* Re: [PATCH v2] kcm: remove any offset before parsing messages
From: Dominique Martinet @ 2018-09-12 5:36 UTC (permalink / raw)
To: Doron Roberts-Kedes, Tom Herbert, Dave Watson
Cc: David S. Miller, netdev, linux-kernel
In-Reply-To: <1536657703-27577-1-git-send-email-asmadeus@codewreck.org>
Dominique Martinet wrote on Tue, Sep 11, 2018:
> Hmm, while trying to benchmark this, I sometimes got hangs in
> kcm_wait_data() for the last packet somehow?
> The sender program was done (exited (zombie) so I assumed the sender
> socket flushed), but the receiver was in kcm_wait_data in kcm_recvmsg
> indicating it parsed a header but there was no skb to peek at?
> But the sock is locked so this shouldn't be racy...
>
> I can get it fairly often with this patch and small messages with an
> offset, but I think it's just because the pull changes some timing - I
> can't hit it with just the clone, and I can hit it with a pull without
> clone as well.... And I don't see how pulling a cloned skb can impact
> the original socket, but I'm a bit fuzzy on this.
This is weird, I cannot reproduce at all without that pull, even if I
add another delay there instead of the pull, so it's not just timing...
I was confusing kcm_recvmsg and kcm_rcv_strparser but I still think
there is a race in kcm_wait_data between the peek and the wait. I have
confirmed on a hang that the sock's sk_receive_queue is not empty so
skb_peek would return something at this point, but it is waiting in
kcm_wait_data's sk_wait_data.. And no event would be coming at this
point since the sender is done.
kcm_wait_data does have the socket lock but the enqueuing counterpart
(kcm_queue_rcv_skb) is apparently called without lock most of the time
(at least, sk->sk_lock.owned is not set most of the times) ; but if I
add a lock_sock() here it can deadlock when a kfree_skb triggers
kcm_rcv_ready if that kfree_skb was done with the lock... ugh.
I thought the mux rx lock would be taken all the time but that appear
not to be the case either, and even if it were I don't see how to make
sk_wait_data with another lock in the first place.
So meh, I'm not sure why the pull messes up with this, I'm tempted to
say this is an old problem but I'm quite annoyed I do not seem to be
able to reproduce it.
I'm really out of time now so unless someone cares it'll wait for a few
more weeks.
(As an unrelated note, wrt to the patch, it might be nice to add a new
kcm socket option so users could say "my bpf program handles offsets,
don't bother with this")
--
Dominique
^ permalink raw reply
* [PATCH bpf-next 00/11] Add socket lookup support
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
This series proposes a new helper for the BPF API which allows BPF programs to
perform lookups for sockets in a network namespace. This would allow programs
to determine early on in processing whether the stack is expecting to receive
the packet, and perform some action (eg drop, forward somewhere) based on this
information.
The series is structured roughly into:
* Misc refactor
* Add the socket pointer type
* Add reference tracking to ensure that socket references are freed
* Extend the BPF API to add sk_lookup_xxx() / sk_release() functions
* Add tests/documentation
The helper proposed in this series includes a parameter for a tuple which must
be filled in by the caller to determine the socket to look up. The simplest
case would be filling with the contents of the packet, ie mapping the packet's
5-tuple into the parameter. In common cases, it may alternatively be useful to
reverse the direction of the tuple and perform a lookup, to find the socket
that initiates this connection; and if the BPF program ever performs a form of
IP address translation, it may further be useful to be able to look up
arbitrary tuples that are not based upon the packet, but instead based on state
held in BPF maps or hardcoded in the BPF program.
Currently, access into the socket's fields are limited to those which are
otherwise already accessible, and are restricted to read-only access.
Changes since RFC:
* Split up sk_lookup() into sk_lookup_tcp(), sk_lookup_udp().
* Only take references on the socket when necessary.
* Make sk_release() only free the socket reference in this case.
* Fix some runtime reference leaks:
* Disallow BPF_LD_[ABS|IND] instructions while holding a reference.
* Disallow bpf_tail_call() while holding a reference.
* Prevent the same instruction being used for reference and other
pointer type.
* Simplify locating copies of a reference during helper calls by caching
the pointer id from the caller.
* Fix kbuild compilation warnings with particular configs.
* Improve code comments describing the new verifier pieces.
* Testing courtesy of Nitin
* Rebase
This tree is also available at:
https://github.com/joestringer/linux/commits/submit/sk-lookup-v1
Joe Stringer (11):
bpf: Add iterator for spilled registers
bpf: Simplify ptr_min_max_vals adjustment
bpf: Generalize ptr_or_null regs check
bpf: Add PTR_TO_SOCKET verifier type
bpf: Macrofy stack state copy
bpf: Add reference tracking to verifier
bpf: Add helper to retrieve socket in BPF
selftests/bpf: Add tests for reference tracking
libbpf: Support loading individual progs
selftests/bpf: Add C tests for reference tracking
Documentation: Describe bpf reference tracking
Documentation/networking/filter.txt | 64 ++
include/linux/bpf.h | 17 +
include/linux/bpf_verifier.h | 37 +-
include/uapi/linux/bpf.h | 54 +-
kernel/bpf/verifier.c | 599 ++++++++++++++----
net/core/filter.c | 175 ++++-
tools/include/uapi/linux/bpf.h | 54 +-
tools/lib/bpf/libbpf.c | 4 +-
tools/lib/bpf/libbpf.h | 3 +
tools/testing/selftests/bpf/Makefile | 2 +-
tools/testing/selftests/bpf/bpf_helpers.h | 12 +
tools/testing/selftests/bpf/test_progs.c | 38 ++
.../selftests/bpf/test_sk_lookup_kern.c | 128 ++++
tools/testing/selftests/bpf/test_verifier.c | 373 ++++++++++-
14 files changed, 1426 insertions(+), 134 deletions(-)
create mode 100644 tools/testing/selftests/bpf/test_sk_lookup_kern.c
--
2.17.1
^ permalink raw reply
* [PATCH bpf-next 01/11] bpf: Add iterator for spilled registers
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
Add this iterator for spilled registers, it concentrates the details of
how to get the current frame's spilled registers into a single macro
while clarifying the intention of the code which is calling the macro.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
include/linux/bpf_verifier.h | 11 +++++++++++
kernel/bpf/verifier.c | 16 +++++++---------
2 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index b42b60a83e19..af262b97f586 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -131,6 +131,17 @@ struct bpf_verifier_state {
u32 curframe;
};
+#define __get_spilled_reg(slot, frame) \
+ (((slot < frame->allocated_stack / BPF_REG_SIZE) && \
+ (frame->stack[slot].slot_type[0] == STACK_SPILL)) \
+ ? &frame->stack[slot].spilled_ptr : NULL)
+
+/* Iterate over 'frame', setting 'reg' to either NULL or a spilled register. */
+#define for_each_spilled_reg(iter, frame, reg) \
+ for (iter = 0, reg = __get_spilled_reg(iter, frame); \
+ iter < frame->allocated_stack / BPF_REG_SIZE; \
+ iter++, reg = __get_spilled_reg(iter, frame))
+
/* linked list of verifier states used to prune search */
struct bpf_verifier_state_list {
struct bpf_verifier_state state;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6ff1bac1795d..97aac6ac1b0d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2219,10 +2219,9 @@ static void __clear_all_pkt_pointers(struct bpf_verifier_env *env,
if (reg_is_pkt_pointer_any(®s[i]))
mark_reg_unknown(env, regs, i);
- for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
- if (state->stack[i].slot_type[0] != STACK_SPILL)
+ for_each_spilled_reg(i, state, reg) {
+ if (!reg)
continue;
- reg = &state->stack[i].spilled_ptr;
if (reg_is_pkt_pointer_any(reg))
__mark_reg_unknown(reg);
}
@@ -3362,10 +3361,9 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
for (j = 0; j <= vstate->curframe; j++) {
state = vstate->frame[j];
- for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
- if (state->stack[i].slot_type[0] != STACK_SPILL)
+ for_each_spilled_reg(i, state, reg) {
+ if (!reg)
continue;
- reg = &state->stack[i].spilled_ptr;
if (reg->type == type && reg->id == dst_reg->id)
reg->range = max(reg->range, new_range);
}
@@ -3610,7 +3608,7 @@ static void mark_map_regs(struct bpf_verifier_state *vstate, u32 regno,
bool is_null)
{
struct bpf_func_state *state = vstate->frame[vstate->curframe];
- struct bpf_reg_state *regs = state->regs;
+ struct bpf_reg_state *reg, *regs = state->regs;
u32 id = regs[regno].id;
int i, j;
@@ -3619,8 +3617,8 @@ static void mark_map_regs(struct bpf_verifier_state *vstate, u32 regno,
for (j = 0; j <= vstate->curframe; j++) {
state = vstate->frame[j];
- for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
- if (state->stack[i].slot_type[0] != STACK_SPILL)
+ for_each_spilled_reg(i, state, reg) {
+ if (!reg)
continue;
mark_map_reg(&state->stack[i].spilled_ptr, 0, id, is_null);
}
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 02/11] bpf: Simplify ptr_min_max_vals adjustment
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
An upcoming commit will add another two pointer types that need very
similar behaviour, so generalise this function now.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
kernel/bpf/verifier.c | 22 ++++++++++-----------
tools/testing/selftests/bpf/test_verifier.c | 14 ++++++-------
2 files changed, 17 insertions(+), 19 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 97aac6ac1b0d..61b60e141b6a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2636,20 +2636,18 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
return -EACCES;
}
- if (ptr_reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
- verbose(env, "R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n",
- dst);
- return -EACCES;
- }
- if (ptr_reg->type == CONST_PTR_TO_MAP) {
- verbose(env, "R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n",
- dst);
+ switch (ptr_reg->type) {
+ case PTR_TO_MAP_VALUE_OR_NULL:
+ verbose(env, "R%d pointer arithmetic on %s prohibited, null-check it first\n",
+ dst, reg_type_str[ptr_reg->type]);
return -EACCES;
- }
- if (ptr_reg->type == PTR_TO_PACKET_END) {
- verbose(env, "R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n",
- dst);
+ case CONST_PTR_TO_MAP:
+ case PTR_TO_PACKET_END:
+ verbose(env, "R%d pointer arithmetic on %s prohibited\n",
+ dst, reg_type_str[ptr_reg->type]);
return -EACCES;
+ default:
+ break;
}
/* In case of 'scalar += pointer', dst_reg inherits pointer type and id.
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 67c412d19c09..ceb55a9f3da9 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -3637,7 +3637,7 @@ static struct bpf_test tests[] = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
- .errstr = "R3 pointer arithmetic on PTR_TO_PACKET_END",
+ .errstr = "R3 pointer arithmetic on pkt_end",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
},
@@ -4780,7 +4780,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.fixup_map1 = { 4 },
- .errstr = "R4 pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL",
+ .errstr = "R4 pointer arithmetic on map_value_or_null",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_SCHED_CLS
},
@@ -4801,7 +4801,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.fixup_map1 = { 4 },
- .errstr = "R4 pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL",
+ .errstr = "R4 pointer arithmetic on map_value_or_null",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_SCHED_CLS
},
@@ -4822,7 +4822,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.fixup_map1 = { 4 },
- .errstr = "R4 pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL",
+ .errstr = "R4 pointer arithmetic on map_value_or_null",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_SCHED_CLS
},
@@ -7137,7 +7137,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.fixup_map_in_map = { 3 },
- .errstr = "R1 pointer arithmetic on CONST_PTR_TO_MAP prohibited",
+ .errstr = "R1 pointer arithmetic on map_ptr prohibited",
.result = REJECT,
},
{
@@ -8811,7 +8811,7 @@ static struct bpf_test tests[] = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
- .errstr = "R3 pointer arithmetic on PTR_TO_PACKET_END",
+ .errstr = "R3 pointer arithmetic on pkt_end",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_XDP,
},
@@ -8830,7 +8830,7 @@ static struct bpf_test tests[] = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
- .errstr = "R3 pointer arithmetic on PTR_TO_PACKET_END",
+ .errstr = "R3 pointer arithmetic on pkt_end",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_XDP,
},
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 03/11] bpf: Generalize ptr_or_null regs check
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
This check will be reused by an upcoming commit for conditional jump
checks for sockets. Refactor it a bit to simplify the later commit.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
kernel/bpf/verifier.c | 43 +++++++++++++++++++++++++------------------
1 file changed, 25 insertions(+), 18 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 61b60e141b6a..f2357c8c90de 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -249,6 +249,11 @@ static bool type_is_pkt_pointer(enum bpf_reg_type type)
type == PTR_TO_PACKET_META;
}
+static bool reg_type_may_be_null(enum bpf_reg_type type)
+{
+ return type == PTR_TO_MAP_VALUE_OR_NULL;
+}
+
/* string representation of 'enum bpf_reg_type' */
static const char * const reg_type_str[] = {
[NOT_INIT] = "?",
@@ -3567,12 +3572,10 @@ static void reg_combine_min_max(struct bpf_reg_state *true_src,
}
}
-static void mark_map_reg(struct bpf_reg_state *regs, u32 regno, u32 id,
- bool is_null)
+static void mark_ptr_or_null_reg(struct bpf_reg_state *reg, u32 id,
+ bool is_null)
{
- struct bpf_reg_state *reg = ®s[regno];
-
- if (reg->type == PTR_TO_MAP_VALUE_OR_NULL && reg->id == id) {
+ if (reg_type_may_be_null(reg->type) && reg->id == id) {
/* Old offset (both fixed and variable parts) should
* have been known-zero, because we don't allow pointer
* arithmetic on pointers that might be NULL.
