diff mbox series

[bpf-next,1/5] bpf: Extend sys_bpf commands for bpf_syscall programs.

Message ID 20220204231710.25139-2-alexei.starovoitov@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: Light skeleton for the kernel. | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 12 this patch: 12
netdev/cc_maintainers warning 7 maintainers not CCed: kpsingh@kernel.org john.fastabend@gmail.com kafai@fb.com songliubraving@fb.com ast@kernel.org yhs@fb.com netdev@vger.kernel.org
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 17 this patch: 17
netdev/checkpatch warning CHECK: No space is necessary after a cast WARNING: line length of 81 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns WARNING: line length of 89 exceeds 80 columns WARNING: line length of 90 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next fail VM_Test

Commit Message

Alexei Starovoitov Feb. 4, 2022, 11:17 p.m. UTC 
From: Alexei Starovoitov <ast@kernel.org>

bpf_sycall programs can be used directly by the kernel modules
to load programs and create maps via kernel skeleton.
. Export bpf_sys_bpf syscall wrapper to be used in kernel skeleton.
. Export bpf_map_get to be used in kernel skeleton.
. Allow prog_run cmd for bpf_syscall programs with recursion check.
. Enable link_create and raw_tp_open cmds.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/syscall.c | 38 ++++++++++++++++++++++++++++++++++----
 1 file changed, 34 insertions(+), 4 deletions(-)

Comments

Yonghong Song Feb. 8, 2022, 5:11 p.m. UTC | #1 
On 2/4/22 3:17 PM, Alexei Starovoitov wrote:
> From: Alexei Starovoitov <ast@kernel.org>
> 
> bpf_sycall programs can be used directly by the kernel modules
> to load programs and create maps via kernel skeleton.
> . Export bpf_sys_bpf syscall wrapper to be used in kernel skeleton.
> . Export bpf_map_get to be used in kernel skeleton.
> . Allow prog_run cmd for bpf_syscall programs with recursion check.
> . Enable link_create and raw_tp_open cmds.
> 
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Acked-by: Yonghong Song <yhs@fb.com>
diff mbox series

Patch

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 72ce1edde950..08ac01acc51e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -985,6 +985,7 @@  struct bpf_map *bpf_map_get(u32 ufd)
 
 	return map;
 }
+EXPORT_SYMBOL(bpf_map_get);
 
 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
 {
@@ -4756,23 +4757,52 @@  static bool syscall_prog_is_valid_access(int off, int size,
 	return true;
 }
 
-BPF_CALL_3(bpf_sys_bpf, int, cmd, void *, attr, u32, attr_size)
+BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
 {
+	struct bpf_prog *prog;
+
 	switch (cmd) {
 	case BPF_MAP_CREATE:
 	case BPF_MAP_UPDATE_ELEM:
 	case BPF_MAP_FREEZE:
 	case BPF_PROG_LOAD:
 	case BPF_BTF_LOAD:
+	case BPF_LINK_CREATE:
+	case BPF_RAW_TRACEPOINT_OPEN:
 		break;
-	/* case BPF_PROG_TEST_RUN:
-	 * is not part of this list to prevent recursive test_run
-	 */
+#ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
+	case BPF_PROG_TEST_RUN:
+		if (attr->test.data_in || attr->test.data_out ||
+		    attr->test.ctx_out || attr->test.duration ||
+		    attr->test.repeat || attr->test.flags)
+			return -EINVAL;
+
+		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
+		if (IS_ERR(prog))
+			return PTR_ERR(prog);
+
+		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
+		    attr->test.ctx_size_in > U16_MAX) {
+			bpf_prog_put(prog);
+			return -EINVAL;
+		}
+
+		if (!__bpf_prog_enter_sleepable(prog)) {
+			/* recursion detected */
+			bpf_prog_put(prog);
+			return -EBUSY;
+		}
+		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
+		__bpf_prog_exit_sleepable(prog, 0 /* bpf_prog_run does runtime stats */);
+		bpf_prog_put(prog);
+		return 0;
+#endif
 	default:
 		return -EINVAL;
 	}
 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
 }
+EXPORT_SYMBOL(bpf_sys_bpf);
 
 static const struct bpf_func_proto bpf_sys_bpf_proto = {
 	.func		= bpf_sys_bpf,