1. 13 12月, 2017 6 次提交
    • J
      bpf: add a bpf_override_function helper · 9802d865
      Josef Bacik 提交于
      Error injection is sloppy and very ad-hoc.  BPF could fill this niche
      perfectly with it's kprobe functionality.  We could make sure errors are
      only triggered in specific call chains that we care about with very
      specific situations.  Accomplish this with the bpf_override_funciton
      helper.  This will modify the probe'd callers return value to the
      specified value and set the PC to an override function that simply
      returns, bypassing the originally probed function.  This gives us a nice
      clean way to implement systematic error injection for all of our code
      paths.
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Acked-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NJosef Bacik <jbacik@fb.com>
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      9802d865
    • J
      btrfs: make open_ctree error injectable · 8556e509
      Josef Bacik 提交于
      This allows us to do error injection with BPF for open_ctree.
      Signed-off-by: NJosef Bacik <jbacik@fb.com>
      Acked-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      8556e509
    • J
      add infrastructure for tagging functions as error injectable · 92ace999
      Josef Bacik 提交于
      Using BPF we can override kprob'ed functions and return arbitrary
      values.  Obviously this can be a bit unsafe, so make this feature opt-in
      for functions.  Simply tag a function with KPROBE_ERROR_INJECT_SYMBOL in
      order to give BPF access to that function for error injection purposes.
      Signed-off-by: NJosef Bacik <jbacik@fb.com>
      Acked-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      92ace999
    • A
      Merge branch 'bpf-tracing-multiprog-tp-query' · a23967c1
      Alexei Starovoitov 提交于
      Yonghong Song says:
      
      ====================
      Commit e87c6bc3 ("bpf: permit multiple bpf attachments
      for a single perf event") added support to attach multiple
      bpf programs to a single perf event. Given a perf event
      (kprobe, uprobe, or kernel tracepoint), the perf ioctl interface
      is used to query bpf programs attached to the same trace event.
      
      There already exists a BPF_PROG_QUERY command for introspection
      currently used by cgroup+bpf. We did have an implementation for
      querying tracepoint+bpf through the same interface. However, it
      looks cleaner to use ioctl() style of api here, since attaching
      bpf prog to tracepoint/kuprobe is also done via ioctl.
      
      Patch #1 had the core implementation and patch #2 added
      a test case in tools bpf selftests suite.
      
      Changelogs:
      v3 -> v4:
        - Fix a compilation error with newer gcc like 6.3.1 while
          old gcc 4.8.5 is okay. I was using &uquery->ids to represent
          the address to the ids array to make it explicit that the
          address is passed, and this syntax is rightly rejected
          by gcc 6.3.1.
      v2 -> v3:
        - Change uapi structure perf_event_query_bpf to be more
          clearer based on Peter's suggestion, and adjust
          other codes accordingly.
      v1 -> v2:
        - Rebase on top of net-next.
        - Use existing bpf_prog_array_length function instead of
          implementing the same functionality in function
          bpf_prog_array_copy_info.
      ====================
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      a23967c1
    • Y
      bpf/tracing: add a bpf test for new ioctl query interface · d279f1f8
      Yonghong Song 提交于
      Added a subtest in test_progs. The tracepoint is
      sched/sched_switch. Multiple bpf programs are attached to
      this tracepoint and the query interface is exercised.
      Signed-off-by: NYonghong Song <yhs@fb.com>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      d279f1f8
    • Y
      bpf/tracing: allow user space to query prog array on the same tp · f371b304
      Yonghong Song 提交于
      Commit e87c6bc3 ("bpf: permit multiple bpf attachments
      for a single perf event") added support to attach multiple
      bpf programs to a single perf event.
      Although this provides flexibility, users may want to know
      what other bpf programs attached to the same tp interface.
      Besides getting visibility for the underlying bpf system,
      such information may also help consolidate multiple bpf programs,
      understand potential performance issues due to a large array,
      and debug (e.g., one bpf program which overwrites return code
      may impact subsequent program results).
      
