From: Steven Rostedt <rostedt@goodmis.org>
To: Alexei Starovoitov <ast@fb.com>
Cc: davem@davemloft.net, daniel@iogearbox.net,
torvalds@linux-foundation.org, peterz@infradead.org,
netdev@vger.kernel.org, kernel-team@fb.com,
linux-api@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH v6 bpf-next 08/11] bpf: introduce BPF_RAW_TRACEPOINT
Date: Tue, 27 Mar 2018 17:04:38 -0400 [thread overview]
Message-ID: <20180327170438.77c0f8fd@gandalf.local.home> (raw)
In-Reply-To: <20180327145824.602dfdec@gandalf.local.home>
On Tue, 27 Mar 2018 14:58:24 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> +extern struct bpf_raw_event_map *__start__bpf_raw_tp[];
> +extern struct bpf_raw_event_map *__stop__bpf_raw_tp[];
> +
> +struct bpf_raw_event_map *bpf_find_raw_tracepoint(const char *name)
> +{
> + struct bpf_raw_event_map* const *btp = __start__bpf_raw_tp;
> +
> + for (; btp < __stop__bpf_raw_tp; btp++)
> + if (!strcmp((*btp)->tp->name, name))
> + return *btp;
> + return NULL;
> +}
> +
OK, this part is broken, and for some reason it didn't include my
changes to bpf_probe.h. I also tested this without setting BPF_EVENTS,
so I wasn't actually testing it.
I added a test in event_trace_init() to make sure that it worked:
(Not included in the patch below)
{
struct bpf_raw_event_map *btp;
btp = bpf_find_raw_tracepoint("sched_switch");
if (btp)
printk("found BPF_RAW_TRACEPOINT: %s %pS\n",
btp->tp->name, btp->bpf_func);
else
printk("COULD NOT FIND BPF_RAW_TRACEPOINT\n");
}
And it found the tracepoint.
Here's take two....
You can add my: Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 1ab0e520d6fc..4fab7392e237 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -178,6 +178,15 @@
#define TRACE_SYSCALLS()
#endif
+#ifdef CONFIG_BPF_EVENTS
+#define BPF_RAW_TP() . = ALIGN(8); \
+ VMLINUX_SYMBOL(__start__bpf_raw_tp) = .; \
+ KEEP(*(__bpf_raw_tp_map)) \
+ VMLINUX_SYMBOL(__stop__bpf_raw_tp) = .;
+#else
+#define BPF_RAW_TP()
+#endif
+
#ifdef CONFIG_SERIAL_EARLYCON
#define EARLYCON_TABLE() STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__earlycon_table) = .; \
@@ -576,6 +585,7 @@
*(.init.rodata) \
FTRACE_EVENTS() \
TRACE_SYSCALLS() \
+ BPF_RAW_TP() \
KPROBE_BLACKLIST() \
ERROR_INJECT_WHITELIST() \
MEM_DISCARD(init.rodata) \
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 399ebe6f90cf..fb4778c0a248 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -470,8 +470,9 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx);
int perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog);
void perf_event_detach_bpf_prog(struct perf_event *event);
int perf_event_query_prog_array(struct perf_event *event, void __user *info);
-int bpf_probe_register(struct tracepoint *tp, struct bpf_prog *prog);
-int bpf_probe_unregister(struct tracepoint *tp, struct bpf_prog *prog);
+int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog);
+int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog);
+struct bpf_raw_event_map *bpf_find_raw_tracepoint(const char *name);
#else
static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
{
@@ -491,14 +492,18 @@ perf_event_query_prog_array(struct perf_event *event, void __user *info)
{
return -EOPNOTSUPP;
}
-static inline int bpf_probe_register(struct tracepoint *tp, struct bpf_prog *p)
+static inline int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *p)
{
return -EOPNOTSUPP;
}
-static inline int bpf_probe_unregister(struct tracepoint *tp, struct bpf_prog *p)
+static inline int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *p)
{
return -EOPNOTSUPP;
}
+static inline struct bpf_raw_event_map *bpf_find_raw_tracepoint(const char *name)
+{
+ return NULL;
+}
#endif
enum {
diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h
index 39a283c61c51..35db8dd48c4c 100644
--- a/include/linux/tracepoint-defs.h
