* [PATCH iproute2 -master 2/3] tc, bpf: further improve error reporting
2016-04-08 22:32 [PATCH iproute2 -master 0/3] Minor tc/bpf updates Daniel Borkmann
2016-04-08 22:32 ` [PATCH iproute2 -master 1/3] tc, bpf: add new csum and tunnel signatures Daniel Borkmann
@ 2016-04-08 22:32 ` Daniel Borkmann
2016-04-08 22:32 ` [PATCH iproute2 -master 3/3] tc, bpf: add support for map pre/allocation Daniel Borkmann
2016-04-11 21:55 ` [PATCH iproute2 -master 0/3] Minor tc/bpf updates Stephen Hemminger
3 siblings, 0 replies; 5+ messages in thread
From: Daniel Borkmann @ 2016-04-08 22:32 UTC (permalink / raw)
To: stephen; +Cc: netdev, alexei.starovoitov, Daniel Borkmann
Make it easier to spot issues when loading the object file fails. This
includes reporting in what pinned object specs differ, better indication
when we've reached instruction limits. Don't retry to load a non relo
program once we failed with bpf(2), and report out of bounds tail call key.
Also, add truncation of huge log outputs by default. Sometimes errors are
quite easy to spot by only looking at the tail of the verifier log, but
logs can get huge in size e.g. up to few MB (due to verifier checking all
possible program paths). Thus, by default limit output to the last 4096
bytes and indicate that it's truncated. For the full log, the verbose option
can be used.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
tc/tc_bpf.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++-------------
tc/tc_bpf.h | 4 +++
2 files changed, 69 insertions(+), 17 deletions(-)
diff --git a/tc/tc_bpf.c b/tc/tc_bpf.c
index d94af82..0c59427 100644
--- a/tc/tc_bpf.c
+++ b/tc/tc_bpf.c
@@ -184,7 +184,7 @@ static int bpf_ops_parse(int argc, char **argv, struct sock_filter *bpf_ops,
}
if (i != bpf_len) {
- fprintf(stderr, "Parsed program length is less than encodedlength parameter!\n");
+ fprintf(stderr, "Parsed program length is less than encoded length parameter!\n");
ret = -EINVAL;
goto out;
}
@@ -214,6 +214,27 @@ void bpf_print_ops(FILE *f, struct rtattr *bpf_ops, __u16 len)
ops[i].jf, ops[i].k);
}
+static void bpf_map_pin_report(const struct bpf_elf_map *pin,
+ const struct bpf_elf_map *obj)
+{
+ fprintf(stderr, "Map specification differs from pinned file!\n");
+
+ if (obj->type != pin->type)
+ fprintf(stderr, " - Type: %u (obj) != %u (pin)\n",
+ obj->type, pin->type);
+ if (obj->size_key != pin->size_key)
+ fprintf(stderr, " - Size key: %u (obj) != %u (pin)\n",
+ obj->size_key, pin->size_key);
+ if (obj->size_value != pin->size_value)
+ fprintf(stderr, " - Size value: %u (obj) != %u (pin)\n",
+ obj->size_value, pin->size_value);
+ if (obj->max_elem != pin->max_elem)
+ fprintf(stderr, " - Max elems: %u (obj) != %u (pin)\n",
+ obj->max_elem, pin->max_elem);
+
+ fprintf(stderr, "\n");
+}
+
static int bpf_map_selfcheck_pinned(int fd, const struct bpf_elf_map *map,
int length)
{
@@ -256,7 +277,7 @@ static int bpf_map_selfcheck_pinned(int fd, const struct bpf_elf_map *map,
if (!memcmp(&tmp, &zero, length))
return 0;
- fprintf(stderr, "Map specs from pinned file differ!\n");
+ bpf_map_pin_report(&tmp, map);
return -EINVAL;
}
}
@@ -735,7 +756,19 @@ bpf_dump_error(struct bpf_elf_ctx *ctx, const char *format, ...)
