Two minor conflicts:
1) net/ipv4/route.c, adding a new local variable while
moving another local variable and removing it's
initial assignment.
2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
One pretty prints the port mode differently, whilst another
changes the driver to try and obtain the port mode from
the port node rather than the switch node.
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexei Starovoitov says:
====================
pull-request: bpf 2020-09-15
The following pull-request contains BPF updates for your *net* tree.
We've added 12 non-merge commits during the last 19 day(s) which contain
a total of 10 files changed, 47 insertions(+), 38 deletions(-).
The main changes are:
1) docs/bpf fixes, from Andrii.
2) ld_abs fix, from Daniel.
3) socket casting helpers fix, from Martin.
4) hash iterator fixes, from Yonghong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.
Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking fixes from David Miller:
1) Use netif_rx_ni() when necessary in batman-adv stack, from Jussi
Kivilinna.
2) Fix loss of RTT samples in rxrpc, from David Howells.
3) Memory leak in hns_nic_dev_probe(), from Dignhao Liu.
4) ravb module cannot be unloaded, fix from Yuusuke Ashizuka.
5) We disable BH for too lokng in sctp_get_port_local(), add a
cond_resched() here as well, from Xin Long.
6) Fix memory leak in st95hf_in_send_cmd, from Dinghao Liu.
7) Out of bound access in bpf_raw_tp_link_fill_link_info(), from
Yonghong Song.
8) Missing of_node_put() in mt7530 DSA driver, from Sumera
Priyadarsini.
9) Fix crash in bnxt_fw_reset_task(), from Michael Chan.
10) Fix geneve tunnel checksumming bug in hns3, from Yi Li.
11) Memory leak in rxkad_verify_response, from Dinghao Liu.
12) In tipc, don't use smp_processor_id() in preemptible context. From
Tuong Lien.
13) Fix signedness issue in mlx4 memory allocation, from Shung-Hsi Yu.
14) Missing clk_disable_prepare() in gemini driver, from Dan Carpenter.
15) Fix ABI mismatch between driver and firmware in nfp, from Louis
Peens.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (110 commits)
net/smc: fix sock refcounting in case of termination
net/smc: reset sndbuf_desc if freed
net/smc: set rx_off for SMCR explicitly
net/smc: fix toleration of fake add_link messages
tg3: Fix soft lockup when tg3_reset_task() fails.
doc: net: dsa: Fix typo in config code sample
net: dp83867: Fix WoL SecureOn password
nfp: flower: fix ABI mismatch between driver and firmware
tipc: fix shutdown() of connectionless socket
ipv6: Fix sysctl max for fib_multipath_hash_policy
drivers/net/wan/hdlc: Change the default of hard_header_len to 0
net: gemini: Fix another missing clk_disable_unprepare() in probe
net: bcmgenet: fix mask check in bcmgenet_validate_flow()
amd-xgbe: Add support for new port mode
net: usb: dm9601: Add USB ID of Keenetic Plus DSL
vhost: fix typo in error message
net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init()
pktgen: fix error message with wrong function name
net: ethernet: ti: am65-cpsw: fix rmii 100Mbit link mode
cxgb4: fix thermal zone device registration
...
Currently, for hashmap, the bpf iterator will grab a bucket lock, a
spinlock, before traversing the elements in the bucket. This can ensure
all bpf visted elements are valid. But this mechanism may cause
deadlock if update/deletion happens to the same bucket of the
visited map in the program. For example, if we added bpf_map_update_elem()
call to the same visited element in selftests bpf_iter_bpf_hash_map.c,
we will have the following deadlock:
============================================
WARNING: possible recursive locking detected
5.9.0-rc1+ #841 Not tainted
--------------------------------------------
test_progs/1750 is trying to acquire lock:
ffff9a5bb73c5e70 (&htab->buckets[i].raw_lock){....}-{2:2}, at: htab_map_update_elem+0x1cf/0x410
but task is already holding lock:
ffff9a5bb73c5e20 (&htab->buckets[i].raw_lock){....}-{2:2}, at: bpf_hash_map_seq_find_next+0x94/0x120
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&htab->buckets[i].raw_lock);
lock(&htab->buckets[i].raw_lock);
*** DEADLOCK ***
...
Call Trace:
dump_stack+0x78/0xa0
__lock_acquire.cold.74+0x209/0x2e3
lock_acquire+0xba/0x380
? htab_map_update_elem+0x1cf/0x410
? __lock_acquire+0x639/0x20c0
_raw_spin_lock_irqsave+0x3b/0x80
? htab_map_update_elem+0x1cf/0x410
htab_map_update_elem+0x1cf/0x410
? lock_acquire+0xba/0x380
bpf_prog_ad6dab10433b135d_dump_bpf_hash_map+0x88/0xa9c
? find_held_lock+0x34/0xa0
bpf_iter_run_prog+0x81/0x16e
__bpf_hash_map_seq_show+0x145/0x180
bpf_seq_read+0xff/0x3d0
vfs_read+0xad/0x1c0
ksys_read+0x5f/0xe0
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
...
The bucket_lock first grabbed in seq_ops->next() called by bpf_seq_read(),
and then grabbed again in htab_map_update_elem() in the bpf program, causing
deadlocks.