@@ -3585,11 +3588,13 @@ static void mark_map_reg(struct bpf_reg_state *regs, u32 regno, u32 id,
}
if (is_null) {
reg->type = SCALAR_VALUE;
- } else if (reg->map_ptr->inner_map_meta) {
- reg->type = CONST_PTR_TO_MAP;
- reg->map_ptr = reg->map_ptr->inner_map_meta;
- } else {
- reg->type = PTR_TO_MAP_VALUE;
+ } else if (reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
+ if (reg->map_ptr->inner_map_meta) {
+ reg->type = CONST_PTR_TO_MAP;
+ reg->map_ptr = reg->map_ptr->inner_map_meta;
+ } else {
+ reg->type = PTR_TO_MAP_VALUE;
+ }
}
/* We don't need id from this point onwards anymore, thus we
* should better reset it, so that state pruning has chances
@@ -3602,8 +3607,8 @@ static void mark_map_reg(struct bpf_reg_state *regs, u32 regno, u32 id,
/* The logic is similar to find_good_pkt_pointers(), both could eventually
* be folded together at some point.
*/
-static void mark_map_regs(struct bpf_verifier_state *vstate, u32 regno,
- bool is_null)
+static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno,
+ bool is_null)
{
struct bpf_func_state *state = vstate->frame[vstate->curframe];
struct bpf_reg_state *reg, *regs = state->regs;
@@ -3611,14 +3616,14 @@ static void mark_map_regs(struct bpf_verifier_state *vstate, u32 regno,
int i, j;
for (i = 0; i < MAX_BPF_REG; i++)
- mark_map_reg(regs, i, id, is_null);
+ mark_ptr_or_null_reg(®s[i], id, is_null);
for (j = 0; j <= vstate->curframe; j++) {
state = vstate->frame[j];
for_each_spilled_reg(i, state, reg) {
if (!reg)
continue;
- mark_map_reg(&state->stack[i].spilled_ptr, 0, id, is_null);
+ mark_ptr_or_null_reg(reg, id, is_null);
}
}
}
@@ -3820,12 +3825,14 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
/* detect if R == 0 where R is returned from bpf_map_lookup_elem() */
if (BPF_SRC(insn->code) == BPF_K &&
insn->imm == 0 && (opcode == BPF_JEQ || opcode == BPF_JNE) &&
- dst_reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
- /* Mark all identical map registers in each branch as either
+ reg_type_may_be_null(dst_reg->type)) {
+ /* Mark all identical registers in each branch as either
* safe or unknown depending R == 0 or R != 0 conditional.
*/
- mark_map_regs(this_branch, insn->dst_reg, opcode == BPF_JNE);
- mark_map_regs(other_branch, insn->dst_reg, opcode == BPF_JEQ);
+ mark_ptr_or_null_regs(this_branch, insn->dst_reg,
+ opcode == BPF_JNE);
+ mark_ptr_or_null_regs(other_branch, insn->dst_reg,
+ opcode == BPF_JEQ);
} else if (!try_match_pkt_pointers(insn, dst_reg, ®s[insn->src_reg],
this_branch, other_branch) &&
is_pointer_value(env, insn->dst_reg)) {
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 04/11] bpf: Add PTR_TO_SOCKET verifier type
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
Teach the verifier a little bit about a new type of pointer, a
PTR_TO_SOCKET. This pointer type is accessed from BPF through the
'struct bpf_sock' structure.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
include/linux/bpf.h | 17 +++++
include/linux/bpf_verifier.h | 2 +
kernel/bpf/verifier.c | 125 ++++++++++++++++++++++++++++++-----
net/core/filter.c | 30 +++++----
4 files changed, 147 insertions(+), 27 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 523481a3471b..6ec93f3d66dd 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -154,6 +154,7 @@ enum bpf_arg_type {
ARG_PTR_TO_CTX, /* pointer to context */
ARG_ANYTHING, /* any (initialized) argument is ok */
+ ARG_PTR_TO_SOCKET, /* pointer to bpf_sock */
};
/* type of values returned from helper functions */
@@ -162,6 +163,7 @@ enum bpf_return_type {
RET_VOID, /* function doesn't return anything */
RET_PTR_TO_MAP_VALUE, /* returns a pointer to map elem value */
RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
+ RET_PTR_TO_SOCKET_OR_NULL, /* returns a pointer to a socket or NULL */
};
/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
@@ -212,6 +214,8 @@ enum bpf_reg_type {
PTR_TO_PACKET_META, /* skb->data - meta_len */
PTR_TO_PACKET, /* reg points to skb->data */
PTR_TO_PACKET_END, /* skb->data + headlen */
+ PTR_TO_SOCKET, /* reg points to struct bpf_sock */
+ PTR_TO_SOCKET_OR_NULL, /* reg points to struct bpf_sock or NULL */
};
/* The information passed from prog-specific *_is_valid_access
@@ -334,6 +338,11 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
unsigned long off, unsigned long len);
+typedef u32 (*bpf_convert_ctx_access_t)(enum bpf_access_type type,
+ const struct bpf_insn *src,
+ struct bpf_insn *dst,
+ struct bpf_prog *prog,
+ u32 *target_size);
u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy);
@@ -827,4 +836,12 @@ extern const struct bpf_func_proto bpf_get_local_storage_proto;
void bpf_user_rnd_init_once(void);
u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+bool bpf_sock_is_valid_access(int off, int size, enum bpf_access_type type,
+ struct bpf_insn_access_aux *info);
+u32 bpf_sock_convert_ctx_access(enum bpf_access_type type,
+ const struct bpf_insn *si,
+ struct bpf_insn *insn_buf,
+ struct bpf_prog *prog,
+ u32 *target_size);
+
#endif /* _LINUX_BPF_H */
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index af262b97f586..23a2b17bfd75 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -58,6 +58,8 @@ struct bpf_reg_state {
* offset, so they can share range knowledge.
* For PTR_TO_MAP_VALUE_OR_NULL this is used to share which map value we
* came from, when one is tested for != NULL.
+ * For PTR_TO_SOCKET this is used to share which pointers retain the
+ * same reference to the socket, to determine proper reference freeing.
*/
u32 id;
/* For scalar types (SCALAR_VALUE), this represents our knowledge of
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index f2357c8c90de..111e031cf65d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -80,8 +80,8 @@ static const struct bpf_verifier_ops * const bpf_verifier_ops[] = {
* (like pointer plus pointer becomes SCALAR_VALUE type)
*
* When verifier sees load or store instructions the type of base register
- * can be: PTR_TO_MAP_VALUE, PTR_TO_CTX, PTR_TO_STACK. These are three pointer
- * types recognized by check_mem_access() function.
+ * can be: PTR_TO_MAP_VALUE, PTR_TO_CTX, PTR_TO_STACK, PTR_TO_SOCKET. These are
+ * four pointer types recognized by check_mem_access() function.
*
* PTR_TO_MAP_VALUE means that this register is pointing to 'map element value'
* and the range of [ptr, ptr + map's value_size) is accessible.
@@ -266,6 +266,8 @@ static const char * const reg_type_str[] = {
[PTR_TO_PACKET] = "pkt",
[PTR_TO_PACKET_META] = "pkt_meta",
[PTR_TO_PACKET_END] = "pkt_end",
+ [PTR_TO_SOCKET] = "sock",
+ [PTR_TO_SOCKET_OR_NULL] = "sock_or_null",
};
static char slot_type_char[] = {
@@ -971,6 +973,8 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
case PTR_TO_PACKET_META:
case PTR_TO_PACKET_END:
case CONST_PTR_TO_MAP:
+ case PTR_TO_SOCKET:
+ case PTR_TO_SOCKET_OR_NULL:
return true;
default:
return false;
@@ -1326,6 +1330,28 @@ static int check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int off,
return -EACCES;
}
+static int check_sock_access(struct bpf_verifier_env *env, u32 regno, int off,
+ int size, enum bpf_access_type t)
+{
+ struct bpf_reg_state *regs = cur_regs(env);
+ struct bpf_reg_state *reg = ®s[regno];
+ struct bpf_insn_access_aux info;
+
+ if (reg->smin_value < 0) {
+ verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n",
+ regno);
+ return -EACCES;
+ }
+
+ if (!bpf_sock_is_valid_access(off, size, t, &info)) {
+ verbose(env, "invalid bpf_sock_ops access off=%d size=%d\n",
+ off, size);
+ return -EACCES;
+ }
+
+ return 0;
+}
+
static bool __is_pointer_value(bool allow_ptr_leaks,
const struct bpf_reg_state *reg)
{
@@ -1441,6 +1467,9 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
*/
strict = true;
break;
+ case PTR_TO_SOCKET:
+ pointer_desc = "sock ";
+ break;
default:
break;
}
@@ -1697,6 +1726,16 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
err = check_packet_access(env, regno, off, size, false);
if (!err && t == BPF_READ && value_regno >= 0)
mark_reg_unknown(env, regs, value_regno);
+
+ } else if (reg->type == PTR_TO_SOCKET) {
+ if (t == BPF_WRITE) {
+ verbose(env, "cannot write into socket\n");
+ return -EACCES;
+ }
+ err = check_sock_access(env, regno, off, size, t);
+ if (!err && value_regno >= 0)
+ mark_reg_unknown(env, regs, value_regno);
+
} else {
verbose(env, "R%d invalid mem access '%s'\n", regno,
reg_type_str[reg->type]);
@@ -1918,6 +1957,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
err = check_ctx_reg(env, reg, regno);
if (err < 0)
return err;
+ } else if (arg_type == ARG_PTR_TO_SOCKET) {
+ expected_type = PTR_TO_SOCKET;
+ if (type != expected_type)
+ goto err_type;
} else if (arg_type_is_mem_ptr(arg_type)) {
expected_type = PTR_TO_STACK;
/* One exception here. In case function allows for NULL to be
@@ -2511,6 +2554,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
}
regs[BPF_REG_0].map_ptr = meta.map_ptr;
regs[BPF_REG_0].id = ++env->id_gen;
+ } else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
+ regs[BPF_REG_0].id = ++env->id_gen;
} else {
verbose(env, "unknown return type %d of func %s#%d\n",
fn->ret_type, func_id_name(func_id), func_id);
@@ -2648,6 +2695,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
return -EACCES;
case CONST_PTR_TO_MAP:
case PTR_TO_PACKET_END:
+ case PTR_TO_SOCKET:
+ case PTR_TO_SOCKET_OR_NULL:
verbose(env, "R%d pointer arithmetic on %s prohibited\n",
dst, reg_type_str[ptr_reg->type]);
return -EACCES;
@@ -3595,6 +3644,8 @@ static void mark_ptr_or_null_reg(struct bpf_reg_state *reg, u32 id,
} else {
reg->type = PTR_TO_MAP_VALUE;
}
+ } else if (reg->type == PTR_TO_SOCKET_OR_NULL) {
+ reg->type = PTR_TO_SOCKET;
}
/* We don't need id from this point onwards anymore, thus we
* should better reset it, so that state pruning has chances
@@ -4369,6 +4420,8 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur,
case PTR_TO_CTX:
case CONST_PTR_TO_MAP:
case PTR_TO_PACKET_END:
+ case PTR_TO_SOCKET:
+ case PTR_TO_SOCKET_OR_NULL:
/* Only valid matches are exact, which memcmp() above
* would have accepted
*/
@@ -4646,6 +4699,37 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
return 0;
}
+/* Return true if it's OK to have the same insn return a different type. */
+static bool reg_type_mismatch_ok(enum bpf_reg_type type)
+{
+ switch (type) {
+ case PTR_TO_CTX:
+ case PTR_TO_SOCKET:
+ case PTR_TO_SOCKET_OR_NULL:
+ return false;
+ default:
+ return true;
+ }
+}
+
+/* If an instruction was previously used with particular pointer types, then we
+ * need to be careful to avoid cases such as the below, where it may be ok
+ * for one branch accessing the pointer, but not ok for the other branch:
+ *
+ * R1 = sock_ptr
+ * goto X;
+ * ...
+ * R1 = some_other_valid_ptr;
+ * goto X;
+ * ...