va_end(vl);
if (ctx->log && ctx->log[0]) {
- fprintf(stderr, "%s\n", ctx->log);
+ if (ctx->verbose) {
+ fprintf(stderr, "%s\n", ctx->log);
+ } else {
+ unsigned int off = 0, len = strlen(ctx->log);
+
+ if (len > BPF_MAX_LOG) {
+ off = len - BPF_MAX_LOG;
+ fprintf(stderr, "Skipped %u bytes, use \'verb\' option for the full verbose log.\n[...]\n",
+ off);
+ }
+ fprintf(stderr, "%s\n", ctx->log + off);
+ }
+
memset(ctx->log, 0, ctx->log_size);
}
}
@@ -1055,14 +1088,16 @@ static void bpf_prog_report(int fd, const char *section,
const struct bpf_elf_prog *prog,
struct bpf_elf_ctx *ctx)
{
- fprintf(stderr, "Prog section \'%s\' %s%s (%d)!\n", section,
+ unsigned int insns = prog->size / sizeof(struct bpf_insn);
+
+ fprintf(stderr, "\nProg section \'%s\' %s%s (%d)!\n", section,
fd < 0 ? "rejected: " : "loaded",
fd < 0 ? strerror(errno) : "",
fd < 0 ? errno : fd);
fprintf(stderr, " - Type: %u\n", prog->type);
- fprintf(stderr, " - Instructions: %zu\n",
- prog->size / sizeof(struct bpf_insn));
+ fprintf(stderr, " - Instructions: %u (%u over limit)\n",
+ insns, insns > BPF_MAXINSNS ? insns - BPF_MAXINSNS : 0);
fprintf(stderr, " - License: %s\n\n", prog->license);
bpf_dump_error(ctx, "Verifier analysis:\n\n");
@@ -1283,6 +1318,11 @@ static int bpf_fetch_strtab(struct bpf_elf_ctx *ctx, int section,
return 0;
}
+static bool bpf_has_map_data(const struct bpf_elf_ctx *ctx)
+{
+ return ctx->sym_tab && ctx->str_tab && ctx->sec_maps;
+}
+
static int bpf_fetch_ancillary(struct bpf_elf_ctx *ctx)
{
struct bpf_elf_sec_data data;
@@ -1306,13 +1346,13 @@ static int bpf_fetch_ancillary(struct bpf_elf_ctx *ctx)
!strcmp(data.sec_name, ".strtab"))
ret = bpf_fetch_strtab(ctx, i, &data);
if (ret < 0) {
- fprintf(stderr, "Error parsing section %d! Perhapscheck with readelf -a?\n",
+ fprintf(stderr, "Error parsing section %d! Perhaps check with readelf -a?\n",
i);
break;
}
}
- if (ctx->sym_tab && ctx->str_tab && ctx->sec_maps) {
+ if (bpf_has_map_data(ctx)) {
ret = bpf_maps_attach_all(ctx);
if (ret < 0) {
fprintf(stderr, "Error loading maps into kernel!\n");
@@ -1348,7 +1388,7 @@ static int bpf_fetch_prog(struct bpf_elf_ctx *ctx, const char *section)
fd = bpf_prog_attach(section, &prog, ctx);
if (fd < 0)
- continue;
+ break;
ctx->sec_done[i] = true;
break;
@@ -1412,7 +1452,8 @@ static int bpf_apply_relo_data(struct bpf_elf_ctx *ctx,
return 0;
}
-static int bpf_fetch_prog_relo(struct bpf_elf_ctx *ctx, const char *section)
+static int bpf_fetch_prog_relo(struct bpf_elf_ctx *ctx, const char *section,
+ bool *lderr)
{
struct bpf_elf_sec_data data_relo, data_insn;
struct bpf_elf_prog prog;
@@ -1442,8 +1483,10 @@ static int bpf_fetch_prog_relo(struct bpf_elf_ctx *ctx, const char *section)
prog.license = ctx->license;
fd = bpf_prog_attach(section, &prog, ctx);
- if (fd < 0)
- continue;
+ if (fd < 0) {
+ *lderr = true;
+ break;
+ }
ctx->sec_done[i] = true;
ctx->sec_done[idx] = true;
@@ -1455,11 +1498,12 @@ static int bpf_fetch_prog_relo(struct bpf_elf_ctx *ctx, const char *section)
static int bpf_fetch_prog_sec(struct bpf_elf_ctx *ctx, const char *section)
{
+ bool lderr = false;
