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Yonghong Song 528bff0cdb tools: bpftool: fix a bitfield pretty print issue
Commit b12d6ec097 ("bpf: btf: add btf print functionality")
added btf pretty print functionality to bpftool.
There is a problem though in printing a bitfield whose type
has modifiers.

For example, for a type like
  typedef int ___int;
  struct tmp_t {
          int a:3;
          ___int b:3;
  };
Suppose we have a map
  struct bpf_map_def SEC("maps") tmpmap = {
          .type = BPF_MAP_TYPE_HASH,
          .key_size = sizeof(__u32),
          .value_size = sizeof(struct tmp_t),
          .max_entries = 1,
  };
and the hash table is populated with one element with
key 0 and value (.a = 1 and .b = 2).

In BTF, the struct member "b" will have a type "typedef" which
points to an int type. The current implementation does not
pass the bit offset during transition from typedef to int type,
hence incorrectly print the value as
  $ bpftool m d id 79
  [{
          "key": 0,
          "value": {
              "a": 0x1,
              "b": 0x1
          }
      }
  ]

This patch fixed the issue by carrying bit_offset along the type
chain during bit_field print. The correct result can be printed as
  $ bpftool m d id 76
  [{
          "key": 0,
          "value": {
              "a": 0x1,
              "b": 0x2
          }
      }
  ]

The kernel pretty print is implemented correctly and does not
have this issue.

Fixes: b12d6ec097 ("bpf: btf: add btf print functionality")
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-28 16:40:02 -08:00
arch sparc: Adjust bpf JIT prologue for PSEUDO calls. 2018-11-27 09:46:52 +01:00
block SCSI: fix queue cleanup race before queue initialization is done 2018-11-14 08:19:10 -07:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: user - Zeroize whole structure given to user space 2018-11-09 17:35:43 +08:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-11-24 09:19:38 -08:00
drivers Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/net-queue 2018-11-28 11:33:35 -08:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Changes since last update: 2018-11-24 09:11:52 -08:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2018-11-28 11:02:45 -08:00
init memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel bpf: btf: check name validity for various types 2018-11-28 16:03:04 -08:00
lib Char/Misc driver fixes for 4.20-rc4 2018-11-22 08:43:06 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
mm mm/memblock.c: fix a typo in __next_mem_pfn_range() comments 2018-11-18 10:15:10 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2018-11-28 11:02:45 -08:00
samples VFIO updates for v4.20 2018-10-31 11:01:38 -07:00
scripts scripts/spdxcheck.py: make python3 compliant 2018-11-18 10:15:10 -08:00
security selinux/stable-4.20 PR 20181115 2018-11-15 11:26:09 -06:00
sound ALSA: hda/ca0132 - fix AE-5 pincfg 2018-11-19 12:18:43 +01:00
tools tools: bpftool: fix a bitfield pretty print issue 2018-11-28 16:40:02 -08:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks" 2018-10-26 16:25:19 -07:00
.clang-format page cache: Convert find_get_pages_contig to XArray 2018-10-21 10:46:34 -04:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap mailmap: Update email for Punit Agrawal 2018-11-05 10:02:11 +00:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: update OMAP MMC entry 2018-11-18 10:15:09 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS bpf, doc: add entries of who looks over which jits 2018-11-26 18:11:48 -08:00
Makefile Linux 4.20-rc3 2018-11-18 13:33:44 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.