+ * R2 = *(u32 *)(R1 + 0);
+ */
+static bool reg_type_mismatch(enum bpf_reg_type src, enum bpf_reg_type prev)
+{
+ return src != prev && (!reg_type_mismatch_ok(src) ||
+ !reg_type_mismatch_ok(prev));
+}
+
static int do_check(struct bpf_verifier_env *env)
{
struct bpf_verifier_state *state;
@@ -4778,9 +4862,7 @@ static int do_check(struct bpf_verifier_env *env)
*/
*prev_src_type = src_reg_type;
- } else if (src_reg_type != *prev_src_type &&
- (src_reg_type == PTR_TO_CTX ||
- *prev_src_type == PTR_TO_CTX)) {
+ } else if (reg_type_mismatch(src_reg_type, *prev_src_type)) {
/* ABuser program is trying to use the same insn
* dst_reg = *(u32*) (src_reg + off)
* with different pointer types:
@@ -4826,8 +4908,8 @@ static int do_check(struct bpf_verifier_env *env)
if (*prev_dst_type == NOT_INIT) {
*prev_dst_type = dst_reg_type;
} else if (dst_reg_type != *prev_dst_type &&
- (dst_reg_type == PTR_TO_CTX ||
- *prev_dst_type == PTR_TO_CTX)) {
+ (!reg_type_mismatch_ok(dst_reg_type) ||
+ !reg_type_mismatch_ok(*prev_dst_type))) {
verbose(env, "same insn cannot be used with different pointers\n");
return -EINVAL;
}
@@ -5244,10 +5326,14 @@ static void sanitize_dead_code(struct bpf_verifier_env *env)
}
}
-/* convert load instructions that access fields of 'struct __sk_buff'
- * into sequence of instructions that access fields of 'struct sk_buff'
+/* convert load instructions that access fields of a context type into a
+ * sequence of instructions that access fields of the underlying structure:
+ * struct __sk_buff -> struct sk_buff
+ * struct bpf_sock_ops -> struct sock
*/
-static int convert_ctx_accesses(struct bpf_verifier_env *env)
+static int convert_ctx_accesses(struct bpf_verifier_env *env,
+ bpf_convert_ctx_access_t convert_ctx_access,
+ enum bpf_reg_type ctx_type)
{
const struct bpf_verifier_ops *ops = env->ops;
int i, cnt, size, ctx_field_size, delta = 0;
@@ -5274,12 +5360,14 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
}
}
- if (!ops->convert_ctx_access || bpf_prog_is_dev_bound(env->prog->aux))
+ if (!convert_ctx_access || bpf_prog_is_dev_bound(env->prog->aux))
return 0;
insn = env->prog->insnsi + delta;
for (i = 0; i < insn_cnt; i++, insn++) {
+ enum bpf_reg_type ptr_type;
+
if (insn->code == (BPF_LDX | BPF_MEM | BPF_B) ||
insn->code == (BPF_LDX | BPF_MEM | BPF_H) ||
insn->code == (BPF_LDX | BPF_MEM | BPF_W) ||
@@ -5321,7 +5409,8 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
continue;
}
- if (env->insn_aux_data[i + delta].ptr_type != PTR_TO_CTX)
+ ptr_type = env->insn_aux_data[i + delta].ptr_type;
+ if (ptr_type != ctx_type)
continue;
ctx_field_size = env->insn_aux_data[i + delta].ctx_field_size;
@@ -5354,8 +5443,8 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
}
target_size = 0;
- cnt = ops->convert_ctx_access(type, insn, insn_buf, env->prog,
- &target_size);
+ cnt = convert_ctx_access(type, insn, insn_buf, env->prog,
+ &target_size);
if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf) ||
(ctx_field_size && !target_size)) {
verbose(env, "bpf verifier is misconfigured\n");
@@ -5899,7 +5988,13 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
if (ret == 0)
/* program is valid, convert *(u32*)(ctx + off) accesses */
- ret = convert_ctx_accesses(env);
+ ret = convert_ctx_accesses(env, env->ops->convert_ctx_access,
+ PTR_TO_CTX);
+
+ if (ret == 0)
+ /* Convert *(u32*)(sock_ops + off) accesses */
+ ret = convert_ctx_accesses(env, bpf_sock_convert_ctx_access,
+ PTR_TO_SOCKET);
if (ret == 0)
ret = fixup_bpf_calls(env);
diff --git a/net/core/filter.c b/net/core/filter.c
index 8cb242b4400f..23e6e5202138 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5375,23 +5375,29 @@ static bool __sock_filter_check_size(int off, int size,
return size == size_default;
}
-static bool sock_filter_is_valid_access(int off, int size,
- enum bpf_access_type type,
- const struct bpf_prog *prog,
- struct bpf_insn_access_aux *info)
+bool bpf_sock_is_valid_access(int off, int size, enum bpf_access_type type,
+ struct bpf_insn_access_aux *info)
{
if (off < 0 || off >= sizeof(struct bpf_sock))
return false;
if (off % size != 0)
return false;
- if (!__sock_filter_check_attach_type(off, type,
- prog->expected_attach_type))
- return false;
if (!__sock_filter_check_size(off, size, info))
return false;
return true;
}
+static bool sock_filter_is_valid_access(int off, int size,
+ enum bpf_access_type type,
+ const struct bpf_prog *prog,
+ struct bpf_insn_access_aux *info)
+{
+ if (!__sock_filter_check_attach_type(off, type,
+ prog->expected_attach_type))
+ return false;
+ return bpf_sock_is_valid_access(off, size, type, info);
+}
+
static int bpf_unclone_prologue(struct bpf_insn *insn_buf, bool direct_write,
const struct bpf_prog *prog, int drop_verdict)
{
@@ -6059,10 +6065,10 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
return insn - insn_buf;
}
-static u32 sock_filter_convert_ctx_access(enum bpf_access_type type,
- const struct bpf_insn *si,
- struct bpf_insn *insn_buf,
- struct bpf_prog *prog, u32 *target_size)
+u32 bpf_sock_convert_ctx_access(enum bpf_access_type type,
+ const struct bpf_insn *si,
+ struct bpf_insn *insn_buf,
+ struct bpf_prog *prog, u32 *target_size)
{
struct bpf_insn *insn = insn_buf;
int off;
@@ -6974,7 +6980,7 @@ const struct bpf_prog_ops lwt_seg6local_prog_ops = {
const struct bpf_verifier_ops cg_sock_verifier_ops = {
.get_func_proto = sock_filter_func_proto,
.is_valid_access = sock_filter_is_valid_access,
- .convert_ctx_access = sock_filter_convert_ctx_access,
+ .convert_ctx_access = bpf_sock_convert_ctx_access,
};
const struct bpf_prog_ops cg_sock_prog_ops = {
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 05/11] bpf: Macrofy stack state copy
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
An upcoming commit will need very similar copy/realloc boilerplate, so
refactor the existing stack copy/realloc functions into macros to
simplify it.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
kernel/bpf/verifier.c | 106 ++++++++++++++++++++++++------------------
1 file changed, 60 insertions(+), 46 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 111e031cf65d..faa83b3d7011 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -387,60 +387,74 @@ static void print_verifier_state(struct bpf_verifier_env *env,
verbose(env, "\n");
}
-static int copy_stack_state(struct bpf_func_state *dst,
- const struct bpf_func_state *src)
-{
- if (!src->stack)
- return 0;
- if (WARN_ON_ONCE(dst->allocated_stack < src->allocated_stack)) {
- /* internal bug, make state invalid to reject the program */
- memset(dst, 0, sizeof(*dst));
- return -EFAULT;
- }
- memcpy(dst->stack, src->stack,
- sizeof(*src->stack) * (src->allocated_stack / BPF_REG_SIZE));
- return 0;
-}
+#define COPY_STATE_FN(NAME, COUNT, FIELD, SIZE) \
+static int copy_##NAME##_state(struct bpf_func_state *dst, \
+ const struct bpf_func_state *src) \
+{ \
+ if (!src->FIELD) \
+ return 0; \
+ if (WARN_ON_ONCE(dst->COUNT < src->COUNT)) { \
+ /* internal bug, make state invalid to reject the program */ \
+ memset(dst, 0, sizeof(*dst)); \
+ return -EFAULT; \
+ } \
+ memcpy(dst->FIELD, src->FIELD, \
+ sizeof(*src->FIELD) * (src->COUNT / SIZE)); \
+ return 0; \
+}
+/* copy_stack_state() */
+COPY_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
+#undef COPY_STATE_FN
+
+#define REALLOC_STATE_FN(NAME, COUNT, FIELD, SIZE) \
+static int realloc_##NAME##_state(struct bpf_func_state *state, int size, \
+ bool copy_old) \
+{ \
+ u32 old_size = state->COUNT; \
+ struct bpf_##NAME##_state *new_##FIELD; \
+ int slot = size / SIZE; \
+ \
+ if (size <= old_size || !size) { \
+ if (copy_old) \
+ return 0; \
+ state->COUNT = slot * SIZE; \
+ if (!size && old_size) { \
+ kfree(state->FIELD); \
+ state->FIELD = NULL; \
+ } \
+ return 0; \
+ } \
+ new_##FIELD = kmalloc_array(slot, sizeof(struct bpf_##NAME##_state), \
+ GFP_KERNEL); \
+ if (!new_##FIELD) \
+ return -ENOMEM; \
+ if (copy_old) { \
+ if (state->FIELD) \
+ memcpy(new_##FIELD, state->FIELD, \
+ sizeof(*new_##FIELD) * (old_size / SIZE)); \
+ memset(new_##FIELD + old_size / SIZE, 0, \
+ sizeof(*new_##FIELD) * (size - old_size) / SIZE); \
+ } \
+ state->COUNT = slot * SIZE; \
+ kfree(state->FIELD); \
+ state->FIELD = new_##FIELD; \
+ return 0; \
+}
+/* realloc_stack_state() */
+REALLOC_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
+#undef REALLOC_STATE_FN
/* do_check() starts with zero-sized stack in struct bpf_verifier_state to
* make it consume minimal amount of memory. check_stack_write() access from
* the program calls into realloc_func_state() to grow the stack size.
- * Note there is a non-zero parent pointer inside each reg of bpf_verifier_state
- * which this function copies over. It points to corresponding reg in previous
- * bpf_verifier_state which is never reallocated
+ * Note there is a non-zero 'parent' pointer inside bpf_verifier_state
+ * which realloc_stack_state() copies over. It points to previous
+ * bpf_verifier_state which is never reallocated.
*/
static int realloc_func_state(struct bpf_func_state *state, int size,
bool copy_old)
{
- u32 old_size = state->allocated_stack;
- struct bpf_stack_state *new_stack;
- int slot = size / BPF_REG_SIZE;
-
- if (size <= old_size || !size) {
- if (copy_old)
- return 0;
- state->allocated_stack = slot * BPF_REG_SIZE;
- if (!size && old_size) {
- kfree(state->stack);
- state->stack = NULL;
- }
- return 0;
- }
- new_stack = kmalloc_array(slot, sizeof(struct bpf_stack_state),
- GFP_KERNEL);
- if (!new_stack)
- return -ENOMEM;
- if (copy_old) {
- if (state->stack)
- memcpy(new_stack, state->stack,
- sizeof(*new_stack) * (old_size / BPF_REG_SIZE));
- memset(new_stack + old_size / BPF_REG_SIZE, 0,
- sizeof(*new_stack) * (size - old_size) / BPF_REG_SIZE);
- }
- state->allocated_stack = slot * BPF_REG_SIZE;
- kfree(state->stack);
- state->stack = new_stack;
- return 0;
+ return realloc_stack_state(state, size, copy_old);
}
static void free_func_state(struct bpf_func_state *state)
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 06/11] bpf: Add reference tracking to verifier
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
Allow helper functions to acquire a reference and return it into a
register. Specific pointer types such as the PTR_TO_SOCKET will
implicitly represent such a reference. The verifier must ensure that
these references are released exactly once in each path through the
program.
To achieve this, this commit assigns an id to the pointer and tracks it
in the 'bpf_func_state', then when the function or program exits,
verifies that all of the acquired references have been freed. When the
pointer is passed to a function that frees the reference, it is removed
from the 'bpf_func_state` and all existing copies of the pointer in
registers are marked invalid.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
include/linux/bpf_verifier.h | 24 ++-
kernel/bpf/verifier.c | 303 ++++++++++++++++++++++++++++++++---
2 files changed, 306 insertions(+), 21 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 23a2b17bfd75..23f222e0cb0b 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -104,6 +104,17 @@ struct bpf_stack_state {
u8 slot_type[BPF_REG_SIZE];
};
+struct bpf_reference_state {
+ /* Track each reference created with a unique id, even if the same
+ * instruction creates the reference multiple times (eg, via CALL).
+ */
+ int id;
+ /* Instruction where the allocation of this reference occurred. This
+ * is used purely to inform the user of a reference leak.
+ */
+ int insn_idx;
+};
+
/* state of the program:
* type of all registers and stack info
*/
@@ -121,7 +132,9 @@ struct bpf_func_state {
*/
u32 subprogno;
- /* should be second to last. See copy_func_state() */
+ /* The following fields should be last. See copy_func_state() */
+ int acquired_refs;
+ struct bpf_reference_state *refs;
int allocated_stack;
struct bpf_stack_state *stack;
};
@@ -217,11 +230,16 @@ __printf(2, 0) void bpf_verifier_vlog(struct bpf_verifier_log *log,
__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
const char *fmt, ...);
-static inline struct bpf_reg_state *cur_regs(struct bpf_verifier_env *env)
+static inline struct bpf_func_state *cur_func(struct bpf_verifier_env *env)
{
struct bpf_verifier_state *cur = env->cur_state;
- return cur->frame[cur->curframe]->regs;
+ return cur->frame[cur->curframe];
+}
+
+static inline struct bpf_reg_state *cur_regs(struct bpf_verifier_env *env)
+{
+ return cur_func(env)->regs;
}
int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index faa83b3d7011..67c62ef67d37 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1,5 +1,6 @@
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
* Copyright (c) 2016 Facebook
+ * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
@@ -140,6 +141,18 @@ static const struct bpf_verifier_ops * const bpf_verifier_ops[] = {
*
* After the call R0 is set to return type of the function and registers R1-R5
* are set to NOT_INIT to indicate that they are no longer readable.
+ *
+ * The following reference types represent a potential reference to a kernel
+ * resource which, after first being allocated, must be checked and freed by
+ * the BPF program:
+ * - PTR_TO_SOCKET_OR_NULL, PTR_TO_SOCKET
+ *
+ * When the verifier sees a helper call return a reference type, it allocates a
+ * pointer id for the reference and stores it in the current function state.
+ * Similar to the way that PTR_TO_MAP_VALUE_OR_NULL is converted into
+ * PTR_TO_MAP_VALUE, PTR_TO_SOCKET_OR_NULL becomes PTR_TO_SOCKET when the type
+ * passes through a NULL-check conditional. For the branch wherein the state is
+ * changed to CONST_IMM, the verifier releases the reference.
