From: Alexei Starovoitov <ast@kernel•org>
To: "David S . Miller" <davem@davemloft•net>
Cc: <daniel@iogearbox•net>, <peterz@infradead•org>, <acme@kernel•org>,
<netdev@vger•kernel.org>, <kernel-team@fb•com>
Subject: [PATCH bpf-next 2/3] bpf: emit RECORD_MMAP events for bpf prog load/unload
Date: Wed, 19 Sep 2018 15:39:34 -0700 [thread overview]
Message-ID: <20180919223935.999270-3-ast@kernel.org> (raw)
In-Reply-To: <20180919223935.999270-1-ast@kernel.org>
use perf_event_mmap_bpf_prog() helper to notify user space
about JITed bpf programs.
Use RECORD_MMAP perf event to tell user space where JITed bpf program was loaded.
Use empty program name as unload indication.
Signed-off-by: Alexei Starovoitov <ast@kernel•org>
---
kernel/bpf/core.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 3f5bf1af0826..ddf11fdafd36 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -384,7 +384,7 @@ bpf_get_prog_addr_region(const struct bpf_prog *prog,
*symbol_end = addr + hdr->pages * PAGE_SIZE;
}
-static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
+static char *bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
{
const char *end = sym + KSYM_NAME_LEN;
@@ -402,9 +402,10 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
if (prog->aux->name[0])
- snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
+ sym += snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
else
*sym = 0;
+ return sym;
}
static __always_inline unsigned long
@@ -480,23 +481,40 @@ static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
void bpf_prog_kallsyms_add(struct bpf_prog *fp)
{
+ unsigned long symbol_start, symbol_end;
+ char buf[KSYM_NAME_LEN], *sym;
+
if (!bpf_prog_kallsyms_candidate(fp) ||
!capable(CAP_SYS_ADMIN))
return;
+ bpf_get_prog_addr_region(fp, &symbol_start, &symbol_end);
+ sym = bpf_get_prog_name(fp, buf);
+ sym++; /* sym - buf is the length of the name including trailing 0 */
+ while (!IS_ALIGNED(sym - buf, sizeof(u64)))
+ *sym++ = 0;
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_add(fp->aux);
spin_unlock_bh(&bpf_lock);
+ perf_event_mmap_bpf_prog(symbol_start, symbol_end - symbol_start,
+ buf, sym - buf);
}
void bpf_prog_kallsyms_del(struct bpf_prog *fp)
{
+ unsigned long symbol_start, symbol_end;
+ /* mmap_record.filename cannot be NULL and has to be u64 aligned */
+ char buf[sizeof(u64)] = {};
+
if (!bpf_prog_kallsyms_candidate(fp))
return;
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_del(fp->aux);
spin_unlock_bh(&bpf_lock);
+ bpf_get_prog_addr_region(fp, &symbol_start, &symbol_end);
+ perf_event_mmap_bpf_prog(symbol_start, symbol_end - symbol_start,
+ buf, sizeof(buf));
}
static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
--
2.17.1
next prev parent reply other threads:[~2018-09-20 4:19 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-19 22:39 [PATCH bpf-next 0/3] perf, bpf: reveal invisible bpf programs Alexei Starovoitov
2018-09-19 22:39 ` [PATCH bpf-next 1/3] perf/core: introduce perf_event_mmap_bpf_prog Alexei Starovoitov
2018-09-19 23:30 ` Song Liu
2018-09-20 0:53 ` Alexei Starovoitov
2018-09-19 22:39 ` Alexei Starovoitov [this message]
2018-09-19 23:44 ` [PATCH bpf-next 2/3] bpf: emit RECORD_MMAP events for bpf prog load/unload Song Liu
2018-09-20 0:59 ` Alexei Starovoitov
2018-09-20 5:48 ` Song Liu
2018-09-20 8:44 ` Peter Zijlstra
2018-09-20 13:25 ` Arnaldo Carvalho de Melo
2018-09-20 13:56 ` Peter Zijlstra
2018-09-21 3:14 ` Alexei Starovoitov
2018-09-21 12:25 ` Arnaldo Carvalho de Melo
2018-09-21 13:55 ` Peter Zijlstra
2018-09-21 13:59 ` Peter Zijlstra
2018-09-21 22:13 ` Alexei Starovoitov
2018-10-15 23:33 ` Song Liu
2018-10-16 23:43 ` David Ahern
2018-10-17 6:43 ` Song Liu
2018-10-17 12:11 ` Arnaldo Carvalho de Melo
2018-10-17 12:50 ` Arnaldo Carvalho de Melo
2018-10-17 16:06 ` Song Liu
2018-11-02 1:08 ` Song Liu
2018-10-17 15:09 ` David Ahern
2018-10-17 16:18 ` Song Liu
2018-10-17 16:36 ` Alexei Starovoitov
2018-10-17 18:53 ` Arnaldo Carvalho de Melo
2018-10-17 19:08 ` Alexei Starovoitov
2018-10-17 21:31 ` Arnaldo Carvalho de Melo
2018-10-17 22:01 ` Alexei Starovoitov
2018-09-20 13:36 ` Peter Zijlstra
2018-09-19 22:39 ` [PATCH perf 3/3] tools/perf: recognize and process RECORD_MMAP events for bpf progs Alexei Starovoitov
2018-09-20 13:36 ` Arnaldo Carvalho de Melo
2018-09-20 14:05 ` Arnaldo Carvalho de Melo
2018-09-21 22:57 ` Song Liu
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