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Menglong Dong 7faeff95e4 bpf: fix probe read error in ___bpf_prog_run() 
I think there is something wrong with BPF_PROBE_MEM in ___bpf_prog_run()
in big-endian machine. Let's make a test and see what will happen if we
want to load a 'u16' with BPF_PROBE_MEM.

Let's make the src value '0x0001', the value of dest register will become
0x0001000000000000, as the value will be loaded to the first 2 byte of
DST with following code:

  bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off));

Obviously, the value in DST is not correct. In fact, we can compare
BPF_PROBE_MEM with LDX_MEM_H:

  DST = *(SIZE *)(unsigned long) (SRC + insn->off);

If the memory load is done by LDX_MEM_H, the value in DST will be 0x1 now.

And I think this error results in the test case 'test_bpf_sk_storage_map'
failing:

  test_bpf_sk_storage_map:PASS:bpf_iter_bpf_sk_storage_map__open_and_load 0 nsec
  test_bpf_sk_storage_map:PASS:socket 0 nsec
  test_bpf_sk_storage_map:PASS:map_update 0 nsec
  test_bpf_sk_storage_map:PASS:socket 0 nsec
  test_bpf_sk_storage_map:PASS:map_update 0 nsec
  test_bpf_sk_storage_map:PASS:socket 0 nsec
  test_bpf_sk_storage_map:PASS:map_update 0 nsec
  test_bpf_sk_storage_map:PASS:attach_iter 0 nsec
  test_bpf_sk_storage_map:PASS:create_iter 0 nsec
  test_bpf_sk_storage_map:PASS:read 0 nsec
  test_bpf_sk_storage_map:FAIL:ipv6_sk_count got 0 expected 3
  $10/26 bpf_iter/bpf_sk_storage_map:FAIL

The code of the test case is simply, it will load sk->sk_family to the
register with BPF_PROBE_MEM and check if it is AF_INET6. With this patch,
now the test case 'bpf_iter' can pass:

  $10  bpf_iter:OK

Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
 		2022-08-30 11:33:35 +08:00
Documentation docs/bpf: Add BPF ring buffer design notes 2022-08-30 11:33:29 +08:00
LICENSES Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
arch bpf: Fix trampoline generation for fmod_ret programs 2022-08-30 11:33:21 +08:00
block Add sysfs attribute to hide disk devices 2022-07-25 16:24:47 +08:00
certs certs: Fix blacklist flag type confusion 2021-04-12 12:52:25 +08:00
crypto crypto: rng - fix crypto_rng_reset() refcounting when !CRYPTO_STATS 2021-05-20 16:07:34 +08:00
drivers bpf: Implement CAP_BPF 2022-08-30 11:33:26 +08:00
fs bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_t 2022-08-30 11:33:28 +08:00
include bpf: Stop caching subprog index in the bpf_pseudo_func insn 2022-08-30 11:33:34 +08:00
init bpf: Introduce BPF_PROG_TYPE_LSM 2022-08-30 11:33:21 +08:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2021-03-16 16:27:51 +08:00
kernel bpf: fix probe read error in ___bpf_prog_run() 2022-08-30 11:33:35 +08:00
lib bug: Remove redundant condition check in report_bug 2021-05-20 16:07:55 +08:00
mm uaccess: Add strict non-pagefault kernel-space read function 2022-08-30 11:33:18 +08:00
net bpf: Add selftests for BPF_MODIFY_RETURN 2022-08-30 11:33:31 +08:00
package config: enable CONFIG_ZRAM 2022-08-24 17:40:05 +08:00
samples kfifo: fix ternary sign extension bugs 2021-05-20 16:08:01 +08:00
scripts bpf: fix selftest case compile error for bpf_timer 2022-08-30 11:33:34 +08:00
security bpf: Implement bpf_local_storage for inodes 2022-08-30 11:33:29 +08:00
sound ALSA: usb: midi: don't return -ENOMEM when usb_urb_ep_type_check fails 2021-05-20 16:07:59 +08:00
tools selftests/bpf: check packet range again in bpf_sk_assign_test() 2022-08-30 11:33:35 +08:00
usr Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
virt KVM: Stop looking for coalesced MMIO zones if the bus is destroyed 2021-05-20 16:07:44 +08:00
.clang-format Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.cocciconfig Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.get_maintainer.ignore Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.gitattributes Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.gitignore Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
COPYING Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
CREDITS Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kbuild Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
MAINTAINERS bpf: Introduce BPF_PROG_TYPE_LSM 2022-08-30 11:33:21 +08:00
Makefile bpf: Resolve BTF IDs in vmlinux image 2022-08-30 11:33:27 +08:00
README Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
README.md Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
backport_remove_lists.txt Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
tools_key.pub Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00

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Tencent Linux Kernel 4.0