*/
/* verifier_state + insn_idx are pushed to stack when branch is encountered */
@@ -189,6 +202,7 @@ struct bpf_call_arg_meta {
int access_size;
s64 msize_smax_value;
u64 msize_umax_value;
+ int ptr_id;
};
static DEFINE_MUTEX(bpf_verifier_lock);
@@ -251,7 +265,42 @@ static bool type_is_pkt_pointer(enum bpf_reg_type type)
static bool reg_type_may_be_null(enum bpf_reg_type type)
{
- return type == PTR_TO_MAP_VALUE_OR_NULL;
+ return type == PTR_TO_MAP_VALUE_OR_NULL ||
+ type == PTR_TO_SOCKET_OR_NULL;
+}
+
+static bool type_is_refcounted(enum bpf_reg_type type)
+{
+ return type == PTR_TO_SOCKET;
+}
+
+static bool type_is_refcounted_or_null(enum bpf_reg_type type)
+{
+ return type == PTR_TO_SOCKET || type == PTR_TO_SOCKET_OR_NULL;
+}
+
+static bool reg_is_refcounted(const struct bpf_reg_state *reg)
+{
+ return type_is_refcounted(reg->type);
+}
+
+static bool reg_is_refcounted_or_null(const struct bpf_reg_state *reg)
+{
+ return type_is_refcounted_or_null(reg->type);
+}
+
+static bool arg_type_is_refcounted(enum bpf_arg_type type)
+{
+ return type == ARG_PTR_TO_SOCKET;
+}
+
+/* Determine whether the function releases some resources allocated by another
+ * function call. The first reference type argument will be assumed to be
+ * released by release_reference().
+ */
+static bool is_release_function(enum bpf_func_id func_id)
+{
+ return false;
}
/* string representation of 'enum bpf_reg_type' */
@@ -384,6 +433,12 @@ static void print_verifier_state(struct bpf_verifier_env *env,
else
verbose(env, "=%s", types_buf);
}
+ if (state->acquired_refs && state->refs[0].id) {
+ verbose(env, " refs=%d", state->refs[0].id);
+ for (i = 1; i < state->acquired_refs; i++)
+ if (state->refs[i].id)
+ verbose(env, ",%d", state->refs[i].id);
+ }
verbose(env, "\n");
}
@@ -402,6 +457,8 @@ static int copy_##NAME##_state(struct bpf_func_state *dst, \
sizeof(*src->FIELD) * (src->COUNT / SIZE)); \
return 0; \
}
+/* copy_reference_state() */
+COPY_STATE_FN(reference, acquired_refs, refs, 1)
/* copy_stack_state() */
COPY_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
#undef COPY_STATE_FN
@@ -440,6 +497,8 @@ static int realloc_##NAME##_state(struct bpf_func_state *state, int size, \
state->FIELD = new_##FIELD; \
return 0; \
}
+/* realloc_reference_state() */
+REALLOC_STATE_FN(reference, acquired_refs, refs, 1)
/* realloc_stack_state() */
REALLOC_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
#undef REALLOC_STATE_FN
@@ -451,16 +510,89 @@ REALLOC_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
* which realloc_stack_state() copies over. It points to previous
* bpf_verifier_state which is never reallocated.
*/
-static int realloc_func_state(struct bpf_func_state *state, int size,
- bool copy_old)
+static int realloc_func_state(struct bpf_func_state *state, int stack_size,
+ int refs_size, bool copy_old)
{
- return realloc_stack_state(state, size, copy_old);
+ int err = realloc_reference_state(state, refs_size, copy_old);
+ if (err)
+ return err;
+ return realloc_stack_state(state, stack_size, copy_old);
+}
+
+/* Acquire a pointer id from the env and update the state->refs to include
+ * this new pointer reference.
+ * On success, returns a valid pointer id to associate with the register
+ * On failure, returns a negative errno.
+ */
+static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx)
+{
+ struct bpf_func_state *state = cur_func(env);
+ int new_ofs = state->acquired_refs;
+ int id, err;
+
+ err = realloc_reference_state(state, state->acquired_refs + 1, true);
+ if (err)
+ return err;
+ id = ++env->id_gen;
+ state->refs[new_ofs].id = id;
+ state->refs[new_ofs].insn_idx = insn_idx;
+
+ return id;
+}
+
+/* release function corresponding to acquire_reference_state(). Idempotent. */
+static int __release_reference_state(struct bpf_func_state *state, int ptr_id)
+{
+ int i, last_idx;
+
+ if (!ptr_id)
+ return 0;
+
+ last_idx = state->acquired_refs - 1;
+ for (i = 0; i < state->acquired_refs; i++) {
+ if (state->refs[i].id == ptr_id) {
+ if (last_idx && i != last_idx)
+ memcpy(&state->refs[i], &state->refs[last_idx],
+ sizeof(*state->refs));
+ memset(&state->refs[last_idx], 0, sizeof(*state->refs));
+ state->acquired_refs--;
+ return 0;
+ }
+ }
+ return -EFAULT;
+}
+
+/* variation on the above for cases where we expect that there must be an
+ * outstanding reference for the specified ptr_id.
+ */
+static int release_reference_state(struct bpf_verifier_env *env, int ptr_id)
+{
+ struct bpf_func_state *state = cur_func(env);
+ int err;
+
+ err = __release_reference_state(state, ptr_id);
+ if (WARN_ON_ONCE(err != 0))
+ verbose(env, "verifier internal error: can't release reference\n");
+ return err;
+}
+
+static int transfer_reference_state(struct bpf_func_state *dst,
+ struct bpf_func_state *src)
+{
+ int err = realloc_reference_state(dst, src->acquired_refs, false);
+ if (err)
+ return err;
+ err = copy_reference_state(dst, src);
+ if (err)
+ return err;
+ return 0;
}
static void free_func_state(struct bpf_func_state *state)
{
if (!state)
return;
+ kfree(state->refs);
kfree(state->stack);
kfree(state);
}
@@ -486,10 +618,14 @@ static int copy_func_state(struct bpf_func_state *dst,
{
int err;
- err = realloc_func_state(dst, src->allocated_stack, false);
+ err = realloc_func_state(dst, src->allocated_stack, src->acquired_refs,
+ false);
+ if (err)
+ return err;
+ memcpy(dst, src, offsetof(struct bpf_func_state, acquired_refs));
+ err = copy_reference_state(dst, src);
if (err)
return err;
- memcpy(dst, src, offsetof(struct bpf_func_state, allocated_stack));
return copy_stack_state(dst, src);
}
@@ -1013,7 +1149,7 @@ static int check_stack_write(struct bpf_verifier_env *env,
enum bpf_reg_type type;
err = realloc_func_state(state, round_up(slot + 1, BPF_REG_SIZE),
- true);
+ state->acquired_refs, true);
if (err)
return err;
/* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0,
@@ -1975,6 +2111,12 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
expected_type = PTR_TO_SOCKET;
if (type != expected_type)
goto err_type;
+ if (meta->ptr_id || !reg->id) {
+ verbose(env, "verifier internal error: mismatched references meta=%d, reg=%d\n",
+ meta->ptr_id, reg->id);
+ return -EFAULT;
+ }
+ meta->ptr_id = reg->id;
} else if (arg_type_is_mem_ptr(arg_type)) {
expected_type = PTR_TO_STACK;
/* One exception here. In case function allows for NULL to be
@@ -2262,10 +2404,32 @@ static bool check_arg_pair_ok(const struct bpf_func_proto *fn)
return true;
}
+static bool check_refcount_ok(const struct bpf_func_proto *fn)
+{
+ int count = 0;
+
+ if (arg_type_is_refcounted(fn->arg1_type))
+ count++;
+ if (arg_type_is_refcounted(fn->arg2_type))
+ count++;
+ if (arg_type_is_refcounted(fn->arg3_type))
+ count++;
+ if (arg_type_is_refcounted(fn->arg4_type))
+ count++;
+ if (arg_type_is_refcounted(fn->arg5_type))
+ count++;
+
+ /* We only support one arg being unreferenced at the moment,
+ * which is sufficient for the helper functions we have right now.
+ */
+ return count <= 1;
+}
+
static int check_func_proto(const struct bpf_func_proto *fn)
{
return check_raw_mode_ok(fn) &&
- check_arg_pair_ok(fn) ? 0 : -EINVAL;
+ check_arg_pair_ok(fn) &&
+ check_refcount_ok(fn) ? 0 : -EINVAL;
}
/* Packet data might have moved, any old PTR_TO_PACKET[_META,_END]
@@ -2298,12 +2462,45 @@ static void clear_all_pkt_pointers(struct bpf_verifier_env *env)
__clear_all_pkt_pointers(env, vstate->frame[i]);
}
+static void release_reg_references(struct bpf_verifier_env *env,
+ struct bpf_func_state *state, int id)
+{
+ struct bpf_reg_state *regs = state->regs, *reg;
+ int i;
+
+ for (i = 0; i < MAX_BPF_REG; i++)
+ if (regs[i].id == id)
+ mark_reg_unknown(env, regs, i);
+
+ for_each_spilled_reg(i, state, reg) {
+ if (!reg)
+ continue;
+ if (reg_is_refcounted(reg) && reg->id == id)
+ __mark_reg_unknown(reg);
+ }
+}
+
+/* The pointer with the specified id has released its reference to kernel
+ * resources. Identify all copies of the same pointer and clear the reference.
+ */
+static int release_reference(struct bpf_verifier_env *env,
+ struct bpf_call_arg_meta *meta)
+{
+ struct bpf_verifier_state *vstate = env->cur_state;
+ int i;
+
+ for (i = 0; i <= vstate->curframe; i++)
+ release_reg_references(env, vstate->frame[i], meta->ptr_id);
+
+ return release_reference_state(env, meta->ptr_id);
+}
+
static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
int *insn_idx)
{
struct bpf_verifier_state *state = env->cur_state;
struct bpf_func_state *caller, *callee;
- int i, subprog, target_insn;
+ int i, err, subprog, target_insn;
if (state->curframe + 1 >= MAX_CALL_FRAMES) {
verbose(env, "the call stack of %d frames is too deep\n",
@@ -2341,6 +2538,11 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
state->curframe + 1 /* frameno within this callchain */,
subprog /* subprog number within this prog */);
+ /* Transfer references to the callee */
+ err = transfer_reference_state(callee, caller);
+ if (err)
+ return err;
+
/* copy r1 - r5 args that callee can access. The copy includes parent
* pointers, which connects us up to the liveness chain
*/
@@ -2373,6 +2575,7 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
struct bpf_verifier_state *state = env->cur_state;
struct bpf_func_state *caller, *callee;
struct bpf_reg_state *r0;
+ int err;
callee = state->frame[state->curframe];
r0 = &callee->regs[BPF_REG_0];
@@ -2392,6 +2595,11 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
/* return to the caller whatever r0 had in the callee */
caller->regs[BPF_REG_0] = *r0;
+ /* Transfer references to the caller */
+ err = transfer_reference_state(caller, callee);
+ if (err)
+ return err;
+
*insn_idx = callee->callsite + 1;
if (env->log.level) {
verbose(env, "returning from callee:\n");
@@ -2448,6 +2656,18 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
return 0;
}
+static int check_reference_leak(struct bpf_verifier_env *env)
+{
+ struct bpf_func_state *state = cur_func(env);
+ int i;
+
+ for (i = 0; i < state->acquired_refs; i++) {
+ verbose(env, "Unreleased reference id=%d alloc_insn=%d\n",
+ state->refs[i].id, state->refs[i].insn_idx);
+ }
+ return state->acquired_refs ? -EINVAL : 0;
+}
+
static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
{
const struct bpf_func_proto *fn = NULL;
@@ -2526,6 +2746,18 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
return err;
}
+ if (func_id == BPF_FUNC_tail_call) {
+ err = check_reference_leak(env);
+ if (err) {
+ verbose(env, "tail_call would lead to reference leak\n");
+ return err;
+ }
+ } else if (is_release_function(func_id)) {
+ err = release_reference(env, &meta);
+ if (err)
+ return err;
+ }
+
regs = cur_regs(env);
/* check that flags argument in get_local_storage(map, flags) is 0,
@@ -2569,9 +2801,12 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
regs[BPF_REG_0].map_ptr = meta.map_ptr;
regs[BPF_REG_0].id = ++env->id_gen;
} else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
+ int id = acquire_reference_state(env, insn_idx);
+ if (id < 0)
+ return id;
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
- regs[BPF_REG_0].id = ++env->id_gen;
+ regs[BPF_REG_0].id = id;
} else {
verbose(env, "unknown return type %d of func %s#%d\n",
fn->ret_type, func_id_name(func_id), func_id);
@@ -3635,7 +3870,8 @@ static void reg_combine_min_max(struct bpf_reg_state *true_src,
}
}
-static void mark_ptr_or_null_reg(struct bpf_reg_state *reg, u32 id,
+static void mark_ptr_or_null_reg(struct bpf_func_state *state,
+ struct bpf_reg_state *reg, u32 id,
bool is_null)
{
if (reg_type_may_be_null(reg->type) && reg->id == id) {
@@ -3661,11 +3897,13 @@ static void mark_ptr_or_null_reg(struct bpf_reg_state *reg, u32 id,
} else if (reg->type == PTR_TO_SOCKET_OR_NULL) {
reg->type = PTR_TO_SOCKET;
}
- /* We don't need id from this point onwards anymore, thus we
- * should better reset it, so that state pruning has chances
- * to take effect.
- */
- reg->id = 0;
+ if (is_null || !reg_is_refcounted(reg)) {
+ /* We don't need id from this point onwards anymore,
+ * thus we should better reset it, so that state
+ * pruning has chances to take effect.