Actually, we do not need bucket_lock here, we can just use rcu_read_lock()
similar to netlink iterator where the rcu_read_{lock,unlock} likes below:
seq_ops->start():
rcu_read_lock();
seq_ops->next():
rcu_read_unlock();
/* next element */
rcu_read_lock();
seq_ops->stop();
rcu_read_unlock();
Compared to old bucket_lock mechanism, if concurrent updata/delete happens,
we may visit stale elements, miss some elements, or repeat some elements.
I think this is a reasonable compromise. For users wanting to avoid
stale, missing/repeated accesses, bpf_map batch access syscall interface
can be used.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200902235340.2001375-1-yhs@fb.com
Daniel Borkmann says:
====================
pull-request: bpf-next 2020-09-01
The following pull-request contains BPF updates for your *net-next* tree.
There are two small conflicts when pulling, resolve as follows:
1) Merge conflict in tools/lib/bpf/libbpf.c between 88a8212028 ("libbpf: Factor
out common ELF operations and improve logging") in bpf-next and 1e891e513e
("libbpf: Fix map index used in error message") in net-next. Resolve by taking
the hunk in bpf-next:
[...]
scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx);
data = elf_sec_data(obj, scn);
if (!scn || !data) {
pr_warn("elf: failed to get %s map definitions for %s\n",
MAPS_ELF_SEC, obj->path);
return -EINVAL;
}
[...]
2) Merge conflict in drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c between
9647c57b11 ("xsk: i40e: ice: ixgbe: mlx5: Test for dma_need_sync earlier for
better performance") in bpf-next and e20f0dbf20 ("net/mlx5e: RX, Add a prefetch
command for small L1_CACHE_BYTES") in net-next. Resolve the two locations by retaining
net_prefetch() and taking xsk_buff_dma_sync_for_cpu() from bpf-next. Should look like:
[...]
xdp_set_data_meta_invalid(xdp);
xsk_buff_dma_sync_for_cpu(xdp, rq->xsk_pool);
net_prefetch(xdp->data);
[...]
We've added 133 non-merge commits during the last 14 day(s) which contain
a total of 246 files changed, 13832 insertions(+), 3105 deletions(-).
The main changes are:
1) Initial support for sleepable BPF programs along with bpf_copy_from_user() helper
for tracing to reliably access user memory, from Alexei Starovoitov.
2) Add BPF infra for writing and parsing TCP header options, from Martin KaFai Lau.
3) bpf_d_path() helper for returning full path for given 'struct path', from Jiri Olsa.
4) AF_XDP support for shared umems between devices and queues, from Magnus Karlsson.
5) Initial prep work for full BPF-to-BPF call support in libbpf, from Andrii Nakryiko.
6) Generalize bpf_sk_storage map & add local storage for inodes, from KP Singh.
7) Implement sockmap/hash updates from BPF context, from Lorenz Bauer.
8) BPF xor verification for scalar types & add BPF link iterator, from Yonghong Song.
9) Use target's prog type for BPF_PROG_TYPE_EXT prog verification, from Udip Pant.
10) Rework BPF tracing samples to use libbpf loader, from Daniel T. Lee.
11) Fix xdpsock sample to really cycle through all buffers, from Weqaar Janjua.
12) Improve type safety for tun/veth XDP frame handling, from Maciej Żenczykowski.
13) Various smaller cleanups and improvements all over the place.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The functions bq_enqueue(), bq_flush_to_queue(), and bq_xmit_all() in
{cpu,dev}map.c always return zero. Changing the return type from int
to void makes the code easier to follow.
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200901083928.6199-1-bjorn.topel@gmail.com
Technically the bpf programs can sleep while attached to bpf_lsm_file_mprotect,
but such programs need to access user memory. So they're in might_fault()
category. Which means they cannot be called from file_mprotect lsm hook that
takes write lock on mm->mmap_lock.
Adjust the test accordingly.
Also add might_fault() to __bpf_prog_enter_sleepable() to catch such deadlocks early.
Fixes: 1e6c62a882 ("bpf: Introduce sleepable BPF programs")
Fixes: e68a144547 ("selftests/bpf: Add sleepable tests")
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200831201651.82447-1-alexei.starovoitov@gmail.com
Sleepable BPF programs can now use copy_from_user() to access user memory.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-4-alexei.starovoitov@gmail.com
Introduce sleepable BPF programs that can request such property for themselves
via BPF_F_SLEEPABLE flag at program load time. In such case they will be able
to use helpers like bpf_copy_from_user() that might sleep. At present only
fentry/fexit/fmod_ret and lsm programs can request to be sleepable and only
when they are attached to kernel functions that are known to allow sleeping.
The non-sleepable programs are relying on implicit rcu_read_lock() and
migrate_disable() to protect life time of programs, maps that they use and
per-cpu kernel structures used to pass info between bpf programs and the
kernel. The sleepable programs cannot be enclosed into rcu_read_lock().
migrate_disable() maps to preempt_disable() in non-RT kernels, so the progs
should not be enclosed in migrate_disable() as well. Therefore
rcu_read_lock_trace is used to protect the life time of sleepable progs.
There are many networking and tracing program types. In many cases the
'struct bpf_prog *' pointer itself is rcu protected within some other kernel
data structure and the kernel code is using rcu_dereference() to load that
program pointer and call BPF_PROG_RUN() on it. All these cases are not touched.
Instead sleepable bpf programs are allowed with bpf trampoline only. The
program pointers are hard-coded into generated assembly of bpf trampoline and
synchronize_rcu_tasks_trace() is used to protect the life time of the program.
The same trampoline can hold both sleepable and non-sleepable progs.
