diff mbox series

[v7,bpf-next,5/5] bpf: Add BPF_KFUNC_{START,END}_defs macros

Message ID 20231013204426.1074286-6-davemarchevsky@fb.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series Open-coded task_vma iter | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-VM_Test-0 success Logs for ShellCheck
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2833 this patch: 2833
netdev/cc_maintainers warning 25 maintainers not CCed: yonghong.song@linux.dev mhiramat@kernel.org dsahern@kernel.org john.fastabend@gmail.com hawk@kernel.org sdf@google.com pablo@netfilter.org netfilter-devel@vger.kernel.org fw@strlen.de jolsa@kernel.org davem@davemloft.net kadlec@netfilter.org haoluo@google.com song@kernel.org coreteam@netfilter.org rostedt@goodmis.org kuba@kernel.org kpsingh@kernel.org linux-trace-kernel@vger.kernel.org martin.lau@linux.dev pabeni@redhat.com steffen.klassert@secunet.com edumazet@google.com netdev@vger.kernel.org herbert@gondor.apana.org.au
netdev/build_clang success Errors and warnings before: 1517 this patch: 1517
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 2919 this patch: 2919
netdev/checkpatch fail CHECK: Please use a blank line after function/struct/union/enum declarations ERROR: Macros with multiple statements should be enclosed in a do - while loop WARNING: macros should not use a trailing semicolon
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR success PR summary
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Commit Message

Dave Marchevsky Oct. 13, 2023, 8:44 p.m. UTC 
BPF kfuncs are meant to be called from BPF programs. Accordingly, most
kfuncs are not called from anywhere in the kernel, which the
-Wmissing-prototypes warning is unhappy about. We've peppered
__diag_ignore_all("-Wmissing-prototypes", ... everywhere kfuncs are
defined in the codebase to suppress this warning.

This patch adds two macros meant to bound one or many kfunc definitions.
BPF_KFUNC_START_DEFS currently expands to __diag_push + the
aforementioned __diag_ignore_all, and BPF_KFUNC_END_DEFS to the
corresponding __diag_pop. All existing kfunc definitions which use these
__diag calls to suppress -Wmissing-prototypes are migrated to use the
newly-introduced macros.

In the future we might need to ignore different warnings or do other
kfunc-specific things. This nonfunctional change will make it easier to
make such modifications for all kfunc defs.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
---
 include/linux/btf.h              |  7 +++++++
 kernel/bpf/bpf_iter.c            |  6 ++----
 kernel/bpf/cpumask.c             |  6 ++----
 kernel/bpf/helpers.c             |  6 ++----
 kernel/bpf/map_iter.c            |  6 ++----
 kernel/bpf/task_iter.c           |  6 ++----
 kernel/trace/bpf_trace.c         |  6 ++----
 net/bpf/test_run.c               |  7 +++----
 net/core/filter.c                | 13 ++++---------
 net/core/xdp.c                   |  6 ++----
 net/ipv4/fou_bpf.c               |  6 ++----
 net/netfilter/nf_conntrack_bpf.c |  6 ++----
 net/netfilter/nf_nat_bpf.c       |  6 ++----
 net/xfrm/xfrm_interface_bpf.c    |  6 ++----
 14 files changed, 36 insertions(+), 57 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/btf.h b/include/linux/btf.h
index 928113a80a95..249d3d2351ad 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -83,6 +83,13 @@ 
  */
 #define __bpf_kfunc __used noinline
 
+#define BPF_KFUNC_START_DEFS				\
+	__diag_push();					\
+	__diag_ignore_all("-Wmissing-prototypes",	\
+			  "Global kfuncs as their definitions will be in BTF");
+
+#define BPF_KFUNC_END_DEFS __diag_pop();
+
 /*
  * Return the name of the passed struct, if exists, or halt the build if for
  * example the structure gets renamed. In this way, developers have to revisit
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 833faa04461b..da165abe8490 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -782,9 +782,7 @@  struct bpf_iter_num_kern {
 	int end; /* final value, exclusive */
 } __aligned(8);
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
 
 __bpf_kfunc int bpf_iter_num_new(struct bpf_iter_num *it, int start, int end)
 {
@@ -843,4 +841,4 @@  __bpf_kfunc void bpf_iter_num_destroy(struct bpf_iter_num *it)
 	s->cur = s->end = 0;
 }
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index 6983af8e093c..34e9f2cfa211 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -34,9 +34,7 @@  static bool cpu_valid(u32 cpu)
 	return cpu < nr_cpu_ids;
 }
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global kfuncs as their definitions will be in BTF");
+BPF_KFUNC_START_DEFS
 