+ */
+ reg->id = 0;
+ }
}
}
@@ -3680,15 +3918,18 @@ static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno,
u32 id = regs[regno].id;
int i, j;
+ if (reg_is_refcounted_or_null(®s[regno]) && is_null)
+ __release_reference_state(state, id);
+
for (i = 0; i < MAX_BPF_REG; i++)
- mark_ptr_or_null_reg(®s[i], id, is_null);
+ mark_ptr_or_null_reg(state, ®s[i], id, is_null);
for (j = 0; j <= vstate->curframe; j++) {
state = vstate->frame[j];
for_each_spilled_reg(i, state, reg) {
if (!reg)
continue;
- mark_ptr_or_null_reg(reg, id, is_null);
+ mark_ptr_or_null_reg(state, reg, id, is_null);
}
}
}
@@ -4020,6 +4261,16 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
if (err)
return err;
+ /* Disallow usage of BPF_LD_[ABS|IND] with reference tracking, as
+ * gen_ld_abs() may terminate the program at runtime, leading to
+ * reference leak.
+ */
+ err = check_reference_leak(env);
+ if (err) {
+ verbose(env, "BPF_LD_[ABS|IND] cannot be mixed with socket references\n");
+ return err;
+ }
+
if (regs[BPF_REG_6].type != PTR_TO_CTX) {
verbose(env,
"at the time of BPF_LD_ABS|IND R6 != pointer to skb\n");
@@ -4511,6 +4762,14 @@ static bool stacksafe(struct bpf_func_state *old,
return true;
}
+static bool refsafe(struct bpf_func_state *old, struct bpf_func_state *cur)
+{
+ if (old->acquired_refs != cur->acquired_refs)
+ return false;
+ return !memcmp(old->refs, cur->refs,
+ sizeof(*old->refs) * old->acquired_refs);
+}
+
/* compare two verifier states
*
* all states stored in state_list are known to be valid, since
@@ -4556,6 +4815,9 @@ static bool func_states_equal(struct bpf_func_state *old,
if (!stacksafe(old, cur, idmap))
goto out_free;
+
+ if (!refsafe(old, cur))
+ goto out_free;
ret = true;
out_free:
kfree(idmap);
@@ -4837,6 +5099,7 @@ static int do_check(struct bpf_verifier_env *env)
regs = cur_regs(env);
env->insn_aux_data[insn_idx].seen = true;
+
if (class == BPF_ALU || class == BPF_ALU64) {
err = check_alu_op(env, insn);
if (err)
@@ -5003,6 +5266,10 @@ static int do_check(struct bpf_verifier_env *env)
continue;
}
+ err = check_reference_leak(env);
+ if (err)
+ return err;
+
/* eBPF calling convetion is such that R0 is used
* to return the value from eBPF program.
* Make sure that it's readable at this time
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 07/11] bpf: Add helper to retrieve socket in BPF
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
This patch adds new BPF helper functions, bpf_sk_lookup_tcp() and
bpf_sk_lookup_udp() which allows BPF programs to find out if there is a
socket listening on this host, and returns a socket pointer which the
BPF program can then access to determine, for instance, whether to
forward or drop traffic. bpf_sk_lookup_xxx() may take a reference on the
socket, so when a BPF program makes use of this function, it must
subsequently pass the returned pointer into the newly added sk_release()
to return the reference.
By way of example, the following pseudocode would filter inbound
connections at XDP if there is no corresponding service listening for
the traffic:
struct bpf_sock_tuple tuple;
struct bpf_sock_ops *sk;
populate_tuple(ctx, &tuple); // Extract the 5tuple from the packet
sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof tuple, netns, 0);
if (!sk) {
// Couldn't find a socket listening for this traffic. Drop.
return TC_ACT_SHOT;
}
bpf_sk_release(sk, 0);
return TC_ACT_OK;
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
include/uapi/linux/bpf.h | 54 +++++++-
kernel/bpf/verifier.c | 8 +-
net/core/filter.c | 145 ++++++++++++++++++++++
tools/include/uapi/linux/bpf.h | 54 +++++++-
tools/testing/selftests/bpf/bpf_helpers.h | 12 ++
5 files changed, 270 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 66917a4eba27..8ed6e293113f 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2141,6 +2141,41 @@ union bpf_attr {
* request in the skb.
* Return
* 0 on success, or a negative error in case of failure.
+ *
+ * struct bpf_sock_ops *bpf_sk_lookup_tcp(ctx, tuple, tuple_size, netns, flags)
+ * Decription
+ * Look for TCP socket matching 'tuple'. The return value must
+ * be checked, and if non-NULL, released via bpf_sk_release().
+ * @ctx: pointer to ctx
+ * @tuple: pointer to struct bpf_sock_tuple
+ * @tuple_size: size of the tuple
+ * @netns: network namespace id
+ * @flags: flags value
+ * Return
+ * pointer to socket ops on success, or
+ * NULL in case of failure
+ *
+ * struct bpf_sock_ops *bpf_sk_lookup_udp(ctx, tuple, tuple_size, netns, flags)
+ * Decription
+ * Look for UDP socket matching 'tuple'. The return value must
+ * be checked, and if non-NULL, released via bpf_sk_release().
+ * @ctx: pointer to ctx
+ * @tuple: pointer to struct bpf_sock_tuple
+ * @tuple_size: size of the tuple
+ * @netns: network namespace id
+ * @flags: flags value
+ * Return
+ * pointer to socket ops on success, or
+ * NULL in case of failure
+ *
+ * int bpf_sk_release(sock, flags)
+ * Description
+ * Release the reference held by 'sock'.
+ * @sock: Pointer reference to release. Must be found via
+ * bpf_sk_lookup_xxx().
+ * @flags: flags value
+ * Return
+ * 0 on success, or a negative error in case of failure.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2226,7 +2261,10 @@ union bpf_attr {
FN(get_current_cgroup_id), \
FN(get_local_storage), \
FN(sk_select_reuseport), \
- FN(skb_ancestor_cgroup_id),
+ FN(skb_ancestor_cgroup_id), \
+ FN(sk_lookup_tcp), \
+ FN(sk_lookup_udp), \
+ FN(sk_release),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -2395,6 +2433,20 @@ struct bpf_sock {
*/
};
+struct bpf_sock_tuple {
+ union {
+ __be32 ipv6[4];
+ __be32 ipv4;
+ } saddr;
+ union {
+ __be32 ipv6[4];
+ __be32 ipv4;
+ } daddr;
+ __be16 sport;
+ __be16 dport;
+ __u8 family;
+};
+
#define XDP_PACKET_HEADROOM 256
/* User return codes for XDP prog type.
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 67c62ef67d37..37feedaaa1c3 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -153,6 +153,12 @@ static const struct bpf_verifier_ops * const bpf_verifier_ops[] = {
* PTR_TO_MAP_VALUE, PTR_TO_SOCKET_OR_NULL becomes PTR_TO_SOCKET when the type
* passes through a NULL-check conditional. For the branch wherein the state is
* changed to CONST_IMM, the verifier releases the reference.
+ *
+ * For each helper function that allocates a reference, such as
+ * bpf_sk_lookup_tcp(), there is a corresponding release function, such as
+ * bpf_sk_release(). When a reference type passes into the release function,
+ * the verifier also releases the reference. If any unchecked or unreleased
+ * reference remains at the end of the program, the verifier rejects it.
*/
/* verifier_state + insn_idx are pushed to stack when branch is encountered */
@@ -300,7 +306,7 @@ static bool arg_type_is_refcounted(enum bpf_arg_type type)
*/
static bool is_release_function(enum bpf_func_id func_id)
{
- return false;
+ return func_id == BPF_FUNC_sk_release;
}
/* string representation of 'enum bpf_reg_type' */
diff --git a/net/core/filter.c b/net/core/filter.c
index 23e6e5202138..b092cae8efd5 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -58,13 +58,17 @@
#include <net/busy_poll.h>
#include <net/tcp.h>
#include <net/xfrm.h>
+#include <net/udp.h>
#include <linux/bpf_trace.h>
#include <net/xdp_sock.h>
#include <linux/inetdevice.h>
+#include <net/inet_hashtables.h>
+#include <net/inet6_hashtables.h>
#include <net/ip_fib.h>
#include <net/flow.h>
#include <net/arp.h>
#include <net/ipv6.h>
+#include <net/net_namespace.h>
#include <linux/seg6_local.h>
#include <net/seg6.h>
#include <net/seg6_local.h>
@@ -4811,6 +4815,135 @@ static const struct bpf_func_proto bpf_lwt_seg6_adjust_srh_proto = {
};
#endif /* CONFIG_IPV6_SEG6_BPF */
+struct sock *sk_lookup(struct net *net, struct bpf_sock_tuple *tuple,
+ struct sk_buff *skb, u8 proto)
+{
+ int dif = skb->dev->ifindex;
+ bool refcounted = false;
+ struct sock *sk = NULL;
+
+ if (tuple->family == AF_INET) {
+ int sdif = inet_sdif(skb);
+
+ if (proto == IPPROTO_TCP)
+ sk = __inet_lookup(net, &tcp_hashinfo, skb, 0,
+ tuple->saddr.ipv4, tuple->sport,
+ tuple->daddr.ipv4, tuple->dport,
+ dif, sdif, &refcounted);
+ else
+ sk = __udp4_lib_lookup(net,
+ tuple->saddr.ipv4, tuple->sport,
+ tuple->daddr.ipv4, tuple->dport,
+ dif, sdif, &udp_table, skb);
+#if IS_ENABLED(CONFIG_IPV6)
+ } else {
+ struct in6_addr *src6 = (struct in6_addr *)&tuple->saddr.ipv6;
+ struct in6_addr *dst6 = (struct in6_addr *)&tuple->daddr.ipv6;
+ int sdif = inet6_sdif(skb);
+
+ if (proto == IPPROTO_TCP)
+ sk = __inet6_lookup(net, &tcp_hashinfo, skb, 0,
+ src6, tuple->sport,
+ dst6, tuple->dport,
+ dif, sdif, &refcounted);
+ else
+ sk = __udp6_lib_lookup(net, src6, tuple->sport,
+ dst6, tuple->dport,
+ dif, sdif, &udp_table, skb);
+ }
+#endif
+
+ if (unlikely(sk && !refcounted && !sock_flag(sk, SOCK_RCU_FREE))) {
+ WARN_ONCE(1, "Found non-RCU, unreferenced socket!");
+ sk = NULL;
+ }
+ return sk;
+}
+
+/* bpf_sk_lookup performs the core lookup for different types of sockets,
+ * taking a reference on the socket if it doesn't have the flag SOCK_RCU_FREE.
+ * Returns the socket as an 'unsigned long' to simplify the casting in the
+ * callers to satisfy BPF_CALL declarations.
+ */
+static unsigned long
+bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
+ u8 proto, u32 netns_id, u64 flags)
+{
+ struct net *caller_net = dev_net(skb->dev);
+ struct sock *sk = NULL;
+ struct net *net;
+
+ if (unlikely(len != sizeof(struct bpf_sock_tuple) || flags ||
+ (tuple->family != AF_INET && tuple->family != AF_INET6)))
+ goto out;
+
+ if (netns_id)
+ net = get_net_ns_by_id(caller_net, netns_id);
+ else
+ net = caller_net;
+ if (unlikely(!net))
+ goto out;
+ sk = sk_lookup(net, tuple, skb, proto);
+ put_net(net);
+
+ if (sk)
+ sk = sk_to_full_sk(sk);
+out:
+ return (unsigned long) sk;
+}
+
+BPF_CALL_5(bpf_sk_lookup_tcp, struct sk_buff *, skb,
+ struct bpf_sock_tuple *, tuple, u32, len, u32, netns_id, u64, flags)
+{
+ return bpf_sk_lookup(skb, tuple, len, IPPROTO_TCP, netns_id, flags);
+}
+
+static const struct bpf_func_proto bpf_sk_lookup_tcp_proto = {
+ .func = bpf_sk_lookup_tcp,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_SOCKET_OR_NULL,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_ANYTHING,
+ .arg5_type = ARG_ANYTHING,
+};
+
+BPF_CALL_5(bpf_sk_lookup_udp, struct sk_buff *, skb,
+ struct bpf_sock_tuple *, tuple, u32, len, u32, netns_id, u64, flags)
+{
+ return bpf_sk_lookup(skb, tuple, len, IPPROTO_UDP, netns_id, flags);
+}
+
+static const struct bpf_func_proto bpf_sk_lookup_udp_proto = {
+ .func = bpf_sk_lookup_udp,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_SOCKET_OR_NULL,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_ANYTHING,
+ .arg5_type = ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_sk_release, struct sock *, sk, u64, flags)
+{
+ if (!sock_flag(sk, SOCK_RCU_FREE))
+ sock_gen_put(sk);
+
+ if (unlikely(flags))
+ return -EINVAL;
+ return 0;
+}
+
+static const struct bpf_func_proto bpf_sk_release_proto = {
+ .func = bpf_sk_release,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_SOCKET,
+ .arg2_type = ARG_ANYTHING,
+};
+
bool bpf_helper_changes_pkt_data(void *func)
{
if (func == bpf_skb_vlan_push ||
@@ -5017,6 +5150,12 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_skb_ancestor_cgroup_id:
return &bpf_skb_ancestor_cgroup_id_proto;
#endif
+ case BPF_FUNC_sk_lookup_tcp:
+ return &bpf_sk_lookup_tcp_proto;
+ case BPF_FUNC_sk_lookup_udp:
+ return &bpf_sk_lookup_udp_proto;
+ case BPF_FUNC_sk_release:
+ return &bpf_sk_release_proto;
default:
return bpf_base_func_proto(func_id);
}
@@ -5117,6 +5256,12 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sk_redirect_hash_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
+ case BPF_FUNC_sk_lookup_tcp:
+ return &bpf_sk_lookup_tcp_proto;
+ case BPF_FUNC_sk_lookup_udp:
+ return &bpf_sk_lookup_udp_proto;
+ case BPF_FUNC_sk_release:
+ return &bpf_sk_release_proto;
default:
return bpf_base_func_proto(func_id);
}
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 66917a4eba27..8ed6e293113f 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2141,6 +2141,41 @@ union bpf_attr {
* request in the skb.