int ret = -1;
- if (ctx->sym_tab)
- ret = bpf_fetch_prog_relo(ctx, section);
- if (ret < 0)
+ if (bpf_has_map_data(ctx))
+ ret = bpf_fetch_prog_relo(ctx, section, &lderr);
+ if (ret < 0 && !lderr)
ret = bpf_fetch_prog(ctx, section);
return ret;
@@ -1504,8 +1548,12 @@ static int bpf_fill_prog_arrays(struct bpf_elf_ctx *ctx)
ret = bpf_map_update(ctx->map_fds[idx], &key_id,
&fd, BPF_ANY);
- if (ret < 0)
- return -ENOENT;
+ if (ret < 0) {
+ if (errno == E2BIG)
+ fprintf(stderr, "Tail call key %u for map %u out of bounds?\n",
+ key_id, map_id);
+ return -errno;
+ }
ctx->sec_done[i] = true;
}
diff --git a/tc/tc_bpf.h b/tc/tc_bpf.h
index 93f7f0e..30306de 100644
--- a/tc/tc_bpf.h
+++ b/tc/tc_bpf.h
@@ -33,6 +33,10 @@ enum {
#define BPF_ENV_UDS "TC_BPF_UDS"
#define BPF_ENV_MNT "TC_BPF_MNT"
+#ifndef BPF_MAX_LOG
+# define BPF_MAX_LOG 4096
+#endif
+
#ifndef BPF_FS_MAGIC
# define BPF_FS_MAGIC 0xcafe4a11
#endif
--
1.9.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH iproute2 -master 3/3] tc, bpf: add support for map pre/allocation
2016-04-08 22:32 [PATCH iproute2 -master 0/3] Minor tc/bpf updates Daniel Borkmann
2016-04-08 22:32 ` [PATCH iproute2 -master 1/3] tc, bpf: add new csum and tunnel signatures Daniel Borkmann
2016-04-08 22:32 ` [PATCH iproute2 -master 2/3] tc, bpf: further improve error reporting Daniel Borkmann
@ 2016-04-08 22:32 ` Daniel Borkmann
2016-04-11 21:55 ` [PATCH iproute2 -master 0/3] Minor tc/bpf updates Stephen Hemminger
3 siblings, 0 replies; 5+ messages in thread
From: Daniel Borkmann @ 2016-04-08 22:32 UTC (permalink / raw)
To: stephen; +Cc: netdev, alexei.starovoitov, Daniel Borkmann
Follow-up to kernel commit 6c9059817432 ("bpf: pre-allocate hash map
elements"). Add flags support, so that we can pass in BPF_F_NO_PREALLOC
flag for disallowing preallocation. Update examples accordingly and also
remove the BPF_* map helper macros from them as they were not very useful.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
examples/bpf/bpf_cyclic.c | 9 ++++++++-
examples/bpf/bpf_graft.c | 8 +++++++-
examples/bpf/bpf_prog.c | 2 ++
examples/bpf/bpf_shared.c | 8 +++++++-
examples/bpf/bpf_tailcall.c | 29 +++++++++++++++++++++++++----
include/bpf_api.h | 45 ---------------------------------------------
include/bpf_elf.h | 1 +
tc/tc_bpf.c | 16 ++++++++++++----
8 files changed, 62 insertions(+), 56 deletions(-)
diff --git a/examples/bpf/bpf_cyclic.c b/examples/bpf/bpf_cyclic.c
index 36745a3..11d1c06 100644
--- a/examples/bpf/bpf_cyclic.c
+++ b/examples/bpf/bpf_cyclic.c
@@ -6,7 +6,14 @@
*/
#define JMP_MAP_ID 0xabccba
-BPF_PROG_ARRAY(jmp_tc, JMP_MAP_ID, PIN_OBJECT_NS, 1);
+struct bpf_elf_map __section_maps jmp_tc = {
+ .type = BPF_MAP_TYPE_PROG_ARRAY,
+ .id = JMP_MAP_ID,
+ .size_key = sizeof(uint32_t),
+ .size_value = sizeof(uint32_t),
+ .pinning = PIN_OBJECT_NS,
+ .max_elem = 1,
+};
__section_tail(JMP_MAP_ID, 0)
int cls_loop(struct __sk_buff *skb)
diff --git a/examples/bpf/bpf_graft.c b/examples/bpf/bpf_graft.c
index 20784ff..07113d4 100644
--- a/examples/bpf/bpf_graft.c
+++ b/examples/bpf/bpf_graft.c
@@ -33,7 +33,13 @@
* [...]