 /**
  * bpf_cpumask_create() - Create a mutable BPF cpumask.
@@ -407,7 +405,7 @@  __bpf_kfunc u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1,
 	return cpumask_any_and_distribute(src1, src2);
 }
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(cpumask_kfunc_btf_ids)
 BTF_ID_FLAGS(func, bpf_cpumask_create, KF_ACQUIRE | KF_RET_NULL)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 62a53ebfedf9..0d86b7939f0b 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1888,9 +1888,7 @@  void bpf_rb_root_free(const struct btf_field *field, void *rb_root,
 	}
 }
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
 
 __bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
 {
@@ -2496,7 +2494,7 @@  __bpf_kfunc void bpf_throw(u64 cookie)
 	WARN(1, "A call to BPF exception callback should never return\n");
 }
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(generic_btf_ids)
 #ifdef CONFIG_KEXEC_CORE
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
index 6fc9dae9edc8..eb8848fdae87 100644
--- a/kernel/bpf/map_iter.c
+++ b/kernel/bpf/map_iter.c
@@ -193,9 +193,7 @@  static int __init bpf_map_iter_init(void)
 
 late_initcall(bpf_map_iter_init);
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
 
 __bpf_kfunc s64 bpf_map_sum_elem_count(const struct bpf_map *map)
 {
@@ -213,7 +211,7 @@  __bpf_kfunc s64 bpf_map_sum_elem_count(const struct bpf_map *map)
 	return ret;
 }
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(bpf_map_iter_kfunc_ids)
 BTF_ID_FLAGS(func, bpf_map_sum_elem_count, KF_TRUSTED_ARGS)
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index fef17628341f..eb026242bd30 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -824,9 +824,7 @@  struct bpf_iter_task_vma_kern {
 	struct bpf_iter_task_vma_kern_data *data;
 } __attribute__((aligned(8)));
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
 
 __bpf_kfunc int bpf_iter_task_vma_new(struct bpf_iter_task_vma *it,
 				      struct task_struct *task, u64 addr)
@@ -892,7 +890,7 @@  __bpf_kfunc void bpf_iter_task_vma_destroy(struct bpf_iter_task_vma *it)
 	}
 }
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 DEFINE_PER_CPU(struct mmap_unlock_irq_work, mmap_unlock_work);
 
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index df697c74d519..53d6c9dfe39d 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1252,9 +1252,7 @@  static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
 };
 
 #ifdef CONFIG_KEYS
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "kfuncs which will be used in BPF programs");
+BPF_KFUNC_START_DEFS
 
 /**
  * bpf_lookup_user_key - lookup a key by its serial
@@ -1404,7 +1402,7 @@  __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
 }
 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(key_sig_kfunc_set)
 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 0841f8d82419..74b9776560b7 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -503,9 +503,8 @@  static int bpf_test_finish(const union bpf_attr *kattr,
  * architecture dependent calling conventions. 7+ can be supported in the
  * future.
  */
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
+
 __bpf_kfunc int bpf_fentry_test1(int a)
 {
 	return a + 1;
@@ -605,7 +604,7 @@  __bpf_kfunc void bpf_kfunc_call_memb_release(struct prog_test_member *p)
 {
 }
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(bpf_test_modify_return_ids)
 BTF_ID_FLAGS(func, bpf_modify_return_test)
diff --git a/net/core/filter.c b/net/core/filter.c
index cc2e4babc85f..f90e5c3dc9a1 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -11751,9 +11751,7 @@  bpf_sk_base_func_proto(enum bpf_func_id func_id)
 	return func;
 }
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
 __bpf_kfunc int bpf_dynptr_from_skb(struct sk_buff *skb, u64 flags,
 				    struct bpf_dynptr_kern *ptr__uninit)
 {
@@ -11800,7 +11798,7 @@  __bpf_kfunc int bpf_sock_addr_set_sun_path(struct bpf_sock_addr_kern *sa_kern,
 
 	return 0;
 }
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 int bpf_dynptr_from_skb_rdonly(struct sk_buff *skb, u64 flags,
 			       struct bpf_dynptr_kern *ptr__uninit)
@@ -11863,10 +11861,7 @@  static int __init bpf_kfunc_init(void)
 }
 late_initcall(bpf_kfunc_init);
 
-/* Disables missing prototype warnings */
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
 
