* Re: KASAN: use-after-free Read in __dev_queue_xmit
From: Willem de Bruijn @ 2018-05-09 21:05 UTC (permalink / raw)
To: Eric Dumazet
Cc: Eric Biggers, syzbot, alexander.deucher, Andrey Konovalov,
Anoob Soman, chris, David Miller, Reshetova, Elena,
Greg Kroah-Hartman, Kees Cook, LKML, Mike Maloney, mchehab,
netdev, Rosen, Rami, Sowmini Varadhan, syzkaller-bugs,
Willem de Bruijn
In-Reply-To: <e7be4d14-be04-c40d-82ad-2050876f9ce9@gmail.com>
On Wed, May 9, 2018 at 3:36 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
>
> On 05/09/2018 12:21 PM, Willem de Bruijn wrote:
>
>> Indeed. The skb shared info struct is zeroed by dev_validate_header
>> as a result of dev->hard_header_len exceeding skb->end - skb->data.
>>
>> Not exactly sure yet how this can happen. The hard header length space
>> is accounted for during allocation as reserved memory. But,
>> packet_alloc_skb does call skb_reserve(), moving skb->data
>> effectively beyond this reserved region.
>>
>> It may be incorrect to pass skb->data to dev_validate_header, as that
>> does not point to the start of the ll_header anymore. Still figuring out what
>> the right fix is..
>>
>
> I believe the bug happens if the sock_wmalloc() call at line 1921 has to sleep.
>
> device can change (or at lest dev->hard_header_len can change)
>
> So we need to bailout if reserved/hhlen had changed.
>
> Or revert some patches, since dev_hold() and dev_put() are no longer high cost,
> since it is now using per cpu counter.
Oh nice, another bug :/
That seems quite plausible.
This reproducer does not modify hard_header_len, however.
It sends a long array of zero byte requests with sendmmsg to
eventually exceed so_rcvbuf of the error queue. Hard header
length is 116 throughout.
^ permalink raw reply
* [RFC bpf-next 00/11] Add socket lookup support
From: Joe Stringer @ 2018-05-09 21:06 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, tgraf, kafai
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() / 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.
A few open points:
* Currently, the lookup interface only returns either a valid socket or a NULL
pointer. This means that if there is any kind of issue with the tuple, such
as it provides an unsupported protocol number, or the socket can't be found,
then we are unable to differentiate these cases from one another. One natural
approach to improve this could be to return an ERR_PTR from the
bpf_sk_lookup() helper. This would be more complicated but maybe it's
worthwhile.
* No ordering is defined between sockets. If the tuple could find multiple
sockets, then it will arbitrarily return one. It is up to the caller to
handle this. If we wish to handle this more reliably in future, we could
encode an ordering preference in the flags field.
* Currently this helper is only defined for TC hook point, but it should also
be valid at XDP and perhaps some other hooks.
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 | 19 +-
include/linux/bpf_verifier.h | 31 +-
include/uapi/linux/bpf.h | 39 +-
kernel/bpf/verifier.c | 548 ++++++++++++++++++----
net/core/filter.c | 132 +++++-
tools/include/uapi/linux/bpf.h | 40 +-
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 | 7 +
tools/testing/selftests/bpf/test_progs.c | 38 ++
tools/testing/selftests/bpf/test_sk_lookup_kern.c | 127 +++++
tools/testing/selftests/bpf/test_verifier.c | 373 ++++++++++++++-
14 files changed, 1299 insertions(+), 128 deletions(-)
create mode 100644 tools/testing/selftests/bpf/test_sk_lookup_kern.c
--
2.14.1
^ permalink raw reply
* [RFC bpf-next 01/11] bpf: Add iterator for spilled registers
From: Joe Stringer @ 2018-05-09 21:06 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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>
---
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 8f70dc181e23..a613b52ce939 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -133,6 +133,17 @@ 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 d92d9c37affd..f40e089c3893 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2216,10 +2216,9 @@ 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);
}
@@ -3326,10 +3325,9 @@ 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);
}
@@ -3574,7 +3572,7 @@ 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;
@@ -3583,8 +3581,8 @@ 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);
}
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 02/11] bpf: Simplify ptr_min_max_vals adjustment
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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>
---
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 f40e089c3893..a32b560072d7 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2602,20 +2602,18 @@ 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 275b4570b5b8..53439f40e1de 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -3497,7 +3497,7 @@ 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,
},
@@ -4525,7 +4525,7 @@ 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
},
@@ -4546,7 +4546,7 @@ 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
},
@@ -4567,7 +4567,7 @@ 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
},
@@ -6864,7 +6864,7 @@ 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,
},
{
@@ -8538,7 +8538,7 @@ 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,
},
@@ -8557,7 +8557,7 @@ 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,
},
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 03/11] bpf: Generalize ptr_or_null regs check
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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>
---
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 a32b560072d7..1b31b805dea4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -227,6 +227,11 @@ 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] = "?",
@@ -3531,12 +3536,10 @@ 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.
@@ -3549,11 +3552,13 @@ 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
@@ -3566,8 +3571,8 @@ 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;
@@ -3575,14 +3580,14 @@ 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);
}
}
}
@@ -3784,12 +3789,14 @@ 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)) {
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 04/11] bpf: Add PTR_TO_SOCKET verifier type
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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 | 19 +++++++++-
include/linux/bpf_verifier.h | 2 ++
kernel/bpf/verifier.c | 86 ++++++++++++++++++++++++++++++++++++++------
net/core/filter.c | 30 +++++++++-------
4 files changed, 114 insertions(+), 23 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index a38e474bf7ee..a03b4b0edcb6 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -136,7 +136,7 @@ enum bpf_arg_type {
/* the following constraints used to prototype bpf_memcmp() and other
* functions that access data on eBPF program stack
*/
- ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value) */
+ ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value, socket) */
ARG_PTR_TO_MEM_OR_NULL, /* pointer to valid memory or NULL */
ARG_PTR_TO_UNINIT_MEM, /* pointer to memory does not need to be initialized,
* helper function must fill all bytes or clear
@@ -148,6 +148,7 @@ 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 */
@@ -155,6 +156,7 @@ enum bpf_return_type {
RET_INTEGER, /* function returns integer */
RET_VOID, /* function doesn't return anything */
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
@@ -205,6 +207,8 @@ 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
@@ -326,6 +330,11 @@ 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);
@@ -729,4 +738,12 @@ extern const struct bpf_func_proto bpf_sock_map_update_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 a613b52ce939..9dcd87f1d322 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -57,6 +57,8 @@ 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;
/* Ordering of fields matters. See states_equal() */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1b31b805dea4..d38c7c1e9da6 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.