* Return
* 0 on success, or a negative error in case of failure.
+ *
+ * struct bpf_sock_ops *bpf_sk_lookup_tcp(ctx, tuple, tuple_size, netns, flags)
+ * Decription
+ * Look for TCP socket matching 'tuple'. The return value must
+ * be checked, and if non-NULL, released via bpf_sk_release().
+ * @ctx: pointer to ctx
+ * @tuple: pointer to struct bpf_sock_tuple
+ * @tuple_size: size of the tuple
+ * @netns: network namespace id
+ * @flags: flags value
+ * Return
+ * pointer to socket ops on success, or
+ * NULL in case of failure
+ *
+ * struct bpf_sock_ops *bpf_sk_lookup_udp(ctx, tuple, tuple_size, netns, flags)
+ * Decription
+ * Look for UDP socket matching 'tuple'. The return value must
+ * be checked, and if non-NULL, released via bpf_sk_release().
+ * @ctx: pointer to ctx
+ * @tuple: pointer to struct bpf_sock_tuple
+ * @tuple_size: size of the tuple
+ * @netns: network namespace id
+ * @flags: flags value
+ * Return
+ * pointer to socket ops on success, or
+ * NULL in case of failure
+ *
+ * int bpf_sk_release(sock, flags)
+ * Description
+ * Release the reference held by 'sock'.
+ * @sock: Pointer reference to release. Must be found via
+ * bpf_sk_lookup_xxx().
+ * @flags: flags value
+ * Return
+ * 0 on success, or a negative error in case of failure.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2226,7 +2261,10 @@ union bpf_attr {
FN(get_current_cgroup_id), \
FN(get_local_storage), \
FN(sk_select_reuseport), \
- FN(skb_ancestor_cgroup_id),
+ FN(skb_ancestor_cgroup_id), \
+ FN(sk_lookup_tcp), \
+ FN(sk_lookup_udp), \
+ FN(sk_release),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -2395,6 +2433,20 @@ struct bpf_sock {
*/
};
+struct bpf_sock_tuple {
+ union {
+ __be32 ipv6[4];
+ __be32 ipv4;
+ } saddr;
+ union {
+ __be32 ipv6[4];
+ __be32 ipv4;
+ } daddr;
+ __be16 sport;
+ __be16 dport;
+ __u8 family;
+};
+
#define XDP_PACKET_HEADROOM 256
/* User return codes for XDP prog type.
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index e4be7730222d..88ce00c3aa0f 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -143,6 +143,18 @@ static unsigned long long (*bpf_skb_cgroup_id)(void *ctx) =
(void *) BPF_FUNC_skb_cgroup_id;
static unsigned long long (*bpf_skb_ancestor_cgroup_id)(void *ctx, int level) =
(void *) BPF_FUNC_skb_ancestor_cgroup_id;
+static struct bpf_sock *(*bpf_sk_lookup_tcp)(void *ctx,
+ struct bpf_sock_tuple *tuple,
+ int size, unsigned int netns_id,
+ unsigned long long flags) =
+ (void *) BPF_FUNC_sk_lookup_tcp;
+static struct bpf_sock *(*bpf_sk_lookup_udp)(void *ctx,
+ struct bpf_sock_tuple *tuple,
+ int size, unsigned int netns_id,
+ unsigned long long flags) =
+ (void *) BPF_FUNC_sk_lookup_udp;
+static int (*bpf_sk_release)(struct bpf_sock *sk, unsigned long long flags) =
+ (void *) BPF_FUNC_sk_release;
/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 08/11] selftests/bpf: Add tests for reference tracking
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
reference tracking: leak potential reference
reference tracking: leak potential reference on stack
reference tracking: leak potential reference on stack 2
reference tracking: zero potential reference
reference tracking: copy and zero potential references
reference tracking: release reference without check
reference tracking: release reference
reference tracking: release reference twice
reference tracking: release reference twice inside branch
reference tracking: alloc, check, free in one subbranch
reference tracking: alloc, check, free in both subbranches
reference tracking in call: free reference in subprog
reference tracking in call: free reference in subprog and outside
reference tracking in call: alloc & leak reference in subprog
reference tracking in call: alloc in subprog, release outside
reference tracking in call: sk_ptr leak into caller stack
reference tracking in call: sk_ptr spill into caller stack
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
tools/testing/selftests/bpf/test_verifier.c | 359 ++++++++++++++++++++
1 file changed, 359 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index ceb55a9f3da9..eb760ead257a 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -3,6 +3,7 @@
*
* Copyright (c) 2014 PLUMgrid, http://plumgrid.com
* Copyright (c) 2017 Facebook
+ * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
@@ -177,6 +178,23 @@ static void bpf_fill_rand_ld_dw(struct bpf_test *self)
self->retval = (uint32_t)res;
}
+#define BPF_SK_LOOKUP \
+ /* struct bpf_sock_tuple tuple = {} */ \
+ BPF_MOV64_IMM(BPF_REG_2, 0), \
+ BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -8), \
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -16), \
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -24), \
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -32), \
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -40), \
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -48), \
+ /* sk = sk_lookup_tcp(ctx, &tuple, sizeof tuple, 0, 0) */ \
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), \
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -48), \
+ BPF_MOV64_IMM(BPF_REG_3, 44), \
+ BPF_MOV64_IMM(BPF_REG_4, 0), \
+ BPF_MOV64_IMM(BPF_REG_5, 0), \
+ BPF_EMIT_CALL(BPF_FUNC_sk_lookup_tcp)
+
static struct bpf_test tests[] = {
{
"add+sub+mul",
@@ -12441,6 +12459,222 @@ static struct bpf_test tests[] = {
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
+ {
+ "reference tracking: leak potential reference",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), /* leak reference */
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: leak potential reference on stack",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: leak potential reference on stack 2",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: zero potential reference",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_IMM(BPF_REG_0, 0), /* leak reference */
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: copy and zero potential references",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_MOV64_IMM(BPF_REG_7, 0), /* leak reference */
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: release reference without check",
+ .insns = {
+ BPF_SK_LOOKUP,
+ /* reference in r0 may be NULL */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "type=sock_or_null expected=sock",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: release reference",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = ACCEPT,
+ },
+ {
+ "reference tracking: release reference 2",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = ACCEPT,
+ },
+ {
+ "reference tracking: release reference twice",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "type=inv expected=sock",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: release reference twice inside branch",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), /* goto end */
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "type=inv expected=sock",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: alloc, check, free in one subbranch",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct __sk_buff, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct __sk_buff, data_end)),
+ BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 16),
+ /* if (offsetof(skb, mark) > data_len) exit; */
+ BPF_JMP_REG(BPF_JLE, BPF_REG_0, BPF_REG_3, 1),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_2,
+ offsetof(struct __sk_buff, mark)),
+ BPF_SK_LOOKUP,
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 1), /* mark == 0? */
+ /* Leak reference in R0 */
+ BPF_EXIT_INSN(),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), /* sk NULL? */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking: alloc, check, free in both subbranches",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct __sk_buff, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct __sk_buff, data_end)),
+ BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 16),
+ /* if (offsetof(skb, mark) > data_len) exit; */
+ BPF_JMP_REG(BPF_JLE, BPF_REG_0, BPF_REG_3, 1),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_2,
+ offsetof(struct __sk_buff, mark)),
+ BPF_SK_LOOKUP,
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 5), /* mark == 0? */
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), /* sk NULL? */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), /* sk NULL? */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = ACCEPT,
+ },
+ {
+ "reference tracking in call: free reference in subprog",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), /* unchecked reference */
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+
+ /* subprog 1 */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = ACCEPT,
+ },
{
"pass modified ctx pointer to helper, 1",
.insns = {
@@ -12511,6 +12745,131 @@ static struct bpf_test tests[] = {
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
+ {
+ "reference tracking in call: free reference in subprog and outside",
+ .insns = {
+ BPF_SK_LOOKUP,
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), /* unchecked reference */
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 3),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+
+ /* subprog 1 */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "type=inv expected=sock",
+ .result = REJECT,
+ },
+ {
+ "reference tracking in call: alloc & leak reference in subprog",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 3),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+
+ /* subprog 1 */
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_4),
+ BPF_SK_LOOKUP,
+ /* spill unchecked sk_ptr into stack of caller */
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_0, 0),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking in call: alloc in subprog, release outside",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 5),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+
+ /* subprog 1 */
+ BPF_SK_LOOKUP,
+ BPF_EXIT_INSN(), /* return sk */
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .retval = POINTER_VALUE,
+ .result = ACCEPT,
+ },
+ {
+ "reference tracking in call: sk_ptr leak into caller stack",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+
+ /* subprog 1 */
+ BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 5),
+ /* spill unchecked sk_ptr into stack of caller */
+ BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_5, 0),
+ BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+
+ /* subprog 2 */
+ BPF_SK_LOOKUP,
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .errstr = "Unreleased reference",
+ .result = REJECT,
+ },
+ {
+ "reference tracking in call: sk_ptr spill into caller stack",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+
+ /* subprog 1 */
+ BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 9),
+ /* spill unchecked sk_ptr into stack of caller */
+ BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_5, 0),
+ BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
+ /* now the sk_ptr is verified, free the reference */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_4, 0),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+
+ /* subprog 2 */
+ BPF_SK_LOOKUP,
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = ACCEPT,
+ },
};
static int probe_filter_length(const struct bpf_insn *fp)
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 09/11] libbpf: Support loading individual progs
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
Allow the individual program load to be invoked. This will help with
testing, where a single ELF may contain several sections, some of which
denote subprograms that are expected to fail verification, along with
some which are expected to pass verification. By allowing programs to be
iterated and individually loaded, each program can be independently
checked against its expected verification result.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
tools/lib/bpf/libbpf.c | 4 ++--
tools/lib/bpf/libbpf.h | 3 +++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 8476da7f2720..aadf05f6bfa0 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -227,7 +227,7 @@ struct bpf_object {
};
#define obj_elf_valid(o) ((o)->efile.elf)
-static void bpf_program__unload(struct bpf_program *prog)
+void bpf_program__unload(struct bpf_program *prog)
{
int i;
@@ -1375,7 +1375,7 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type,
return ret;
}
-static int
+int
bpf_program__load(struct bpf_program *prog,
char *license, u32 kern_version)
{
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index e3b00e23e181..40e4395f1c07 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -126,10 +126,13 @@ void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex);
const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
+int bpf_program__load(struct bpf_program *prog, char *license,
+ u32 kern_version);
int bpf_program__fd(struct bpf_program *prog);
int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
int instance);
int bpf_program__pin(struct bpf_program *prog, const char *path);
+void bpf_program__unload(struct bpf_program *prog);
struct bpf_insn;
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 10/11] selftests/bpf: Add C tests for reference tracking
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
tools/testing/selftests/bpf/Makefile | 2 +-
tools/testing/selftests/bpf/test_progs.c | 38 ++++++
.../selftests/bpf/test_sk_lookup_kern.c | 128 ++++++++++++++++++
3 files changed, 167 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/test_sk_lookup_kern.c
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index fff7fb1285fc..311b7bc9e37a 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -35,7 +35,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o \
test_lwt_seg6local.o sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \
get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \
- test_skb_cgroup_id_kern.o