      Commit 2541517c ("tracing, perf: Implement BPF programs
      attached to kprobes") utilized the existing perf ioctl
      interface and added the command PERF_EVENT_IOC_SET_BPF
      to attach a bpf program to a tracepoint. This patch adds a new
      ioctl command, given a perf event fd, to query the bpf program
      array attached to the same perf tracepoint event.
      
      The new uapi ioctl command:
        PERF_EVENT_IOC_QUERY_BPF
      
      The new uapi/linux/perf_event.h structure:
        struct perf_event_query_bpf {
             __u32	ids_len;
             __u32	prog_cnt;
             __u32	ids[0];
        };
      
      User space provides buffer "ids" for kernel to copy to.
      When returning from the kernel, the number of available
      programs in the array is set in "prog_cnt".
      
      The usage:
        struct perf_event_query_bpf *query =
          malloc(sizeof(*query) + sizeof(u32) * ids_len);
        query.ids_len = ids_len;
        err = ioctl(pmu_efd, PERF_EVENT_IOC_QUERY_BPF, query);
        if (err == 0) {
          /* query.prog_cnt is the number of available progs,
           * number of progs in ids: (ids_len == 0) ? 0 : query.prog_cnt
           */
        } else if (errno == ENOSPC) {
          /* query.ids_len number of progs copied,
           * query.prog_cnt is the number of available progs
           */
        } else {
            /* other errors */
        }
      Signed-off-by: NYonghong Song <yhs@fb.com>
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      f371b304
  2. 12 12月, 2017 1 次提交
  3. 09 12月, 2017 3 次提交
    • D
      Merge branch 'bpf-bpftool-makefile-cleanups' · 97c50589
      Daniel Borkmann 提交于
      Quentin Monnet says:
      
      ====================
      First patch of this series cleans up the two Makefiles (Makefile and
      Documentation/Makefile) and make their contents more consistent.
      
      The second one add "uninstall" and "doc-uninstall" targets, to remove
      files previously installed on the system with "install" and "doc-install"
      targets.
      ====================
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      97c50589
    • Q
      tools: bpftool: create "uninstall", "doc-uninstall" make targets · d3244248
      Quentin Monnet 提交于
      Create two targets to remove executable and documentation that would
      have been previously installed with `make install` and `make
      doc-install`.
      
      Also create a "QUIET_UNINST" helper in tools/scripts/Makefile.include.
      
      Do not attempt to remove directories /usr/local/sbin and
      /usr/share/bash-completions/completions, even if they are empty, as
      those specific directories probably already existed on the system before
      we installed the program, and we do not wish to break other makefiles
      that might assume their existence. Do remvoe /usr/local/share/man/man8
      if empty however, as this directory does not seem to exist by default.
      Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      d3244248
    • Q
      tools: bpftool: harmonise Makefile and Documentation/Makefile · 658e85aa
      Quentin Monnet 提交于
      Several minor fixes and harmonisation items for Makefiles:
      
      * Use the same mechanism for verbose/non-verbose output in two files
        ("$(Q)"), for all commands.
      * Use calls to "QUIET_INSTALL" and equivalent in Makefile. In
        particular, use "call(descend, ...)" instead of "make -C" to run
        documentation targets.
      * Add a "doc-clean" target, aligned on "doc" and "doc-install".
      * Make "install" target in Makefile depend on "bpftool".
      * Remove condition on DESTDIR to initialise prefix in doc Makefile.
      * Remove modification of VPATH based on OUTPUT, it is unused.
      * Formatting: harmonise spaces around equal signs.
      * Make install path for man pages /usr/local/man instead of
        /usr/local/share/man (respects the Makefile conventions, and the
        latter is usually a symbolic link to the former anyway).
      * Do not erase prefix if set by user in bpftool Makefile.
      * Fix install target for bpftool: append DESTDIR to install path.
      Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      658e85aa
  4. 08 12月, 2017 11 次提交
  5. 07 12月, 2017 13 次提交
  6. 06 12月, 2017 6 次提交