@@ -244,6 +244,8 @@ 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 void print_liveness(struct bpf_verifier_env *env,
@@ -977,6 +979,8 @@ 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;
@@ -1360,6 +1364,28 @@ 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)
{
@@ -1475,6 +1501,9 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
*/
strict = true;
break;
+ case PTR_TO_SOCKET:
+ pointer_desc = "sock ";
+ break;
default:
break;
}
@@ -1723,6 +1752,16 @@ 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 && t == BPF_READ && 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]);
@@ -1941,6 +1980,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
expected_type = PTR_TO_CTX;
if (type != expected_type)
goto err_type;
+ } 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
@@ -2477,6 +2520,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
insn_aux->map_ptr = meta.map_ptr;
else if (insn_aux->map_ptr != meta.map_ptr)
insn_aux->map_ptr = BPF_MAP_PTR_POISON;
+ } 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);
@@ -2614,6 +2661,8 @@ 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;
@@ -3559,6 +3608,8 @@ 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
@@ -4333,6 +4384,8 @@ 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
*/
@@ -5188,10 +5241,14 @@ 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;
@@ -5218,12 +5275,14 @@ 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) ||
@@ -5237,7 +5296,8 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
else
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;
@@ -5269,8 +5329,8 @@ 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");
@@ -5785,7 +5845,13 @@ 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 0baa715e4699..4c35152fb3a8 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4496,23 +4496,29 @@ 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)
{
@@ -5153,10 +5159,10 @@ 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;
@@ -5926,7 +5932,7 @@ const struct bpf_prog_ops lwt_xmit_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 = {
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 05/11] bpf: Macrofy stack state copy
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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 | 104 ++++++++++++++++++++++++++++----------------------
1 file changed, 59 insertions(+), 45 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d38c7c1e9da6..f426ebf2b6bf 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -347,60 +347,74 @@ 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 bpf_verifier_state
- * which this function copies over. It points to previous bpf_verifier_state
- * which is never reallocated
+ * 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)
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 06/11] bpf: Add reference tracking to verifier
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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 | 18 ++-
kernel/bpf/verifier.c | 295 ++++++++++++++++++++++++++++++++++++++++---
2 files changed, 292 insertions(+), 21 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 9dcd87f1d322..8dbee360b3ec 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -104,6 +104,11 @@ struct bpf_stack_state {
u8 slot_type[BPF_REG_SIZE];
};
+struct bpf_reference_state {
+ int id;
+ int insn_idx; /* allocation insn */
+};
+
/* state of the program:
* type of all registers and stack info
*/
@@ -122,7 +127,9 @@ 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;
};
@@ -218,11 +225,16 @@ void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
__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 f426ebf2b6bf..92b9a5dc465a 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 */
@@ -229,7 +242,42 @@ 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' */
@@ -344,6 +392,12 @@ static void print_verifier_state(struct bpf_verifier_env *env,
if (state->stack[i].slot_type[0] == STACK_ZERO)
verbose(env, " fp%d=0", (-i - 1) * BPF_REG_SIZE);
}
+ 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");
}
@@ -362,6 +416,8 @@ 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
@@ -400,6 +456,8 @@ 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
@@ -411,16 +469,89 @@ 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);
}
@@ -446,10 +577,14 @@ 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);
}
@@ -1019,7 +1154,7 @@ 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,
@@ -2259,10 +2394,32 @@ 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]
@@ -2295,12 +2452,57 @@ 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_verifier_state *vstate = env->cur_state;
+ struct bpf_reg_state *regs = cur_regs(env);
+ int i, ptr_id = 0;
+
+ for (i = BPF_REG_1; i < BPF_REG_6; i++) {
+ if (reg_is_refcounted(®s[i])) {
+ ptr_id = regs[i].id;
+ break;
+ }
+ }
+ if (WARN_ON_ONCE(!ptr_id)) {
+ /* references must be special pointer types that are checked
+ * against argument requirements for the release function. */
+ verbose(env, "verifier internal error: can't locate refcounted arg\n");
+ return -EFAULT;
+ }
+ for (i = 0; i <= vstate->curframe; i++)
+ release_reg_references(env, vstate->frame[i], ptr_id);
+
+ return release_reference_state(env, 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",
@@ -2338,6 +2540,11 @@ 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 */
for (i = BPF_REG_1; i <= BPF_REG_5; i++)
callee->regs[i] = caller->regs[i];
@@ -2368,6 +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];
@@ -2387,6 +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");
@@ -2498,6 +2711,15 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
return err;
}
+ /* If the function is a release() function, mark all copies of the same
+ * pointer as "freed" in all registers and in the stack.
+ */
+ if (is_release_function(func_id)) {
+ err = release_reference(env);
+ if (err)
+ return err;
+ }
+
regs = cur_regs(env);
/* reset caller saved regs */
for (i = 0; i < CALLER_SAVED_REGS; i++) {
@@ -2535,9 +2757,12 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
else if (insn_aux->map_ptr != meta.map_ptr)
insn_aux->map_ptr = BPF_MAP_PTR_POISON;
} 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);
@@ -3599,7 +3824,8 @@ 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) {
@@ -3625,11 +3851,13 @@ 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;
+ }
}
}
@@ -3644,15 +3872,18 @@ 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);
}
}
}
@@ -4475,6 +4706,14 @@ 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
@@ -4520,6 +4759,9 @@ 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);
@@ -4669,6 +4911,18 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
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 do_check(struct bpf_verifier_env *env)
{
struct bpf_verifier_state *state;
@@ -4763,6 +5017,7 @@ 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)
@@ -4931,6 +5186,10 @@ 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
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 07/11] bpf: Add helper to retrieve socket in BPF
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-joe@wand.net.nz>
This patch adds a new BPF helper function, sk_lookup() 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. sk_lookup()
takes 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(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 | 39 +++++++++++-
kernel/bpf/verifier.c | 8 ++-
net/core/filter.c | 102 ++++++++++++++++++++++++++++++
tools/include/uapi/linux/bpf.h | 40 +++++++++++-
tools/testing/selftests/bpf/bpf_helpers.h | 7 ++
5 files changed, 193 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index d615c777b573..29f38838dbca 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1828,6 +1828,25 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure.
*
+ * struct bpf_sock_ops *bpf_sk_lookup(ctx, tuple, tuple_size, netns, flags)
+ * Decription
+ * Look for 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
+ * @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().
