Simplify BPF verifierl log furthre by omitting default (and frequently
irrelevant) off=0 and imm=0 parts for non-SCALAR_VALUE registers. As can
be seen from fixed tests, this is often a visual noise for PTR_TO_CTX
register and even for PTR_TO_PACKET registers.
Omitting default values follows the rest of register state logic: we
omit default values to keep verifier log succinct and to highlight
interesting state that deviates from default one. E.g., we do the same
for var_off, when it's unknown, which gives no additional information.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
kernel/bpf/log.c | 10 ++---
.../testing/selftests/bpf/prog_tests/align.c | 42 +++++++++----------
.../selftests/bpf/prog_tests/log_buf.c | 4 +-
.../selftests/bpf/prog_tests/spin_lock.c | 14 +++----
.../selftests/bpf/progs/exceptions_assert.c | 10 ++---
5 files changed, 39 insertions(+), 41 deletions(-)
diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c
index c209ab1ec2b5..20b4f81087da 100644
--- a/kernel/bpf/log.c
+++ b/kernel/bpf/log.c
@@ -602,16 +602,14 @@ static void print_reg_state(struct bpf_verifier_env *env, const struct bpf_reg_s
reg->map_ptr->key_size,
reg->map_ptr->value_size);
}
- if (t != SCALAR_VALUE)
+ if (t != SCALAR_VALUE && reg->off)
verbose_a("off=%d", reg->off);
if (type_is_pkt_pointer(t))
verbose_a("r=%d", reg->range);
if (tnum_is_const(reg->var_off)) {
- /* Typically an immediate SCALAR_VALUE, but
- * could be a pointer whose offset is too big
- * for reg->off
- */
- verbose_a("imm=%llx", reg->var_off.value);
+ /* a pointer register with fixed offset */
+ if (reg->var_off.value)
+ verbose_a("imm=%llx", reg->var_off.value);
} else {
print_scalar_ranges(env, reg, &sep);
if (!tnum_is_unknown(reg->var_off)) {
diff --git a/tools/testing/selftests/bpf/prog_tests/align.c b/tools/testing/selftests/bpf/prog_tests/align.c
index 465c1c3a3d3c..4ebd0da898f5 100644
--- a/tools/testing/selftests/bpf/prog_tests/align.c
+++ b/tools/testing/selftests/bpf/prog_tests/align.c
@@ -40,7 +40,7 @@ static struct bpf_align_test tests[] = {
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
- {0, "R1", "ctx(off=0,imm=0)"},
+ {0, "R1", "ctx()"},
{0, "R10", "fp0"},
{0, "R3_w", "2"},
{1, "R3_w", "4"},
@@ -68,7 +68,7 @@ static struct bpf_align_test tests[] = {
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
- {0, "R1", "ctx(off=0,imm=0)"},
+ {0, "R1", "ctx()"},
{0, "R10", "fp0"},
{0, "R3_w", "1"},
{1, "R3_w", "2"},
@@ -97,7 +97,7 @@ static struct bpf_align_test tests[] = {
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
- {0, "R1", "ctx(off=0,imm=0)"},
+ {0, "R1", "ctx()"},
{0, "R10", "fp0"},
{0, "R3_w", "4"},
{1, "R3_w", "8"},
@@ -119,7 +119,7 @@ static struct bpf_align_test tests[] = {
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
- {0, "R1", "ctx(off=0,imm=0)"},
+ {0, "R1", "ctx()"},
{0, "R10", "fp0"},
{0, "R3_w", "7"},
{1, "R3_w", "7"},
@@ -162,13 +162,13 @@ static struct bpf_align_test tests[] = {
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
- {6, "R0_w", "pkt(off=8,r=8,imm=0)"},
+ {6, "R0_w", "pkt(off=8,r=8)"},
{6, "R3_w", "var_off=(0x0; 0xff)"},
{7, "R3_w", "var_off=(0x0; 0x1fe)"},
{8, "R3_w", "var_off=(0x0; 0x3fc)"},
{9, "R3_w", "var_off=(0x0; 0x7f8)"},
{10, "R3_w", "var_off=(0x0; 0xff0)"},
- {12, "R3_w", "pkt_end(off=0,imm=0)"},
+ {12, "R3_w", "pkt_end()"},
{17, "R4_w", "var_off=(0x0; 0xff)"},
{18, "R4_w", "var_off=(0x0; 0x1fe0)"},
{19, "R4_w", "var_off=(0x0; 0xff0)"},
@@ -235,11 +235,11 @@ static struct bpf_align_test tests[] = {
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
- {2, "R5_w", "pkt(off=0,r=0,imm=0)"},
- {4, "R5_w", "pkt(off=14,r=0,imm=0)"},
- {5, "R4_w", "pkt(off=14,r=0,imm=0)"},
- {9, "R2", "pkt(off=0,r=18,imm=0)"},
- {10, "R5", "pkt(off=14,r=18,imm=0)"},
+ {2, "R5_w", "pkt(r=0)"},
+ {4, "R5_w", "pkt(off=14,r=0)"},
+ {5, "R4_w", "pkt(off=14,r=0)"},
+ {9, "R2", "pkt(r=18)"},
+ {10, "R5", "pkt(off=14,r=18)"},
{10, "R4_w", "var_off=(0x0; 0xff)"},
{13, "R4_w", "var_off=(0x0; 0xffff)"},
{14, "R4_w", "var_off=(0x0; 0xffff)"},
@@ -299,7 +299,7 @@ static struct bpf_align_test tests[] = {
/* Calculated offset in R6 has unknown value, but known
* alignment of 4.
