Fix bug in handling bpf_testmod unloading that will cause test_progs exiting
prematurely if bpf_testmod unloading failed. This is especially problematic
when running a subset of test_progs that doesn't require root permissions and
doesn't rely on bpf_testmod, yet will fail immediately due to exit(1) in
unload_bpf_testmod().
Fixes: 9f7fa22589 ("selftests/bpf: Add bpf_testmod kernel module for testing")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210126065019.1268027-1-andrii@kernel.org
There exists many build warnings when make M=samples/bpf on the Loongson
platform, this issue is MIPS related, x86 compiles just fine.
Here are some warnings:
CC samples/bpf/ibumad_user.o
samples/bpf/ibumad_user.c: In function ‘dump_counts’:
samples/bpf/ibumad_user.c:46:24: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned int’} [-Wformat=]
printf("0x%02x : %llu\n", key, value);
~~~^ ~~~~~
%lu
CC samples/bpf/offwaketime_user.o
samples/bpf/offwaketime_user.c: In function ‘print_ksym’:
samples/bpf/offwaketime_user.c:34:17: warning: format ‘%llx’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned int’} [-Wformat=]
printf("%s/%llx;", sym->name, addr);
~~~^ ~~~~
%lx
samples/bpf/offwaketime_user.c: In function ‘print_stack’:
samples/bpf/offwaketime_user.c:68:17: warning: format ‘%lld’ expects argument of type ‘long long int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned int’} [-Wformat=]
printf(";%s %lld\n", key->waker, count);
~~~^ ~~~~~
%ld
MIPS needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
'int-ll64.h' in arch/mips/include/uapi/asm/types.h, then it can avoid
build warnings when printing __u64 with %llu, %llx or %lld.
The header tools/include/linux/types.h defines __SANE_USERSPACE_TYPES__,
it seems that we can include <linux/types.h> in the source files which
have build warnings, but it has no effect due to actually it includes
usr/include/linux/types.h instead of tools/include/linux/types.h, the
problem is that "usr/include" is preferred first than "tools/include"
in samples/bpf/Makefile, that sounds like a ugly hack to -Itools/include
before -Iusr/include.
So define __SANE_USERSPACE_TYPES__ for MIPS in samples/bpf/Makefile
is proper, if add "TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__" in
samples/bpf/Makefile, it appears the following error:
Auto-detecting system features:
... libelf: [ on ]
... zlib: [ on ]
... bpf: [ OFF ]
BPF API too old
make[3]: *** [Makefile:293: bpfdep] Error 1
make[2]: *** [Makefile:156: all] Error 2
With #ifndef __SANE_USERSPACE_TYPES__ in tools/include/linux/types.h,
the above error has gone and this ifndef change does not hurt other
compilations.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/1611551146-14052-1-git-send-email-yangtiezhu@loongson.cn
For very large ELF objects (with many sections), we could
get special value SHN_XINDEX (65535) for elf object's string
table index - e_shstrndx.
Call elf_getshdrstrndx to get the proper string table index,
instead of reading it directly from ELF header.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210121202203.9346-4-jolsa@kernel.org
Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE.
We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom
call in do_tcp_getsockopt using the on-stack data. This removes
3% overhead for locking/unlocking the socket.
Without this patch:
3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt
|
--3.30%--__cgroup_bpf_run_filter_getsockopt
|
--0.81%--__kmalloc
With the patch applied:
0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern
Note, exporting uapi/tcp.h requires removing netinet/tcp.h
from test_progs.h because those headers have confliciting
definitions.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com
llvm patch https://reviews.llvm.org/D84002 permitted
to emit empty rodata datasec if the elf .rodata section
contains read-only data from local variables. These
local variables will be not emitted as BTF_KIND_VARs
since llvm converted these local variables as
static variables with private linkage without debuginfo
types. Such an empty rodata datasec will make
skeleton code generation easy since for skeleton
a rodata struct will be generated if there is a
.rodata elf section. The existence of a rodata
btf datasec is also consistent with the existence
of a rodata map created by libbpf.
The btf with such an empty rodata datasec will fail
in the kernel though as kernel will reject a datasec
with zero vlen and zero size. For example, for the below code,
int sys_enter(void *ctx)
{
int fmt[6] = {1, 2, 3, 4, 5, 6};
int dst[6];
bpf_probe_read(dst, sizeof(dst), fmt);
return 0;
}
We got the below btf (bpftool btf dump ./test.o):
[1] PTR '(anon)' type_id=0
[2] FUNC_PROTO '(anon)' ret_type_id=3 vlen=1
'ctx' type_id=1
[3] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
[4] FUNC 'sys_enter' type_id=2 linkage=global
[5] INT 'char' size=1 bits_offset=0 nr_bits=8 encoding=SIGNED
[6] ARRAY '(anon)' type_id=5 index_type_id=7 nr_elems=4
[7] INT '__ARRAY_SIZE_TYPE__' size=4 bits_offset=0 nr_bits=32 encoding=(none)
[8] VAR '_license' type_id=6, linkage=global-alloc
[9] DATASEC '.rodata' size=0 vlen=0
[10] DATASEC 'license' size=0 vlen=1
type_id=8 offset=0 size=4
When loading the ./test.o to the kernel with bpftool,
we see the following error:
libbpf: Error loading BTF: Invalid argument(22)
libbpf: magic: 0xeb9f
...
