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Daniel T. Lee 32e621e554 libbpf: fix samples/bpf build failure due to undefined UINT32_MAX
Currently, building bpf samples will cause the following error.

    ./tools/lib/bpf/bpf.h:132:27: error: 'UINT32_MAX' undeclared here (not in a function) ..
     #define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */
                               ^
    ./samples/bpf/bpf_load.h:31:25: note: in expansion of macro 'BPF_LOG_BUF_SIZE'
     extern char bpf_log_buf[BPF_LOG_BUF_SIZE];
                             ^~~~~~~~~~~~~~~~

Due to commit 4519efa6f8 ("libbpf: fix BPF_LOG_BUF_SIZE off-by-one error")
hard-coded size of BPF_LOG_BUF_SIZE has been replaced with UINT32_MAX which is
defined in <stdint.h> header.

Even with this change, bpf selftests are running fine since these are built
with clang and it includes header(-idirafter) from clang/6.0.0/include.
(it has <stdint.h>)

    clang -I. -I./include/uapi -I../../../include/uapi -idirafter /usr/local/include -idirafter /usr/include \
    -idirafter /usr/lib/llvm-6.0/lib/clang/6.0.0/include -idirafter /usr/include/x86_64-linux-gnu \
    -Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm -c progs/test_sysctl_prog.c -o - | \
    llc -march=bpf -mcpu=generic  -filetype=obj -o /linux/tools/testing/selftests/bpf/test_sysctl_prog.o

But bpf samples are compiled with GCC, and it only searches and includes
headers declared at the target file. As '#include <stdint.h>' hasn't been
declared in tools/lib/bpf/bpf.h, it causes build failure of bpf samples.

    gcc -Wp,-MD,./samples/bpf/.sockex3_user.o.d -Wall -Wmissing-prototypes -Wstrict-prototypes \
    -O2 -fomit-frame-pointer -std=gnu89 -I./usr/include -I./tools/lib/ -I./tools/testing/selftests/bpf/ \
    -I./tools/  lib/ -I./tools/include -I./tools/perf -c -o ./samples/bpf/sockex3_user.o ./samples/bpf/sockex3_user.c;

This commit add declaration of '#include <stdint.h>' to tools/lib/bpf/bpf.h
to fix this problem.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-25 23:34:10 +02:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-04-22 21:35:55 -07:00
LICENSES LICENSES: Add GCC runtime library exception text 2019-01-16 14:54:15 -07:00
arch net: socket: implement 64-bit timestamps 2019-04-19 14:07:40 -07:00
block block: do not leak memory in bio_copy_user_iov() 2019-04-10 16:14:40 -06:00
certs kexec, KEYS: Make use of platform keyring for signature verify 2019-02-04 17:34:07 -05:00
crypto lib/lzo: separate lzo-rle from lzo 2019-03-07 18:32:03 -08:00
drivers net: pass net_device argument to the eth_get_headlen 2019-04-23 18:36:34 +02:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-04-22 21:35:55 -07:00
include net: pass net_device argument to the eth_get_headlen 2019-04-23 18:36:34 +02:00
init init/main: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
ipc rhashtable: use bit_spin_locks to protect hash bucket. 2019-04-07 19:12:12 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-04-22 21:35:55 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
mm Merge branch 'page-refs' (page ref overflow) 2019-04-14 15:09:40 -07:00
net bpf: update skb->protocol in bpf_skb_net_grow 2019-04-24 01:32:26 +02:00
samples samples/bpf: fix build with new clang 2019-04-05 16:28:36 +02:00
scripts kbuild: handle old pahole more gracefully when generating BTF 2019-04-16 09:47:50 +02:00
security apparmor: Restore Y/N in /sys for apparmor's "enabled" 2019-04-10 04:24:48 -07:00
sound ASoC: Fixes for v5.1 2019-04-11 14:36:30 +02:00
tools libbpf: fix samples/bpf build failure due to undefined UINT32_MAX 2019-04-25 23:34:10 +02:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt KVM: fix spectrev1 gadgets 2019-04-16 15:38:07 +02:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-04-11 17:00:05 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.