When rcu_read_lock_trace is held it means that some sleepable bpf program is
running from bpf trampoline. Those programs can use bpf arrays and preallocated
hash/lru maps. These map types are waiting on programs to complete via
synchronize_rcu_tasks_trace();
Updates to trampoline now has to do synchronize_rcu_tasks_trace() and
synchronize_rcu_tasks() to wait for sleepable progs to finish and for
trampoline assembly to finish.
This is the first step of introducing sleepable progs. Eventually dynamically
allocated hash maps can be allowed and networking program types can become
sleepable too.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-3-alexei.starovoitov@gmail.com
Most of the maps do not use max_entries during verification time.
Thus, those map_meta_equal() do not need to enforce max_entries
when it is inserted as an inner map during runtime. The max_entries
check is removed from the default implementation bpf_map_meta_equal().
The prog_array_map and xsk_map are exception. Its map_gen_lookup
uses max_entries to generate inline lookup code. Thus, they will
implement its own map_meta_equal() to enforce max_entries.
Since there are only two cases now, the max_entries check
is not refactored and stays in its own .c file.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200828011813.1970516-1-kafai@fb.com
Some properties of the inner map is used in the verification time.
When an inner map is inserted to an outer map at runtime,
bpf_map_meta_equal() is currently used to ensure those properties
of the inserting inner map stays the same as the verification
time.
In particular, the current bpf_map_meta_equal() checks max_entries which
turns out to be too restrictive for most of the maps which do not use
max_entries during the verification time. It limits the use case that
wants to replace a smaller inner map with a larger inner map. There are
some maps do use max_entries during verification though. For example,
the map_gen_lookup in array_map_ops uses the max_entries to generate
the inline lookup code.
To accommodate differences between maps, the map_meta_equal is added
to bpf_map_ops. Each map-type can decide what to check when its
map is used as an inner map during runtime.
Also, some map types cannot be used as an inner map and they are
currently black listed in bpf_map_meta_alloc() in map_in_map.c.
It is not unusual that the new map types may not aware that such
blacklist exists. This patch enforces an explicit opt-in
and only allows a map to be used as an inner map if it has
implemented the map_meta_equal ops. It is based on the
discussion in [1].
All maps that support inner map has its map_meta_equal points
to bpf_map_meta_equal in this patch. A later patch will
relax the max_entries check for most maps. bpf_types.h
counts 28 map types. This patch adds 23 ".map_meta_equal"
by using coccinelle. -5 for
BPF_MAP_TYPE_PROG_ARRAY
BPF_MAP_TYPE_(PERCPU)_CGROUP_STORAGE
BPF_MAP_TYPE_STRUCT_OPS
BPF_MAP_TYPE_ARRAY_OF_MAPS
BPF_MAP_TYPE_HASH_OF_MAPS
The "if (inner_map->inner_map_meta)" check in bpf_map_meta_alloc()
is moved such that the same error is returned.
[1]: https://lore.kernel.org/bpf/20200522022342.899756-1-kafai@fb.com/
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200828011806.1970400-1-kafai@fb.com
bpf selftest test_progs/test_sk_assign failed with llvm 11 and llvm 12.
Compared to llvm 10, llvm 11 and 12 generates xor instruction which
is not handled properly in verifier. The following illustrates the
problem:
16: (b4) w5 = 0
17: ... R5_w=inv0 ...
...
132: (a4) w5 ^= 1
133: ... R5_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ...
...
37: (bc) w8 = w5
38: ... R5=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
R8_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ...
...
41: (bc) w3 = w8
42: ... R3_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ...
45: (56) if w3 != 0x0 goto pc+1
... R3_w=inv0 ...
46: (b7) r1 = 34
47: R1_w=inv34 R7=pkt(id=0,off=26,r=38,imm=0)
47: (0f) r7 += r1
48: R1_w=invP34 R3_w=inv0 R7_w=pkt(id=0,off=60,r=38,imm=0)
48: (b4) w9 = 0
49: R1_w=invP34 R3_w=inv0 R7_w=pkt(id=0,off=60,r=38,imm=0)
49: (69) r1 = *(u16 *)(r7 +0)
invalid access to packet, off=60 size=2, R7(id=0,off=60,r=38)
R7 offset is outside of the packet
At above insn 132, w5 = 0, but after w5 ^= 1, we give a really conservative
value of w5. At insn 45, in reality the condition should be always false.
But due to conservative value for w3, the verifier evaluates it could be
true and this later leads to verifier failure complaining potential
packet out-of-bound access.
This patch implemented proper XOR support in verifier.
In the above example, we have:
132: R5=invP0
132: (a4) w5 ^= 1
133: R5_w=invP1
...
37: (bc) w8 = w5
...
41: (bc) w3 = w8
42: R3_w=invP1
...
45: (56) if w3 != 0x0 goto pc+1
47: R3_w=invP1
...
processed 353 insns ...
and the verifier can verify the program successfully.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200825064608.2017937-1-yhs@fb.com
This patch adds changes in verifier to make decisions such as granting
of read / write access or enforcement of return code status based on
the program type of the target program while using dynamic program
extension (of type BPF_PROG_TYPE_EXT).
The BPF_PROG_TYPE_EXT type can be used to extend types such as XDP, SKB
and others. Since the BPF_PROG_TYPE_EXT program type on itself is just a
placeholder for those, we need this extended check for those extended
programs to actually work with proper access, while using this option.