+ * @flags: flags value
+ * Return
+ * 0 on success, or a negative error in case of failure.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -1898,7 +1917,9 @@ union bpf_attr {
FN(xdp_adjust_tail), \
FN(skb_get_xfrm_state), \
FN(get_stack), \
- FN(skb_load_bytes_relative),
+ FN(skb_load_bytes_relative), \
+ FN(sk_lookup), \
+ FN(sk_release),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -2060,6 +2081,22 @@ 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;
+ __u32 dst_if;
+ __u8 family;
+ __u8 proto;
+};
+
#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 92b9a5dc465a..579012c483e4 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(),
+ * 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 */
@@ -277,7 +283,7 @@ 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 4c35152fb3a8..751c255d17d3 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -58,8 +58,12 @@
#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 <net/inet_hashtables.h>
+#include <net/inet6_hashtables.h>
+#include <net/net_namespace.h>
/**
* sk_filter_trim_cap - run a packet through a socket filter
@@ -4032,6 +4036,96 @@ static const struct bpf_func_proto bpf_skb_get_xfrm_state_proto = {
};
#endif
+struct sock *
+sk_lookup(struct net *net, struct bpf_sock_tuple *tuple) {
+ int dst_if = (int)tuple->dst_if;
+ struct in6_addr *src6;
+ struct in6_addr *dst6;
+
+ if (tuple->family == AF_INET6) {
+ src6 = (struct in6_addr *)&tuple->saddr.ipv6;
+ dst6 = (struct in6_addr *)&tuple->daddr.ipv6;
+ } else if (tuple->family != AF_INET) {
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+
+ if (tuple->proto == IPPROTO_TCP) {
+ if (tuple->family == AF_INET)
+ return inet_lookup(net, &tcp_hashinfo, NULL, 0,
+ tuple->saddr.ipv4, tuple->sport,
+ tuple->daddr.ipv4, tuple->dport,
+ dst_if);
+ else
+ return inet6_lookup(net, &tcp_hashinfo, NULL, 0,
+ src6, tuple->sport,
+ dst6, tuple->dport, dst_if);
+ } else if (tuple->proto == IPPROTO_UDP) {
+ if (tuple->family == AF_INET)
+ return udp4_lib_lookup(net, tuple->saddr.ipv4,
+ tuple->sport, tuple->daddr.ipv4,
+ tuple->dport, dst_if);
+ else
+ return udp6_lib_lookup(net, src6, tuple->sport,
+ dst6, tuple->dport, dst_if);
+ } else {
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+
+ return NULL;
+}
+
+BPF_CALL_5(bpf_sk_lookup, struct sk_buff *, skb,
+ struct bpf_sock_tuple *, tuple, u32, len, u32, netns_id, u64, flags)
+{
+ struct net *caller_net = dev_net(skb->dev);
+ struct sock *sk = NULL;
+ struct net *net;
+
+ /* XXX: Perform verification-time checking of tuple size? */
+ if (unlikely(len != sizeof(struct bpf_sock_tuple) || flags))
+ goto out;
+
+ net = get_net_ns_by_id(caller_net, netns_id);
+ if (unlikely(!net))
+ goto out;
+
+ sk = sk_lookup(net, tuple);
+ put_net(net);
+ if (IS_ERR_OR_NULL(sk))
+ sk = NULL;
+ else
+ sk = sk_to_full_sk(sk);
+out:
+ return (unsigned long) sk;
+}
+
+static const struct bpf_func_proto bpf_sk_lookup_proto = {
+ .func = bpf_sk_lookup,
+ .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)
+{
+ 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,
+};
+
static const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)
{
@@ -4181,6 +4275,10 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_skb_get_xfrm_state:
return &bpf_skb_get_xfrm_state_proto;
#endif
+ case BPF_FUNC_sk_lookup:
+ return &bpf_sk_lookup_proto;
+ case BPF_FUNC_sk_release:
+ return &bpf_sk_release_proto;
default:
return bpf_base_func_proto(func_id);
}
@@ -4292,6 +4390,10 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_get_socket_uid_proto;
case BPF_FUNC_sk_redirect_map:
return &bpf_sk_redirect_map_proto;
+ case BPF_FUNC_sk_lookup:
+ return &bpf_sk_lookup_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 fff51c187d1e..29f38838dbca 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -117,6 +117,7 @@ enum bpf_map_type {
BPF_MAP_TYPE_DEVMAP,
BPF_MAP_TYPE_SOCKMAP,
BPF_MAP_TYPE_CPUMAP,
+ BPF_MAP_TYPE_XSKMAP,
};
enum bpf_prog_type {
@@ -1827,6 +1828,25 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure.
*
+ * struct bpf_sock_ops *bpf_sk_lookup(ctx, tuple, tuple_size, netns, flags)
+ * Decription
+ * Look for 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
+ * @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().
+ * @flags: flags value
+ * Return
+ * 0 on success, or a negative error in case of failure.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -1897,7 +1917,9 @@ union bpf_attr {
FN(xdp_adjust_tail), \
FN(skb_get_xfrm_state), \
FN(get_stack), \
- FN(skb_load_bytes_relative),
+ FN(skb_load_bytes_relative), \
+ FN(sk_lookup), \
+ FN(sk_release),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -2059,6 +2081,22 @@ 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;
+ __u32 dst_if;
+ __u8 family;
+ __u8 proto;
+};
+
#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 265f8e0e8ada..4dc311ea0c16 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -103,6 +103,13 @@ static int (*bpf_skb_get_xfrm_state)(void *ctx, int index, void *state,
(void *) BPF_FUNC_skb_get_xfrm_state;
static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) =
(void *) BPF_FUNC_get_stack;
+static struct bpf_sock *(*bpf_sk_lookup)(void *ctx,
+ struct bpf_sock_tuple *tuple,
+ int size, unsigned int netns_id,
+ unsigned long long flags) =
+ (void *) BPF_FUNC_sk_lookup;
+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
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 08/11] selftests/bpf: Add tests for reference tracking
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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 53439f40e1de..150c7c19eb51 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
@@ -152,6 +153,23 @@ static void bpf_fill_jump_around_ld_abs(struct bpf_test *self)
insn[i] = BPF_EXIT_INSN();
}
+#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(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)
+
static struct bpf_test tests[] = {
{
"add+sub+mul",
@@ -11974,6 +11992,347 @@ static struct bpf_test tests[] = {
.result = ACCEPT,
.retval = 10,
},
+ {
+ "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,
+ },
+ {
+ "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)
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 09/11] libbpf: Support loading individual progs
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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 7bcdca13083a..04e3754bcf30 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -268,7 +268,7 @@ 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;
@@ -1338,7 +1338,7 @@ 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 197f9ce2248c..c07e9969e4ed 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -112,10 +112,13 @@ void *bpf_program__priv(struct bpf_program *prog);
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;
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 10/11] selftests/bpf: Add C tests for reference tracking
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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 +++++++
tools/testing/selftests/bpf/test_sk_lookup_kern.c | 127 ++++++++++++++++++++++
3 files changed, 166 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 9d762184b805..cf71baa9d51d 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -33,7 +33,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \
test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \
- test_get_stack_rawtp.o
+ test_get_stack_rawtp.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 ed197eef1cfc..6d868a031b00 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1409,6 +1409,43 @@ static void test_get_stack_raw_tp(void)
bpf_object__close(obj);
}
+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();
@@ -1427,6 +1464,7 @@ int main(void)
test_stacktrace_build_id();
test_stacktrace_map_raw_tp();
test_get_stack_raw_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..4f7383a31916
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_sk_lookup_kern.c
@@ -0,0 +1,127 @@
+/* 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;
+
+ 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;
+
+ tuple->family = AF_INET;
+ tuple->proto = iph->protocol;
+ 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);
+
+ tuple->family = AF_INET6;
+ tuple->proto = ip6h->nexthdr;
+ *((struct in6_addr *)&tuple->saddr.ipv6) = ip6h->saddr;
+ *((struct in6_addr *)&tuple->daddr.ipv6) = ip6h->daddr;
+ }
+
+ if (tuple->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(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(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(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(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(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;
+}
--
2.14.1
^ permalink raw reply related
* [RFC bpf-next 11/11] Documentation: Describe bpf reference tracking
From: Joe Stringer @ 2018-05-09 21:07 UTC (permalink / raw)
To: daniel; +Cc: netdev, ast, john.fastabend, kafai
In-Reply-To: <20180509210709.7201-1-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 5032e1263bc9..77be17977bc5 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
@@ -1168,6 +1176,13 @@ 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
--------------------
@@ -1441,6 +1456,55 @@ 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),
+ 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#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),
+ 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#65
+ 8: (95) exit
+ Unreleased reference id=1, alloc_insn=7
+
Testing
-------
--
2.14.1
^ permalink raw reply related
* [PATCH net] hv_netvsc: set master device
From: Stephen Hemminger @ 2018-05-09 21:09 UTC (permalink / raw)
To: davem; +Cc: netdev, Stephen Hemminger, Stephen Hemminger
The hyper-v transparent bonding should have used master_dev_link.