*/
- {6, "R2_w", "pkt(off=0,r=8,imm=0)"},
+ {6, "R2_w", "pkt(r=8)"},
{7, "R6_w", "var_off=(0x0; 0x3fc)"},
/* Offset is added to packet pointer R5, resulting in
* known fixed offset, and variable offset from R6.
@@ -337,7 +337,7 @@ static struct bpf_align_test tests[] = {
/* Constant offset is added to R5 packet pointer,
* resulting in reg->off value of 14.
*/
- {26, "R5_w", "pkt(off=14,r=8,"},
+ {26, "R5_w", "pkt(off=14,r=8)"},
/* Variable offset is added to R5, resulting in a
* variable offset of (4n). See comment for insn #18
* for R4 = R5 trick.
@@ -397,7 +397,7 @@ static struct bpf_align_test tests[] = {
/* Calculated offset in R6 has unknown value, but known
* alignment of 4.
*/
- {6, "R2_w", "pkt(off=0,r=8,imm=0)"},
+ {6, "R2_w", "pkt(r=8)"},
{7, "R6_w", "var_off=(0x0; 0x3fc)"},
/* Adding 14 makes R6 be (4n+2) */
{8, "R6_w", "var_off=(0x2; 0x7fc)"},
@@ -459,7 +459,7 @@ static struct bpf_align_test tests[] = {
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = REJECT,
.matches = {
- {3, "R5_w", "pkt_end(off=0,imm=0)"},
+ {3, "R5_w", "pkt_end()"},
/* (ptr - ptr) << 2 == unknown, (4n) */
{5, "R5_w", "var_off=(0x0; 0xfffffffffffffffc)"},
/* (4n) + 14 == (4n+2). We blow our bounds, because
@@ -513,7 +513,7 @@ static struct bpf_align_test tests[] = {
/* Calculated offset in R6 has unknown value, but known
* alignment of 4.
*/
- {6, "R2_w", "pkt(off=0,r=8,imm=0)"},
+ {6, "R2_w", "pkt(r=8)"},
{8, "R6_w", "var_off=(0x0; 0x3fc)"},
/* Adding 14 makes R6 be (4n+2) */
{9, "R6_w", "var_off=(0x2; 0x7fc)"},
@@ -566,7 +566,7 @@ static struct bpf_align_test tests[] = {
/* Calculated offset in R6 has unknown value, but known
* alignment of 4.
*/
- {6, "R2_w", "pkt(off=0,r=8,imm=0)"},
+ {6, "R2_w", "pkt(r=8)"},
{9, "R6_w", "var_off=(0x0; 0x3c)"},
/* Adding 14 makes R6 be (4n+2) */
{10, "R6_w", "var_off=(0x2; 0x7c)"},
@@ -659,14 +659,14 @@ static int do_test_single(struct bpf_align_test *test)
/* Check the next line as well in case the previous line
* did not have a corresponding bpf insn. Example:
* func#0 @0
- * 0: R1=ctx(off=0,imm=0) R10=fp0
+ * 0: R1=ctx() R10=fp0
* 0: (b7) r3 = 2 ; R3_w=2
*
* Sometimes it's actually two lines below, e.g. when
* searching for "6: R3_w=scalar(umax=255,var_off=(0x0; 0xff))":
- * from 4 to 6: R0_w=pkt(off=8,r=8,imm=0) R1=ctx(off=0,imm=0) R2_w=pkt(off=0,r=8,imm=0) R3_w=pkt_end(off=0,imm=0) R10=fp0
- * 6: R0_w=pkt(off=8,r=8,imm=0) R1=ctx(off=0,imm=0) R2_w=pkt(off=0,r=8,imm=0) R3_w=pkt_end(off=0,imm=0) R10=fp0
- * 6: (71) r3 = *(u8 *)(r2 +0) ; R2_w=pkt(off=0,r=8,imm=0) R3_w=scalar(umax=255,var_off=(0x0; 0xff))
+ * from 4 to 6: R0_w=pkt(off=8,r=8) R1=ctx() R2_w=pkt(r=8) R3_w=pkt_end() R10=fp0
+ * 6: R0_w=pkt(off=8,r=8) R1=ctx() R2_w=pkt(r=8) R3_w=pkt_end() R10=fp0
+ * 6: (71) r3 = *(u8 *)(r2 +0) ; R2_w=pkt(r=8) R3_w=scalar(umax=255,var_off=(0x0; 0xff))