Specifically, it introduces following changes:
- may_access_direct_pkt_data:
allow access to packet data based on the target prog
- check_return_code:
enforce return code based on the target prog
(currently, this check is skipped for EXT program)
- check_ld_abs:
check for 'may_access_skb' based on the target prog
- check_map_prog_compatibility:
enforce the map compatibility check based on the target prog
- may_update_sockmap:
allow sockmap update based on the target prog
Some other occurrences of prog->type is left as it without replacing
with the 'resolved' type:
- do_check_common() and check_attach_btf_id():
already have specific logic to handle the EXT prog type
- jit_subprogs() and bpf_check():
Not changed for jit compilation or while inferring env->ops
Next few patches in this series include selftests for some of these cases.
Signed-off-by: Udip Pant <udippant@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200825232003.2877030-2-udippant@fb.com
Adding support to define sorted set of BTF ID values.
Following defines sorted set of BTF ID values:
BTF_SET_START(btf_allowlist_d_path)
BTF_ID(func, vfs_truncate)
BTF_ID(func, vfs_fallocate)
BTF_ID(func, dentry_open)
BTF_ID(func, vfs_getattr)
BTF_ID(func, filp_close)
BTF_SET_END(btf_allowlist_d_path)
It defines following 'struct btf_id_set' variable to access
values and count:
struct btf_id_set btf_allowlist_d_path;
Adding 'allowed' callback to struct bpf_func_proto, to allow
verifier the check on allowed callers.
Adding btf_id_set_contains function, which will be used by
allowed callbacks to verify the caller's BTF ID value is
within allowed set.
Also removing extra '\' in __BTF_ID_LIST macro.
Added BTF_SET_START_GLOBAL macro for global sets.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-10-jolsa@kernel.org
Adding btf_struct_ids_match function to check if given address provided
by BTF object + offset is also address of another nested BTF object.
This allows to pass an argument to helper, which is defined via parent
BTF object + offset, like for bpf_d_path (added in following changes):
SEC("fentry/filp_close")
int BPF_PROG(prog_close, struct file *file, void *id)
{
...
ret = bpf_d_path(&file->f_path, ...
The first bpf_d_path argument is hold by verifier as BTF file object
plus offset of f_path member.
The btf_struct_ids_match function will walk the struct file object and
check if there's nested struct path object on the given offset.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-9-jolsa@kernel.org
Adding btf_struct_walk function that walks through the
struct type + given offset and returns following values:
enum bpf_struct_walk_result {
/* < 0 error */
WALK_SCALAR = 0,
WALK_PTR,
WALK_STRUCT,
};
WALK_SCALAR - when SCALAR_VALUE is found
WALK_PTR - when pointer value is found, its ID is stored
in 'next_btf_id' output param
WALK_STRUCT - when nested struct object is found, its ID is stored
in 'next_btf_id' output param
It will be used in following patches to get all nested
struct objects for given type and offset.
The btf_struct_access now calls btf_struct_walk function,
as long as it gets nested structs as return value.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-8-jolsa@kernel.org
Andrii suggested we can simply jump to again label
instead of making recursion call.
Suggested-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-7-jolsa@kernel.org
Adding type_id pointer as argument to __btf_resolve_size
to return also BTF ID of the resolved type. It will be
used in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-6-jolsa@kernel.org
If the resolved type is array, make btf_resolve_size return also
ID of the elem type. It will be needed in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-5-jolsa@kernel.org
Moving btf_resolve_size into __btf_resolve_size and
keeping btf_resolve_size public with just first 3
arguments, because the rest of the arguments are not
used by outside callers.
Following changes are adding more arguments, which
are not useful to outside callers. They will be added
to the __btf_resolve_size function.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-4-jolsa@kernel.org
The CC_CAN_LINK checks that the host compiler can link, but bpf_preload
relies on libbpf which in turn needs libelf to be present during linking.
allmodconfig runs in odd setups with cross compilers and missing host
libraries like libelf. Instead of extending kconfig with every possible
library that bpf_preload might need disallow building BPF_PRELOAD in
such build-only configurations.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adds support for both bpf_{sk, inode}_storage_{get, delete} to be used
in LSM programs. These helpers are not used for tracing programs
(currently) as their usage is tied to the life-cycle of the object and
should only be used where the owning object won't be freed (when the
owning object is passed as an argument to the LSM hook). Thus, they
are safer to use in LSM hooks than tracing. Usage of local storage in
tracing programs will probably follow a per function based whitelist
approach.
Since the UAPI helper signature for bpf_sk_storage expect a bpf_sock,
it, leads to a compilation warning for LSM programs, it's also updated
to accept a void * pointer instead.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-7-kpsingh@chromium.org
Similar to bpf_local_storage for sockets, add local storage for inodes.
The life-cycle of storage is managed with the life-cycle of the inode.
i.e. the storage is destroyed along with the owning inode.
The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the
security blob which are now stackable and can co-exist with other LSMs.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-6-kpsingh@chromium.org
Commit f2e10bff16 ("bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link")
added link query for raw_tp. One of fields in link_info is to
fill a user buffer with tp_name. The Scurrent checking only
declares "ulen && !ubuf" as invalid. So "!ulen && ubuf" will be
valid. Later on, we do "copy_to_user(ubuf, tp_name, ulen - 1)" which
may overwrite user memory incorrectly.
This patch fixed the problem by disallowing "!ulen && ubuf" case as well.
