perf trace: Fix setting of augmented payload when using eBPF + raw_syscalls
tip-bot for Arnaldo Carvalho de Melo
merge botCommit-ID: cd26ea6d50a207ee37e0364ecc2d196d6c9671e8 Gitweb: https://git.kernel.org/tip/cd26ea6d50a207ee37e0364ecc2d196d6c9671e8 Author: Arnaldo Carvalho de Melo <[email protected]> AuthorDate: Sat, 3 Nov 2018 08:19:56 -0300 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Sat, 3 Nov 2018 08:19:56 -0300
perf trace: Fix setting of augmented payload when using eBPF + raw_syscalls
For now with BPF raw_augmented we hook into raw_syscalls:sys_enter and there we get all 6 syscall args plus the tracepoint common fields (sizeof(long)) and the syscall_nr (another long). So we check if that is the case and if so don't look after the sc->args_size, but always after the full raw_syscalls:sys_enter payload, which is fixed.
We'll revisit this later to pass s->args_size to the BPF augmenter (now tools/perf/examples/bpf/augmented_raw_syscalls.c, so that it copies only what we need for each syscall, like what happens when we use syscalls:sys_enter_NAME, so that we reduce the kernel/userspace traffic to just what is needed for each syscall.
Cc Adrian Hunter <[email protected]>
Cc David Ahern <[email protected]>
Cc Jiri Olsa <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Wang Nan <[email protected]>
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
--- tools/perf/builtin-trace.c | 37 ++++++++++++++++++++++++++++++------- 1 file changed, 30 insertions(+), 7 deletions(-)
tools/perf/builtin-trace.c +30 -7
@@ -108,6 +108,7 @@ struct trace { } stats;unsigned int max_stack;unsigned int min_stack; +bool raw_augmented_syscalls;bool not_ev_qualifier;bool live;bool full_time;
@@ -1724,13 +1725,28 @@ static int trace__fprintf_sample(struct trace *trace, struct perf_evsel *evsel,return printed; } -static void *syscall__augmented_args (struct syscall *sc,struct perf_sample *sample,int *augmented_args_size) +static void *syscall__augmented_args (struct syscall *sc,struct perf_sample *sample,int *augmented_args_size,bool raw_augmented) {void *augmented_args =NULL ; +/* +* For now with BPF raw_augmented we hook into raw_syscalls:sys_enter +* and there we get all 6 syscall args plus the tracepoint common +* fields (sizeof(long)) and the syscall_nr (another long). So we check +* if that is the case and if so don't look after the sc->args_size, +* but always after the full raw_syscalls:sys_enter payload, which is +* fixed. +* +* We'll revisit this later to pass s->args_size to the BPF augmenter +* (now tools/perf/examples/bpf/augmented_raw_syscalls.c, so that it +* copies only what we need for each syscall, like what happens when we +* use syscalls:sys_enter_NAME, so that we reduce the kernel/userspace +* traffic to just what is needed for each syscall. +*/ +int args_size = raw_augmented ? (8 * (int )sizeof (long )) : sc->args_size; - *augmented_args_size = sample->raw_size - sc->args_size; + *augmented_args_size = sample->raw_size - args_size;if (*augmented_args_size >0 ) - augmented_args = sample->raw_data + sc->args_size; + augmented_args = sample->raw_data + args_size;return augmented_args; }
@@ -1780,7 +1796,7 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,* here and avoid using augmented syscalls when the evsel is the raw_syscalls one. */ if (evsel != trace->syscalls.events.sys_enter) - augmented_args =syscall__augmented_args (sc, sample, &augmented_args_size); + augmented_args =syscall__augmented_args (sc, sample, &augmented_args_size, trace->raw_augmented_syscalls); ttrace->entry_time = sample->time; msg = ttrace->entry_str; printed +=scnprintf (msg + printed, trace__entry_str_size - printed,"%s(" , sc->name);
@@ -1833,7 +1849,7 @@ static int trace__fprintf_sys_enter(struct trace *trace, struct perf_evsel *evse goto out_put; args =perf_evsel__sc_tp_ptr (evsel, args, sample); - augmented_args =syscall__augmented_args (sc, sample, &augmented_args_size); + augmented_args =syscall__augmented_args (sc, sample, &augmented_args_size, trace->raw_augmented_syscalls);syscall__scnprintf_args (sc, msg,sizeof (msg), args, augmented_args, augmented_args_size, trace, thread);fprintf (trace->output,"%s" , msg); err =0 ;
@@ -3501,8 +3517,15 @@ int cmd_trace(int argc, const char **argv) evsel->handler = trace__sys_enter;evlist__for_each_entry (trace.evlist, evsel) { -if (strstarts (perf_evsel__name (evsel),"syscalls:sys_exit_" ) || -strcmp (perf_evsel__name (evsel),"raw_syscalls:sys_exit" ) ==0 ) { +bool raw_syscalls_sys_exit =strcmp (perf_evsel__name (evsel),"raw_syscalls:sys_exit" ) ==0 ; + +if (raw_syscalls_sys_exit) { + trace.raw_augmented_syscalls = true; + goto init_augmented_syscall_tp; + } + +if (strstarts (perf_evsel__name (evsel),"syscalls:sys_exit_" )) { +init_augmented_syscall_tp:perf_evsel__init_augmented_syscall_tp (evsel);perf_evsel__init_augmented_syscall_tp_ret (evsel); evsel->handler = trace__sys_exit;