diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 5318dcb2085e5c969a6fb5d0a7dcd748108a8539..3221be1b9cccd18319b8586e87554bd57f2d46dc 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -170,6 +170,61 @@ The following three commands are equivalent:
| **# bpftool map pin id 10 /sys/fs/bpf/map**
| **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00**
+Note that map update can also be used in order to change the program references
+hold by a program array map. This can be used, for example, to change the
+programs used for tail-call jumps at runtime, without having to reload the
+entry-point program. Below is an example for this use case: we load a program
+defining a prog array map, and with a main function that contains a tail call
+to other programs that can be used either to "process" packets or to "debug"
+processing. Note that the prog array map MUST be pinned into the BPF virtual
+file system for the map update to work successfully, as kernel flushes prog
+array maps when they have no more references from user space (and the update
+would be lost as soon as bpftool exits).
+
+|
+| **# bpftool prog loadall tail_calls.o /sys/fs/bpf/foo type xdp**
+| **# bpftool prog --bpffs**
+
+::
+
+ 545: xdp name main_func tag 674b4b5597193dc3 gpl
+ loaded_at 2018-12-12T15:02:58+0000 uid 0
+ xlated 240B jited 257B memlock 4096B map_ids 294
+ pinned /sys/fs/bpf/foo/xdp
+ 546: xdp name bpf_func_process tag e369a529024751fc gpl
+ loaded_at 2018-12-12T15:02:58+0000 uid 0
+ xlated 200B jited 164B memlock 4096B
+ pinned /sys/fs/bpf/foo/process
+ 547: xdp name bpf_func_debug tag 0b597868bc7f0976 gpl
+ loaded_at 2018-12-12T15:02:58+0000 uid 0
+ xlated 200B jited 164B memlock 4096B
+ pinned /sys/fs/bpf/foo/debug
+
+**# bpftool map**
+
+::
+
+ 294: prog_array name jmp_table flags 0x0
+ key 4B value 4B max_entries 1 memlock 4096B
+ owner_prog_type xdp owner jited
+
+|
+| **# bpftool map pin id 294 /sys/fs/bpf/bar**
+| **# bpftool map dump pinned /sys/fs/bpf/bar**
+
+::
+
+ Found 0 elements
+
+|
+| **# bpftool map update pinned /sys/fs/bpf/bar key 0 0 0 0 value pinned /sys/fs/bpf/foo/debug**
+| **# bpftool map dump pinned /sys/fs/bpf/bar**
+
+::
+
+ key: 00 00 00 00 value: 22 02 00 00
+ Found 1 element
+
SEE ALSO
========
**bpf**\ (2),
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index bb1aeb98b6dad6d4655fb8b4558d2794401b2e2e..53920ffc48dd444ae8093bf9ef05338d63d2c057 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -158,83 +158,94 @@ OPTIONS
When showing BPF programs, show file names of pinned
programs.
+ -m, --mapcompat
+ Allow loading maps with unknown map definitions.
+
EXAMPLES
========
**# bpftool prog show**
+
::
- 10: xdp name some_prog tag 005a3d2123620c8b gpl
- loaded_at Sep 29/20:11 uid 0
- xlated 528B jited 370B memlock 4096B map_ids 10
+ 10: xdp name some_prog tag 005a3d2123620c8b gpl
+ loaded_at 2017-09-29T20:11:00+0000 uid 0
+ xlated 528B jited 370B memlock 4096B map_ids 10
**# bpftool --json --pretty prog show**
::
- {
- "programs": [{
- "id": 10,
- "type": "xdp",
- "tag": "005a3d2123620c8b",
- "gpl_compatible": true,
- "loaded_at": "Sep 29/20:11",
- "uid": 0,
- "bytes_xlated": 528,
- "jited": true,
- "bytes_jited": 370,
- "bytes_memlock": 4096,
- "map_ids": [10
- ]
- }
- ]
- }
+ [{
+ "id": 10,
+ "type": "xdp",
+ "tag": "005a3d2123620c8b",
+ "gpl_compatible": true,
+ "loaded_at": 1506715860,
+ "uid": 0,
+ "bytes_xlated": 528,
+ "jited": true,
+ "bytes_jited": 370,
+ "bytes_memlock": 4096,
+ "map_ids": [10
+ ]
+ }
+ ]
|
| **# bpftool prog dump xlated id 10 file /tmp/t**
| **# ls -l /tmp/t**
-| -rw------- 1 root root 560 Jul 22 01:42 /tmp/t
-**# bpftool prog dum jited tag 005a3d2123620c8b**
+::
+
+ -rw------- 1 root root 560 Jul 22 01:42 /tmp/t
+
+**# bpftool prog dump jited tag 005a3d2123620c8b**
::
- push %rbp
- mov %rsp,%rbp
- sub $0x228,%rsp
- sub $0x28,%rbp
- mov %rbx,0x0(%rbp)
+ 0: push %rbp
+ 1: mov %rsp,%rbp
+ 2: sub $0x228,%rsp
+ 3: sub $0x28,%rbp
+ 4: mov %rbx,0x0(%rbp)
|
| **# mount -t bpf none /sys/fs/bpf/**
| **# bpftool prog pin id 10 /sys/fs/bpf/prog**
| **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2**
| **# ls -l /sys/fs/bpf/**
-| -rw------- 1 root root 0 Jul 22 01:43 prog
-| -rw------- 1 root root 0 Jul 22 01:44 prog2
-**# bpftool prog dum jited pinned /sys/fs/bpf/prog opcodes**
+::
+
+ -rw------- 1 root root 0 Jul 22 01:43 prog
+ -rw------- 1 root root 0 Jul 22 01:44 prog2
+
+**# bpftool prog dump jited pinned /sys/fs/bpf/prog opcodes**
::
- push %rbp
- 55
- mov %rsp,%rbp