*/
-BPF_PROG_ARRAY(jmp_tc, 0, PIN_GLOBAL_NS, 1);
+struct bpf_elf_map __section_maps jmp_tc = {
+ .type = BPF_MAP_TYPE_PROG_ARRAY,
+ .size_key = sizeof(uint32_t),
+ .size_value = sizeof(uint32_t),
+ .pinning = PIN_GLOBAL_NS,
+ .max_elem = 1,
+};
__section("aaa")
int cls_aaa(struct __sk_buff *skb)
diff --git a/examples/bpf/bpf_prog.c b/examples/bpf/bpf_prog.c
index f15e876..d6caf37 100644
--- a/examples/bpf/bpf_prog.c
+++ b/examples/bpf/bpf_prog.c
@@ -192,6 +192,7 @@ struct bpf_elf_map __section("maps") map_proto = {
.size_key = sizeof(uint8_t),
.size_value = sizeof(struct count_tuple),
.max_elem = 256,
+ .flags = BPF_F_NO_PREALLOC,
};
struct bpf_elf_map __section("maps") map_queue = {
@@ -200,6 +201,7 @@ struct bpf_elf_map __section("maps") map_queue = {
.size_key = sizeof(uint32_t),
.size_value = sizeof(struct count_queue),
.max_elem = 1024,
+ .flags = BPF_F_NO_PREALLOC,
};
struct bpf_elf_map __section("maps") map_drops = {
diff --git a/examples/bpf/bpf_shared.c b/examples/bpf/bpf_shared.c
index 7fe9ef3..21fe6f1 100644
--- a/examples/bpf/bpf_shared.c
+++ b/examples/bpf/bpf_shared.c
@@ -18,7 +18,13 @@
* instance is being created.
*/
-BPF_ARRAY4(map_sh, 0, PIN_OBJECT_NS, 1); /* or PIN_GLOBAL_NS, or PIN_NONE */
+struct bpf_elf_map __section_maps map_sh = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .size_key = sizeof(uint32_t),
+ .size_value = sizeof(uint32_t),
+ .pinning = PIN_OBJECT_NS, /* or PIN_GLOBAL_NS, or PIN_NONE */
+ .max_elem = 1,
+};
__section("egress")
int emain(struct __sk_buff *skb)
diff --git a/examples/bpf/bpf_tailcall.c b/examples/bpf/bpf_tailcall.c
index f545430..1a30426 100644
--- a/examples/bpf/bpf_tailcall.c
+++ b/examples/bpf/bpf_tailcall.c
@@ -26,10 +26,31 @@
* classifier behaviour.
*/
-BPF_PROG_ARRAY(jmp_tc, FOO, PIN_OBJECT_NS, MAX_JMP_SIZE);
-BPF_PROG_ARRAY(jmp_ex, BAR, PIN_OBJECT_NS, 1);
-
-BPF_ARRAY4(map_sh, 0, PIN_OBJECT_NS, 1);
+struct bpf_elf_map __section_maps jmp_tc = {
+ .type = BPF_MAP_TYPE_PROG_ARRAY,
+ .id = FOO,
+ .size_key = sizeof(uint32_t),
+ .size_value = sizeof(uint32_t),
+ .pinning = PIN_OBJECT_NS,
+ .max_elem = MAX_JMP_SIZE,
+};
+
+struct bpf_elf_map __section_maps jmp_ex = {
+ .type = BPF_MAP_TYPE_PROG_ARRAY,
+ .id = BAR,
+ .size_key = sizeof(uint32_t),
+ .size_value = sizeof(uint32_t),
+ .pinning = PIN_OBJECT_NS,
+ .max_elem = 1,
+};
+
+struct bpf_elf_map __section_maps map_sh = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .size_key = sizeof(uint32_t),
+ .size_value = sizeof(uint32_t),
+ .pinning = PIN_OBJECT_NS,
+ .max_elem = 1,
+};
__section_tail(FOO, ENTRY_0)
int cls_case1(struct __sk_buff *skb)
diff --git a/include/bpf_api.h b/include/bpf_api.h
index 0f278f0..1b250d2 100644
--- a/include/bpf_api.h
+++ b/include/bpf_api.h
@@ -99,51 +99,6 @@
char ____license[] __section_license = NAME
#endif
-#ifndef __BPF_MAP
-# define __BPF_MAP(NAME, TYPE, ID, SIZE_KEY, SIZE_VALUE, PIN, MAX_ELEM) \
- struct bpf_elf_map __section_maps NAME = { \
- .type = (TYPE), \
- .id = (ID), \
- .size_key = (SIZE_KEY), \
- .size_value = (SIZE_VALUE), \
- .pinning = (PIN), \
- .max_elem = (MAX_ELEM), \
- }
-#endif
-
-#ifndef BPF_HASH
-# define BPF_HASH(NAME, ID, SIZE_KEY, SIZE_VALUE, PIN, MAX_ELEM) \
- __BPF_MAP(NAME, BPF_MAP_TYPE_HASH, ID, SIZE_KEY, SIZE_VALUE, \
- PIN, MAX_ELEM)
-#endif
-
