diff mbox series

[bpf-next,v9,01/10] bpf: add bpf_func_t and trampoline helpers

Message ID 20220610165803.2860154-2-sdf@google.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: cgroup_sock lsm flavor | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Clearly marked for bpf-next, async
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: 1432 this patch: 1432
netdev/cc_maintainers warning 5 maintainers not CCed: songliubraving@fb.com yhs@fb.com john.fastabend@gmail.com kafai@fb.com kpsingh@kernel.org
netdev/build_clang success Errors and warnings before: 166 this patch: 166
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1439 this patch: 1439
netdev/checkpatch warning WARNING: line length of 84 exceeds 80 columns WARNING: line length of 86 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns WARNING: line length of 95 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-VM_Test-2 success Logs for Kernel LATEST on ubuntu-latest with llvm-15
bpf/vmtest-bpf-next-VM_Test-1 success Logs for Kernel LATEST on ubuntu-latest with gcc
bpf/vmtest-bpf-next-VM_Test-3 fail Logs for Kernel LATEST on z15 with gcc

Commit Message

Stanislav Fomichev June 10, 2022, 4:57 p.m. UTC 
I'll be adding lsm cgroup specific helpers that grab
trampoline mutex.

No functional changes.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 include/linux/bpf.h     | 11 ++++---
 kernel/bpf/trampoline.c | 63 +++++++++++++++++++++--------------------
 2 files changed, 38 insertions(+), 36 deletions(-)

Comments

Martin KaFai Lau June 16, 2022, 7:53 p.m. UTC | #1 
On Fri, Jun 10, 2022 at 09:57:54AM -0700, Stanislav Fomichev wrote:
> I'll be adding lsm cgroup specific helpers that grab
> trampoline mutex.
> 
> No functional changes.
> 
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Martin KaFai Lau <kafai@fb.com>
diff mbox series

Patch

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 8e6092d0ea95..b0af68b6297b 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -53,6 +53,8 @@  typedef u64 (*bpf_callback_t)(u64, u64, u64, u64, u64);
 typedef int (*bpf_iter_init_seq_priv_t)(void *private_data,
 					struct bpf_iter_aux_info *aux);
 typedef void (*bpf_iter_fini_seq_priv_t)(void *private_data);
+typedef unsigned int (*bpf_func_t)(const void *,
+				   const struct bpf_insn *);
 struct bpf_iter_seq_info {
 	const struct seq_operations *seq_ops;
 	bpf_iter_init_seq_priv_t init_seq_private;
@@ -863,8 +865,7 @@  struct bpf_dispatcher {
 static __always_inline __nocfi unsigned int bpf_dispatcher_nop_func(
 	const void *ctx,
 	const struct bpf_insn *insnsi,
-	unsigned int (*bpf_func)(const void *,
-				 const struct bpf_insn *))
+	bpf_func_t bpf_func)
 {
 	return bpf_func(ctx, insnsi);
 }
@@ -893,8 +894,7 @@  int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs);
 	noinline __nocfi unsigned int bpf_dispatcher_##name##_func(	\
 		const void *ctx,					\
 		const struct bpf_insn *insnsi,				\
-		unsigned int (*bpf_func)(const void *,			\
-					 const struct bpf_insn *))	\
+		bpf_func_t bpf_func)					\
 	{								\
 		return bpf_func(ctx, insnsi);				\
 	}								\
@@ -905,8 +905,7 @@  int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs);
 	unsigned int bpf_dispatcher_##name##_func(			\
 		const void *ctx,					\
 		const struct bpf_insn *insnsi,				\
-		unsigned int (*bpf_func)(const void *,			\
-					 const struct bpf_insn *));	\
+		bpf_func_t bpf_func);					\
 	extern struct bpf_dispatcher bpf_dispatcher_##name;
 #define BPF_DISPATCHER_FUNC(name) bpf_dispatcher_##name##_func
 #define BPF_DISPATCHER_PTR(name) (&bpf_dispatcher_##name)
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 93c7675f0c9e..5466e15be61f 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -410,7 +410,7 @@  static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog)
 	}
 }
 
-int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
 {
 	enum bpf_tramp_prog_type kind;
 	struct bpf_tramp_link *link_exiting;
@@ -418,44 +418,33 @@  int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline
 	int cnt = 0, i;
 
 	kind = bpf_attach_type_to_tramp(link->link.prog);
-	mutex_lock(&tr->mutex);
-	if (tr->extension_prog) {
+	if (tr->extension_prog)
 		/* cannot attach fentry/fexit if extension prog is attached.
 		 * cannot overwrite extension prog either.
 		 */
-		err = -EBUSY;
-		goto out;
-	}
+		return -EBUSY;
 
 	for (i = 0; i < BPF_TRAMP_MAX; i++)
 		cnt += tr->progs_cnt[i];
 
 	if (kind == BPF_TRAMP_REPLACE) {
 		/* Cannot attach extension if fentry/fexit are in use. */
-		if (cnt) {
-			err = -EBUSY;
-			goto out;
-		}
+		if (cnt)
+			return -EBUSY;
 		tr->extension_prog = link->link.prog;
-		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,
-					 link->link.prog->bpf_func);
-		goto out;
-	}
-	if (cnt >= BPF_MAX_TRAMP_LINKS) {
-		err = -E2BIG;
-		goto out;
+		return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,
+					  link->link.prog->bpf_func);
 	}
-	if (!hlist_unhashed(&link->tramp_hlist)) {
+	if (cnt >= BPF_MAX_TRAMP_LINKS)
+		return -E2BIG;
+	if (!hlist_unhashed(&link->tramp_hlist))
 		/* prog already linked */
-		err = -EBUSY;
-		goto out;
-	}
+		return -EBUSY;
 	hlist_for_each_entry(link_exiting, &tr->progs_hlist[kind], tramp_hlist) {
 		if (link_exiting->link.prog != link->link.prog)
 			continue;
 		/* prog already linked */
-		err = -EBUSY;
-		goto out;
+		return -EBUSY;
 	}
 
 	hlist_add_head(&link->tramp_hlist, &tr->progs_hlist[kind]);
@@ -465,30 +454,44 @@  int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline
 		hlist_del_init(&link->tramp_hlist);
 		tr->progs_cnt[kind]--;
 	}
-out:
+	return err;
+}
+
+int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+{
+	int err;
+
+	mutex_lock(&tr->mutex);
+	err = __bpf_trampoline_link_prog(link, tr);
 	mutex_unlock(&tr->mutex);
 	return err;
 }
 
-/* bpf_trampoline_unlink_prog() should never fail. */
-int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
 {
 	enum bpf_tramp_prog_type kind;
 	int err;
 
 	kind = bpf_attach_type_to_tramp(link->link.prog);
-	mutex_lock(&tr->mutex);
 	if (kind == BPF_TRAMP_REPLACE) {
 		WARN_ON_ONCE(!tr->extension_prog);
 		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP,
 					 tr->extension_prog->bpf_func, NULL);
 		tr->extension_prog = NULL;
-		goto out;
+		return err;
 	}
 	hlist_del_init(&link->tramp_hlist);
 	tr->progs_cnt[kind]--;
-	err = bpf_trampoline_update(tr);
-out:
+	return bpf_trampoline_update(tr);
+}
+
+/* bpf_trampoline_unlink_prog() should never fail. */
+int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+{
+	int err;
+
+	mutex_lock(&tr->mutex);
+	err = __bpf_trampoline_unlink_prog(link, tr);
 	mutex_unlock(&tr->mutex);
 	return err;
 }