67306f84ca
Add a selftest to test:
* default bpf_read_branch_records() behavior
* BPF_F_GET_BRANCH_RECORDS_SIZE flag behavior
* error path on non branch record perf events
* using helper to write to stack
* using helper to write to global
On host with hardware counter support:
# ./test_progs -t perf_branches
#27/1 perf_branches_hw:OK
#27/2 perf_branches_no_hw:OK
#27 perf_branches:OK
Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED
On host without hardware counter support (VM):
# ./test_progs -t perf_branches
#27/1 perf_branches_hw:OK
#27/2 perf_branches_no_hw:OK
#27 perf_branches:OK
Summary: 1/2 PASSED, 1 SKIPPED, 0 FAILED
Also sync tools/include/uapi/linux/bpf.h.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200218030432.4600-3-dxu@dxuuu.xyz
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.