-#ifndef BPF_ARRAY
-# define BPF_ARRAY(NAME, ID, SIZE_VALUE, PIN, MAX_ELEM) \
- __BPF_MAP(NAME, BPF_MAP_TYPE_ARRAY, ID, sizeof(uint32_t), \
- SIZE_VALUE, PIN, MAX_ELEM)
-#endif
-
-#ifndef BPF_ARRAY2
-# define BPF_ARRAY2(NAME, ID, PIN, MAX_ELEM) \
- BPF_ARRAY(NAME, ID, sizeof(uint16_t), PIN, MAX_ELEM)
-#endif
-
-#ifndef BPF_ARRAY4
-# define BPF_ARRAY4(NAME, ID, PIN, MAX_ELEM) \
- BPF_ARRAY(NAME, ID, sizeof(uint32_t), PIN, MAX_ELEM)
-#endif
-
-#ifndef BPF_ARRAY8
-# define BPF_ARRAY8(NAME, ID, PIN, MAX_ELEM) \
- BPF_ARRAY(NAME, ID, sizeof(uint64_t), PIN, MAX_ELEM)
-#endif
-
-#ifndef BPF_PROG_ARRAY
-# define BPF_PROG_ARRAY(NAME, ID, PIN, MAX_ELEM) \
- __BPF_MAP(NAME, BPF_MAP_TYPE_PROG_ARRAY, ID, sizeof(uint32_t), \
- sizeof(uint32_t), PIN, MAX_ELEM)
-#endif
-
/** Classifier helper */
#ifndef BPF_H_DEFAULT
diff --git a/include/bpf_elf.h b/include/bpf_elf.h
index 31a8974..36cc988 100644
--- a/include/bpf_elf.h
+++ b/include/bpf_elf.h
@@ -32,6 +32,7 @@ struct bpf_elf_map {
__u32 size_key;
__u32 size_value;
__u32 max_elem;
+ __u32 flags;
__u32 id;
__u32 pinning;
};
diff --git a/tc/tc_bpf.c b/tc/tc_bpf.c
index 0c59427..fe927ac 100644
--- a/tc/tc_bpf.c
+++ b/tc/tc_bpf.c
@@ -231,6 +231,9 @@ static void bpf_map_pin_report(const struct bpf_elf_map *pin,
if (obj->max_elem != pin->max_elem)
fprintf(stderr, " - Max elems: %u (obj) != %u (pin)\n",
obj->max_elem, pin->max_elem);
+ if (obj->flags != pin->flags)
+ fprintf(stderr, " - Flags: %#x (obj) != %#x (pin)\n",
+ obj->flags, pin->flags);
fprintf(stderr, "\n");
}
@@ -261,6 +264,8 @@ static int bpf_map_selfcheck_pinned(int fd, const struct bpf_elf_map *map,
tmp.size_value = val;
else if (sscanf(buff, "max_entries:\t%u", &val) == 1)
tmp.max_elem = val;
+ else if (sscanf(buff, "map_flags:\t%i", &val) == 1)
+ tmp.flags = val;
}
fclose(fp);
@@ -796,8 +801,9 @@ static int bpf_log_realloc(struct bpf_elf_ctx *ctx)
return 0;
}
-static int bpf_map_create(enum bpf_map_type type, unsigned int size_key,
- unsigned int size_value, unsigned int max_elem)
+static int bpf_map_create(enum bpf_map_type type, uint32_t size_key,
+ uint32_t size_value, uint32_t max_elem,
+ uint32_t flags)
{
union bpf_attr attr;
@@ -806,6 +812,7 @@ static int bpf_map_create(enum bpf_map_type type, unsigned int size_key,
attr.key_size = size_key;
attr.value_size = size_value;
attr.max_entries = max_elem;
+ attr.map_flags = flags;
return bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}
@@ -1147,7 +1154,8 @@ static void bpf_map_report(int fd, const char *name,
fprintf(stderr, " - Pinning: %u\n", map->pinning);
fprintf(stderr, " - Size key: %u\n", map->size_key);
fprintf(stderr, " - Size value: %u\n", map->size_value);
- fprintf(stderr, " - Max elems: %u\n\n", map->max_elem);
+ fprintf(stderr, " - Max elems: %u\n", map->max_elem);
+ fprintf(stderr, " - Flags: %#x\n\n", map->flags);
}
static int bpf_map_attach(const char *name, const struct bpf_elf_map *map,
@@ -1174,7 +1182,7 @@ static int bpf_map_attach(const char *name, const struct bpf_elf_map *map,
errno = 0;
fd = bpf_map_create(map->type, map->size_key, map->size_value,
- map->max_elem);
+ map->max_elem, map->flags);
if (fd < 0 || ctx->verbose) {
bpf_map_report(fd, name, map, ctx);
if (fd < 0)
--
1.9.3
^ permalink raw reply related [flat|nested] 5+ messages in thread