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e32cb12ff5
Add the __NR_bpf definitions to fix the following build errors for mips:
$ cd tools/bpf/bpftool
$ make
[...]
bpf.c:54:4: error: #error __NR_bpf not defined. libbpf does not support your arch.
# error __NR_bpf not defined. libbpf does not support your arch.
^~~~~
bpf.c: In function ‘sys_bpf’:
bpf.c:66:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
return syscall(__NR_bpf, cmd, attr, size);
^~~~~~~~
__NR_brk
[...]
In file included from gen_loader.c:15:0:
skel_internal.h: In function ‘skel_sys_bpf’:
skel_internal.h:53:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
return syscall(__NR_bpf, cmd, attr, size);
^~~~~~~~
__NR_brk
We can see the following generated definitions:
$ grep -r "#define __NR_bpf" arch/mips
arch/mips/include/generated/uapi/asm/unistd_o32.h:#define __NR_bpf (__NR_Linux + 355)
arch/mips/include/generated/uapi/asm/unistd_n64.h:#define __NR_bpf (__NR_Linux + 315)
arch/mips/include/generated/uapi/asm/unistd_n32.h:#define __NR_bpf (__NR_Linux + 319)
The __NR_Linux is defined in arch/mips/include/uapi/asm/unistd.h:
$ grep -r "#define __NR_Linux" arch/mips
arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux 4000
arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux 5000
arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux 6000
That is to say, __NR_bpf is:
4000 + 355 = 4355 for mips o32,
6000 + 319 = 6319 for mips n32,
5000 + 315 = 5315 for mips n64.
So use the GCC pre-defined macro _ABIO32, _ABIN32 and _ABI64 [1] to define
the corresponding __NR_bpf.
This patch is similar with commit bad1926dd2 ("bpf, s390: fix build for
libbpf and selftest suite").
[1] https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/mips/mips.h#l549
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1637804167-8323-1-git-send-email-yangtiezhu@loongson.cn
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.