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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-07-16 20:55:57 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-07-30 00:34:41 +0300 |
| commit | 8d5da2649d8211e63c5f65ccf8945f2c46a9c0b8 (patch) | |
| tree | b253336f074c366aae78cf9f01da18c2b4f3a1e5 | |
| parent | bf134ca6c8eafd7ddc28840f767259b97e950bac (diff) | |
| download | linux-8d5da2649d8211e63c5f65ccf8945f2c46a9c0b8.tar.xz | |
perf augmented_raw_syscalls: Support copying two string syscall args
Starting with the renameat and renameat2 syscall, that both receive as
second and fourth parameters a pathname:
# perf trace -e rename* mv one ANOTHER
LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
mv: cannot stat 'one': No such file or directory
renameat2(AT_FDCWD, "one", AT_FDCWD, "ANOTHER", RENAME_NOREPLACE) = -1 ENOENT (No such file or directory)
#
Since the per CPU scratch buffer map has space for two maximum sized
pathnames, the verifier is satisfied that there will be no overrun.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-x2uboyg5kx2wqeru288209b6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/builtin-trace.c | 2 | ||||
| -rw-r--r-- | tools/perf/examples/bpf/augmented_raw_syscalls.c | 20 |
2 files changed, 22 insertions, 0 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index a681b8c2ee4e..c64f7c99db15 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -873,9 +873,11 @@ static struct syscall_fmt { { .name = "recvmsg", .arg = { [2] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, }, { .name = "renameat", + .bpf_prog_name = { .sys_enter = "!syscalls:sys_enter_renameat", }, .arg = { [0] = { .scnprintf = SCA_FDAT, /* olddirfd */ }, [2] = { .scnprintf = SCA_FDAT, /* newdirfd */ }, }, }, { .name = "renameat2", + .bpf_prog_name = { .sys_enter = "!syscalls:sys_enter_renameat", }, .arg = { [0] = { .scnprintf = SCA_FDAT, /* olddirfd */ }, [2] = { .scnprintf = SCA_FDAT, /* newdirfd */ }, [4] = { .scnprintf = SCA_RENAMEAT2_FLAGS, /* flags */ }, }, }, diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c index ce308b9a317c..df52d92e1c69 100644 --- a/tools/perf/examples/bpf/augmented_raw_syscalls.c +++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c @@ -70,6 +70,7 @@ pid_filter(pids_filtered); struct augmented_args_filename { struct syscall_enter_args args; struct augmented_filename filename; + struct augmented_filename filename2; }; bpf_map(augmented_filename_map, PERCPU_ARRAY, int, struct augmented_args_filename, 1); @@ -148,6 +149,25 @@ int sys_enter_openat(struct syscall_enter_args *args) return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, augmented_args, len); } +SEC("!syscalls:sys_enter_renameat") +int sys_enter_renameat(struct syscall_enter_args *args) +{ + int key = 0; + struct augmented_args_filename *augmented_args = bpf_map_lookup_elem(&augmented_filename_map, &key); + const void *oldpath_arg = (const void *)args->args[1], + *newpath_arg = (const void *)args->args[3]; + unsigned int len = sizeof(augmented_args->args), oldpath_len; + + if (augmented_args == NULL) + return 1; /* Failure: don't filter */ + + oldpath_len = augmented_filename__read(&augmented_args->filename, oldpath_arg, sizeof(augmented_args->filename.value)); + len += oldpath_len + augmented_filename__read((void *)(&augmented_args->filename) + oldpath_len, newpath_arg, sizeof(augmented_args->filename.value)); + + /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ + return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, augmented_args, len); +} + SEC("raw_syscalls:sys_enter") int sys_enter(struct syscall_enter_args *args) { |