From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andriin@fb.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
Martin KaFai Lau <kafai@fb.com>, David Miller <davem@redhat.com>,
John Fastabend <john.fastabend@gmail.com>,
Wenbo Zhang <ethercflow@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Brendan Gregg <bgregg@netflix.com>,
Florent Revest <revest@chromium.org>,
Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH v9 bpf-next 09/14] bpf: Add BTF_SET_START/END macros
Date: Sat, 1 Aug 2020 19:03:17 +0200 [thread overview]
Message-ID: <20200801170322.75218-10-jolsa@kernel.org> (raw)
In-Reply-To: <20200801170322.75218-1-jolsa@kernel.org>
Adding support to define sorted set of BTF ID values.
Following defines sorted set of BTF ID values:
BTF_SET_START(btf_allowlist_d_path)
BTF_ID(func, vfs_truncate)
BTF_ID(func, vfs_fallocate)
BTF_ID(func, dentry_open)
BTF_ID(func, vfs_getattr)
BTF_ID(func, filp_close)
BTF_SET_END(btf_allowlist_d_path)
It defines following 'struct btf_id_set' variable to access
values and count:
struct btf_id_set btf_allowlist_d_path;
Adding 'allowed' callback to struct bpf_func_proto, to allow
verifier the check on allowed callers.
Adding btf_id_set_contains function, which will be used by
allowed callbacks to verify the caller's BTF ID value is
within allowed set.
Also removing extra '\' in __BTF_ID_LIST macro.
Added BTF_SET_START_GLOBAL macro for global sets.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/bpf.h | 4 +++
include/linux/btf_ids.h | 51 ++++++++++++++++++++++++++++++++++-
kernel/bpf/btf.c | 14 ++++++++++
kernel/bpf/verifier.c | 5 ++++
tools/include/linux/btf_ids.h | 51 ++++++++++++++++++++++++++++++++++-
5 files changed, 123 insertions(+), 2 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 8206d5e324be..865860d80d39 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -309,6 +309,7 @@ struct bpf_func_proto {
* for this argument.
*/
int *ret_btf_id; /* return value btf_id */
+ bool (*allowed)(const struct bpf_prog *prog);
};
/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
@@ -1849,4 +1850,7 @@ enum bpf_text_poke_type {
int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
void *addr1, void *addr2);
+struct btf_id_set;
+bool btf_id_set_contains(struct btf_id_set *set, u32 id);
+
#endif /* _LINUX_BPF_H */
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 4867d549e3c1..210b086188a3 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -3,6 +3,11 @@
#ifndef _LINUX_BTF_IDS_H
#define _LINUX_BTF_IDS_H
+struct btf_id_set {
+ u32 cnt;
+ u32 ids[];
+};
+
#ifdef CONFIG_DEBUG_INFO_BTF
#include <linux/compiler.h> /* for __PASTE */
@@ -62,7 +67,7 @@ asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
"." #scope " " #name "; \n" \
#name ":; \n" \
-".popsection; \n"); \
+".popsection; \n");
#define BTF_ID_LIST(name) \
__BTF_ID_LIST(name, local) \
@@ -88,12 +93,56 @@ asm( \
".zero 4 \n" \
".popsection; \n");
+/*
+ * The BTF_SET_START/END macros pair defines sorted list of
+ * BTF IDs plus its members count, with following layout:
+ *
+ * BTF_SET_START(list)
+ * BTF_ID(type1, name1)
+ * BTF_ID(type2, name2)
+ * BTF_SET_END(list)
+ *
+ * __BTF_ID__set__list:
+ * .zero 4
+ * list:
+ * __BTF_ID__type1__name1__3:
+ * .zero 4
+ * __BTF_ID__type2__name2__4:
+ * .zero 4