 /* bpf_sock_destroy: Destroy the given socket with ECONNABORTED error code.
  *
@@ -11900,7 +11895,7 @@  __bpf_kfunc int bpf_sock_destroy(struct sock_common *sock)
 	return sk->sk_prot->diag_destroy(sk, ECONNABORTED);
 }
 
-__diag_pop()
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(bpf_sk_iter_kfunc_ids)
 BTF_ID_FLAGS(func, bpf_sock_destroy, KF_TRUSTED_ARGS)
diff --git a/net/core/xdp.c b/net/core/xdp.c
index df4789ab512d..aed01f0a3acc 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -696,9 +696,7 @@  struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf)
 	return nxdpf;
 }
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in vmlinux BTF");
+BPF_KFUNC_START_DEFS
 
 /**
  * bpf_xdp_metadata_rx_timestamp - Read XDP frame RX timestamp.
@@ -738,7 +736,7 @@  __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
 	return -EOPNOTSUPP;
 }
 
-__diag_pop();
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(xdp_metadata_kfunc_ids)
 #define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
diff --git a/net/ipv4/fou_bpf.c b/net/ipv4/fou_bpf.c
index 3760a14b6b57..9ba0030215b3 100644
--- a/net/ipv4/fou_bpf.c
+++ b/net/ipv4/fou_bpf.c
@@ -22,9 +22,7 @@  enum bpf_fou_encap_type {
 	FOU_BPF_ENCAP_GUE,
 };
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in BTF");
+BPF_KFUNC_START_DEFS
 
 /* bpf_skb_set_fou_encap - Set FOU encap parameters
  *
@@ -100,7 +98,7 @@  __bpf_kfunc int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
 	return 0;
 }
 
-__diag_pop()
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(fou_kfunc_set)
 BTF_ID_FLAGS(func, bpf_skb_set_fou_encap)
diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c
index b21799d468d2..a8f37b9c30ec 100644
--- a/net/netfilter/nf_conntrack_bpf.c
+++ b/net/netfilter/nf_conntrack_bpf.c
@@ -230,9 +230,7 @@  static int _nf_conntrack_btf_struct_access(struct bpf_verifier_log *log,
 	return 0;
 }
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in nf_conntrack BTF");
+BPF_KFUNC_START_DEFS
 
 /* bpf_xdp_ct_alloc - Allocate a new CT entry
  *
@@ -467,7 +465,7 @@  __bpf_kfunc int bpf_ct_change_status(struct nf_conn *nfct, u32 status)
 	return nf_ct_change_status_common(nfct, status);
 }
 
-__diag_pop()
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(nf_ct_kfunc_set)
 BTF_ID_FLAGS(func, bpf_xdp_ct_alloc, KF_ACQUIRE | KF_RET_NULL)
diff --git a/net/netfilter/nf_nat_bpf.c b/net/netfilter/nf_nat_bpf.c
index 141ee7783223..df04343839ee 100644
--- a/net/netfilter/nf_nat_bpf.c
+++ b/net/netfilter/nf_nat_bpf.c
@@ -12,9 +12,7 @@ 
 #include <net/netfilter/nf_conntrack_core.h>
 #include <net/netfilter/nf_nat.h>
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in nf_nat BTF");
+BPF_KFUNC_START_DEFS
 
 /* bpf_ct_set_nat_info - Set source or destination nat address
  *
@@ -54,7 +52,7 @@  __bpf_kfunc int bpf_ct_set_nat_info(struct nf_conn___init *nfct,
 	return nf_nat_setup_info(ct, &range, manip) == NF_DROP ? -ENOMEM : 0;
 }
 
-__diag_pop()
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(nf_nat_kfunc_set)
 BTF_ID_FLAGS(func, bpf_ct_set_nat_info, KF_TRUSTED_ARGS)
diff --git a/net/xfrm/xfrm_interface_bpf.c b/net/xfrm/xfrm_interface_bpf.c
index d74f3fd20f2b..8321779d515d 100644
--- a/net/xfrm/xfrm_interface_bpf.c
+++ b/net/xfrm/xfrm_interface_bpf.c
@@ -27,9 +27,7 @@  struct bpf_xfrm_info {
 	int link;
 };
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in xfrm_interface BTF");
+BPF_KFUNC_START_DEFS
 
 /* bpf_skb_get_xfrm_info - Get XFRM metadata
  *
@@ -93,7 +91,7 @@  __bpf_kfunc int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx, const struct bp
 	return 0;
 }
 
-__diag_pop()
+BPF_KFUNC_END_DEFS
 
 BTF_SET8_START(xfrm_ifc_kfunc_set)
 BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)