* [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr
@ 2019-07-01 17:38 Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 1/3] " Stanislav Fomichev
` (3 more replies)
0 siblings, 4 replies; 6+ messages in thread
From: Stanislav Fomichev @ 2019-07-01 17:38 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
Clang can generate 8-byte stores for user_ip6 & msg_src_ip6,
let's support that on the verifier side.
v3:
* fix comments spelling an -> and (Andrii Nakryiko)
v2:
* Add simple cover letter (Yonghong Song)
* Update comments (Yonghong Song)
* Remove [4] selftests (Yonghong Song)
Stanislav Fomichev (3):
bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr
bpf: sync bpf.h to tools/
selftests/bpf: add verifier tests for wide stores
include/linux/filter.h | 6 ++++
include/uapi/linux/bpf.h | 6 ++--
net/core/filter.c | 22 +++++++-----
tools/include/uapi/linux/bpf.h | 6 ++--
tools/testing/selftests/bpf/test_verifier.c | 17 +++++++--
.../selftests/bpf/verifier/wide_store.c | 36 +++++++++++++++++++
6 files changed, 76 insertions(+), 17 deletions(-)
create mode 100644 tools/testing/selftests/bpf/verifier/wide_store.c
--
2.22.0.410.gd8fdbe21b5-goog
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH bpf-next v3 1/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr
2019-07-01 17:38 [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr Stanislav Fomichev
@ 2019-07-01 17:38 ` Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 2/3] bpf: sync bpf.h to tools/ Stanislav Fomichev
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Stanislav Fomichev @ 2019-07-01 17:38 UTC (permalink / raw)
To: netdev, bpf
Cc: davem, ast, daniel, Stanislav Fomichev, Andrii Nakryiko,
Yonghong Song, kernel test robot
Since commit cd17d7770578 ("bpf/tools: sync bpf.h") clang decided
that it can do a single u64 store into user_ip6[2] instead of two
separate u32 ones:
# 17: (18) r2 = 0x100000000000000
# ; ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2);
# 19: (7b) *(u64 *)(r1 +16) = r2
# invalid bpf_context access off=16 size=8
From the compiler point of view it does look like a correct thing
to do, so let's support it on the kernel side.
Credit to Andrii Nakryiko for a proper implementation of
bpf_ctx_wide_store_ok.
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Fixes: cd17d7770578 ("bpf/tools: sync bpf.h")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
include/linux/filter.h | 6 ++++++
include/uapi/linux/bpf.h | 6 +++---
net/core/filter.c | 22 ++++++++++++++--------
3 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 1fe53e78c7e3..6d944369ca87 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -747,6 +747,12 @@ bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default)
return size <= size_default && (size & (size - 1)) == 0;
}
+#define bpf_ctx_wide_store_ok(off, size, type, field) \
+ (size == sizeof(__u64) && \
+ off >= offsetof(type, field) && \
+ off + sizeof(__u64) <= offsetofend(type, field) && \
+ off % sizeof(__u64) == 0)
+
#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index cffea1826a1f..dcdc606e57d6 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3240,7 +3240,7 @@ struct bpf_sock_addr {
__u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write.
* Stored in network byte order.
*/
- __u32 user_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write.
+ __u32 user_ip6[4]; /* Allows 1,2,4-byte read and 4,8-byte write.
* Stored in network byte order.
*/
__u32 user_port; /* Allows 4-byte read and write.
@@ -3249,10 +3249,10 @@ struct bpf_sock_addr {
__u32 family; /* Allows 4-byte read, but no write */
__u32 type; /* Allows 4-byte read, but no write */
__u32 protocol; /* Allows 4-byte read, but no write */
- __u32 msg_src_ip4; /* Allows 1,2,4-byte read an 4-byte write.
+ __u32 msg_src_ip4; /* Allows 1,2,4-byte read and 4-byte write.
* Stored in network byte order.
*/
- __u32 msg_src_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write.
+ __u32 msg_src_ip6[4]; /* Allows 1,2,4-byte read and 4,8-byte write.
* Stored in network byte order.