+ test_skb_cgroup_id_kern.o test_sk_lookup_kern.o
# Order correspond to 'make run_tests' order
TEST_PROGS := test_kmod.sh \
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 63a671803ed6..e8becca9c521 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1698,6 +1698,43 @@ static void test_task_fd_query_tp(void)
"sys_enter_read");
}
+static void test_reference_tracking()
+{
+ const char *file = "./test_sk_lookup_kern.o";
+ struct bpf_object *obj;
+ struct bpf_program *prog;
+ __u32 duration;
+ int err = 0;
+
+ obj = bpf_object__open(file);
+ if (IS_ERR(obj)) {
+ error_cnt++;
+ return;
+ }
+
+ bpf_object__for_each_program(prog, obj) {
+ const char *title;
+
+ /* Ignore .text sections */
+ title = bpf_program__title(prog, false);
+ if (strstr(title, ".text") != NULL)
+ continue;
+
+ bpf_program__set_type(prog, BPF_PROG_TYPE_SCHED_CLS);
+
+ /* Expect verifier failure if test name has 'fail' */
+ if (strstr(title, "fail") != NULL) {
+ libbpf_set_print(NULL, NULL, NULL);
+ err = !bpf_program__load(prog, "GPL", 0);
+ libbpf_set_print(printf, printf, NULL);
+ } else {
+ err = bpf_program__load(prog, "GPL", 0);
+ }
+ CHECK(err, title, "\n");
+ }
+ bpf_object__close(obj);
+}
+
int main(void)
{
jit_enabled = is_jit_enabled();
@@ -1719,6 +1756,7 @@ int main(void)
test_get_stack_raw_tp();
test_task_fd_query_rawtp();
test_task_fd_query_tp();
+ test_reference_tracking();
printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
diff --git a/tools/testing/selftests/bpf/test_sk_lookup_kern.c b/tools/testing/selftests/bpf/test_sk_lookup_kern.c
new file mode 100644
index 000000000000..321a2299a3ac
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_sk_lookup_kern.c
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
+
+#include <stddef.h>
+#include <string.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/pkt_cls.h>
+#include <linux/tcp.h>
+#include <sys/socket.h>
+#include "bpf_helpers.h"
+#include "bpf_endian.h"
+
+int _version SEC("version") = 1;
+char _license[] SEC("license") = "GPL";
+
+/* Fill 'tuple' with L3 info, and attempt to find L4. On fail, return NULL. */
+static void *fill_ip(struct bpf_sock_tuple *tuple, void *data, __u64 nh_off,
+ void *data_end, __u16 eth_proto)
+{
+ __u64 ihl_len;
+ __u8 proto;
+
+ if (eth_proto == bpf_htons(ETH_P_IP)) {
+ struct iphdr *iph = (struct iphdr *)(data + nh_off);
+
+ if (iph + 1 > data_end)
+ return NULL;
+ ihl_len = iph->ihl * 4;
+ proto = iph->protocol;
+
+ tuple->family = AF_INET;
+ tuple->saddr.ipv4 = iph->saddr;
+ tuple->daddr.ipv4 = iph->daddr;
+ } else if (eth_proto == bpf_htons(ETH_P_IPV6)) {
+ struct ipv6hdr *ip6h = (struct ipv6hdr *)(data + nh_off);
+
+ if (ip6h + 1 > data_end)
+ return NULL;
+ ihl_len = sizeof(*ip6h);
+ proto = ip6h->nexthdr;
+
+ tuple->family = AF_INET6;
+ *((struct in6_addr *)&tuple->saddr.ipv6) = ip6h->saddr;
+ *((struct in6_addr *)&tuple->daddr.ipv6) = ip6h->daddr;
+ }
+
+ if (proto != IPPROTO_TCP)
+ return NULL;
+
+ return data + nh_off + ihl_len;
+}
+
+SEC("sk_lookup_success")
+int bpf_sk_lookup_test0(struct __sk_buff *skb)
+{
+ void *data_end = (void *)(long)skb->data_end;
+ void *data = (void *)(long)skb->data;
+ struct ethhdr *eth = (struct ethhdr *)(data);
+ struct bpf_sock_tuple tuple = {};
+ struct tcphdr *tcp;
+ struct bpf_sock *sk;
+ void *l4;
+
+ if (eth + 1 > data_end)
+ return TC_ACT_SHOT;
+
+ l4 = fill_ip(&tuple, data, sizeof(*eth), data_end, eth->h_proto);
+ if (!l4 || l4 + sizeof *tcp > data_end)
+ return TC_ACT_SHOT;
+
+ tcp = l4;
+ tuple.sport = tcp->source;
+ tuple.dport = tcp->dest;
+
+ sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0);
+ if (sk)
+ bpf_sk_release(sk, 0);
+ return sk ? TC_ACT_OK : TC_ACT_UNSPEC;
+}
+
+SEC("fail_no_release")
+int bpf_sk_lookup_test1(struct __sk_buff *skb)
+{
+ struct bpf_sock_tuple tuple = {};
+
+ bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0);
+ return 0;
+}
+
+SEC("fail_release_twice")
+int bpf_sk_lookup_test2(struct __sk_buff *skb)
+{
+ struct bpf_sock_tuple tuple = {};
+ struct bpf_sock *sk;
+
+ sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0);
+ bpf_sk_release(sk, 0);
+ bpf_sk_release(sk, 0);
+ return 0;
+}
+
+SEC("fail_release_unchecked")
+int bpf_sk_lookup_test3(struct __sk_buff *skb)
+{
+ struct bpf_sock_tuple tuple = {};
+ struct bpf_sock *sk;
+
+ sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0);
+ bpf_sk_release(sk, 0);
+ return 0;
+}
+
+void lookup_no_release(struct __sk_buff *skb)
+{
+ struct bpf_sock_tuple tuple = {};
+ bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0);
+}
+
+SEC("fail_no_release_subcall")
+int bpf_sk_lookup_test4(struct __sk_buff *skb)
+{
+ lookup_no_release(skb);
+ return 0;
+}
--
2.17.1
^ permalink raw reply related
* [PATCH bpf-next 11/11] Documentation: Describe bpf reference tracking
From: Joe Stringer @ 2018-09-12 0:36 UTC (permalink / raw)
To: daniel
Cc: netdev, ast, john.fastabend, tgraf, kafai, nitin.hande,
mauricio.vasquez
In-Reply-To: <20180912003640.28316-1-joe@wand.net.nz>
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
Documentation/networking/filter.txt | 64 +++++++++++++++++++++++++++++
1 file changed, 64 insertions(+)
diff --git a/Documentation/networking/filter.txt b/Documentation/networking/filter.txt
index e6b4ebb2b243..4443ce958862 100644
--- a/Documentation/networking/filter.txt
+++ b/Documentation/networking/filter.txt
@@ -1125,6 +1125,14 @@ pointer type. The types of pointers describe their base, as follows:
PTR_TO_STACK Frame pointer.
PTR_TO_PACKET skb->data.
PTR_TO_PACKET_END skb->data + headlen; arithmetic forbidden.
+ PTR_TO_SOCKET Pointer to struct bpf_sock_ops, implicitly refcounted.
+ PTR_TO_SOCKET_OR_NULL
+ Either a pointer to a socket, or NULL; socket lookup
+ returns this type, which becomes a PTR_TO_SOCKET when
+ checked != NULL. PTR_TO_SOCKET is reference-counted,
+ so programs must release the reference through the
+ socket release function before the end of the program.
+ Arithmetic on these pointers is forbidden.
However, a pointer may be offset from this base (as a result of pointer
arithmetic), and this is tracked in two parts: the 'fixed offset' and 'variable
offset'. The former is used when an exactly-known value (e.g. an immediate
@@ -1171,6 +1179,13 @@ over the Ethernet header, then reads IHL and addes (IHL * 4), the resulting
pointer will have a variable offset known to be 4n+2 for some n, so adding the 2
bytes (NET_IP_ALIGN) gives a 4-byte alignment and so word-sized accesses through
that pointer are safe.
+The 'id' field is also used on PTR_TO_SOCKET and PTR_TO_SOCKET_OR_NULL, common
+to all copies of the pointer returned from a socket lookup. This has similar
+behaviour to the handling for PTR_TO_MAP_VALUE_OR_NULL->PTR_TO_MAP_VALUE, but
+it also handles reference tracking for the pointer. PTR_TO_SOCKET implicitly
+represents a reference to the corresponding 'struct sock'. To ensure that the
+reference is not leaked, it is imperative to NULL-check the reference and in
+the non-NULL case, and pass the valid reference to the socket release function.
Direct packet access
--------------------
@@ -1444,6 +1459,55 @@ Error:
8: (7a) *(u64 *)(r0 +0) = 1
R0 invalid mem access 'imm'
+Program that performs a socket lookup then sets the pointer to NULL without
+checking it:
+value:
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -8),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_MOV64_IMM(BPF_REG_3, 4),
+ BPF_MOV64_IMM(BPF_REG_4, 0),
+ BPF_MOV64_IMM(BPF_REG_5, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_lookup_tcp),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+Error:
+ 0: (b7) r2 = 0
+ 1: (63) *(u32 *)(r10 -8) = r2
+ 2: (bf) r2 = r10
+ 3: (07) r2 += -8
+ 4: (b7) r3 = 4
+ 5: (b7) r4 = 0
+ 6: (b7) r5 = 0
+ 7: (85) call bpf_sk_lookup_tcp#65
+ 8: (b7) r0 = 0
+ 9: (95) exit
+ Unreleased reference id=1, alloc_insn=7
+
+Program that performs a socket lookup but does not NULL-check the returned
+value:
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -8),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_MOV64_IMM(BPF_REG_3, 4),
+ BPF_MOV64_IMM(BPF_REG_4, 0),
+ BPF_MOV64_IMM(BPF_REG_5, 0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_lookup_tcp),
+ BPF_EXIT_INSN(),
+Error:
+ 0: (b7) r2 = 0
+ 1: (63) *(u32 *)(r10 -8) = r2
+ 2: (bf) r2 = r10
+ 3: (07) r2 += -8
+ 4: (b7) r3 = 4
+ 5: (b7) r4 = 0
+ 6: (b7) r5 = 0
+ 7: (85) call bpf_sk_lookup_tcp#65
+ 8: (95) exit
+ Unreleased reference id=1, alloc_insn=7
+
Testing
-------
--
2.17.1
^ permalink raw reply related
* Re: [PATCH] net: dsa: mv88e6xxx: Add MV88E6352 DT compatible
From: Andrew Lunn @ 2018-09-12 0:46 UTC (permalink / raw)
To: Marek Vasut; +Cc: netdev
In-Reply-To: <30900c22-1717-c907-7129-f2dcb90bbc6c@denx.de>
On Wed, Sep 12, 2018 at 02:04:54AM +0200, Marek Vasut wrote:
> On 09/12/2018 01:32 AM, Andrew Lunn wrote:
> >> compatible = "marvell,mv88e6352", "marvell,mv88e6085";
> >
> > Just "marvell,mv88e6085";
> >
> > Please take a look at all the other DT files using the Marvell
> > chips. You will only ever find "marvell,mv88e6085" or
> > "marvell,mv88e6190", because everything is compatible to one of these
> > two.
>
> Well, until you find a difference between those chips which you cannot
> discern based solely on the ID register content. Then it's better to
> have a compatible to match on which matches the actual chip.
Hi Marek
We have been around this loop before. The problem with putting in a
more specific compatible is that nothing is validating it. So it is
going to be wrong, simple because people cut/paste, and don't
necessary change it. So when we do need to look at it, we cannot look
at it, because it is wrong.
I would only add a more specific compatible if and when we need it, it
is actually used, and we can verify it is correct.
Andrew
^ permalink raw reply
* Re: Regression caused by commit 7bb05b85bc2d ("r8169: don't use MSI-X on RTL8106e")
From: Kai-Heng Feng @ 2018-09-12 5:57 UTC (permalink / raw)
To: Jian-Hong Pan
Cc: Thomas Gleixner, Linux Netdev List, Linux Kernel Mailing List,
Daniel Drake
In-Reply-To: <CAPpJ_ecuPysq2SE7=X7ip-3M=4yOcwuu6m_2292WgYA8j6gqjw@mail.gmail.com>
at 12:56, Jian-Hong Pan <jian-hong@endlessm.com> wrote:
> 2018-09-12 11:42 GMT+08:00 Kai-Heng Feng <kai.heng.feng@canonical.com>:
>> Hi Jian-Hong,
>>
>> There's a Dell machine with RTL8106e stops to work after S3 since the
>> commit
>> introduced.
>> So I am wondering if it's possible to revert the commit and use
>> DMI/subsystem id based quirk table?
>>
>> It's because of commit bc976233a872 ("genirq/msi, x86/vector: Prevent
>> reservation mode for non maskable MSI") cleared the reservation mode,
>> and I
>> can see this after S3:
>>
>> [ 94.872838] do_IRQ: 3.33 No irq handler for vector
>>
>> If the device uses MSI-X instead of MSI, the issue doesn't happen
>> because of
>> reservation mode.
>
> Interesting! Opposite symptom!
> Could you help try the patch
> https://marc.info/?l=linux-pci&m=153629858601668&w=4 with and without
> reverting the commit?
Same issue after applying this patch. MSI-X works, MSI doesn't work.
>
> If the patch does not work, another suggestion: You can try falling
> back to only PCI_IRQ_LEGACY.
This device is capable of using MSI-X, I don't think falls back to use
legacy is a good idea.
Instead, using a quirk table should be more appropriate.
Kai-Heng
>
> Regards,
> Jian-Hong Pan
>
>> Hi Thomas,
>>
>> Is it something should be handled by x86 BIOS? Because I don't see this
>> issue when I use Suspend-to-Idle, which doesn't use BIOS to do suspend.
>>
>> Kai-Heng
^ permalink raw reply
* Re: [PATCH] xen-netback: remove unecessary condition check before debugfs_remove_recursive
From: David Miller @ 2018-09-12 6:02 UTC (permalink / raw)
To: zhongjiang; +Cc: paul.durrant, wei.liu2, xen-devel, netdev, linux-kernel
In-Reply-To: <1536414822-32911-1-git-send-email-zhongjiang@huawei.com>
From: zhong jiang <zhongjiang@huawei.com>
Date: Sat, 8 Sep 2018 21:53:42 +0800
> debugfs_remove_recursive has taken IS_ERR_OR_NULL into account. So just
> remove the condition check before debugfs_remove_recursive.
>
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Applied to net-next.
^ permalink raw reply
* Re: [PATCH v2] ethernet: hnae: drop adhoc assert() macros
From: David Miller @ 2018-09-12 6:07 UTC (permalink / raw)
To: igor.stoppa
Cc: igor.stoppa, huangdaode, yisen.zhuang, salil.mehta, netdev,
linux-kernel
In-Reply-To: <20180908150142.27976-1-igor.stoppa@huawei.com>
From: Igor Stoppa <igor.stoppa@gmail.com>
Date: Sat, 8 Sep 2018 18:01:42 +0300
> Replace assert() with a less misleading test_condition() using WARN()
> Drop one check which had bitrotted and didn't compile anymore.
>
> Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
I'm still kind of not happy about this.
Make the driver use kernel interfaces like WARN_ON_ONCE()
etc. directly instead of defining alias CPP macros private to the
driver.
If it needs to be conditional upon DEBUG, we have pr_debug() and
the likes as well.
Thank you.
^ permalink raw reply
* Re: [PATCH net-next v3 01/17] asm: simd context helper API
From: Kevin Easton @ 2018-09-12 6:14 UTC (permalink / raw)
To: Jason A. Donenfeld
Cc: linux-kernel, netdev, davem, gregkh, Andy Lutomirski,
Thomas Gleixner, Samuel Neves, linux-arch
In-Reply-To: <20180911010838.8818-2-Jason@zx2c4.com>
On Mon, Sep 10, 2018 at 07:08:21PM -0600, Jason A. Donenfeld wrote:
> Sometimes it's useful to amortize calls to XSAVE/XRSTOR and the related
> FPU/SIMD functions over a number of calls, because FPU restoration is
> quite expensive. This adds a simple header for carrying out this pattern:
>
> simd_context_t simd_context = simd_get();
> while ((item = get_item_from_queue()) != NULL) {
> encrypt_item(item, simd_context);
> simd_context = simd_relax(simd_context);
> }
> simd_put(simd_context);
>
> The relaxation step ensures that we don't trample over preemption, and
> the get/put API should be a familiar paradigm in the kernel.
