From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
"Andrii Nakryiko" <andriin@fb.com>, "Yonghong Song" <yhs@fb.com>,
"Song Liu" <songliubraving@fb.com>,
"Martin KaFai Lau" <kafai@fb.com>,
"Jakub Kicinski" <kuba@kernel.org>,
"David Miller" <davem@redhat.com>,
"Björn Töpel" <bjorn.topel@intel.com>,
"John Fastabend" <john.fastabend@gmail.com>,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"Arnaldo Carvalho de Melo" <acme@redhat.com>,
"Song Liu" <song@kernel.org>
Subject: [PATCH 10/15] bpf: Add trampolines to kallsyms
Date: Thu, 12 Mar 2020 20:56:05 +0100 [thread overview]
Message-ID: <20200312195610.346362-11-jolsa@kernel.org> (raw)
In-Reply-To: <20200312195610.346362-1-jolsa@kernel.org>
Adding trampolines to kallsyms. It's displayed as
bpf_trampoline_<ID> [bpf]
where ID is the BTF id of the trampoline function.
Adding bpf_image_ksym_add/del functions that setup
the start/end values and call KSYMBOL perf events
handlers.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/bpf.h | 3 +++
kernel/bpf/trampoline.c | 28 ++++++++++++++++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 83920cbce24c..7edbf30cf2b2 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -513,6 +513,7 @@ struct bpf_trampoline {
/* Executable image of trampoline */
void *image;
u64 selector;
+ struct bpf_ksym ksym;
};
#define BPF_DISPATCHER_MAX 48 /* Fits in 2048B */
@@ -585,6 +586,8 @@ struct bpf_image {
bool is_bpf_image_address(unsigned long address);
void *bpf_image_alloc(void);
/* Called only from JIT-enabled code, so there's no need for stubs. */
+void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym);
+void bpf_image_ksym_del(struct bpf_ksym *ksym);
void bpf_ksym_add(struct bpf_ksym *ksym);
void bpf_ksym_del(struct bpf_ksym *ksym);
#else
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 221a17af1f81..36549c9afec4 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -5,6 +5,7 @@
#include <linux/filter.h>
#include <linux/ftrace.h>
#include <linux/rbtree_latch.h>
+#include <linux/perf_event.h>
/* dummy _ops. The verifier will operate on target program's ops. */
const struct bpf_verifier_ops bpf_extension_verifier_ops = {
@@ -96,6 +97,30 @@ bool is_bpf_image_address(unsigned long addr)
return ret;
}
+void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym)
+{
+ ksym->start = (unsigned long) data;
+ ksym->end = ksym->start + BPF_IMAGE_SIZE;
+ bpf_ksym_add(ksym);
+ perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
+ BPF_IMAGE_SIZE, false, ksym->name);
+}
+
+void bpf_image_ksym_del(struct bpf_ksym *ksym)
+{
+ bpf_ksym_del(ksym);
+ perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
+ BPF_IMAGE_SIZE, true, ksym->name);
+}
+
+static void bpf_trampoline_ksym_add(struct bpf_trampoline *tr)
+{
+ struct bpf_ksym *ksym = &tr->ksym;
+
+ snprintf(ksym->name, KSYM_NAME_LEN, "bpf_trampoline_%llu", tr->key);
+ bpf_image_ksym_add(tr->image, ksym);
+}
+
struct bpf_trampoline *bpf_trampoline_lookup(u64 key)
{
struct bpf_trampoline *tr;
@@ -131,6 +156,8 @@ struct bpf_trampoline *bpf_trampoline_lookup(u64 key)
for (i = 0; i < BPF_TRAMP_MAX; i++)
INIT_HLIST_HEAD(&tr->progs_hlist[i]);
tr->image = image;
+ INIT_LIST_HEAD_RCU(&tr->ksym.lnode);
+ bpf_trampoline_ksym_add(tr);
out:
mutex_unlock(&trampoline_mutex);
return tr;
@@ -368,6 +395,7 @@ void bpf_trampoline_put(struct bpf_trampoline *tr)
goto out;
if (WARN_ON_ONCE(!hlist_empty(&tr->progs_hlist[BPF_TRAMP_FEXIT])))
goto out;
+ bpf_image_ksym_del(&tr->ksym);
image = container_of(tr->image, struct bpf_image, data);
latch_tree_erase(&image->tnode, &image_tree, &image_tree_ops);
/* wait for tasks to get out of trampoline before freeing it */
--
2.24.1
next prev parent reply other threads:[~2020-03-12 19:57 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 19:55 [PATCHv5 00/15] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-03-12 19:55 ` [PATCH 01/15] x86/mm: Rename is_kernel_text to __is_kernel_text Jiri Olsa
2020-03-12 19:55 ` [PATCH 02/15] bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER Jiri Olsa
2020-03-12 19:55 ` [PATCH 03/15] bpf: Add struct bpf_ksym Jiri Olsa
2020-03-12 19:55 ` [PATCH 04/15] bpf: Add name to " Jiri Olsa
2020-03-12 19:56 ` [PATCH 05/15] bpf: Move lnode list node " Jiri Olsa
2020-03-12 19:56 ` [PATCH 06/15] bpf: Move ksym_tnode to bpf_ksym Jiri Olsa
2020-03-12 19:56 ` [PATCH 07/15] bpf: Add bpf_ksym_find function Jiri Olsa
2020-03-12 19:56 ` [PATCH 08/15] bpf: Add prog flag to struct bpf_ksym object Jiri Olsa
2020-03-12 19:56 ` [PATCH 09/15] bpf: Add bpf_ksym_add/del functions Jiri Olsa
2020-03-12 19:56 ` Jiri Olsa [this message]
2020-03-12 19:56 ` [PATCH 11/15] bpf: Add dispatchers to kallsyms Jiri Olsa
2020-03-12 19:56 ` [PATCH 12/15] bpf: Remove bpf_image tree Jiri Olsa
2020-03-12 19:56 ` [PATCH 13/15] perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event Jiri Olsa
2020-04-06 12:54 ` Arnaldo Carvalho de Melo
2020-04-06 13:00 ` Jiri Olsa
2020-03-12 19:56 ` [PATCH 14/15] perf tools: Set ksymbol dso as loaded on arrival Jiri Olsa
2020-03-12 19:56 ` [PATCH 15/15] perf annotate: Add base support for bpf_image Jiri Olsa
2020-03-13 2:39 ` [PATCHv5 00/15] bpf: Add trampoline and dispatcher to /proc/kallsyms Alexei Starovoitov
2020-03-13 8:31 ` Jiri Olsa
2020-04-03 15:32 ` Arnaldo Carvalho de Melo
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