*/
__bpf_md_ptr(struct bpf_sock *, sk);
diff --git a/net/core/filter.c b/net/core/filter.c
index 4836264f82ee..2520dbc539fc 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6851,6 +6851,16 @@ static bool sock_addr_is_valid_access(int off, int size,
if (!bpf_ctx_narrow_access_ok(off, size, size_default))
return false;
} else {
+ if (bpf_ctx_wide_store_ok(off, size,
+ struct bpf_sock_addr,
+ user_ip6))
+ return true;
+
+ if (bpf_ctx_wide_store_ok(off, size,
+ struct bpf_sock_addr,
+ msg_src_ip6))
+ return true;
+
if (size != size_default)
return false;
}
@@ -7691,9 +7701,6 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type,
/* SOCK_ADDR_STORE_NESTED_FIELD_OFF() has semantic similar to
* SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF() but for store operation.
*
- * It doesn't support SIZE argument though since narrow stores are not
- * supported for now.
- *
* In addition it uses Temporary Field TF (member of struct S) as the 3rd
* "register" since two registers available in convert_ctx_access are not
* enough: we can't override neither SRC, since it contains value to store, nor
@@ -7701,7 +7708,7 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type,
* instructions. But we need a temporary place to save pointer to nested
* structure whose field we want to store to.
*/
-#define SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, OFF, TF) \
+#define SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, SIZE, OFF, TF) \
do { \
int tmp_reg = BPF_REG_9; \
if (si->src_reg == tmp_reg || si->dst_reg == tmp_reg) \
@@ -7712,8 +7719,7 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type,
offsetof(S, TF)); \
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(S, F), tmp_reg, \
si->dst_reg, offsetof(S, F)); \
- *insn++ = BPF_STX_MEM( \
- BPF_FIELD_SIZEOF(NS, NF), tmp_reg, si->src_reg, \
+ *insn++ = BPF_STX_MEM(SIZE, tmp_reg, si->src_reg, \
bpf_target_off(NS, NF, FIELD_SIZEOF(NS, NF), \
target_size) \
+ OFF); \
@@ -7725,8 +7731,8 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type,
TF) \
do { \
if (type == BPF_WRITE) { \
- SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, OFF, \
- TF); \
+ SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, SIZE, \
+ OFF, TF); \
} else { \
SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF( \
S, NS, F, NF, SIZE, OFF); \
--
2.22.0.410.gd8fdbe21b5-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH bpf-next v3 2/3] bpf: sync bpf.h to tools/
2019-07-01 17:38 [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 1/3] " Stanislav Fomichev
@ 2019-07-01 17:38 ` Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 3/3] selftests/bpf: add verifier tests for wide stores Stanislav Fomichev
2019-07-08 15:25 ` [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr Daniel Borkmann
3 siblings, 0 replies; 6+ messages in thread
From: Stanislav Fomichev @ 2019-07-01 17:38 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
Sync user_ip6 & msg_src_ip6 comments.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/include/uapi/linux/bpf.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index a396b516a2b2..c59dc921ce83 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3237,7 +3237,7 @@ struct bpf_sock_addr {
__u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write.
* Stored in network byte order.
*/
- __u32 user_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write.
+ __u32 user_ip6[4]; /* Allows 1,2,4-byte read and 4,8-byte write.
* Stored in network byte order.
*/
__u32 user_port; /* Allows 4-byte read and write.
@@ -3246,10 +3246,10 @@ struct bpf_sock_addr {
__u32 family; /* Allows 4-byte read, but no write */
__u32 type; /* Allows 4-byte read, but no write */
__u32 protocol; /* Allows 4-byte read, but no write */
- __u32 msg_src_ip4; /* Allows 1,2,4-byte read an 4-byte write.
+ __u32 msg_src_ip4; /* Allows 1,2,4-byte read and 4-byte write.
* Stored in network byte order.
*/
- __u32 msg_src_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write.
+ __u32 msg_src_ip6[4]; /* Allows 1,2,4-byte read and 4,8-byte write.
* Stored in network byte order.