+++ b/include/linux/tracepoint-defs.h
@@ -36,4 +36,9 @@ struct tracepoint {
u32 num_args;
};
+struct bpf_raw_event_map {
+ struct tracepoint *tp;
+ void *bpf_func;
+};
+
#endif
diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h
index d2cc0663e618..bb8ed2f530ad 100644
--- a/include/trace/bpf_probe.h
+++ b/include/trace/bpf_probe.h
@@ -76,7 +76,13 @@ __bpf_trace_##call(void *__data, proto) \
static inline void bpf_test_probe_##call(void) \
{ \
check_trace_callback_type_##call(__bpf_trace_##template); \
-}
+} \
+static struct bpf_raw_event_map __used \
+ __attribute__((section("__bpf_raw_tp_map"))) \
+__bpf_trace_tp_map_##call= { \
+ .tp = &__tracepoint_##call, \
+ .bpf_func = (void *)__bpf_trace_##template, \
+};
#undef DEFINE_EVENT_PRINT
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index f100c63ff19e..6037a2f0108a 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1312,7 +1312,7 @@ static int bpf_obj_get(const union bpf_attr *attr)
}
struct bpf_raw_tracepoint {
- struct tracepoint *tp;
+ struct bpf_raw_event_map *btp;
struct bpf_prog *prog;
};
@@ -1321,7 +1321,7 @@ static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp)
struct bpf_raw_tracepoint *raw_tp = filp->private_data;
if (raw_tp->prog) {
- bpf_probe_unregister(raw_tp->tp, raw_tp->prog);
+ bpf_probe_unregister(raw_tp->btp, raw_tp->prog);
bpf_prog_put(raw_tp->prog);
}
kfree(raw_tp);
@@ -1339,7 +1339,7 @@ static const struct file_operations bpf_raw_tp_fops = {
static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
{
struct bpf_raw_tracepoint *raw_tp;
- struct tracepoint *tp;
+ struct bpf_raw_event_map *btp;
struct bpf_prog *prog;
char tp_name[128];
int tp_fd, err;
@@ -1349,14 +1349,14 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
return -EFAULT;
tp_name[sizeof(tp_name) - 1] = 0;
- tp = kernel_tracepoint_find_by_name(tp_name);
- if (!tp)
+ btp = bpf_find_raw_tracepoint(tp_name);
+ if (!btp)
return -ENOENT;
raw_tp = kmalloc(sizeof(*raw_tp), GFP_USER | __GFP_ZERO);
if (!raw_tp)
return -ENOMEM;
- raw_tp->tp = tp;
+ raw_tp->btp = btp;
prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd,
BPF_PROG_TYPE_RAW_TRACEPOINT);
@@ -1365,7 +1365,7 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
goto out_free_tp;
}
- err = bpf_probe_register(raw_tp->tp, prog);
+ err = bpf_probe_register(raw_tp->btp, prog);
if (err)
goto out_put_prog;
@@ -1373,7 +1373,7 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp,
O_CLOEXEC);
if (tp_fd < 0) {
- bpf_probe_unregister(raw_tp->tp, prog);
+ bpf_probe_unregister(raw_tp->btp, prog);
err = tp_fd;
goto out_put_prog;
}
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index eb58ef156d36..d0975094cff7 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -965,6 +965,22 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info)
return ret;
}
+extern struct bpf_raw_event_map __start__bpf_raw_tp;
+extern struct bpf_raw_event_map __stop__bpf_raw_tp;
+
+struct bpf_raw_event_map *bpf_find_raw_tracepoint(const char *name)
+{
+ const struct bpf_raw_event_map *btp = &__start__bpf_raw_tp;
+ int i = 0;
+
+ for (; btp < &__stop__bpf_raw_tp; btp++) {
+ i++;
+ if (!strcmp(btp->tp->name, name))
+ return btp;
+ }
+ return NULL;
+}
+
static __always_inline
void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
{
@@ -1020,10 +1036,9 @@ BPF_TRACE_DEFN_x(10);
BPF_TRACE_DEFN_x(11);
BPF_TRACE_DEFN_x(12);
-static int __bpf_probe_register(struct tracepoint *tp, struct bpf_prog *prog)
+static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
{
- unsigned long addr;
- char buf[128];
+ struct tracepoint *tp = btp->tp;
/*
* check that program doesn't access arguments beyond what's
@@ -1032,43 +1047,25 @@ static int __bpf_probe_register(struct tracepoint *tp, struct bpf_prog *prog)
if (prog->aux->max_ctx_offset > tp->num_args * sizeof(u64))
return -EINVAL;
