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 03/15] bpf: Add struct bpf_ksym
Date: Thu, 12 Mar 2020 20:55:58 +0100 [thread overview]
Message-ID: <20200312195610.346362-4-jolsa@kernel.org> (raw)
In-Reply-To: <20200312195610.346362-1-jolsa@kernel.org>
Adding 'struct bpf_ksym' object that will carry the
kallsym information for bpf symbol. Adding the start
and end address to begin with. It will be used by
bpf_prog, bpf_trampoline, bpf_dispatcher objects.
The symbol_start/symbol_end values were originally used
to sort bpf_prog objects. For the address displayed in
/proc/kallsyms we are using prog->bpf_func value.
I'm using the bpf_func value for program symbol start
instead of the symbol_start, because it makes no difference
for sorting bpf_prog objects and we can use it directly as
an address to display it in /proc/kallsyms.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/bpf.h | 6 ++++++
kernel/bpf/core.c | 28 ++++++++++++----------------
2 files changed, 18 insertions(+), 16 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 47cdb98e0e0a..f5fa4c847451 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -471,6 +471,11 @@ int arch_prepare_bpf_trampoline(void *image, void *image_end,
u64 notrace __bpf_prog_enter(void);
void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start);
+struct bpf_ksym {
+ unsigned long start;
+ unsigned long end;
+};
+
enum bpf_tramp_prog_type {
BPF_TRAMP_FENTRY,
BPF_TRAMP_FEXIT,
@@ -653,6 +658,7 @@ struct bpf_prog_aux {
u32 size_poke_tab;
struct latch_tree_node ksym_tnode;
struct list_head ksym_lnode;
+ struct bpf_ksym ksym;
const struct bpf_prog_ops *ops;
struct bpf_map **used_maps;
struct bpf_prog *prog;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 973a20d49749..e2dd2d87c987 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -523,18 +523,16 @@ int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
int bpf_jit_harden __read_mostly;
long bpf_jit_limit __read_mostly;
-static __always_inline void
-bpf_get_prog_addr_region(const struct bpf_prog *prog,
- unsigned long *symbol_start,
- unsigned long *symbol_end)
+static void
+bpf_prog_ksym_set_addr(struct bpf_prog *prog)
{
const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
unsigned long addr = (unsigned long)hdr;
WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
- *symbol_start = addr;
- *symbol_end = addr + hdr->pages * PAGE_SIZE;
+ prog->aux->ksym.start = (unsigned long) prog->bpf_func;
+ prog->aux->ksym.end = addr + hdr->pages * PAGE_SIZE;
}
void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
@@ -575,13 +573,10 @@ void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
static __always_inline unsigned long
bpf_get_prog_addr_start(struct latch_tree_node *n)
{
- unsigned long symbol_start, symbol_end;
const struct bpf_prog_aux *aux;
aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
- bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
-
- return symbol_start;
+ return aux->ksym.start;
}
static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
@@ -593,15 +588,13 @@ static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
{
unsigned long val = (unsigned long)key;
- unsigned long symbol_start, symbol_end;
const struct bpf_prog_aux *aux;
aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
- bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
- if (val < symbol_start)
+ if (val < aux->ksym.start)
return -1;
- if (val >= symbol_end)
+ if (val >= aux->ksym.end)
return 1;
return 0;
@@ -649,6 +642,8 @@ void bpf_prog_kallsyms_add(struct bpf_prog *fp)
!capable(CAP_SYS_ADMIN))
return;
+ bpf_prog_ksym_set_addr(fp);
+
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_add(fp->aux);
spin_unlock_bh(&bpf_lock);
@@ -677,14 +672,15 @@ static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
unsigned long *off, char *sym)
{
- unsigned long symbol_start, symbol_end;
struct bpf_prog *prog;
char *ret = NULL;
rcu_read_lock();
prog = bpf_prog_kallsyms_find(addr);
if (prog) {
- bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end);
+ unsigned long symbol_start = prog->aux->ksym.start;
+ unsigned long symbol_end = prog->aux->ksym.end;
+
bpf_get_prog_name(prog, sym);
ret = sym;
--
2.24.1
next prev parent reply other threads:[~2020-03-12 19:56 UTC|newest]
Thread overview: 22+ 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 ` Jiri Olsa [this message]
2020-03-12 19:55 ` [PATCH 04/15] bpf: Add name to struct bpf_ksym 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 ` [PATCH 10/15] bpf: Add trampolines to kallsyms Jiri Olsa
2020-03-12 19:56 ` [PATCH 11/15] bpf: Add dispatchers " 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
-- strict thread matches above, loose matches on Subject: below --
2020-03-02 14:31 [PATCHv4 " Jiri Olsa
2020-03-02 14:31 ` [PATCH 03/15] bpf: Add struct bpf_ksym Jiri Olsa
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