Given that it's always supposed to be used like that, mightn't it be
better if simd_relax() took a pointer to the context, so the call is
just
simd_relax(&simd_context);
?
The inlining means that there won't actually be a pointer dereference in
the emitted code.
If simd_put() also took a pointer then it could set the context back to
HAVE_NO_SIMD as well?
- Kevin
^ permalink raw reply
* Re: Regression caused by commit 7bb05b85bc2d ("r8169: don't use MSI-X on RTL8106e")
From: Thomas Gleixner @ 2018-09-12 6:32 UTC (permalink / raw)
To: Kai-Heng Feng; +Cc: jian-hong, Linux Netdev List, Linux Kernel Mailing List
In-Reply-To: <5D685053-1A33-4553-8678-A50C542466FD@canonical.com>
On Wed, 12 Sep 2018, Kai-Heng Feng wrote:
> There's a Dell machine with RTL8106e stops to work after S3 since the
> commit introduced. So I am wondering if it's possible to revert the
> commit and use DMI/subsystem id based quirk table?
Probably.
> It's because of commit bc976233a872 ("genirq/msi, x86/vector: Prevent
> reservation mode for non maskable MSI") cleared the reservation mode, and I
> can see this after S3:
>
> [ 94.872838] do_IRQ: 3.33 No irq handler for vector
It's not because of that commit, really. There is a interrupt sent after
resume to the wrong vector for whatever reason. The MSI vector cannot be
masked it seems in the device, but the driver should quiescen the device to
a point where it does not send interrupts.
> If the device uses MSI-X instead of MSI, the issue doesn't happen because of
> reservation mode.
Reservation mode has absolutely nothing to do with that. What prevents the
issue is the fact that MSI-X can be masked by the IRQ core.
> Is it something should be handled by x86 BIOS? Because I don't see this issue
> when I use Suspend-to-Idle, which doesn't use BIOS to do suspend.
Suspend to idle works completely different and I don't see the BIOS at
fault here. it's more an issue of MSI not being maskable on that device,
which can't be fixed in BIOS or it's some half quiescened state which is
used when suspending and that's a pure driver issue.
Thanks,
tglx
^ permalink raw reply
* [PATCHv4 iproute2] bridge/mdb: fix missing new line when show bridge mdb
From: Hangbin Liu @ 2018-09-12 1:39 UTC (permalink / raw)
To: netdev; +Cc: Phil Sutter, Stephen Hemminger, David Ahern, Hangbin Liu
In-Reply-To: <1536118423-20604-1-git-send-email-liuhangbin@gmail.com>
The bridge mdb show is broken on current iproute2. e.g.
]# bridge mdb show
34: br0 veth0_br 224.1.1.2 temp 34: br0 veth0_br 224.1.1.1 temp
After fix:
]# bridge mdb show
34: br0 veth0_br 224.1.1.2 temp
34: br0 veth0_br 224.1.1.1 temp
v2: Use json print lib as Stephen suggested.
v3: No need to use is_json_context() as print_string() could handle both cases.
v4: use new function print_nl() to print new line in non-json mode.
Reported-by: Ying Xu <yinxu@redhat.com>
Fixes: c7c1a1ef51aea ("bridge: colorize output and use JSON print library")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
bridge/mdb.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/bridge/mdb.c b/bridge/mdb.c
index cc1b454..841a361 100644
--- a/bridge/mdb.c
+++ b/bridge/mdb.c
@@ -107,6 +107,10 @@ static void br_print_router_ports(FILE *f, struct rtattr *attr,
fprintf(f, "%s ", port_ifname);
}
}
+
+ if (!show_stats)
+ print_nl();
+
close_json_array(PRINT_JSON, NULL);
}
@@ -157,6 +161,8 @@ static void print_mdb_entry(FILE *f, int ifindex, const struct br_mdb_entry *e,
print_string(PRINT_ANY, "timer", " %s",
format_timer(timer));
}
+
+ print_nl();
close_json_object();
}
--
2.5.5
^ permalink raw reply related
* [PATCH v2] PCI: Reprogram bridge prefetch registers on resume
From: Daniel Drake @ 2018-09-12 6:45 UTC (permalink / raw)
To: bhelgaas-hpIqsD4AKlfQT0dZR+AlfA
Cc: andy.shevchenko-VuQAYsv1563Yd54FQh9/CA,
mika.westerberg-VuQAYsv1563Yd54FQh9/CA,
linux-pm-u79uwXL29TY76Z2rM5mHXA, linux-pci-u79uwXL29TY76Z2rM5mHXA,
rafael.j.wysocki-ral2JQCrhuEAvxtiuMwx3w,
nic_swsd-Rasf1IRRPZFBDgjK7y7TUQ,
keith.busch-ral2JQCrhuEAvxtiuMwx3w, netdev-u79uwXL29TY76Z2rM5mHXA,
nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW,
rchang-eYqpPyKDWXRBDgjK7y7TUQ, linux-6IF/jdPJHihWk0Htik3J/w,
davem-fT/PcQaiUtIeIZ0/mPfg9Q,
jonathan.derrick-ral2JQCrhuEAvxtiuMwx3w,
hkallweit1-Re5JQEeQqe8AvxtiuMwx3w
On 38+ Intel-based Asus products, the nvidia GPU becomes unusable
after S3 suspend/resume. The affected products include multiple
generations of nvidia GPUs and Intel SoCs. After resume, nouveau logs
many errors such as:
fifo: fault 00 [READ] at 0000005555555000 engine 00 [GR] client 04 [HUB/FE] reason 4a [] on channel -1 [007fa91000 unknown]
DRM: failed to idle channel 0 [DRM]
Similarly, the nvidia proprietary driver also fails after resume
(black screen, 100% CPU usage in Xorg process). We shipped a sample
to Nvidia for diagnosis, and their response indicated that it's a
problem with the parent PCI bridge (on the Intel SoC), not the GPU.
Runtime suspend/resume works fine, only S3 suspend is affected.
We found a workaround: on resume, rewrite the Intel PCI bridge
'Prefetchable Base Upper 32 Bits' register (PCI_PREF_BASE_UPPER32). In
the cases that I checked, this register has value 0 and we just have to
rewrite that value.
Linux already saves and restores PCI config space during suspend/resume,
but this register was being skipped because upon resume, it already
has value 0 (the correct, pre-suspend value).
Intel appear to have previously acknowledged this behaviour and the
requirement to rewrite this register.
https://bugzilla.kernel.org/show_bug.cgi?id=116851#c23
Based on that, rewrite the prefetch register values even when that
appears unnecessary.
We have confirmed this solution on all the affected models we have
in-hands (X542UQ, UX533FD, X530UN, V272UN).
Additionally, this solves an issue where r8169 MSI-X interrupts were
broken after S3 suspend/resume on Asus X441UAR. This issue was recently
worked around in commit 7bb05b85bc2d ("r8169: don't use MSI-X on
RTL8106e"). It also fixes the same issue on RTL6186evl/8111evl on an
Aimfor-tech laptop that we had not yet patched. I suspect it will also
fix the issue that was worked around in commit 7c53a722459c ("r8169:
don't use MSI-X on RTL8168g").
Thomas Martitz reports that this change also solves an issue where
the AMD Radeon Polaris 10 GPU on the HP Zbook 14u G5 is unresponsive
after S3 suspend/resume.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201069
Signed-off-by: Daniel Drake <drake@endlessm.com>
---
Notes:
Replaces patch:
PCI: add prefetch quirk to work around Asus/Nvidia suspend issues
Some of the more verbose info was moved to bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=201069
This patch is aimed at v4.19 (and maybe v4.18-stable); we may follow
up with more intrusive improvements for v4.20+.
v2: reimplement the register restore within the existing
pci_restore_config_space() code.
drivers/pci/pci.c | 31 +++++++++++++++++++++----------
1 file changed, 21 insertions(+), 10 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 29ff9619b5fa..e1704100e72d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1289,13 +1289,15 @@ int pci_save_state(struct pci_dev *dev)
EXPORT_SYMBOL(pci_save_state);
static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
- u32 saved_val, int retry)
+ u32 saved_val, int retry, bool force)
{
u32 val;
- pci_read_config_dword(pdev, offset, &val);
- if (val == saved_val)
- return;
+ if (!force) {
+ pci_read_config_dword(pdev, offset, &val);
+ if (val == saved_val)
+ return;
+ }
for (;;) {
pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n",
@@ -1313,25 +1315,34 @@ static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
}
static void pci_restore_config_space_range(struct pci_dev *pdev,
- int start, int end, int retry)
+ int start, int end, int retry,
+ bool force)
{
int index;
for (index = end; index >= start; index--)
pci_restore_config_dword(pdev, 4 * index,
pdev->saved_config_space[index],
- retry);
+ retry, force);
}
static void pci_restore_config_space(struct pci_dev *pdev)
{
if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
- pci_restore_config_space_range(pdev, 10, 15, 0);
+ pci_restore_config_space_range(pdev, 10, 15, 0, false);
/* Restore BARs before the command register. */
- pci_restore_config_space_range(pdev, 4, 9, 10);
- pci_restore_config_space_range(pdev, 0, 3, 0);
+ pci_restore_config_space_range(pdev, 4, 9, 10, false);
+ pci_restore_config_space_range(pdev, 0, 3, 0, false);
+ } else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+ pci_restore_config_space_range(pdev, 12, 15, 0, false);
+ /* Force rewriting of prefetch registers to avoid
+ * S3 resume issues on Intel PCI bridges that occur when
+ * these registers are not explicitly written.
+ */
+ pci_restore_config_space_range(pdev, 9, 11, 0, true);
+ pci_restore_config_space_range(pdev, 0, 8, 0, false);
} else {
- pci_restore_config_space_range(pdev, 0, 15, 0);
+ pci_restore_config_space_range(pdev, 0, 15, 0, false);
}
}
--
2.17.1
_______________________________________________
Nouveau mailing list
Nouveau@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/nouveau
^ permalink raw reply related
* Re: [PATCH 1/2] erspan: return PACKET_REJECT when the appropriate tunnel is not found
From: David Miller @ 2018-09-12 6:52 UTC (permalink / raw)
To: yanhaishuang; +Cc: kuznet, netdev, linux-kernel, u9012063
In-Reply-To: <1536589188-27550-1-git-send-email-yanhaishuang@cmss.chinamobile.com>
From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Mon, 10 Sep 2018 22:19:47 +0800
> If erspan tunnel hasn't been established, we'd better send icmp port
> unreachable message after receive erspan packets.
>
> Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
> Cc: William Tu <u9012063@gmail.com>
> Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Applied and queued up for -stable.
^ permalink raw reply
* Re: [PATCH 2/2] erspan: fix error handling for erspan tunnel
From: David Miller @ 2018-09-12 6:52 UTC (permalink / raw)
To: yanhaishuang; +Cc: kuznet, netdev, linux-kernel, u9012063
In-Reply-To: <1536589188-27550-2-git-send-email-yanhaishuang@cmss.chinamobile.com>
From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Mon, 10 Sep 2018 22:19:48 +0800
> When processing icmp unreachable message for erspan tunnel, tunnel id
> should be erspan_net_id instead of ipgre_net_id.
>
> Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
> Cc: William Tu <u9012063@gmail.com>
> Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Applied and queued up for -stable.
^ permalink raw reply
* Re: [PATCH] net: ipv4: Use BUG_ON directly instead of a if condition followed by BUG
From: David Miller @ 2018-09-12 6:54 UTC (permalink / raw)
To: zhongjiang; +Cc: edumazet, kuznet, yoshfuji, netdev, linux-kernel
In-Reply-To: <1536590282-23899-1-git-send-email-zhongjiang@huawei.com>
From: zhong jiang <zhongjiang@huawei.com>
Date: Mon, 10 Sep 2018 22:38:02 +0800
> The if condition can be removed if we use BUG_ON directly.
> The issule is detected with the help of Coccinelle.
>
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
You keep asking if this is worthy to do.
I think the most worthy thing to do is actually build test your
patches.
^ permalink raw reply
* [PATCH 1/2] r8169: Align ASPM/CLKREQ setting function with vendor driver
From: Kai-Heng Feng @ 2018-09-12 6:58 UTC (permalink / raw)
To: nic_swsd; +Cc: davem, hkallweit1, netdev, linux-kernel, Kai-Heng Feng
There's a small delay after setting ASPM in vendor drivers, r8101 and
r8168.
In addition, those drivers enable ASPM before ClkReq, also change that
to align with vendor driver.
I haven't seen anything bad becasue of this, but I think it's better to
keep in sync with vendor driver.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
drivers/net/ethernet/realtek/r8169.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index b08d51bf7a20..5091e9fd601f 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -4775,12 +4775,14 @@ static void rtl_pcie_state_l2l3_enable(struct rtl8169_private *tp, bool enable)
static void rtl_hw_aspm_clkreq_enable(struct rtl8169_private *tp, bool enable)
{
if (enable) {
- RTL_W8(tp, Config2, RTL_R8(tp, Config2) | ClkReqEn);
RTL_W8(tp, Config5, RTL_R8(tp, Config5) | ASPM_en);
+ RTL_W8(tp, Config2, RTL_R8(tp, Config2) | ClkReqEn);
} else {
RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
}
+
+ udelay(10);
}
static void rtl_hw_start_8168bb(struct rtl8169_private *tp)
--
2.17.1
^ permalink raw reply related
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