*/
__bpf_md_ptr(struct bpf_sock *, sk);
--
2.22.0.410.gd8fdbe21b5-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH bpf-next v3 3/3] selftests/bpf: add verifier tests for wide stores
2019-07-01 17:38 [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 1/3] " Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 2/3] bpf: sync bpf.h to tools/ Stanislav Fomichev
@ 2019-07-01 17:38 ` Stanislav Fomichev
2019-07-01 17:50 ` Yonghong Song
2019-07-08 15:25 ` [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr Daniel Borkmann
3 siblings, 1 reply; 6+ messages in thread
From: Stanislav Fomichev @ 2019-07-01 17:38 UTC (permalink / raw)
To: netdev, bpf
Cc: davem, ast, daniel, Stanislav Fomichev, Andrii Nakryiko,
Yonghong Song
Make sure that wide stores are allowed at proper (aligned) addresses.
Note that user_ip6 is naturally aligned on 8-byte boundary, so
correct addresses are user_ip6[0] and user_ip6[2]. msg_src_ip6 is,
however, aligned on a 4-byte bondary, so only msg_src_ip6[1]
can be wide-stored.
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/testing/selftests/bpf/test_verifier.c | 17 +++++++--
.../selftests/bpf/verifier/wide_store.c | 36 +++++++++++++++++++
2 files changed, 50 insertions(+), 3 deletions(-)
create mode 100644 tools/testing/selftests/bpf/verifier/wide_store.c
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index c5514daf8865..b0773291012a 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -105,6 +105,7 @@ struct bpf_test {
__u64 data64[TEST_DATA_LEN / 8];
};
} retvals[MAX_TEST_RUNS];
+ enum bpf_attach_type expected_attach_type;
};
/* Note we want this to be 64 bit aligned so that the end of our array is
@@ -850,6 +851,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
int fd_prog, expected_ret, alignment_prevented_execution;
int prog_len, prog_type = test->prog_type;
struct bpf_insn *prog = test->insns;
+ struct bpf_load_program_attr attr;
int run_errs, run_successes;
int map_fds[MAX_NR_MAPS];
const char *expected_err;
@@ -881,8 +883,17 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
pflags |= BPF_F_STRICT_ALIGNMENT;
if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS)
pflags |= BPF_F_ANY_ALIGNMENT;
- fd_prog = bpf_verify_program(prog_type, prog, prog_len, pflags,
- "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 4);
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_type = prog_type;
+ attr.expected_attach_type = test->expected_attach_type;
+ attr.insns = prog;
+ attr.insns_cnt = prog_len;
+ attr.license = "GPL";
+ attr.log_level = 4;
+ attr.prog_flags = pflags;
+
+ fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog));
if (fd_prog < 0 && !bpf_probe_prog_type(prog_type, 0)) {
printf("SKIP (unsupported program type %d)\n", prog_type);
skips++;
@@ -912,7 +923,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
printf("FAIL\nUnexpected success to load!\n");
goto fail_log;
}
- if (!strstr(bpf_vlog, expected_err)) {
+ if (!expected_err || !strstr(bpf_vlog, expected_err)) {
printf("FAIL\nUnexpected error message!\n\tEXP: %s\n\tRES: %s\n",
expected_err, bpf_vlog);
goto fail_log;
diff --git a/tools/testing/selftests/bpf/verifier/wide_store.c b/tools/testing/selftests/bpf/verifier/wide_store.c
new file mode 100644
index 000000000000..8fe99602ded4
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/wide_store.c
@@ -0,0 +1,36 @@
+#define BPF_SOCK_ADDR(field, off, res, err) \
+{ \
+ "wide store to bpf_sock_addr." #field "[" #off "]", \
+ .insns = { \
+ BPF_MOV64_IMM(BPF_REG_0, 1), \
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, \
+ offsetof(struct bpf_sock_addr, field[off])), \
+ BPF_EXIT_INSN(), \
+ }, \
+ .result = res, \
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, \