Fixes: f2e10bff16 ("bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200821191054.714731-1-yhs@fb.com
Allow calling bpf_map_update_elem on sockmap and sockhash from a BPF
context. The synchronization required for this is a bit fiddly: we
need to prevent the socket from changing its state while we add it
to the sockmap, since we rely on getting a callback via
sk_prot->unhash. However, we can't just lock_sock like in
sock_map_sk_acquire because that might sleep. So instead we disable
softirq processing and use bh_lock_sock to prevent further
modification.
Yet, this is still not enough. BPF can be called in contexts where
the current CPU might have locked a socket. If the BPF can get
a hold of such a socket, inserting it into a sockmap would lead to
a deadlock. One straight forward example are sock_ops programs that
have ctx->sk, but the same problem exists for kprobes, etc.
We deal with this by allowing sockmap updates only from known safe
contexts. Improper usage is rejected by the verifier.
I've audited the enabled contexts to make sure they can't run in
a locked context. It's possible that CGROUP_SKB and others are
safe as well, but the auditing here is much more difficult. In
any case, we can extend the safe contexts when the need arises.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200821102948.21918-6-lmb@cloudflare.com
The verifier assumes that map values are simple blobs of memory, and
therefore treats ARG_PTR_TO_MAP_VALUE, etc. as such. However, there are
map types where this isn't true. For example, sockmap and sockhash store
sockets. In general this isn't a big problem: we can just
write helpers that explicitly requests PTR_TO_SOCKET instead of
ARG_PTR_TO_MAP_VALUE.
The one exception are the standard map helpers like map_update_elem,
map_lookup_elem, etc. Here it would be nice we could overload the
function prototype for different kinds of maps. Unfortunately, this
isn't entirely straight forward:
We only know the type of the map once we have resolved meta->map_ptr
in check_func_arg. This means we can't swap out the prototype
in check_helper_call until we're half way through the function.
Instead, modify check_func_arg to treat ARG_PTR_TO_MAP_VALUE to
mean "the native type for the map" instead of "pointer to memory"
for sockmap and sockhash. This means we don't have to modify the
function prototype at all
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200821102948.21918-5-lmb@cloudflare.com
Don't go via map->ops to call sock_map_update_elem, since we know
what function to call in bpf_map_update_value. Since we currently
don't allow calling map_update_elem from BPF context, we can remove
ops->map_update_elem and rename the function to sock_map_update_elem_sys.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200821102948.21918-4-lmb@cloudflare.com
For bpf_map_elem and bpf_sk_local_storage bpf iterators,
additional map_id should be shown for fdinfo and
userspace query. For example, the following is for
a bpf_map_elem iterator.
$ cat /proc/1753/fdinfo/9
pos: 0
flags: 02000000
mnt_id: 14
link_type: iter
link_id: 34
prog_tag: 104be6d3fe45e6aa
prog_id: 173
target_name: bpf_map_elem
map_id: 127
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200821184419.574240-1-yhs@fb.com
This patch implemented bpf_link callback functions
show_fdinfo and fill_link_info to support link_query
interface.
The general interface for show_fdinfo and fill_link_info
will print/fill the target_name. Each targets can
register show_fdinfo and fill_link_info callbacks
to print/fill more target specific information.
For example, the below is a fdinfo result for a bpf
task iterator.
$ cat /proc/1749/fdinfo/7
pos: 0
flags: 02000000
mnt_id: 14
link_type: iter
link_id: 11
prog_tag: 990e1f8152f7e54f
prog_id: 59
target_name: task
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200821184418.574122-1-yhs@fb.com
Add kernel module with user mode driver that populates bpffs with
BPF iterators.
$ mount bpffs /my/bpffs/ -t bpf
$ ls -la /my/bpffs/
total 4
drwxrwxrwt 2 root root 0 Jul 2 00:27 .
drwxr-xr-x 19 root root 4096 Jul 2 00:09 ..
-rw------- 1 root root 0 Jul 2 00:27 maps.debug
-rw------- 1 root root 0 Jul 2 00:27 progs.debug
The user mode driver will load BPF Type Formats, create BPF maps, populate BPF
maps, load two BPF programs, attach them to BPF iterators, and finally send two
bpf_link IDs back to the kernel.
The kernel will pin two bpf_links into newly mounted bpffs instance under
names "progs.debug" and "maps.debug". These two files become human readable.
$ cat /my/bpffs/progs.debug
id name attached
11 dump_bpf_map bpf_iter_bpf_map
12 dump_bpf_prog bpf_iter_bpf_prog
27 test_pkt_access
32 test_main test_pkt_access test_pkt_access
33 test_subprog1 test_pkt_access_subprog1 test_pkt_access
34 test_subprog2 test_pkt_access_subprog2 test_pkt_access
35 test_subprog3 test_pkt_access_subprog3 test_pkt_access
36 new_get_skb_len get_skb_len test_pkt_access
37 new_get_skb_ifindex get_skb_ifindex test_pkt_access
38 new_get_constant get_constant test_pkt_access
The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about
all BPF programs currently loaded in the system. This information is unstable
and will change from kernel to kernel as ".debug" suffix conveys.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
The program and map iterators work similar to seq_file-s.
Once the program is pinned in bpffs it can be read with "cat" tool
to print human readable output. In this case about BPF programs and maps.
For example:
$ cat /sys/fs/bpf/progs.debug
id name attached
5 dump_bpf_map bpf_iter_bpf_map
6 dump_bpf_prog bpf_iter_bpf_prog
$ cat /sys/fs/bpf/maps.debug
id name max_entries
3 iterator.rodata 1
To avoid kernel build dependency on clang 10 separate bpf skeleton generation
into manual "make" step and instead check-in generated .skel.h into git.