The netvsc device should look like a master bond device not
like the upper side of a tunnel.
This makes the semantics the same so that userspace applications
looking at network devices see the correct master relationshipship.
Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
drivers/net/hyperv/netvsc_drv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index ecc84954c511..da07ccdf84bf 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1840,7 +1840,8 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
goto rx_handler_failed;
}
- ret = netdev_upper_dev_link(vf_netdev, ndev, NULL);
+ ret = netdev_master_upper_dev_link(vf_netdev, ndev,
+ NULL, NULL, NULL);
if (ret != 0) {
netdev_err(vf_netdev,
"can not set master device %s (err = %d)\n",
--
2.17.0
^ permalink raw reply related
* [PATCH net-next 1/1] net sched actions: fix invalid pointer dereferencing if skbedit flags missing
From: Roman Mashak @ 2018-05-09 21:18 UTC (permalink / raw)
To: davem
Cc: netdev, kernel, jhs, xiyou.wangcong, jiri, alexander.duyck,
Roman Mashak
When application fails to pass flags in netlink TLV for a new skbedit action,
the kernel results in the following oops:
[ 8.307732] BUG: unable to handle kernel paging request at 0000000000021130
[ 8.309167] PGD 80000000193d1067 P4D 80000000193d1067 PUD 180e0067 PMD 0
[ 8.310595] Oops: 0000 [#1] SMP PTI
[ 8.311334] Modules linked in: kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper serio_raw
[ 8.314190] CPU: 1 PID: 397 Comm: tc Not tainted 4.17.0-rc3+ #357
[ 8.315252] RIP: 0010:__tcf_idr_release+0x33/0x140
[ 8.316203] RSP: 0018:ffffa0718038f840 EFLAGS: 00010246
[ 8.317123] RAX: 0000000000000001 RBX: 0000000000021100 RCX: 0000000000000000
[ 8.319831] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000021100
[ 8.321181] RBP: 0000000000000000 R08: 000000000004adf8 R09: 0000000000000122
[ 8.322645] R10: 0000000000000000 R11: ffffffff9e5b01ed R12: 0000000000000000
[ 8.324157] R13: ffffffff9e0d3cc0 R14: 0000000000000000 R15: 0000000000000000
[ 8.325590] FS: 00007f591292e700(0000) GS:ffff8fcf5bc40000(0000) knlGS:0000000000000000
[ 8.327001] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8.327987] CR2: 0000000000021130 CR3: 00000000180e6004 CR4: 00000000001606a0
[ 8.329289] Call Trace:
[ 8.329735] tcf_skbedit_init+0xa7/0xb0
[ 8.330423] tcf_action_init_1+0x362/0x410
[ 8.331139] ? try_to_wake_up+0x44/0x430
[ 8.331817] tcf_action_init+0x103/0x190
[ 8.332511] tc_ctl_action+0x11a/0x220
[ 8.333174] rtnetlink_rcv_msg+0x23d/0x2e0
[ 8.333902] ? _cond_resched+0x16/0x40
[ 8.334569] ? __kmalloc_node_track_caller+0x5b/0x2c0
[ 8.335440] ? rtnl_calcit.isra.31+0xf0/0xf0
[ 8.336178] netlink_rcv_skb+0xdb/0x110
[ 8.336855] netlink_unicast+0x167/0x220
[ 8.337550] netlink_sendmsg+0x2a7/0x390
[ 8.338258] sock_sendmsg+0x30/0x40
[ 8.338865] ___sys_sendmsg+0x2c5/0x2e0
[ 8.339531] ? pagecache_get_page+0x27/0x210
[ 8.340271] ? filemap_fault+0xa2/0x630
[ 8.340943] ? page_add_file_rmap+0x108/0x200
[ 8.341732] ? alloc_set_pte+0x2aa/0x530
[ 8.342573] ? finish_fault+0x4e/0x70
[ 8.343332] ? __handle_mm_fault+0xbc1/0x10d0
[ 8.344337] ? __sys_sendmsg+0x53/0x80
[ 8.345040] __sys_sendmsg+0x53/0x80
[ 8.345678] do_syscall_64+0x4f/0x100
[ 8.346339] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 8.347206] RIP: 0033:0x7f591191da67
[ 8.347831] RSP: 002b:00007fff745abd48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 8.349179] RAX: ffffffffffffffda RBX: 00007fff745abe70 RCX: 00007f591191da67
[ 8.350431] RDX: 0000000000000000 RSI: 00007fff745abdc0 RDI: 0000000000000003
[ 8.351659] RBP: 000000005af35251 R08: 0000000000000001 R09: 0000000000000000
[ 8.352922] R10: 00000000000005f1 R11: 0000000000000246 R12: 0000000000000000
[ 8.354183] R13: 00007fff745afed0 R14: 0000000000000001 R15: 00000000006767c0
[ 8.355400] Code: 41 89 d4 53 89 f5 48 89 fb e8 aa 20 fd ff 85 c0 0f 84 ed 00
00 00 48 85 db 0f 84 cf 00 00 00 40 84 ed 0f 85 cd 00 00 00 45 84 e4 <8b> 53 30
74 0d 85 d2 b8 ff ff ff ff 0f 8f b3 00 00 00 8b 43 2c
[ 8.358699] RIP: __tcf_idr_release+0x33/0x140 RSP: ffffa0718038f840
[ 8.359770] CR2: 0000000000021130
[ 8.360438] ---[ end trace 60c66be45dfc14f0 ]---
The caller calls action's ->init() and passes pointer to "struct tc_action *a",
which later may initialized to point at the existing action, otherwise
"struct tc_action *a" is still invalid, and therefore dereferencing it is error.
So checking flags should be done as early as possible, before idr lookups.
