[PATCH 27/85] perf augmented_raw_syscalls: Move the probe_read_str to a separate function

From: Arnaldo Carvalho de Melo
Date: Tue Jun 11 2019 - 15:05:33 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

One more step into copying multiple filenames to support syscalls like
rename*.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Luis ClÃudio GonÃalves <lclaudio@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-xdqtjexdyp81oomm1rkzeifl@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
.../examples/bpf/augmented_raw_syscalls.c | 27 ++++++++++++-------
1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c
index c9fd3b4d8e55..356513e81ec1 100644
--- a/tools/perf/examples/bpf/augmented_raw_syscalls.c
+++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c
@@ -60,11 +60,27 @@ struct augmented_args_filename {

bpf_map(augmented_filename_map, PERCPU_ARRAY, int, struct augmented_args_filename, 1);

+static inline
+unsigned int augmented_args__read_filename(struct augmented_args_filename *augmented_args,
+ const void *filename_arg, unsigned int filename_len)
+{
+ unsigned int len = sizeof(*augmented_args);
+
+ augmented_args->filename.reserved = 0;
+ augmented_args->filename.size = probe_read_str(&augmented_args->filename.value, filename_len, filename_arg);
+ if (augmented_args->filename.size < sizeof(augmented_args->filename.value)) {
+ len -= sizeof(augmented_args->filename.value) - augmented_args->filename.size;
+ len &= sizeof(augmented_args->filename.value) - 1;
+ }
+
+ return len;
+}
+
SEC("raw_syscalls:sys_enter")
int sys_enter(struct syscall_enter_args *args)
{
struct augmented_args_filename *augmented_args;
- unsigned int len = sizeof(*augmented_args), filename_len;
+ unsigned int len, filename_len;
const void *filename_arg = NULL;
struct syscall *syscall;
int key = 0;
@@ -182,14 +198,7 @@ processed 46 insns (limit 1000000) max_states_per_insn 0 total_states 12 peak_st
loop_iter_last(5)

if (filename_arg != NULL && filename_len <= sizeof(augmented_args->filename.value)) {
- augmented_args->filename.reserved = 0;
- augmented_args->filename.size = probe_read_str(&augmented_args->filename.value,
- filename_len,
- filename_arg);
- if (augmented_args->filename.size < sizeof(augmented_args->filename.value)) {
- len -= sizeof(augmented_args->filename.value) - augmented_args->filename.size;
- len &= sizeof(augmented_args->filename.value) - 1;
- }
+ len = augmented_args__read_filename(augmented_args, filename_arg, filename_len);
} else {
len = sizeof(augmented_args->args);
}
--
2.20.1