From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>
Cc: "Song Liu" <songliubraving@fb.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
"Andrii Nakryiko" <andriin@fb.com>, "Yonghong Song" <yhs@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 04/15] bpf: Add name to struct bpf_ksym
Date: Mon, 2 Mar 2020 15:31:43 +0100 [thread overview]
Message-ID: <20200302143154.258569-5-jolsa@kernel.org> (raw)
In-Reply-To: <20200302143154.258569-1-jolsa@kernel.org>
Adding name to 'struct bpf_ksym' object to carry the name
of the symbol for bpf_prog, bpf_trampoline, bpf_dispatcher.
The current benefit is that name is now generated only when
the symbol is added to the list, so we don't need to generate
it every time it's accessed.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/bpf.h | 2 ++
include/linux/filter.h | 6 ------
kernel/bpf/core.c | 9 ++++++---
kernel/events/core.c | 9 ++++-----
4 files changed, 12 insertions(+), 14 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 5ad8eea1cd37..e7b2e9fc256c 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -18,6 +18,7 @@
#include <linux/refcount.h>
#include <linux/mutex.h>
#include <linux/module.h>
+#include <linux/kallsyms.h>
struct bpf_verifier_env;
struct bpf_verifier_log;
@@ -465,6 +466,7 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start);
struct bpf_ksym {
unsigned long start;
unsigned long end;
+ char name[KSYM_NAME_LEN];
};
enum bpf_tramp_prog_type {
diff --git a/include/linux/filter.h b/include/linux/filter.h
index eafe72644282..a945c250ad53 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1062,7 +1062,6 @@ bpf_address_lookup(unsigned long addr, unsigned long *size,
void bpf_prog_kallsyms_add(struct bpf_prog *fp);
void bpf_prog_kallsyms_del(struct bpf_prog *fp);
-void bpf_get_prog_name(const struct bpf_prog *prog, char *sym);
#else /* CONFIG_BPF_JIT */
@@ -1131,11 +1130,6 @@ static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
{
}
-static inline void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
-{
- sym[0] = '\0';
-}
-
#endif /* CONFIG_BPF_JIT */
void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index e2dd2d87c987..f86cb15d6f2e 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -535,8 +535,10 @@ bpf_prog_ksym_set_addr(struct bpf_prog *prog)
prog->aux->ksym.end = addr + hdr->pages * PAGE_SIZE;
}
-void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
+static void
+bpf_prog_ksym_set_name(struct bpf_prog *prog)
{
+ char *sym = prog->aux->ksym.name;
const char *end = sym + KSYM_NAME_LEN;
const struct btf_type *type;
const char *func_name;
@@ -643,6 +645,7 @@ void bpf_prog_kallsyms_add(struct bpf_prog *fp)
return;
bpf_prog_ksym_set_addr(fp);
+ bpf_prog_ksym_set_name(fp);
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_add(fp->aux);
@@ -681,7 +684,7 @@ const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
unsigned long symbol_start = prog->aux->ksym.start;
unsigned long symbol_end = prog->aux->ksym.end;
- bpf_get_prog_name(prog, sym);
+ strncpy(sym, prog->aux->ksym.name, KSYM_NAME_LEN);
ret = sym;
if (size)
@@ -738,7 +741,7 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
if (it++ != symnum)
continue;
- bpf_get_prog_name(aux->prog, sym);
+ strncpy(sym, aux->ksym.name, KSYM_NAME_LEN);
*value = (unsigned long)aux->prog->bpf_func;
*type = BPF_SYM_ELF_TYPE;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index e453589da97c..a2cfb9e5f262 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8255,23 +8255,22 @@ static void perf_event_bpf_emit_ksymbols(struct bpf_prog *prog,
enum perf_bpf_event_type type)
{
bool unregister = type == PERF_BPF_EVENT_PROG_UNLOAD;
- char sym[KSYM_NAME_LEN];
int i;
if (prog->aux->func_cnt == 0) {
- bpf_get_prog_name(prog, sym);
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF,
(u64)(unsigned long)prog->bpf_func,
- prog->jited_len, unregister, sym);
+ prog->jited_len, unregister,
+ prog->aux->ksym.name);
} else {
for (i = 0; i < prog->aux->func_cnt; i++) {
struct bpf_prog *subprog = prog->aux->func[i];
- bpf_get_prog_name(subprog, sym);
perf_event_ksymbol(
PERF_RECORD_KSYMBOL_TYPE_BPF,
(u64)(unsigned long)subprog->bpf_func,
- subprog->jited_len, unregister, sym);
+ subprog->jited_len, unregister,
+ prog->aux->ksym.name);
}
}
}
--
2.24.1
next prev parent reply other threads:[~2020-03-02 14:32 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-02 14:31 [PATCHv4 00/15] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-03-02 14:31 ` [PATCH 01/15] x86/mm: Rename is_kernel_text to __is_kernel_text Jiri Olsa
2020-03-02 14:31 ` [PATCH 02/15] bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER Jiri Olsa
2020-03-02 14:31 ` [PATCH 03/15] bpf: Add struct bpf_ksym Jiri Olsa
2020-03-02 14:31 ` Jiri Olsa [this message]
2020-03-02 14:31 ` [PATCH 05/15] bpf: Move lnode list node to " Jiri Olsa
2020-03-02 14:31 ` [PATCH 06/15] bpf: Add bpf_ksym_tree tree Jiri Olsa
2020-03-03 18:03 ` Alexei Starovoitov
2020-03-03 20:12 ` Jiri Olsa
2020-03-02 14:31 ` [PATCH 07/15] bpf: Move bpf_tree add/del from bpf_prog_ksym_node_add/del Jiri Olsa
2020-03-02 14:31 ` [PATCH 08/15] bpf: Separate kallsyms add/del functions Jiri Olsa
2020-03-02 14:31 ` [PATCH 09/15] bpf: Add bpf_ksym_add/del functions Jiri Olsa
2020-03-02 14:31 ` [PATCH 10/15] bpf: Rename bpf_tree to bpf_progs_tree Jiri Olsa
2020-03-02 14:31 ` [PATCH 11/15] bpf: Add trampolines to kallsyms Jiri Olsa
2020-03-02 14:31 ` [PATCH 12/15] bpf: Add dispatchers " Jiri Olsa
2020-03-02 14:31 ` [PATCH 13/15] perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event Jiri Olsa
2020-03-02 14:31 ` [PATCH 14/15] perf tools: Set ksymbol dso as loaded on arrival Jiri Olsa
2020-03-02 14:31 ` [PATCH 15/15] perf annotate: Add base support for bpf_image Jiri Olsa
2020-03-12 19:55 [PATCHv5 00/15] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-03-12 19:55 ` [PATCH 04/15] bpf: Add name to struct bpf_ksym Jiri Olsa
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=20200302143154.258569-5-jolsa@kernel.org \
--to=jolsa@kernel.org \
--cc=acme@redhat.com \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=bjorn.topel@intel.com \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@redhat.com \
--cc=hawk@kernel.org \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=kuba@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=song@kernel.org \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/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).