Merge branch 'New nf_conntrack kfuncs for insertion, changing timeout, status'

Kumar Kartikeya Dwivedi says:

====================

Introduce the following new kfuncs:
 - bpf_{xdp,skb}_ct_alloc
 - bpf_ct_insert_entry
 - bpf_ct_{set,change}_timeout
 - bpf_ct_{set,change}_status

The setting of timeout and status on allocated or inserted/looked up CT
is same as the ctnetlink interface, hence code is refactored and shared
with the kfuncs. It is ensured allocated CT cannot be passed to kfuncs
that expected inserted CT, and vice versa. Please see individual patches
for details.

Changelog:
----------
v6 -> v7:
v6: https://lore.kernel.org/bpf/20220719132430.19993-1-memxor@gmail.com

 * Use .long to encode flags (Alexei)
 * Fix description of KF_RET_NULL in documentation (Toke)

v5 -> v6:
v5: https://lore.kernel.org/bpf/20220623192637.3866852-1-memxor@gmail.com

 * Introduce kfunc flags, rework verifier to work with them
 * Add documentation for kfuncs
 * Add comment explaining TRUSTED_ARGS kfunc flag (Alexei)
 * Fix missing offset check for trusted arguments (Alexei)
 * Change nf_conntrack test minimum delta value to 8

v4 -> v5:
v4: https://lore.kernel.org/bpf/cover.1653600577.git.lorenzo@kernel.org

 * Drop read-only PTR_TO_BTF_ID approach, use struct nf_conn___init (Alexei)
 * Drop acquire release pair code that is no longer required (Alexei)
 * Disable writes into nf_conn, use dedicated helpers (Florian, Alexei)
 * Refactor and share ctnetlink code for setting timeout and status
 * Do strict type matching on finding __ref suffix on argument to
   prevent passing nf_conn___init as nf_conn (offset = 0, match on walk)
 * Remove bpf_ct_opts parameter from bpf_ct_insert_entry
 * Update selftests for new additions, add more negative tests

v3 -> v4:
v3: https://lore.kernel.org/bpf/cover.1652870182.git.lorenzo@kernel.org

 * split bpf_xdp_ct_add in bpf_xdp_ct_alloc/bpf_skb_ct_alloc and
   bpf_ct_insert_entry
 * add verifier code to properly populate/configure ct entry
 * improve selftests

v2 -> v3:
v2: https://lore.kernel.org/bpf/cover.1652372970.git.lorenzo@kernel.org

 * add bpf_xdp_ct_add and bpf_ct_refresh_timeout kfunc helpers
 * remove conntrack dependency from selftests
 * add support for forcing kfunc args to be referenced and related selftests

v1 -> v2:
v1: https://lore.kernel.org/bpf/1327f8f5696ff2bc60400e8f3b79047914ccc837.1651595019.git.lorenzo@kernel.org

 * add bpf_ct_refresh_timeout kfunc selftest

Kumar Kartikeya Dwivedi (10):
  bpf: Introduce 8-byte BTF set
  tools/resolve_btfids: Add support for 8-byte BTF sets
  bpf: Switch to new kfunc flags infrastructure
  bpf: Add support for forcing kfunc args to be trusted
  bpf: Add documentation for kfuncs
  net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup
  net: netfilter: Add kfuncs to set and change CT timeout
  selftests/bpf: Add verifier tests for trusted kfunc args
  selftests/bpf: Add negative tests for new nf_conntrack kfuncs
  selftests/bpf: Fix test_verifier failed test in unprivileged mode
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 64 insertions, 4 deletions

diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 252a4befeab1..3cb0741e71d7 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -8,6 +8,15 @@ struct btf_id_set {
 	u32 ids[];
 };
 
+struct btf_id_set8 {
+	u32 cnt;
+	u32 flags;
+	struct {
+		u32 id;
+		u32 flags;
+	} pairs[];
+};
+
 #ifdef CONFIG_DEBUG_INFO_BTF
 
 #include <linux/compiler.h> /* for __PASTE */
@@ -25,7 +34,7 @@ struct btf_id_set {
 
