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>
Subject: [PATCH 04/14] bpf: Add name to struct bpf_ksym
Date: Sat, 8 Feb 2020 16:41:59 +0100 [thread overview]
Message-ID: <20200208154209.1797988-5-jolsa@kernel.org> (raw)
In-Reply-To: <20200208154209.1797988-1-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.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/bpf.h | 2 ++
include/linux/filter.h | 6 ------
kernel/bpf/core.c | 8 +++++---
kernel/events/core.c | 4 ++--
4 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e39ded33fb0c..1327b07057a8 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 09b5939dcad3..f4f0b3ca95ae 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -535,8 +535,9 @@ bpf_get_prog_addr_region(const 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_get_prog_name(const 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 +644,7 @@ void bpf_prog_kallsyms_add(struct bpf_prog *fp)
return;
bpf_get_prog_addr_region(fp);
+ bpf_get_prog_name(fp);
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_add(fp->aux);
@@ -681,7 +683,7 @@ 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 +740,7 @@ 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 2173c23c25b4..c4b01ca30cd4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8250,7 +8250,7 @@ static void perf_event_bpf_emit_ksymbols(struct bpf_prog *prog,
int i;
if (prog->aux->func_cnt == 0) {
- bpf_get_prog_name(prog, sym);
+ strncpy(sym, prog->aux->ksym.name, KSYM_NAME_LEN);
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF,
(u64)(unsigned long)prog->bpf_func,
prog->jited_len, unregister, sym);
@@ -8258,7 +8258,7 @@ static void perf_event_bpf_emit_ksymbols(struct bpf_prog *prog,
for (i = 0; i < prog->aux->func_cnt; i++) {
struct bpf_prog *subprog = prog->aux->func[i];
- bpf_get_prog_name(subprog, sym);
+ strncpy(sym, subprog->aux->ksym.name, KSYM_NAME_LEN);
perf_event_ksymbol(
PERF_RECORD_KSYMBOL_TYPE_BPF,
(u64)(unsigned long)subprog->bpf_func,
--
2.24.1
next prev parent reply other threads:[~2020-02-08 15:42 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-08 15:41 [PATCH 00/14] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-02-08 15:41 ` [PATCH 01/14] x86/mm: Rename is_kernel_text to __is_kernel_text Jiri Olsa
2020-02-08 15:41 ` [PATCH 02/14] bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER Jiri Olsa
2020-02-08 15:41 ` [PATCH 03/14] bpf: Add struct bpf_ksym Jiri Olsa
2020-02-08 15:41 ` Jiri Olsa [this message]
2020-02-08 15:42 ` [PATCH 05/14] bpf: Add lnode list node to " Jiri Olsa
2020-02-08 15:42 ` [PATCH 06/14] bpf: Add bpf_kallsyms_tree tree Jiri Olsa
2020-02-11 18:21 ` Andrii Nakryiko
2020-02-12 10:49 ` Jiri Olsa
2020-02-08 15:42 ` [PATCH 07/14] bpf: Move bpf_tree add/del from bpf_prog_ksym_node_add/del Jiri Olsa
2020-02-08 15:42 ` [PATCH 08/14] bpf: Separate kallsyms add/del functions Jiri Olsa
2020-02-08 15:42 ` [PATCH 09/14] bpf: Add bpf_ksym_add/del functions Jiri Olsa
2020-02-08 15:42 ` [PATCH 10/14] bpf: Re-initialize lnode in bpf_ksym_del Jiri Olsa
2020-02-11 18:28 ` Andrii Nakryiko
2020-02-12 10:43 ` Jiri Olsa
2020-02-08 15:42 ` [PATCH 11/14] bpf: Rename bpf_tree to bpf_progs_tree Jiri Olsa
2020-02-08 15:42 ` [PATCH 12/14] bpf: Add trampolines to kallsyms Jiri Olsa
2020-02-11 18:51 ` Andrii Nakryiko
2020-02-12 11:10 ` Jiri Olsa
2020-02-12 16:33 ` Andrii Nakryiko
2020-02-12 22:58 ` Jiri Olsa
2020-02-12 23:02 ` Jiri Olsa
2020-02-08 15:42 ` [PATCH 13/14] bpf: Add dispatchers " Jiri Olsa
2020-02-11 19:03 ` Andrii Nakryiko
2020-02-12 10:52 ` Jiri Olsa
2020-02-08 15:42 ` [PATCH 14/14] bpf: Sort bpf kallsyms symbols Jiri Olsa
2020-02-11 19:12 ` Andrii Nakryiko
2020-02-10 15:51 ` [PATCH 00/14] bpf: Add trampoline and dispatcher to /proc/kallsyms Björn Töpel
2020-02-10 16:17 ` Jiri Olsa
2020-02-11 19:32 ` Arnaldo Carvalho de Melo
2020-02-12 11:13 ` Jiri Olsa
2020-02-12 13:31 ` Arnaldo Carvalho de Melo
2020-02-12 22:40 ` Jiri Olsa
2020-02-13 16:23 ` Jiri Olsa
2020-02-11 19:13 ` Arnaldo Carvalho de Melo
2020-02-12 10:46 ` Jiri Olsa
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