- snprintf(buf, sizeof(buf), "__bpf_trace_%s", tp->name);
- addr = kallsyms_lookup_name(buf);
- if (!addr)
- return -ENOENT;
-
- return tracepoint_probe_register(tp, (void *)addr, prog);
+ return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
}
-int bpf_probe_register(struct tracepoint *tp, struct bpf_prog *prog)
+int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
{
int err;
mutex_lock(&bpf_event_mutex);
- err = __bpf_probe_register(tp, prog);
+ err = __bpf_probe_register(btp, prog);
mutex_unlock(&bpf_event_mutex);
return err;
}
-static int __bpf_probe_unregister(struct tracepoint *tp, struct bpf_prog *prog)
-{
- unsigned long addr;
- char buf[128];
-
- snprintf(buf, sizeof(buf), "__bpf_trace_%s", tp->name);
- addr = kallsyms_lookup_name(buf);
- if (!addr)
- return -ENOENT;
-
- return tracepoint_probe_unregister(tp, (void *)addr, prog);
-}
-
-int bpf_probe_unregister(struct tracepoint *tp, struct bpf_prog *prog)
+int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
{
int err;
mutex_lock(&bpf_event_mutex);
- err = __bpf_probe_unregister(tp, prog);
+ err = tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
mutex_unlock(&bpf_event_mutex);
return err;
}
next prev parent reply other threads:[~2018-03-27 21:04 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-27 2:46 [PATCH v6 bpf-next 00/11] bpf, tracing: introduce bpf raw tracepoints Alexei Starovoitov
2018-03-27 2:46 ` [PATCH v6 bpf-next 01/11] treewide: remove large struct-pass-by-value from tracepoint arguments Alexei Starovoitov
2018-03-27 2:46 ` [PATCH v6 bpf-next 02/11] net/mediatek: disambiguate mt76 vs mt7601u trace events Alexei Starovoitov
2018-03-27 2:46 ` [PATCH v6 bpf-next 03/11] net/mac802154: disambiguate mac80215 vs mac802154 " Alexei Starovoitov
2018-03-27 2:46 ` [PATCH v6 bpf-next 04/11] net/wireless/iwlwifi: fix iwlwifi_dev_ucode_error tracepoint Alexei Starovoitov
2018-03-27 2:47 ` [PATCH v6 bpf-next 05/11] macro: introduce COUNT_ARGS() macro Alexei Starovoitov
2018-03-27 2:47 ` [PATCH v6 bpf-next 06/11] tracepoint: compute num_args at build time Alexei Starovoitov
2018-03-27 15:15 ` Steven Rostedt
2018-03-27 2:47 ` [PATCH v6 bpf-next 07/11] tracepoint: introduce kernel_tracepoint_find_by_name Alexei Starovoitov
2018-03-27 14:07 ` Steven Rostedt
2018-03-27 14:18 ` Mathieu Desnoyers
2018-03-27 14:42 ` Steven Rostedt
2018-03-27 15:53 ` Alexei Starovoitov
2018-03-27 16:09 ` Mathieu Desnoyers
2018-03-27 16:36 ` Daniel Borkmann
2018-03-27 2:47 ` [PATCH v6 bpf-next 08/11] bpf: introduce BPF_RAW_TRACEPOINT Alexei Starovoitov
2018-03-27 17:02 ` Steven Rostedt
2018-03-27 17:11 ` Steven Rostedt
2018-03-27 18:58 ` Steven Rostedt
2018-03-27 21:04 ` Steven Rostedt [this message]
2018-03-27 22:48 ` Alexei Starovoitov
2018-03-27 23:13 ` Mathieu Desnoyers
2018-03-28 0:00 ` Alexei Starovoitov
2018-03-28 0:44 ` Mathieu Desnoyers
2018-03-28 0:51 ` Alexei Starovoitov
2018-03-28 14:06 ` Steven Rostedt
2018-03-27 18:45 ` Alexei Starovoitov
2018-03-27 19:00 ` Steven Rostedt
2018-03-27 19:07 ` Steven Rostedt
2018-03-27 19:10 ` Steven Rostedt
2018-03-27 19:10 ` Mathieu Desnoyers
2018-03-27 2:47 ` [PATCH v6 bpf-next 09/11] libbpf: add bpf_raw_tracepoint_open helper Alexei Starovoitov
2018-03-27 2:47 ` [PATCH v6 bpf-next 10/11] samples/bpf: raw tracepoint test Alexei Starovoitov
2018-03-27 2:47 ` [PATCH v6 bpf-next 11/11] selftests/bpf: test for bpf_get_stackid() from raw tracepoints Alexei Starovoitov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180327170438.77c0f8fd@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=ast@fb.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=keescook@chromium.org \
--cc=kernel-team@fb.com \
--cc=linux-api@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=netdev@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).