+ *
+ */
+#define __BTF_SET_START(name, scope) \
+asm( \
+".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
+"." #scope " __BTF_ID__set__" #name "; \n" \
+"__BTF_ID__set__" #name ":; \n" \
+".zero 4 \n" \
+".popsection; \n");
+
+#define BTF_SET_START(name) \
+__BTF_ID_LIST(name, local) \
+__BTF_SET_START(name, local)
+
+#define BTF_SET_START_GLOBAL(name) \
+__BTF_ID_LIST(name, globl) \
+__BTF_SET_START(name, globl)
+
+#define BTF_SET_END(name) \
+asm( \
+".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
+".size __BTF_ID__set__" #name ", .-" #name " \n" \
+".popsection; \n"); \
+extern struct btf_id_set name;
+
#else
#define BTF_ID_LIST(name) static u32 name[5];
#define BTF_ID(prefix, name)
#define BTF_ID_UNUSED
#define BTF_ID_LIST_GLOBAL(name) u32 name[1];
+#define BTF_SET_START(name) static struct btf_id_set name = { 0 };
+#define BTF_SET_START_GLOBAL(name) static struct btf_id_set name = { 0 };
+#define BTF_SET_END(name)
#endif /* CONFIG_DEBUG_INFO_BTF */
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index ba05b15ad599..c51caf508d3d 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -21,6 +21,8 @@
#include <linux/btf_ids.h>
#include <linux/skmsg.h>
#include <linux/perf_event.h>
+#include <linux/bsearch.h>
+#include <linux/btf_ids.h>
#include <net/sock.h>
/* BTF (BPF Type Format) is the meta data format which describes
@@ -4762,3 +4764,15 @@ u32 btf_id(const struct btf *btf)
{
return btf->id;
}
+
+static int btf_id_cmp_func(const void *a, const void *b)
+{
+ const int *pa = a, *pb = b;
+
+ return *pa - *pb;
+}
+
+bool btf_id_set_contains(struct btf_id_set *set, u32 id)
+{
+ return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
+}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index bb6ca19f282d..523c5ecc79dd 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4781,6 +4781,11 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
return -EINVAL;
}
+ if (fn->allowed && !fn->allowed(env->prog)) {
+ verbose(env, "helper call is not allowed in probe\n");
+ return -EINVAL;
+ }
+
/* With LD_ABS/IND some JITs save/restore skb from r1. */
changes_data = bpf_helper_changes_pkt_data(fn->func);
if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) {
diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h
index 4867d549e3c1..210b086188a3 100644
--- a/tools/include/linux/btf_ids.h
+++ b/tools/include/linux/btf_ids.h
@@ -3,6 +3,11 @@
#ifndef _LINUX_BTF_IDS_H
#define _LINUX_BTF_IDS_H
+struct btf_id_set {
+ u32 cnt;
+ u32 ids[];
+};
+
#ifdef CONFIG_DEBUG_INFO_BTF
#include <linux/compiler.h> /* for __PASTE */
@@ -62,7 +67,7 @@ asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
"." #scope " " #name "; \n" \
#name ":; \n" \
-".popsection; \n"); \
+".popsection; \n");
#define BTF_ID_LIST(name) \
__BTF_ID_LIST(name, local) \
@@ -88,12 +93,56 @@ asm( \
".zero 4 \n" \
".popsection; \n");
+/*
+ * The BTF_SET_START/END macros pair defines sorted list of
+ * BTF IDs plus its members count, with following layout:
+ *
+ * BTF_SET_START(list)
+ * BTF_ID(type1, name1)
+ * BTF_ID(type2, name2)
+ * BTF_SET_END(list)
+ *
+ * __BTF_ID__set__list:
+ * .zero 4
+ * list:
+ * __BTF_ID__type1__name1__3:
+ * .zero 4
+ * __BTF_ID__type2__name2__4:
+ * .zero 4
+ *
+ */
+#define __BTF_SET_START(name, scope) \
+asm( \