Signed-off-by: Roman Mashak <mrv@mojatatu.com>
---
net/sched/act_skbedit.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index ddf69fc01bdf..6c88037faf51 100644
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -114,17 +114,15 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
mask = nla_data(tb[TCA_SKBEDIT_MASK]);
}
+ if (!flags)
+ return -EINVAL;
+
parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
exists = tcf_idr_check(tn, parm->index, a, bind);
if (exists && bind)
return 0;
- if (!flags) {
- tcf_idr_release(*a, bind);
- return -EINVAL;
- }
-
if (!exists) {
ret = tcf_idr_create(tn, parm->index, est, a,
&act_skbedit_ops, bind, false);
--
2.7.4
^ permalink raw reply related
* Re: [bpf-next v2 8/9] bpf: Provide helper to do forwarding lookups in kernel FIB table
From: David Ahern @ 2018-05-09 21:29 UTC (permalink / raw)
To: Daniel Borkmann, netdev, borkmann, ast
Cc: davem, shm, roopa, brouer, toke, john.fastabend
In-Reply-To: <88bd5281-2fa6-41d1-98f3-33c3d4a95674@iogearbox.net>
On 5/9/18 2:44 PM, Daniel Borkmann wrote:
> Generally, no objection. However, could we get rid of the two extra includes altogether
> to avoid running into any such dependency issue? Right now the only includes we have in
> the bpf uapi header is linux/types.h and linux/bpf_common.h (latter has no extra deps
> by itself). Both the ETH_ALEN and struct in6_addr are in uapi and therefore never allowed
> to change so we can e.g. avoid to use ETH_ALEN and just have the value instead. In the
> other places of the header we use __u32 remote_ipv6[4], __u32 src_ip6[4] etc to denote
> a v6 address, we could do the same here and should be all good then.
I was able to drop the include of linux/in6.h and still use in6_addr. I
would prefer to keep in6_addr since it works and avoid the need to add
typecasts.
As for ETH_ALEN, I could redefine it but it just kicks the can down the
road. If if_ether.h is included after bpf.h, it will cause redefinition
warnings.
^ permalink raw reply
* Re: pull-request: mac80211-next 2018-05-09
From: Johannes Berg @ 2018-05-09 21:29 UTC (permalink / raw)
To: David Miller; +Cc: netdev, linux-wireless
In-Reply-To: <20180509194034.11992-1-johannes@sipsolutions.net>
Hi,
Sorry, scratch that.
I forgot that this commit:
> Toke Høiland-Jørgensen (3):
> cfg80211: Expose TXQ stats and parameters to userspace
caused a bunch of "too much stack" warnings - I should put in at least
the non-driver fix for that first, and then coordinate with Kalle to
send the driver fixes in too.
johannes
^ permalink raw reply
* Re: [bpf-next v2 8/9] bpf: Provide helper to do forwarding lookups in kernel FIB table
From: David Ahern @ 2018-05-09 21:39 UTC (permalink / raw)
To: Daniel Borkmann, netdev, borkmann, ast
Cc: davem, shm, roopa, brouer, toke, john.fastabend
In-Reply-To: <b2ebbdde-3198-9c58-b4cb-e44602568134@gmail.com>
On 5/9/18 3:29 PM, David Ahern wrote:
> On 5/9/18 2:44 PM, Daniel Borkmann wrote:
>> Generally, no objection. However, could we get rid of the two extra includes altogether
>> to avoid running into any such dependency issue? Right now the only includes we have in
>> the bpf uapi header is linux/types.h and linux/bpf_common.h (latter has no extra deps
>> by itself). Both the ETH_ALEN and struct in6_addr are in uapi and therefore never allowed
>> to change so we can e.g. avoid to use ETH_ALEN and just have the value instead. In the
>> other places of the header we use __u32 remote_ipv6[4], __u32 src_ip6[4] etc to denote
>> a v6 address, we could do the same here and should be all good then.
>
> I was able to drop the include of linux/in6.h and still use in6_addr. I
> would prefer to keep in6_addr since it works and avoid the need to add
> typecasts.
Never mind; that was working because if_ether.h was pulling in skbuff.h
which included in6.h.
>
> As for ETH_ALEN, I could redefine it but it just kicks the can down the
> road. If if_ether.h is included after bpf.h, it will cause redefinition
> warnings.
>
I guess I will continue the open coded magic numbers for mac and ipv6
addresses.
^ permalink raw reply
* Re: [bpf-next v2 8/9] bpf: Provide helper to do forwarding lookups in kernel FIB table
From: Alexei Starovoitov @ 2018-05-09 21:49 UTC (permalink / raw)
To: David Ahern
Cc: Daniel Borkmann, netdev, borkmann, ast, davem, shm, roopa, brouer,
toke, john.fastabend
In-Reply-To: <d6d01920-efd0-7e8b-f9ba-5e3b642160d3@gmail.com>
On Wed, May 09, 2018 at 03:39:52PM -0600, David Ahern wrote:
> On 5/9/18 3:29 PM, David Ahern wrote:
> > On 5/9/18 2:44 PM, Daniel Borkmann wrote:
> >> Generally, no objection. However, could we get rid of the two extra includes altogether
> >> to avoid running into any such dependency issue? Right now the only includes we have in
> >> the bpf uapi header is linux/types.h and linux/bpf_common.h (latter has no extra deps
> >> by itself). Both the ETH_ALEN and struct in6_addr are in uapi and therefore never allowed
> >> to change so we can e.g. avoid to use ETH_ALEN and just have the value instead. In the
> >> other places of the header we use __u32 remote_ipv6[4], __u32 src_ip6[4] etc to denote
> >> a v6 address, we could do the same here and should be all good then.
> >
> > I was able to drop the include of linux/in6.h and still use in6_addr. I
> > would prefer to keep in6_addr since it works and avoid the need to add
> > typecasts.
>
> Never mind; that was working because if_ether.h was pulling in skbuff.h
> which included in6.h.
> >
> > As for ETH_ALEN, I could redefine it but it just kicks the can down the
> > road. If if_ether.h is included after bpf.h, it will cause redefinition
> > warnings.
> >
>
> I guess I will continue the open coded magic numbers for mac and ipv6
> addresses.
That's the only way.
Adding
+#include <linux/if_ether.h>
+#include <linux/in6.h>
to uapi/bpf.h is no-go. It will cause all sorts of breakage
not only to kernel build as we realized, but to various user space apps too.
Please use be32 ipv6[4] and hard coded mac instead.
^ permalink raw reply
* Re: [bpf-next v2 8/9] bpf: Provide helper to do forwarding lookups in kernel FIB table
From: Daniel Borkmann @ 2018-05-09 21:49 UTC (permalink / raw)
To: David Ahern, netdev, borkmann, ast
Cc: davem, shm, roopa, brouer, toke, john.fastabend
In-Reply-To: <d6d01920-efd0-7e8b-f9ba-5e3b642160d3@gmail.com>
On 05/09/2018 11:39 PM, David Ahern wrote:
> On 5/9/18 3:29 PM, David Ahern wrote:
>> On 5/9/18 2:44 PM, Daniel Borkmann wrote:
>>> Generally, no objection. However, could we get rid of the two extra includes altogether
>>> to avoid running into any such dependency issue? Right now the only includes we have in
>>> the bpf uapi header is linux/types.h and linux/bpf_common.h (latter has no extra deps
>>> by itself). Both the ETH_ALEN and struct in6_addr are in uapi and therefore never allowed
>>> to change so we can e.g. avoid to use ETH_ALEN and just have the value instead. In the
>>> other places of the header we use __u32 remote_ipv6[4], __u32 src_ip6[4] etc to denote
>>> a v6 address, we could do the same here and should be all good then.
