4cae8675ea
Since we know what args are strings from reading the syscall descriptions in tracefs and also already mark such args to be beautified using the syscall_arg__scnprintf_filename() helper, all we need is to fill in this info in the 'syscalls' BPF map we were using to state which syscalls the user is interested in, i.e. the syscall filter. Right now just set that with PATH_MAX and unroll the syscall arg in the BPF program, as the verifier isn't liking something clang generates when unrolling the loop. This also makes the augmented_raw_syscalls.c program support all arches, since we removed that set of defines with the hard coded syscall numbers, all should be automatically set for all arches, with the syscall id mapping done correcly. Doing baby steps here, i.e. just the first string arg for a syscall is printed, syscalls with more than one, say, the various rename* syscalls, need further work, but lets get first something that the BPF verifier accepts before increasing the complexity To test it, something like: # perf trace -e string -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c With: # cat ~/.perfconfig [llvm] dump-obj = true clang-opt = -g [trace] #add_events = /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c show_zeros = yes show_duration = no no_inherit = yes show_timestamp = no show_arg_names = no args_alignment = 40 show_prefix = yes # That commented add_events line is needed for developing this augmented_raw_syscalls.c BPF program, as if we add it via the 'add_events' mechanism so as to shorten the 'perf trace' command lines, then we end up not setting up the -v option which precludes us having access to the bpf verifier log :-\ Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Andrii Nakryiko <andriin@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Link: https://lkml.kernel.org/n/tip-dn863ya0cbsqycxuy0olvbt1@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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.