Unlike 'bpftool prog show' in-kernel BTF name is used (when available)
to print full name of BPF program instead of 16-byte truncated name.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200819042759.51280-3-alexei.starovoitov@gmail.com
Refactor the code a bit to extract bpf_link_by_id() helper.
It's similar to existing bpf_prog_by_id().
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200819042759.51280-2-alexei.starovoitov@gmail.com
Currently when traversing all tasks, the next tid
is always increased by one. This may result in
visiting the same task multiple times in a
pid namespace.
This patch fixed the issue by seting the next
tid as pid_nr_ns(pid, ns) + 1, similar to
funciton next_tgid().
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@fb.com
In our production system, we observed rcu stalls when
'bpftool prog` is running.
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: \x097-....: (20999 ticks this GP) idle=302/1/0x4000000000000000 softirq=1508852/1508852 fqs=4913
\x09(t=21031 jiffies g=2534773 q=179750)
NMI backtrace for cpu 7
CPU: 7 PID: 184195 Comm: bpftool Kdump: loaded Tainted: G W 5.8.0-00004-g68bfc7f8c1b4 #6
Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A17 05/03/2019
Call Trace:
<IRQ>
dump_stack+0x57/0x70
nmi_cpu_backtrace.cold+0x14/0x53
? lapic_can_unplug_cpu.cold+0x39/0x39
nmi_trigger_cpumask_backtrace+0xb7/0xc7
rcu_dump_cpu_stacks+0xa2/0xd0
rcu_sched_clock_irq.cold+0x1ff/0x3d9
? tick_nohz_handler+0x100/0x100
update_process_times+0x5b/0x90
tick_sched_timer+0x5e/0xf0
__hrtimer_run_queues+0x12a/0x2a0
hrtimer_interrupt+0x10e/0x280
__sysvec_apic_timer_interrupt+0x51/0xe0
asm_call_on_stack+0xf/0x20
</IRQ>
sysvec_apic_timer_interrupt+0x6f/0x80
asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:task_file_seq_get_next+0x71/0x220
Code: 00 00 8b 53 1c 49 8b 7d 00 89 d6 48 8b 47 20 44 8b 18 41 39 d3 76 75 48 8b 4f 20 8b 01 39 d0 76 61 41 89 d1 49 39 c1 48 19 c0 <48> 8b 49 08 21 d0 48 8d 04 c1 4c 8b 08 4d 85 c9 74 46 49 8b 41 38
RSP: 0018:ffffc90006223e10 EFLAGS: 00000297
RAX: ffffffffffffffff RBX: ffff888f0d172388 RCX: ffff888c8c07c1c0
RDX: 00000000000f017b RSI: 00000000000f017b RDI: ffff888c254702c0
RBP: ffffc90006223e68 R08: ffff888be2a1c140 R09: 00000000000f017b
R10: 0000000000000002 R11: 0000000000100000 R12: ffff888f23c24118
R13: ffffc90006223e60 R14: ffffffff828509a0 R15: 00000000ffffffff
task_file_seq_next+0x52/0xa0
bpf_seq_read+0xb9/0x320
vfs_read+0x9d/0x180
ksys_read+0x5f/0xe0
do_syscall_64+0x38/0x60
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f8815f4f76e
Code: c0 e9 f6 fe ff ff 55 48 8d 3d 76 70 0a 00 48 89 e5 e8 36 06 02 00 66 0f 1f 44 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 52 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5
RSP: 002b:00007fff8f9df578 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000000000170b9c0 RCX: 00007f8815f4f76e
RDX: 0000000000001000 RSI: 00007fff8f9df5b0 RDI: 0000000000000007
RBP: 00007fff8f9e05f0 R08: 0000000000000049 R09: 0000000000000010
R10: 00007f881601fa40 R11: 0000000000000246 R12: 00007fff8f9e05a8
R13: 00007fff8f9e05a8 R14: 0000000001917f90 R15: 000000000000e22e
Note that `bpftool prog` actually calls a task_file bpf iterator
program to establish an association between prog/map/link/btf anon
files and processes.
In the case where the above rcu stall occured, we had a process
having 1587 tasks and each task having roughly 81305 files.
This implied 129 million bpf prog invocations. Unfortunwtely none of
these files are prog/map/link/btf files so bpf iterator/prog needs
to traverse all these files and not able to return to user space
since there are no seq_file buffer overflow.
This patch fixed the issue in bpf_seq_read() to limit the number
of visited objects. If the maximum number of visited objects is
reached, no more objects will be visited in the current syscall.
If there is nothing written in the seq_file buffer, -EAGAIN will
return to the user so user can try again.
The maximum number of visited objects is set at 1 million.
In our Intel Xeon D-2191 2.3GHZ 18-core server, bpf_seq_read()
visiting 1 million files takes around 0.18 seconds.
We did not use cond_resched() since for some iterators, e.g.,
netlink iterator, where rcu read_lock critical section spans between
consecutive seq_ops->next(), which makes impossible to do cond_resched()
in the key while loop of function bpf_seq_read().
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/bpf/20200818222309.2181348-1-yhs@fb.com
With latest `bpftool prog` command, we observed the following kernel
panic.