[6] ARRAY (anon) type_id=5 index_type_id=7 nr_elems=4
[7] INT __ARRAY_SIZE_TYPE__ size=4 bits_offset=0 nr_bits=32 encoding=(none)
[8] VAR _license type_id=6 linkage=1
[9] DATASEC .rodata size=24 vlen=0 vlen == 0
libbpf: Error loading .BTF into kernel: -22. BTF is optional, ignoring.
Basically, libbpf changed .rodata datasec size to 24 since elf .rodata
section size is 24. The kernel then rejected the BTF since vlen = 0.
Note that the above kernel verifier failure can be worked around with
changing local variable "fmt" to a static or global, optionally const, variable.
This patch permits a datasec with vlen = 0 in kernel.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210119153519.3901963-1-yhs@fb.com
There are 3 tests added into verifier's jit tests to trigger x64
jit jump padding.
The first test can be represented as the following assembly code:
1: bpf_call bpf_get_prandom_u32
2: if r0 == 1 goto pc+128
3: if r0 == 2 goto pc+128
...
129: if r0 == 128 goto pc+128
130: goto pc+128
131: goto pc+127
...
256: goto pc+2
257: goto pc+1
258: r0 = 1
259: ret
We first store a random number to r0 and add the corresponding
conditional jumps (2~129) to make verifier believe that those jump
instructions from 130 to 257 are reachable. When the program is sent to
x64 jit, it starts to optimize out the NOP jumps backwards from 257.
Since there are 128 such jumps, the program easily reaches 15 passes and
triggers jump padding.
Here is the x64 jit code of the first test:
0: 0f 1f 44 00 00 nop DWORD PTR [rax+rax*1+0x0]
5: 66 90 xchg ax,ax
7: 55 push rbp
8: 48 89 e5 mov rbp,rsp
b: e8 4c 90 75 e3 call 0xffffffffe375905c
10: 48 83 f8 01 cmp rax,0x1
14: 0f 84 fe 04 00 00 je 0x518
1a: 48 83 f8 02 cmp rax,0x2
1e: 0f 84 f9 04 00 00 je 0x51d
...
f6: 48 83 f8 18 cmp rax,0x18
fa: 0f 84 8b 04 00 00 je 0x58b
100: 48 83 f8 19 cmp rax,0x19
104: 0f 84 86 04 00 00 je 0x590
10a: 48 83 f8 1a cmp rax,0x1a
10e: 0f 84 81 04 00 00 je 0x595
...
500: 0f 84 83 01 00 00 je 0x689
506: 48 81 f8 80 00 00 00 cmp rax,0x80
50d: 0f 84 76 01 00 00 je 0x689
513: e9 71 01 00 00 jmp 0x689
518: e9 6c 01 00 00 jmp 0x689
...
5fe: e9 86 00 00 00 jmp 0x689
603: e9 81 00 00 00 jmp 0x689
608: 0f 1f 00 nop DWORD PTR [rax]
60b: eb 7c jmp 0x689
60d: eb 7a jmp 0x689
...
683: eb 04 jmp 0x689
685: eb 02 jmp 0x689
687: 66 90 xchg ax,ax
689: b8 01 00 00 00 mov eax,0x1
68e: c9 leave
68f: c3 ret
As expected, a 3 bytes NOPs is inserted at 608 due to the transition
from imm32 jmp to imm8 jmp. A 2 bytes NOPs is also inserted at 687 to
replace a NOP jump.
The second test case is tricky. Here is the assembly code:
1: bpf_call bpf_get_prandom_u32
2: if r0 == 1 goto pc+2048
3: if r0 == 2 goto pc+2048
...
2049: if r0 == 2048 goto pc+2048
2050: goto pc+2048
2051: goto pc+16
2052: goto pc+15
...
2064: goto pc+3
2065: goto pc+2
2066: goto pc+1
...
[repeat "goto pc+16".."goto pc+1" 127 times]
...
4099: r0 = 2
4100: ret
There are 4 major parts of the program.
1) 1~2049: Those are instructions to make 2050~4098 reachable. Some of
them also could generate the padding for jmp_cond.
2) 2050: This is the target instruction for the imm32 nop jmp padding.
3) 2051~4098: The repeated "goto 1~16" instructions are designed to be
consumed by the nop jmp optimization. In the end, those
instrucitons become 128 continuous 0 offset jmp and are
optimized out in 1 pass, and this make insn 2050 an imm32
nop jmp in the next pass, so that we can trigger the
5 bytes padding.
4) 4099~4100: Those are the instructions to end the program.