+ .expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, \
+ .errstr = err, \
+}
+
+/* user_ip6[0] is u64 aligned */
+BPF_SOCK_ADDR(user_ip6, 0, ACCEPT,
+ NULL),
+BPF_SOCK_ADDR(user_ip6, 1, REJECT,
+ "invalid bpf_context access off=12 size=8"),
+BPF_SOCK_ADDR(user_ip6, 2, ACCEPT,
+ NULL),
+BPF_SOCK_ADDR(user_ip6, 3, REJECT,
+ "invalid bpf_context access off=20 size=8"),
+
+/* msg_src_ip6[0] is _not_ u64 aligned */
+BPF_SOCK_ADDR(msg_src_ip6, 0, REJECT,
+ "invalid bpf_context access off=44 size=8"),
+BPF_SOCK_ADDR(msg_src_ip6, 1, ACCEPT,
+ NULL),
+BPF_SOCK_ADDR(msg_src_ip6, 2, REJECT,
+ "invalid bpf_context access off=52 size=8"),
+BPF_SOCK_ADDR(msg_src_ip6, 3, REJECT,
+ "invalid bpf_context access off=56 size=8"),
+
+#undef BPF_SOCK_ADDR
--
2.22.0.410.gd8fdbe21b5-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v3 3/3] selftests/bpf: add verifier tests for wide stores
2019-07-01 17:38 ` [PATCH bpf-next v3 3/3] selftests/bpf: add verifier tests for wide stores Stanislav Fomichev
@ 2019-07-01 17:50 ` Yonghong Song
0 siblings, 0 replies; 6+ messages in thread
From: Yonghong Song @ 2019-07-01 17:50 UTC (permalink / raw)
To: Stanislav Fomichev, netdev@vger.kernel.org, bpf@vger.kernel.org
Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net,
Andrii Nakryiko
On 7/1/19 10:38 AM, Stanislav Fomichev wrote:
> Make sure that wide stores are allowed at proper (aligned) addresses.
> Note that user_ip6 is naturally aligned on 8-byte boundary, so
> correct addresses are user_ip6[0] and user_ip6[2]. msg_src_ip6 is,
> however, aligned on a 4-byte bondary, so only msg_src_ip6[1]
> can be wide-stored.
>
> Cc: Andrii Nakryiko <andriin@fb.com>
> Cc: Yonghong Song <yhs@fb.com>
> Acked-by: Andrii Nakryiko <andriin@fb.com>
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr
2019-07-01 17:38 [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr Stanislav Fomichev
` (2 preceding siblings ...)
2019-07-01 17:38 ` [PATCH bpf-next v3 3/3] selftests/bpf: add verifier tests for wide stores Stanislav Fomichev
@ 2019-07-08 15:25 ` Daniel Borkmann
3 siblings, 0 replies; 6+ messages in thread
From: Daniel Borkmann @ 2019-07-08 15:25 UTC (permalink / raw)
To: Stanislav Fomichev, netdev, bpf; +Cc: davem, ast
On 07/01/2019 07:38 PM, Stanislav Fomichev wrote:
> Clang can generate 8-byte stores for user_ip6 & msg_src_ip6,
> let's support that on the verifier side.
>
> v3:
> * fix comments spelling an -> and (Andrii Nakryiko)
>
> v2:
> * Add simple cover letter (Yonghong Song)
> * Update comments (Yonghong Song)
> * Remove [4] selftests (Yonghong Song)
>
> Stanislav Fomichev (3):
> bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr
> bpf: sync bpf.h to tools/
> selftests/bpf: add verifier tests for wide stores
>
> include/linux/filter.h | 6 ++++
> include/uapi/linux/bpf.h | 6 ++--
> net/core/filter.c | 22 +++++++-----
> tools/include/uapi/linux/bpf.h | 6 ++--
> tools/testing/selftests/bpf/test_verifier.c | 17 +++++++--
> .../selftests/bpf/verifier/wide_store.c | 36 +++++++++++++++++++
> 6 files changed, 76 insertions(+), 17 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/verifier/wide_store.c
>
Applied, thanks!
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-07-08 15:42 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2019-07-01 17:38 [PATCH bpf-next v3 0/3] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 1/3] " Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 2/3] bpf: sync bpf.h to tools/ Stanislav Fomichev
2019-07-01 17:38 ` [PATCH bpf-next v3 3/3] selftests/bpf: add verifier tests for wide stores Stanislav Fomichev
2019-07-01 17:50 ` Yonghong Song
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