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD dfe894067 P4D dfe894067 PUD deb663067 PMD 0
Oops: 0010 [#1] SMP
CPU: 9 PID: 6023 ...
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0000:ffffc900002b8f18 EFLAGS: 00010286
RAX: ffff8883a405f400 RBX: ffff888e46a6bf00 RCX: 000000008020000c
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8883a405f400
RBP: ffff888e46a6bf50 R08: 0000000000000000 R09: ffffffff81129600
R10: ffff8883a405f300 R11: 0000160000000000 R12: 0000000000002710
R13: 000000e9494b690c R14: 0000000000000202 R15: 0000000000000009
FS: 00007fd9187fe700(0000) GS:ffff888e46a40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000de5d33002 CR4: 0000000000360ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
rcu_core+0x1a4/0x440
__do_softirq+0xd3/0x2c8
irq_exit+0x9d/0xa0
smp_apic_timer_interrupt+0x68/0x120
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0033:0x47ce80
Code: Bad RIP value.
RSP: 002b:00007fd9187fba40 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000002 RBX: 00007fd931789160 RCX: 000000000000010c
RDX: 00007fd9308cdfb4 RSI: 00007fd9308cdfb4 RDI: 00007ffedd1ea0a8
RBP: 00007fd9187fbab0 R08: 000000000000000e R09: 000000000000002a
R10: 0000000000480210 R11: 00007fd9187fc570 R12: 00007fd9316cc400
R13: 0000000000000118 R14: 00007fd9308cdfb4 R15: 00007fd9317a9380
After further analysis, the bug is triggered by
Commit eaaacd2391 ("bpf: Add task and task/file iterator targets")
which introduced task_file bpf iterator, which traverses all open file
descriptors for all tasks in the current namespace.
The latest `bpftool prog` calls a task_file bpf program to traverse
all files in the system in order to associate processes with progs/maps, etc.
When traversing files for a given task, rcu read_lock is taken to
access all files in a file_struct. But it used get_file() to grab
a file, which is not right. It is possible file->f_count is 0 and
get_file() will unconditionally increase it.
Later put_file() may cause all kind of issues with the above
as one of sympotoms.
The failure can be reproduced with the following steps in a few seconds:
$ cat t.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#define N 10000
int fd[N];
int main() {
int i;
for (i = 0; i < N; i++) {
fd[i] = open("./note.txt", 'r');
if (fd[i] < 0) {
fprintf(stderr, "failed\n");
return -1;
}
}
for (i = 0; i < N; i++)
close(fd[i]);
return 0;
}
$ gcc -O2 t.c
$ cat run.sh
#/bin/bash
for i in {1..100}
do
while true; do ./a.out; done &
done
$ ./run.sh
$ while true; do bpftool prog >& /dev/null; done
This patch used get_file_rcu() which only grabs a file if the
file->f_count is not zero. This is to ensure the file pointer
is always valid. The above reproducer did not fail for more
than 30 minutes.
Fixes: eaaacd2391 ("bpf: Add task and task/file iterator targets")
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/bpf/20200817174214.252601-1-yhs@fb.com
Currently when we look for build id within bpf_get_stackid helper
call, we check the first NOTE section and we fail if build id is
not there.
However on some system (Fedora) there can be multiple NOTE sections
in binaries and build id data is not always the first one, like:
$ readelf -a /usr/bin/ls
...
[ 2] .note.gnu.propert NOTE 0000000000000338 00000338
0000000000000020 0000000000000000 A 0 0 8358
[ 3] .note.gnu.build-i NOTE 0000000000000358 00000358
0000000000000024 0000000000000000 A 0 0 437c
[ 4] .note.ABI-tag NOTE 000000000000037c 0000037c
...
So the stack_map_get_build_id function will fail on build id retrieval
and fallback to BPF_STACK_BUILD_ID_IP.
This patch is changing the stack_map_get_build_id code to iterate
through all the NOTE sections and try to get build id data from
each of them.
When tracing on sched_switch tracepoint that does bpf_get_stackid
helper call kernel build, I can see about 60% increase of successful
build id retrieval. The rest seems fails on -EFAULT.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200812123102.20032-1-jolsa@kernel.org
Commit a5cbe05a66 ("bpf: Implement bpf iterator for
map elements") added bpf iterator support for
map elements. The map element bpf iterator requires
info to identify a particular map. In the above
commit, the attr->link_create.target_fd is used
to carry map_fd and an enum bpf_iter_link_info
is added to uapi to specify the target_fd actually
representing a map_fd:
enum bpf_iter_link_info {
BPF_ITER_LINK_UNSPEC = 0,
BPF_ITER_LINK_MAP_FD = 1,
MAX_BPF_ITER_LINK_INFO,
};
This is an extensible approach as we can grow
enumerator for pid, cgroup_id, etc. and we can
unionize target_fd for pid, cgroup_id, etc.
But in the future, there are chances that
more complex customization may happen, e.g.,
for tasks, it could be filtered based on
both cgroup_id and user_id.
This patch changed the uapi to have fields
__aligned_u64 iter_info;
__u32 iter_info_len;
for additional iter_info for link_create.
The iter_info is defined as
union bpf_iter_link_info {
struct {
__u32 map_fd;
} map;
};
So future extension for additional customization
will be easier. The bpf_iter_link_info will be
passed to target callback to validate and generic
bpf_iter framework does not need to deal it any
more.
Note that map_fd = 0 will be considered invalid
and -EBADF will be returned to user space.