The x64 jit code is like this:
0: 0f 1f 44 00 00 nop DWORD PTR [rax+rax*1+0x0]
5: 66 90 xchg ax,ax
7: 55 push rbp
8: 48 89 e5 mov rbp,rsp
b: e8 bc 7b d5 d3 call 0xffffffffd3d57bcc
10: 48 83 f8 01 cmp rax,0x1
14: 0f 84 7e 66 00 00 je 0x6698
1a: 48 83 f8 02 cmp rax,0x2
1e: 0f 84 74 66 00 00 je 0x6698
24: 48 83 f8 03 cmp rax,0x3
28: 0f 84 6a 66 00 00 je 0x6698
2e: 48 83 f8 04 cmp rax,0x4
32: 0f 84 60 66 00 00 je 0x6698
38: 48 83 f8 05 cmp rax,0x5
3c: 0f 84 56 66 00 00 je 0x6698
42: 48 83 f8 06 cmp rax,0x6
46: 0f 84 4c 66 00 00 je 0x6698
...
666c: 48 81 f8 fe 07 00 00 cmp rax,0x7fe
6673: 0f 1f 40 00 nop DWORD PTR [rax+0x0]
6677: 74 1f je 0x6698
6679: 48 81 f8 ff 07 00 00 cmp rax,0x7ff
6680: 0f 1f 40 00 nop DWORD PTR [rax+0x0]
6684: 74 12 je 0x6698
6686: 48 81 f8 00 08 00 00 cmp rax,0x800
668d: 0f 1f 40 00 nop DWORD PTR [rax+0x0]
6691: 74 05 je 0x6698
6693: 0f 1f 44 00 00 nop DWORD PTR [rax+rax*1+0x0]
6698: b8 02 00 00 00 mov eax,0x2
669d: c9 leave
669e: c3 ret
Since insn 2051~4098 are optimized out right before the padding pass,
there are several conditional jumps from the first part are replaced with
imm8 jmp_cond, and this triggers the 4 bytes padding, for example at
6673, 6680, and 668d. On the other hand, Insn 2050 is replaced with the
5 bytes nops at 6693.
The third test is to invoke the first and second tests as subprogs to test
bpf2bpf. Per the system log, there was one more jit happened with only
one pass and the same jit code was produced.
v4:
- Add the second test case which triggers jmp_cond padding and imm32 nop
jmp padding.
- Add the new test case as another subprog
Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210119102501.511-4-glin@suse.com
Conflicts:
drivers/net/can/dev.c
commit 03f16c5075 ("can: dev: can_restart: fix use after free bug")
commit 3e77f70e73 ("can: dev: move driver related infrastructure into separate subdir")
Code move.
drivers/net/dsa/b53/b53_common.c
commit 8e4052c32d ("net: dsa: b53: fix an off by one in checking "vlan->vid"")
commit b7a9e0da2d ("net: switchdev: remove vid_begin -> vid_end range from VLAN objects")
Field rename.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking fixes from Jakub Kicinski:
"Networking fixes for 5.11-rc5, including fixes from bpf, wireless, and
can trees.
Current release - regressions:
- nfc: nci: fix the wrong NCI_CORE_INIT parameters
Current release - new code bugs:
- bpf: allow empty module BTFs
Previous releases - regressions:
- bpf: fix signed_{sub,add32}_overflows type handling
- tcp: do not mess with cloned skbs in tcp_add_backlog()
- bpf: prevent double bpf_prog_put call from bpf_tracing_prog_attach
- bpf: don't leak memory in bpf getsockopt when optlen == 0
- tcp: fix potential use-after-free due to double kfree()
- mac80211: fix encryption issues with WEP
- devlink: use right genl user_ptr when handling port param get/set
- ipv6: set multicast flag on the multicast route
- tcp: fix TCP_USER_TIMEOUT with zero window
Previous releases - always broken:
- bpf: local storage helpers should check nullness of owner ptr passed
- mac80211: fix incorrect strlen of .write in debugfs
- cls_flower: call nla_ok() before nla_next()
- skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too"
* tag 'net-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (52 commits)
net: systemport: free dev before on error path
net: usb: cdc_ncm: don't spew notifications
net: mscc: ocelot: Fix multicast to the CPU port
tcp: Fix potential use-after-free due to double kfree()
bpf: Fix signed_{sub,add32}_overflows type handling
can: peak_usb: fix use after free bugs
can: vxcan: vxcan_xmit: fix use after free bug
can: dev: can_restart: fix use after free bug
tcp: fix TCP socket rehash stats mis-accounting
net: dsa: b53: fix an off by one in checking "vlan->vid"
tcp: do not mess with cloned skbs in tcp_add_backlog()
selftests: net: fib_tests: remove duplicate log test
net: nfc: nci: fix the wrong NCI_CORE_INIT parameters
sh_eth: Fix power down vs. is_opened flag ordering
net: Disable NETIF_F_HW_TLS_RX when RXCSUM is disabled
netfilter: rpfilter: mask ecn bits before fib lookup
udp: mask TOS bits in udp_v4_early_demux()
xsk: Clear pool even for inactive queues
bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback
sh_eth: Make PHY access aware of Runtime PM to fix reboot crash
...
Andrii Nakryiko
Tiezhu Yang
Florian Lehner
Björn Töpel
Junlin Yang
Jiri Olsa
Stanislav Fomichev
Yonghong Song
Qais Yousef
Gary Lin
Carlos Neira
Jakub Kicinski
Linus Torvalds