+".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
+"." #scope " __BTF_ID__set__" #name "; \n" \
+"__BTF_ID__set__" #name ":; \n" \
+".zero 4 \n" \
+".popsection; \n");
+
+#define BTF_SET_START(name) \
+__BTF_ID_LIST(name, local) \
+__BTF_SET_START(name, local)
+
+#define BTF_SET_START_GLOBAL(name) \
+__BTF_ID_LIST(name, globl) \
+__BTF_SET_START(name, globl)
+
+#define BTF_SET_END(name) \
+asm( \
+".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
+".size __BTF_ID__set__" #name ", .-" #name " \n" \
+".popsection; \n"); \
+extern struct btf_id_set name;
+
#else
#define BTF_ID_LIST(name) static u32 name[5];
#define BTF_ID(prefix, name)
#define BTF_ID_UNUSED
#define BTF_ID_LIST_GLOBAL(name) u32 name[1];
+#define BTF_SET_START(name) static struct btf_id_set name = { 0 };
+#define BTF_SET_START_GLOBAL(name) static struct btf_id_set name = { 0 };
+#define BTF_SET_END(name)
#endif /* CONFIG_DEBUG_INFO_BTF */
--
2.25.4
next prev parent reply other threads:[~2020-08-01 17:04 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-01 17:03 [PATCH v9 bpf-next 00/14] bpf: Add d_path helper Jiri Olsa
2020-08-01 17:03 ` [PATCH v9 bpf-next 01/14] tools resolve_btfids: Add size check to get_id function Jiri Olsa
2020-08-05 6:00 ` Andrii Nakryiko
2020-08-01 17:03 ` [PATCH v9 bpf-next 02/14] tools resolve_btfids: Add support for set symbols Jiri Olsa
2020-08-05 6:04 ` Andrii Nakryiko
2020-08-01 17:03 ` [PATCH v9 bpf-next 03/14] bpf: Move btf_resolve_size into __btf_resolve_size Jiri Olsa
2020-08-01 17:03 ` [PATCH v9 bpf-next 04/14] bpf: Add elem_id pointer as argument to __btf_resolve_size Jiri Olsa
2020-08-01 17:03 ` [PATCH v9 bpf-next 05/14] bpf: Add type_id " Jiri Olsa
2020-08-05 6:05 ` Andrii Nakryiko
2020-08-01 17:03 ` [PATCH v9 bpf-next 06/14] bpf: Remove recursion call in btf_struct_access Jiri Olsa
2020-08-05 6:12 ` Andrii Nakryiko
2020-08-05 17:36 ` Jiri Olsa
2020-08-01 17:03 ` [PATCH v9 bpf-next 07/14] bpf: Factor btf_struct_access function Jiri Olsa
2020-08-05 6:18 ` Andrii Nakryiko
2020-08-01 17:03 ` [PATCH v9 bpf-next 08/14] bpf: Add btf_struct_ids_match function Jiri Olsa
2020-08-05 6:27 ` Andrii Nakryiko
2020-08-05 17:56 ` Jiri Olsa
2020-08-05 21:31 ` Jiri Olsa
2020-08-05 21:57 ` Andrii Nakryiko
2020-08-01 17:03 ` Jiri Olsa [this message]
2020-08-05 6:29 ` [PATCH v9 bpf-next 09/14] bpf: Add BTF_SET_START/END macros Andrii Nakryiko
2020-08-01 17:03 ` [PATCH v9 bpf-next 10/14] bpf: Add d_path helper Jiri Olsa
2020-08-02 3:13 ` Alexei Starovoitov
2020-08-02 18:26 ` Jiri Olsa
2020-08-05 6:35 ` Andrii Nakryiko
2020-08-05 17:58 ` Jiri Olsa
2020-08-05 21:01 ` Jiri Olsa
2020-08-05 21:09 ` Andrii Nakryiko
2020-08-07 0:31 ` KP Singh
2020-08-07 8:35 ` Jiri Olsa
2020-08-07 9:42 ` KP Singh
2020-08-01 17:03 ` [PATCH v9 bpf-next 11/14] bpf: Update .BTF_ids section in btf.rst with sets info Jiri Olsa
2020-08-01 17:03 ` [PATCH v9 bpf-next 12/14] selftests/bpf: Add verifier test for d_path helper Jiri Olsa
2020-08-01 17:03 ` [PATCH v9 bpf-next 13/14] selftests/bpf: Add " Jiri Olsa
2020-08-05 6:40 ` Andrii Nakryiko
2020-08-05 18:00 ` Jiri Olsa
2020-08-01 17:03 ` [PATCH v9 bpf-next 14/14] selftests/bpf: Add set test to resolve_btfids Jiri Olsa
2020-08-05 6:41 ` Andrii Nakryiko
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