin Owens
2024-03-06 20:05 ` [RFC][PATCH 3/4] kprobes: Allow kprobes " Calvin Owens
2024-03-07 7:22 ` Mike Rapoport
2024-03-08 2:46 ` Masami Hiramatsu
2024-03-08 20:36 ` Calvin Owens
2024-03-07 22:16 ` Christophe Leroy
2024-03-08 21:02 ` Calvin Owens
2024-03-08 2:46 ` Masami Hiramatsu
2024-03-08 20:57 ` Calvin Owens
2024-03-06 20:05 ` [RFC][PATCH 4/4] selftests/bpf: Support testing the !MODULES case Calvin Owens
2024-03-06 21:34 ` [RFC][PATCH 0/4] Make bpf_jit and kprobes work with CONFIG_MODULES=n Luis Chamberlain
2024-03-06 23:23 ` Calvin Owens
2024-03-07 1:58 ` Song Liu
2024-03-08 2:50 ` Masami Hiramatsu
2024-03-08 2:55 ` Luis Chamberlain
2024-03-08 20:27 ` Calvin Owens
2024-03-07 7:13 ` Mike Rapoport
2024-03-08 2:45 ` Masami Hiramatsu
2024-03-25 22:46 ` Jarkko Sakkinen
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