Fixes: a5cbe05a66 ("bpf: Implement bpf iterator for map elements")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200805055056.1457463-1-yhs@fb.com
Daniel Borkmann says:
====================
pull-request: bpf-next 2020-08-04
The following pull-request contains BPF updates for your *net-next* tree.
We've added 73 non-merge commits during the last 9 day(s) which contain
a total of 135 files changed, 4603 insertions(+), 1013 deletions(-).
The main changes are:
1) Implement bpf_link support for XDP. Also add LINK_DETACH operation for the BPF
syscall allowing processes with BPF link FD to force-detach, from Andrii Nakryiko.
2) Add BPF iterator for map elements and to iterate all BPF programs for efficient
in-kernel inspection, from Yonghong Song and Alexei Starovoitov.
3) Separate bpf_get_{stack,stackid}() helpers for perf events in BPF to avoid
unwinder errors, from Song Liu.
4) Allow cgroup local storage map to be shared between programs on the same
cgroup. Also extend BPF selftests with coverage, from YiFei Zhu.
5) Add BPF exception tables to ARM64 JIT in order to be able to JIT BPF_PROBE_MEM
load instructions, from Jean-Philippe Brucker.
6) Follow-up fixes on BPF socket lookup in combination with reuseport group
handling. Also add related BPF selftests, from Jakub Sitnicki.
7) Allow to use socket storage in BPF_PROG_TYPE_CGROUP_SOCK-typed programs for
socket create/release as well as bind functions, from Stanislav Fomichev.
8) Fix an info leak in xsk_getsockopt() when retrieving XDP stats via old struct
xdp_statistics, from Peilin Ye.
9) Fix PT_REGS_RC{,_CORE}() macros in libbpf for MIPS arch, from Jerry Crunchtime.
10) Extend BPF kernel test infra with skb->family and skb->{local,remote}_ip{4,6}
fields and allow user space to specify skb->dev via ifindex, from Dmitry Yakunin.
11) Fix a bpftool segfault due to missing program type name and make it more robust
to prevent them in future gaps, from Quentin Monnet.
12) Consolidate cgroup helper functions across selftests and fix a v6 localhost
resolver issue, from John Fastabend.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add LINK_DETACH command to force-detach bpf_link without destroying it. It has
the same behavior as auto-detaching of bpf_link due to cgroup dying for
bpf_cgroup_link or net_device being destroyed for bpf_xdp_link. In such case,
bpf_link is still a valid kernel object, but is defuncts and doesn't hold BPF
program attached to corresponding BPF hook. This functionality allows users
with enough access rights to manually force-detach attached bpf_link without
killing respective owner process.
This patch implements LINK_DETACH for cgroup, xdp, and netns links, mostly
re-using existing link release handling code.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200731182830.286260-2-andriin@fb.com
Daniel Borkmann says:
====================
pull-request: bpf 2020-07-31
The following pull-request contains BPF updates for your *net* tree.
We've added 5 non-merge commits during the last 21 day(s) which contain
a total of 5 files changed, 126 insertions(+), 18 deletions(-).
The main changes are:
1) Fix a map element leak in HASH_OF_MAPS map type, from Andrii Nakryiko.
2) Fix a NULL pointer dereference in __btf_resolve_helper_id() when no
btf_vmlinux is available, from Peilin Ye.
3) Init pos variable in __bpfilter_process_sockopt(), from Christoph Hellwig.
4) Fix a cgroup sockopt verifier test by specifying expected attach type,
from Jean-Philippe Brucker.
Note that when net gets merged into net-next later on, there is a small
merge conflict in kernel/bpf/btf.c between commit 5b801dfb7f ("bpf: Fix
NULL pointer dereference in __btf_resolve_helper_id()") from the bpf tree
and commit 138b9a0511 ("bpf: Remove btf_id helpers resolving") from the
net-next tree.
Resolve as follows: remove the old hunk with the __btf_resolve_helper_id()
function. Change the btf_resolve_helper_id() so it actually tests for a
NULL btf_vmlinux and bails out:
int btf_resolve_helper_id(struct bpf_verifier_log *log,
const struct bpf_func_proto *fn, int arg)
{
int id;
if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID || !btf_vmlinux)
return -EINVAL;
id = fn->btf_id[arg];
if (!id || id > btf_vmlinux->nr_types)
return -EINVAL;
return id;
}
Let me know if you run into any others issues (CC'ing Jiri Olsa so he's in
the loop with regards to merge conflict resolution).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Newline characters are added in two verifier error messages,
refactored in Commit afbf21dce6 ("bpf: Support readonly/readwrite
buffers in verifier"). This way, they do not mix with
messages afterwards.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200728221801.1090349-1-yhs@fb.com
Fix HASH_OF_MAPS bug of not putting inner map pointer on bpf_map_elem_update()
operation. This is due to per-cpu extra_elems optimization, which bypassed
free_htab_elem() logic doing proper clean ups. Make sure that inner map is put
properly in optimized case as well.
Fixes: 8c290e60fa ("bpf: fix hashmap extra_elems logic")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200729040913.2815687-1-andriin@fb.com
Entire net/core subsystem is not built without CONFIG_NET. linux/netdevice.h
just assumes that it's always there, so the easiest way to fix this is to
conditionally compile out bpf_xdp_link_attach() use in bpf/syscall.c.
Fixes: aa8d3a716b ("bpf, xdp: Add bpf_link-based XDP attachment API")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200728190527.110830-1-andriin@fb.com