>>
>> I was able to drop the include of linux/in6.h and still use in6_addr. I
>> would prefer to keep in6_addr since it works and avoid the need to add
>> typecasts.
>
> Never mind; that was working because if_ether.h was pulling in skbuff.h
> which included in6.h.
>
>> As for ETH_ALEN, I could redefine it but it just kicks the can down the
>> road. If if_ether.h is included after bpf.h, it will cause redefinition
>> warnings.
>
> I guess I will continue the open coded magic numbers for mac and ipv6
> addresses.
Agree, it will avoid breakage. We cannot assume that every BPF prog out there has
one specific ordering of if_ether.h and bpf.h includes. Open coding the numbers
seems best here.
^ permalink raw reply
* Re: [PATCH net] tc-testing: fix tdc tests for 'bpf' action
From: Lucas Bates @ 2018-05-09 21:51 UTC (permalink / raw)
To: Davide Caratti
Cc: Roman Mashak, David Miller, Linux Kernel Network Developers
In-Reply-To: <54d69bac92e9c0a216997261ef7b1e0eb0dd28c9.1525884149.git.dcaratti@redhat.com>
On Wed, May 9, 2018 at 12:45 PM, Davide Caratti <dcaratti@redhat.com> wrote:
> - correct a typo in the value of 'matchPattern' of test 282d, potentially
> causing false negative
> - allow errors when 'teardown' executes '$TC action flush action bpf' in
> test 282d, to fix false positive when it is run with act_bpf unloaded
> - correct the value of 'matchPattern' in test e939, causing false positive
> in case the BPF JIT is enabled
>
> Fixes: 440ea4ae1828 ("tc-testing: add selftests for 'bpf' action")
> Signed-off-by: Davide Caratti <dcaratti@redhat.com>
> ---
> tools/testing/selftests/tc-testing/tc-tests/actions/bpf.json | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/tc-testing/tc-tests/actions/bpf.json b/tools/testing/selftests/tc-testing/tc-tests/actions/bpf.json
> index 5b012f4981d4..6f289a49e5ec 100644
> --- a/tools/testing/selftests/tc-testing/tc-tests/actions/bpf.json
> +++ b/tools/testing/selftests/tc-testing/tc-tests/actions/bpf.json
> @@ -66,7 +66,7 @@
> "cmdUnderTest": "$TC action add action bpf object-file _b.o index 667",
> "expExitCode": "0",
> "verifyCmd": "$TC action get action bpf index 667",
> - "matchPattern": "action order [0-9]*: bpf _b.o:\\[action\\] id [0-9]* tag 3b185187f1855c4c default-action pipe.*index 667 ref",
> + "matchPattern": "action order [0-9]*: bpf _b.o:\\[action\\] id [0-9]* tag 3b185187f1855c4c( jited)? default-action pipe.*index 667 ref",
> "matchCount": "1",
> "teardown": [
> "$TC action flush action bpf",
> @@ -92,10 +92,15 @@
> "cmdUnderTest": "$TC action add action bpf object-file _c.o index 667",
> "expExitCode": "255",
> "verifyCmd": "$TC action get action bpf index 667",
> - "matchPattern": "action order [0-9]*: bpf _b.o:\\[action\\] id [0-9].*index 667 ref",
> + "matchPattern": "action order [0-9]*: bpf _c.o:\\[action\\] id [0-9].*index 667 ref",
> "matchCount": "0",
> "teardown": [
> - "$TC action flush action bpf",
> + [
> + "$TC action flush action bpf",
> + 0,
> + 1,
> + 255
> + ],
> "rm -f _c.o"
> ]
> },
> --
> 2.14.3
>
Acked-by: Lucas Bates <lucasb@mojatatu.com>
^ permalink raw reply
* Re: [PATCH] selinux: add AF_UNSPEC and INADDR_ANY checks to selinux_socket_bind()
From: Paul Moore @ 2018-05-09 22:02 UTC (permalink / raw)
To: Stephen Smalley, Alexey Kodanev, Richard Haines
Cc: selinux, Eric Paris, linux-security-module, netdev
In-Reply-To: <CAHC9VhSg9UAmXaK0xsy_h9HfzM4uUBqCNKN5qtf3hHLSi=ZENw@mail.gmail.com>
On Wed, May 9, 2018 at 11:34 AM, Paul Moore <paul@paul-moore.com> wrote:
> On Wed, May 9, 2018 at 11:11 AM, Stephen Smalley <sds@tycho.nsa.gov> wrote:
>> On 05/09/2018 11:01 AM, Paul Moore wrote:
>>> On Wed, May 9, 2018 at 8:37 AM, Stephen Smalley <sds@tycho.nsa.gov> wrote:
>>>> On 05/08/2018 08:25 PM, Paul Moore wrote:
>>>>> On Tue, May 8, 2018 at 2:40 PM, Stephen Smalley <sds@tycho.nsa.gov> wrote:
>>>>>> On 05/08/2018 01:05 PM, Paul Moore wrote:
>>>>>>> On Tue, May 8, 2018 at 10:05 AM, Alexey Kodanev
>>>>>>> <alexey.kodanev@oracle.com> wrote:
>>>>>>>> Commit d452930fd3b9 ("selinux: Add SCTP support") breaks compatibility
>>>>>>>> with the old programs that can pass sockaddr_in with AF_UNSPEC and
>>>>>>>> INADDR_ANY to bind(). As a result, bind() returns EAFNOSUPPORT error.
>>>>>>>> It was found with LTP/asapi_01 test.
>>>>>>>>
>>>>>>>> Similar to commit 29c486df6a20 ("net: ipv4: relax AF_INET check in
>>>>>>>> bind()"), which relaxed AF_INET check for compatibility, add AF_UNSPEC
>>>>>>>> case to AF_INET and make sure that the address is INADDR_ANY.
>>>>>>>>
>>>>>>>> Also, in the end of selinux_socket_bind(), instead of adding AF_UNSPEC
>>>>>>>> to 'address->sa_family == AF_INET', verify AF_INET6 first.
>>>>>>>>
>>>>>>>> Fixes: d452930fd3b9 ("selinux: Add SCTP support")
>>>>>>>> Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
>>>>>>>> ---
>>>>>>>> security/selinux/hooks.c | 12 +++++++++---
>>>>>>>> 1 file changed, 9 insertions(+), 3 deletions(-)
>>>>>>>
>>>>>>> Thanks for finding and reporting this regression.
>>>>>>>
>>>>>>> I think I would prefer to avoid having to duplicate the
>>>>>>> AF_UNSPEC/INADDR_ANY checking logic in the SELinux hook, even though
>>>>>>> it is a small bit of code and unlikely to change. I'm wondering if it
>>>>>>> would be better to check both the socket and sockaddr address family
>>>>>>> in the main if conditional inside selinux_socket_bind(), what do you
>>>>>>> think? Another option would be to go back to just checking the
>>>>>>> soackaddr address family; we moved away from that for a reason which
>>>>>>> escapes at the moment (code cleanliness?), but perhaps that was a
>>>>>>> mistake.
