On Wed, 6 Dec 2017 20:56:49 -0600 Julia Cartwright <ju...@ni.com> wrote:
> The futex syscall is a complicated one. It supports thirteen > multiplexed operations, each with different semantics and encodings for > the syscalls six arguments. > > Manually decoding these arguments is tedious and error prone. > > This plugin provides symbolic names for futex operations, futex flags, > and tries to be intelligent about the intent of specific arguments (for > example, waking operations use 'val' as an integer count, not just an > arbitrary value). > > It doesn't do a full decode of the FUTEX_WAKE_OP's 'val3' argument, > however, this is a good starting point. > > Signed-off-by: Julia Cartwright <ju...@ni.com> Hi Julia, I missed this patch. I just applied it and will be pushing it out soon. Thanks! -- Steve > --- > Makefile | 1 + > plugin_futex.c | 135 > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 136 insertions(+) > create mode 100644 plugin_futex.c > > diff --git a/Makefile b/Makefile > index 5c35143c8867..58b957d9a578 100644 > --- a/Makefile > +++ b/Makefile > @@ -365,6 +365,7 @@ PLUGIN_OBJS += plugin_kvm.o > PLUGIN_OBJS += plugin_mac80211.o > PLUGIN_OBJS += plugin_sched_switch.o > PLUGIN_OBJS += plugin_function.o > +PLUGIN_OBJS += plugin_futex.o > PLUGIN_OBJS += plugin_xen.o > PLUGIN_OBJS += plugin_scsi.o > PLUGIN_OBJS += plugin_cfg80211.o > diff --git a/plugin_futex.c b/plugin_futex.c > new file mode 100644 > index 000000000000..b12c92d91a86 > --- /dev/null > +++ b/plugin_futex.c > @@ -0,0 +1,135 @@ > +/* > + * Copyright (C) 2017 National Instruments Corp. > + * > + * Author: Julia Cartwright <ju...@ni.com> > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; > + * version 2.1 of the License (not later!) > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with this program; if not, see > <http://www.gnu.org/licenses> > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + */ > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <linux/futex.h> > + > +#include "trace-cmd.h" > + > +struct futex_args { > + unsigned long long uaddr; > + unsigned long long op; > + unsigned long long val; > + unsigned long long utime; /* or val2 */ > + unsigned long long uaddr2; > + unsigned long long val3; > +}; > + > +struct futex_op { > + const char *name; > + const char *fmt_val; > + const char *fmt_utime; > + const char *fmt_uaddr2; > + const char *fmt_val3; > +}; > + > +static const struct futex_op futex_op_tbl[] = { > + { "FUTEX_WAIT", " val=0x%08llx", " utime=0x%08llx", > NULL, NULL }, > + { "FUTEX_WAKE", " val=%llu", NULL, > NULL, NULL }, > + { "FUTEX_FD", " val=%llu", NULL, > NULL, NULL }, > + { "FUTEX_REQUEUE", " val=%llu", " val2=%llu", " > uaddr2=0x%08llx", NULL }, > + { "FUTEX_CMP_REQUEUE", " val=%llu", " val2=%llu", " > uaddr2=0x%08llx", " val3=0x%08llx" }, > + { "FUTEX_WAKE_OP", " val=%llu", " val2=%llu", " > uaddr2=0x%08llx", " val3=0x%08llx" }, > + { "FUTEX_LOCK_PI", NULL, " utime=0x%08llx", > NULL, NULL }, > + { "FUTEX_UNLOCK_PI", NULL, NULL, > NULL, NULL }, > + { "FUTEX_TRYLOCK_PI", NULL, NULL, > NULL, NULL }, > + { "FUTEX_WAIT_BITSET", " val=0x%08llx", " utime=0x%08llx", > NULL, " val3=0x%08llx" }, > + { "FUTEX_WAKE_BITSET", " val=%llu", NULL, > NULL, " val3=0x%08llx" }, > + { "FUTEX_WAIT_REQUEUE_PI", " val=0x%08llx", " utime=0x%08llx", " > uaddr2=0x%08llx", " val3=0x%08llx" }, > + { "FUTEX_CMP_REQUEUE_PI", " val=%llu", " val2=%llu", " > uaddr2=0x%08llx", " val3=0x%08llx" }, > +}; > + > + > +static void futex_print(struct trace_seq *s, const struct futex_args *args, > + const struct futex_op *fop) > +{ > + trace_seq_printf(s, " uaddr=0x%08llx", args->uaddr); > + > + if (fop->fmt_val) > + trace_seq_printf(s, fop->fmt_val, args->val); > + > + if (fop->fmt_utime) > + trace_seq_printf(s,fop->fmt_utime, args->utime); > + > + if (fop->fmt_uaddr2) > + trace_seq_printf(s, fop->fmt_uaddr2, args->uaddr2); > + > + if (fop->fmt_val3) > + trace_seq_printf(s, fop->fmt_val3, args->val3); > +} > + > +static int futex_handler(struct trace_seq *s, struct pevent_record *record, > + struct event_format *event, void *context) > +{ > + const struct futex_op *fop; > + struct futex_args args; > + unsigned long long cmd; > + > + if (pevent_get_field_val(s, event, "uaddr", record, &args.uaddr, 1)) > + return 1; > + > + if (pevent_get_field_val(s, event, "op", record, &args.op, 1)) > + return 1; > + > + if (pevent_get_field_val(s, event, "val", record, &args.val, 1)) > + return 1; > + > + if (pevent_get_field_val(s, event, "utime", record, &args.utime, 1)) > + return 1; > + > + if (pevent_get_field_val(s, event, "uaddr2", record, &args.uaddr2, 1)) > + return 1; > + > + if (pevent_get_field_val(s, event, "val3", record, &args.val3, 1)) > + return 1; > + > + cmd = args.op & FUTEX_CMD_MASK; > + if (cmd >= ARRAY_SIZE(futex_op_tbl)) > + return 1; > + > + fop = &futex_op_tbl[cmd]; > + > + trace_seq_printf(s, "op=%s", fop->name); > + > + if (args.op & FUTEX_PRIVATE_FLAG) > + trace_seq_puts(s, "|FUTEX_PRIVATE_FLAG"); > + > + if (args.op & FUTEX_CLOCK_REALTIME) > + trace_seq_puts(s, "|FUTEX_CLOCK_REALTIME"); > + > + futex_print(s, &args, fop); > + return 0; > +} > + > +int PEVENT_PLUGIN_LOADER(struct pevent *pevent) > +{ > + pevent_register_event_handler(pevent, -1, "syscalls", "sys_enter_futex", > + futex_handler, NULL); > + return 0; > +} > + > +void PEVENT_PLUGIN_UNLOADER(struct pevent *pevent) > +{ > + pevent_unregister_event_handler(pevent, -1, "syscalls", > "sys_enter_futex", > + futex_handler, NULL); > +}