 #define BTF_IDS_SECTION ".BTF_ids"
 
-#define ____BTF_ID(symbol)				\
+#define ____BTF_ID(symbol, word)			\
 asm(							\
 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
 ".local " #symbol " ;                          \n"	\
@@ -33,10 +42,11 @@ asm(							\
 ".size  " #symbol ", 4;                        \n"	\
 #symbol ":                                     \n"	\
 ".zero 4                                       \n"	\
+word							\
 ".popsection;                                  \n");
 
-#define __BTF_ID(symbol) \
-	____BTF_ID(symbol)
+#define __BTF_ID(symbol, word) \
+	____BTF_ID(symbol, word)
 
 #define __ID(prefix) \
 	__PASTE(prefix, __COUNTER__)
@@ -46,7 +56,14 @@ asm(							\
  * to 4 zero bytes.
  */
 #define BTF_ID(prefix, name) \
-	__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__))
+	__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__), "")
+
+#define ____BTF_ID_FLAGS(prefix, name, flags) \
+	__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__), ".long " #flags "\n")
+#define __BTF_ID_FLAGS(prefix, name, flags, ...) \
+	____BTF_ID_FLAGS(prefix, name, flags)
+#define BTF_ID_FLAGS(prefix, name, ...) \
+	__BTF_ID_FLAGS(prefix, name, ##__VA_ARGS__, 0)
 
 /*
  * The BTF_ID_LIST macro defines pure (unsorted) list
@@ -145,10 +162,51 @@ asm(							\
 ".popsection;                                 \n");	\
 extern struct btf_id_set name;
 
+/*
+ * The BTF_SET8_START/END macros pair defines sorted list of
+ * BTF IDs and their flags plus its members count, with the
+ * following layout:
+ *
+ * BTF_SET8_START(list)
+ * BTF_ID_FLAGS(type1, name1, flags)
+ * BTF_ID_FLAGS(type2, name2, flags)
+ * BTF_SET8_END(list)
+ *
+ * __BTF_ID__set8__list:
+ * .zero 8
+ * list:
+ * __BTF_ID__type1__name1__3:
+ * .zero 4
+ * .word (1 << 0) | (1 << 2)
+ * __BTF_ID__type2__name2__5:
+ * .zero 4
+ * .word (1 << 3) | (1 << 1) | (1 << 2)
+ *
+ */
+#define __BTF_SET8_START(name, scope)			\
+asm(							\
+".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
+"." #scope " __BTF_ID__set8__" #name ";        \n"	\
+"__BTF_ID__set8__" #name ":;                   \n"	\
+".zero 8                                       \n"	\
+".popsection;                                  \n");
+
+#define BTF_SET8_START(name)				\
+__BTF_ID_LIST(name, local)				\
+__BTF_SET8_START(name, local)
+
+#define BTF_SET8_END(name)				\
+asm(							\
+".pushsection " BTF_IDS_SECTION ",\"a\";      \n"	\
+".size __BTF_ID__set8__" #name ", .-" #name "  \n"	\
+".popsection;                                 \n");	\
+extern struct btf_id_set8 name;
+
 #else
 
 #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
 #define BTF_ID(prefix, name)
+#define BTF_ID_FLAGS(prefix, name, flags)
 #define BTF_ID_UNUSED
 #define BTF_ID_LIST_GLOBAL(name, n) u32 __maybe_unused name[n];
 #define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 __maybe_unused name[1];
@@ -156,6 +214,8 @@ extern struct btf_id_set name;
 #define BTF_SET_START(name) static struct btf_id_set __maybe_unused name = { 0 };
 #define BTF_SET_START_GLOBAL(name) static struct btf_id_set __maybe_unused name = { 0 };
 #define BTF_SET_END(name)
+#define BTF_SET8_START(name) static struct btf_id_set8 __maybe_unused name = { 0 };
+#define BTF_SET8_END(name) static struct btf_id_set8 __maybe_unused name = { 0 };
 
 #endif /* CONFIG_DEBUG_INFO_BTF */