>>>>>>
>>>>>> We've always used the sk->sk_family there; it was only the recent code from Richard that started
>>>>>> using the socket address family.
>>>>>
>>>>> Yes I know, I thought I was the one that suggested it at some point
>>>>> (I'll take the blame) ... although now that I'm looking at the git
>>>>> log, maybe I'm confusing it with something else.
>>>>>
>>>>>>> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
>>>>>>> index 4cafe6a19167..a3789b167667 100644
>>>>>>> --- a/security/selinux/hooks.c
>>>>>>> +++ b/security/selinux/hooks.c
>>>>>>> @@ -4577,6 +4577,7 @@ static int selinux_socket_bind(struct socket *sock, struc>
>>>>>>> {
>>>>>>> struct sock *sk = sock->sk;
>>>>>>> u16 family;
>>>>>>> + u16 family_sa;
>>>>>>> int err;
>>>>>>>
>>>>>>> err = sock_has_perm(sk, SOCKET__BIND);
>>>>>>> @@ -4585,7 +4586,9 @@ static int selinux_socket_bind(struct socket *sock, struc>
>>>>>>>
>>>>>>> /* If PF_INET or PF_INET6, check name_bind permission for the port. */
>>>>>>> family = sk->sk_family;
>>>>>>> - if (family == PF_INET || family == PF_INET6) {
>>>>>>> + family_sa = address->sa_family;
>>>>>>> + if ((family == PF_INET || family == PF_INET6) &&
>>>>>>> + (family_sa == PF_INET || family_sa == PF_INET6)) {
>>>>>>
>>>>>> Wouldn't this allow bypassing the name_bind permission check by passing in AF_UNSPEC?
>>>>>
>>>>> I believe these name_bind permission checkis skipped for AF_UNSPEC
>>>>> already, isn't it? The only way the name_bind check would be
>>>>> triggered is if the source port, snum, was non-zero and I didn't think
>>>>> that was really legal for AF_UNSPEC/INADDR_ANY, is it?
>>>>
>>>> 1) What in inet_bind() prevents that from occurring?
>>>> 2) Regardless, what about the node_bind check?
>>>
>>> Fair enough. As mentioned above, perhaps the right fix is to move the
>>> address family checking back to how it was pre-SCTP.
>>
>> It isn't clear to me how to do that without breaking SCTP multiple address binding, which is why
>> Richard had to switch to checking address->sa_family instead of just using the sk->sk_family.
>> Alexey's original fix might be the simplest solution.
>
> I'm going to have to apologize, I'm traveling at the moment and more
> distracted than usual as a result. Let me take a closer look later
> today. It may be that Alexey's original fix the only practical
> solution, but I really would like to avoid having to duplicate checks
> like that in the SELinux code.
I just had a better look at this and I believe that Alexey and Stephen
are right: this is the best option. My apologies for the noise
earlier. However, while looking at the code I think there are some
additional necessary changes:
* In the case of an SCTP socket, we should return -EINVAL, just as we
do with other address families.
* While not strictly related to AF_UNSPEC, we really should be passing
the address family of the sockaddr, and not the socket, to functions
that need to interpret the bind address/port.
I'm waiting for my kernel to compile so I haven't given this any
sanity testing, but the patch below is what I think we need ...
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4cafe6a19167..5f30045b2053 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4576,6 +4576,7 @@ static int selinux_socket_post_create(struct socket *sock,
int family,
static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, i
nt addrlen)
{
struct sock *sk = sock->sk;
+ struct sk_security_struct *sksec = sk->sk_security;
u16 family;
int err;
@@ -4587,13 +4588,13 @@ static int selinux_socket_bind(struct socket *sock, stru
ct sockaddr *address, in
family = sk->sk_family;
if (family == PF_INET || family == PF_INET6) {
char *addrp;
- struct sk_security_struct *sksec = sk->sk_security;
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
struct sockaddr_in *addr4 = NULL;
struct sockaddr_in6 *addr6 = NULL;
unsigned short snum;
u32 sid, node_perm;
+ u16 family_sa = address->sa_family;
/*
* sctp_bindx(3) calls via selinux_sctp_bind_connect()
@@ -4601,11 +4602,19 @@ static int selinux_socket_bind(struct socket *sock, stru
ct sockaddr *address, in
* need to check address->sa_family as it is possible to have
* sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
*/
- switch (address->sa_family) {
+ switch (family_sa) {
+ case AF_UNSPEC:
case AF_INET:
if (addrlen < sizeof(struct sockaddr_in))
return -EINVAL;
addr4 = (struct sockaddr_in *)address;
+ if (family_sa == AF_UNSPEC) {
+ /* see "__inet_bind()", we only want to allow
+ * AF_UNSPEC if the address is INADDR_ANY */
+ if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
+ goto err_af;
+ family_sa = AF_INET;
+ }
snum = ntohs(addr4->sin_port);
addrp = (char *)&addr4->sin_addr.s_addr;
break;
@@ -4617,15 +4626,14 @@ static int selinux_socket_bind(struct socket *sock, stru
ct sockaddr *address, in
addrp = (char *)&addr6->sin6_addr.s6_addr;
break;
default:
- /* Note that SCTP services expect -EINVAL, whereas
- * others expect -EAFNOSUPPORT.
- */
- if (sksec->sclass == SECCLASS_SCTP_SOCKET)
- return -EINVAL;
- else
- return -EAFNOSUPPORT;
+ goto err_af;
}
+ ad.type = LSM_AUDIT_DATA_NET;
+ ad.u.net = &net;
+ ad.u.net->sport = htons(snum);
+ ad.u.net->family = family_sa;
+
if (snum) {
int low, high;
@@ -4637,10 +4645,6 @@ static int selinux_socket_bind(struct socket *sock, struc
t sockaddr *address, in
snum, &sid);
if (err)
goto out;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->sport = htons(snum);
- ad.u.net->family = family;
err = avc_has_perm(&selinux_state,
sksec->sid, sid,
sksec->sclass,
@@ -4672,16 +4676,11 @@ static int selinux_socket_bind(struct socket *sock, stru
ct sockaddr *address, in
break;
}
- err = sel_netnode_sid(addrp, family, &sid);
+ err = sel_netnode_sid(addrp, family_sa, &sid);
if (err)
goto out;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->sport = htons(snum);
- ad.u.net->family = family;
-
- if (address->sa_family == AF_INET)
+ if (family_sa == AF_INET)
ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
else
ad.u.net->v6info.saddr = addr6->sin6_addr;
@@ -4694,6 +4693,12 @@ static int selinux_socket_bind(struct socket *sock, struc
t sockaddr *address, in
}
out:
return err;
+err_af:
+ /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
+ if (sksec->sclass == SECCLASS_SCTP_SOCKET)
+ return -EINVAL;
+ else
+ return -EAFNOSUPPORT;
}
/* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
--
paul moore
www.paul-moore.com
^ permalink raw reply related
* libbpf backward compatibility (was: [PATCH bpf-next v5 09/10] bpf: btf: Add BTF support to libbpf)
From: Jakub Kicinski @ 2018-05-09 22:17 UTC (permalink / raw)
To: Martin KaFai Lau, Alexei Starovoitov, Daniel Borkmann,
Andrey Ignatov
Cc: netdev, kernel-team, David Beckett
In-Reply-To: <20180418225606.2771620-10-kafai@fb.com>
On Wed, 18 Apr 2018 15:56:05 -0700, Martin KaFai Lau wrote:
> diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> index 39f6a0d64a3b..01bda076310f 100644
> --- a/tools/lib/bpf/bpf.h
> +++ b/tools/lib/bpf/bpf.h
> @@ -26,6 +26,20 @@
> #include <linux/bpf.h>
> #include <stddef.h>
>
> +struct bpf_create_map_attr {
> + const char *name;
> + enum bpf_map_type map_type;
> + __u32 map_flags;
> + __u32 key_size;
> + __u32 value_size;
> + __u32 max_entries;
> + __u32 numa_node;
> + __u32 btf_fd;
> + __u32 btf_key_id;
> + __u32 btf_value_id;
> +};
> +
> +int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr);
> int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
> int key_size, int value_size, int max_entries,
> __u32 map_flags, int node);
> @@ -87,4 +101,6 @@ int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len);
> int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
> __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt);
> int bpf_raw_tracepoint_open(const char *name, int prog_fd);
> +int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
> + bool do_log);
> #endif
Does libbpf have to provide backward compatibility? Are the function
prototypes not supposed to change?