- 48 89 e5
- sub $0x228,%rsp
- 48 81 ec 28 02 00 00
- sub $0x28,%rbp
- 48 83 ed 28
- mov %rbx,0x0(%rbp)
- 48 89 5d 00
+ 0: push %rbp
+ 55
+ 1: mov %rsp,%rbp
+ 48 89 e5
+ 4: sub $0x228,%rsp
+ 48 81 ec 28 02 00 00
+ b: sub $0x28,%rbp
+ 48 83 ed 28
+ f: mov %rbx,0x0(%rbp)
+ 48 89 5d 00
|
| **# bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7**
| **# bpftool prog show pinned /sys/fs/bpf/xdp1**
-| 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl
-| loaded_at 2018-06-25T16:17:31-0700 uid 0
-| xlated 488B jited 336B memlock 4096B map_ids 7
-| **# rm /sys/fs/bpf/xdp1**
-|
+
+::
+
+ 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl
+ loaded_at 2018-06-25T16:17:31-0700 uid 0
+ xlated 488B jited 336B memlock 4096B map_ids 7
+
+**# rm /sys/fs/bpf/xdp1**
SEE ALSO
========
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 99e4027dde75c2b8cb3164362f2e3f2bd7d2175f..24582e8a96fb8edbbcb1962e4141c0d45d37a7cd 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -28,7 +28,7 @@
#define BPF_FS_MAGIC 0xcafe4a11
#endif
-void p_err(const char *fmt, ...)
+void __printf(1, 2) p_err(const char *fmt, ...)
{
va_list ap;
@@ -46,7 +46,7 @@ void p_err(const char *fmt, ...)
va_end(ap);
}
-void p_info(const char *fmt, ...)
+void __printf(1, 2) p_info(const char *fmt, ...)
{
va_list ap;
diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c
index a07d17918725a7e17eae9c727fbdc8b1b9cb9b12..bff7ee026680481a1f5d33464cf4fad52f3c38cd 100644
--- a/tools/bpf/bpftool/json_writer.c
+++ b/tools/bpf/bpftool/json_writer.c
@@ -20,6 +20,7 @@
#include <malloc.h>
#include <inttypes.h>
#include <stdint.h>
+#include <linux/compiler.h>
#include "json_writer.h"
@@ -157,7 +158,8 @@ void jsonw_name(json_writer_t *self, const char *name)
putc(' ', self->out);
}
-void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap)
+void __printf(2, 0)
+jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap)
{
jsonw_eor(self);
putc('"', self->out);
@@ -165,7 +167,7 @@ void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap)
putc('"', self->out);
}
-void jsonw_printf(json_writer_t *self, const char *fmt, ...)
+void __printf(2, 3) jsonw_printf(json_writer_t *self, const char *fmt, ...)
{
va_list ap;
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index d2beb88f0e2eb4298ecb599d46bfe9ed7b4ec3c2..9487345b04a79c1b0677b3bae158530c669596dc 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -147,8 +147,8 @@ int prog_parse_fd(int *argc, char ***argv);
int map_parse_fd(int *argc, char ***argv);
int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len);
-#ifdef HAVE_LIBBFD_SUPPORT
struct bpf_prog_linfo;
+#ifdef HAVE_LIBBFD_SUPPORT
void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
const char *arch, const char *disassembler_options,
const struct btf *btf,
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index ee51279be9c7efb45d086c314864b4ab3857974c..2d1bb7d6ff5113c0014855b18e0adc4cd44472fa 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -32,7 +32,7 @@ static const char * const attach_type_strings[] = {
[__MAX_BPF_ATTACH_TYPE] = NULL,
};
-enum bpf_attach_type parse_attach_type(const char *str)
+static enum bpf_attach_type parse_attach_type(const char *str)
{
enum bpf_attach_type type;
@@ -798,7 +798,7 @@ struct map_replace {
char *name;
};
-int map_replace_compar(const void *p1, const void *p2)
+static int map_replace_compar(const void *p1, const void *p2)
{
const struct map_replace *a = p1, *b = p2;
diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c
index 640ffe86a655335b06343d34d7e5e0246aa50f4c..7073dbe1ff27eee87201ead853228d7be1b12028 100644
--- a/tools/bpf/bpftool/xlated_dumper.c
+++ b/tools/bpf/bpftool/xlated_dumper.c
@@ -81,7 +81,7 @@ struct kernel_sym *kernel_syms_search(struct dump_data *dd,
sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL;
}
-static void print_insn(void *private_data, const char *fmt, ...)
+static void __printf(2, 3) print_insn(void *private_data, const char *fmt, ...)
{
va_list args;
@@ -90,7 +90,7 @@ static void print_insn(void *private_data, const char *fmt, ...)
va_end(args);
}
-static void
+static void __printf(2, 3)
print_insn_for_graph(void *private_data, const char *fmt, ...)
{
char buf[64], *p;
@@ -121,7 +121,8 @@ print_insn_for_graph(void *private_data, const char *fmt, ...)
printf("%s", buf);
}
-static void print_insn_json(void *private_data, const char *fmt, ...)
+static void __printf(2, 3)
+print_insn_json(void *private_data, const char *fmt, ...)
{
unsigned int l = strlen(fmt);
char chomped_fmt[l];