Recently a number of *_xattr functions were added, these are nice for
limiting the number of parameters passed to functions, but they don't
buy us anything in terms of extensibility unless we can grow the
structures. Should structure size be passed in as one of parameters?
^ permalink raw reply
* Re: [PATCH] net/mlx5: Fix mlx5_get_vector_affinity function
From: Guenter Roeck @ 2018-05-09 22:19 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Israel Rukshin, Max Gurtovoy, Matan Barak, Doug Ledford,
linux-rdma, linux-kernel, netdev
In-Reply-To: <alpine.DEB.2.21.1805060929540.1685@nanos.tec.linutronix.de>
On Sun, May 06, 2018 at 09:33:26AM +0200, Thomas Gleixner wrote:
> On Sat, 5 May 2018, Guenter Roeck wrote:
>
> > On Thu, Apr 12, 2018 at 09:49:11AM +0000, Israel Rukshin wrote:
> > > Adding the vector offset when calling to mlx5_vector2eqn() is wrong.
> > > This is because mlx5_vector2eqn() checks if EQ index is equal to vector number
> > > and the fact that the internal completion vectors that mlx5 allocates
> > > don't get an EQ index.
> > >
> > > The second problem here is that using effective_affinity_mask gives the same
> > > CPU for different vectors.
> > > This leads to unmapped queues when calling it from blk_mq_rdma_map_queues().
> > > This doesn't happen when using affinity_hint mask.
> > >
> > Except that affinity_hint is only defined if SMP is enabled. Without:
> >
> > include/linux/mlx5/driver.h: In function ‘mlx5_get_vector_affinity_hint’:
> > include/linux/mlx5/driver.h:1299:13: error:
> > ‘struct irq_desc’ has no member named ‘affinity_hint’
> >
> > Note that this is the only use of affinity_hint outside kernel/irq.
> > Don't other drivers have similar problems ?
>
> Aside of that.
>
> > > static inline const struct cpumask *
> > > -mlx5_get_vector_affinity(struct mlx5_core_dev *dev, int vector)
> > > +mlx5_get_vector_affinity_hint(struct mlx5_core_dev *dev, int vector)
> > > {
> > > - const struct cpumask *mask;
> > > struct irq_desc *desc;
> > > unsigned int irq;
> > > int eqn;
> > > int err;
> > >
> > > - err = mlx5_vector2eqn(dev, MLX5_EQ_VEC_COMP_BASE + vector, &eqn, &irq);
> > > + err = mlx5_vector2eqn(dev, vector, &eqn, &irq);
> > > if (err)
> > > return NULL;
> > >
> > > desc = irq_to_desc(irq);
> > > -#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
> > > - mask = irq_data_get_effective_affinity_mask(&desc->irq_data);
> > > -#else
> > > - mask = desc->irq_common_data.affinity;
> > > -#endif
> > > - return mask;
> > > + return desc->affinity_hint;
>
> NAK.
>
The offending patch is upstream, breaking non-SMP test builds, and I have
not seen any feedback from the submitter. Any suggestion how to proceed ?
Guenter
> Nothing in regular device drivers is supposed to ever fiddle with struct
> irq_desc. The existing code is already a violation of that rule and needs
> to be fixed, but not in that way.
>
> The logic here is completely screwed. affinity_hint is set by the driver,
> so the driver already knows what it is. If the driver does not set it, then
> the thing is NULL.
>
> Thanks,
>
> tglx
>
^ permalink raw reply
* Re: libbpf backward compatibility (was: [PATCH bpf-next v5 09/10] bpf: btf: Add BTF support to libbpf)
From: Jakub Kicinski @ 2018-05-09 22:20 UTC (permalink / raw)
To: Martin KaFai Lau, Alexei Starovoitov, Daniel Borkmann,
Andrey Ignatov
Cc: netdev, kernel-team, David Beckett
In-Reply-To: <20180509151712.7d6826f7@cakuba.netronome.com>
On Wed, 9 May 2018 15:17:12 -0700, Jakub Kicinski wrote:
> On Wed, 18 Apr 2018 15:56:05 -0700, Martin KaFai Lau wrote:
> > diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> > index 39f6a0d64a3b..01bda076310f 100644
> > --- a/tools/lib/bpf/bpf.h
> > +++ b/tools/lib/bpf/bpf.h
> > @@ -26,6 +26,20 @@
> > #include <linux/bpf.h>
> > #include <stddef.h>
> >
> > +struct bpf_create_map_attr {
> > + const char *name;
> > + enum bpf_map_type map_type;
> > + __u32 map_flags;
> > + __u32 key_size;
> > + __u32 value_size;
> > + __u32 max_entries;
> > + __u32 numa_node;
> > + __u32 btf_fd;
> > + __u32 btf_key_id;
> > + __u32 btf_value_id;
> > +};
> > +
> > +int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr);
> > int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
> > int key_size, int value_size, int max_entries,
> > __u32 map_flags, int node);
> > @@ -87,4 +101,6 @@ int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len);
> > int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
> > __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt);
> > int bpf_raw_tracepoint_open(const char *name, int prog_fd);
> > +int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
> > + bool do_log);
> > #endif
>
> Does libbpf have to provide backward compatibility? Are the function
> prototypes not supposed to change?
>
> Recently a number of *_xattr functions were added, these are nice for
> limiting the number of parameters passed to functions, but they don't
> buy us anything in terms of extensibility unless we can grow the
> structures. Should structure size be passed in as one of parameters?
Or is the backward compatibility not at the binary level so we can grow
the structures at will?
^ permalink raw reply
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