*/
while (!(p = strstr(line_ptr, m.reg)) || !strstr(p, m.match)) {
cur_line = -1;
diff --git a/tools/testing/selftests/bpf/prog_tests/log_buf.c b/tools/testing/selftests/bpf/prog_tests/log_buf.c
index fe9a23e65ef4..0f7ea4d7d9f6 100644
--- a/tools/testing/selftests/bpf/prog_tests/log_buf.c
+++ b/tools/testing/selftests/bpf/prog_tests/log_buf.c
@@ -78,7 +78,7 @@ static void obj_load_log_buf(void)
ASSERT_OK_PTR(strstr(libbpf_log_buf, "prog 'bad_prog': BPF program load failed"),
"libbpf_log_not_empty");
ASSERT_OK_PTR(strstr(obj_log_buf, "DATASEC license"), "obj_log_not_empty");
- ASSERT_OK_PTR(strstr(good_log_buf, "0: R1=ctx(off=0,imm=0) R10=fp0"),
+ ASSERT_OK_PTR(strstr(good_log_buf, "0: R1=ctx() R10=fp0"),
"good_log_verbose");
ASSERT_OK_PTR(strstr(bad_log_buf, "invalid access to map value, value_size=16 off=16000 size=4"),
"bad_log_not_empty");
@@ -175,7 +175,7 @@ static void bpf_prog_load_log_buf(void)
opts.log_level = 2;
fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "good_prog", "GPL",
good_prog_insns, good_prog_insn_cnt, &opts);
- ASSERT_OK_PTR(strstr(log_buf, "0: R1=ctx(off=0,imm=0) R10=fp0"), "good_log_2");
+ ASSERT_OK_PTR(strstr(log_buf, "0: R1=ctx() R10=fp0"), "good_log_2");
ASSERT_GE(fd, 0, "good_fd2");
if (fd >= 0)
close(fd);
diff --git a/tools/testing/selftests/bpf/prog_tests/spin_lock.c b/tools/testing/selftests/bpf/prog_tests/spin_lock.c
index ace65224286f..18d451be57c8 100644
--- a/tools/testing/selftests/bpf/prog_tests/spin_lock.c
+++ b/tools/testing/selftests/bpf/prog_tests/spin_lock.c
@@ -13,22 +13,22 @@ static struct {
const char *err_msg;
} spin_lock_fail_tests[] = {
{ "lock_id_kptr_preserve",
- "5: (bf) r1 = r0 ; R0_w=ptr_foo(id=2,ref_obj_id=2,off=0,imm=0) "
- "R1_w=ptr_foo(id=2,ref_obj_id=2,off=0,imm=0) refs=2\n6: (85) call bpf_this_cpu_ptr#154\n"
+ "5: (bf) r1 = r0 ; R0_w=ptr_foo(id=2,ref_obj_id=2) "
+ "R1_w=ptr_foo(id=2,ref_obj_id=2) refs=2\n6: (85) call bpf_this_cpu_ptr#154\n"
"R1 type=ptr_ expected=percpu_ptr_" },
{ "lock_id_global_zero",
- "; R1_w=map_value(map=.data.A,ks=4,vs=4,off=0,imm=0)\n2: (85) call bpf_this_cpu_ptr#154\n"
+ "; R1_w=map_value(map=.data.A,ks=4,vs=4)\n2: (85) call bpf_this_cpu_ptr#154\n"
"R1 type=map_value expected=percpu_ptr_" },
{ "lock_id_mapval_preserve",
"[0-9]\\+: (bf) r1 = r0 ;"
- " R0_w=map_value(id=1,map=array_map,ks=4,vs=8,off=0,imm=0)"
- " R1_w=map_value(id=1,map=array_map,ks=4,vs=8,off=0,imm=0)\n"
+ " R0_w=map_value(id=1,map=array_map,ks=4,vs=8)"
+ " R1_w=map_value(id=1,map=array_map,ks=4,vs=8)\n"
"[0-9]\\+: (85) call bpf_this_cpu_ptr#154\n"
"R1 type=map_value expected=percpu_ptr_" },
{ "lock_id_innermapval_preserve",
"[0-9]\\+: (bf) r1 = r0 ;"
- " R0=map_value(id=2,ks=4,vs=8,off=0,imm=0)"
- " R1_w=map_value(id=2,ks=4,vs=8,off=0,imm=0)\n"
+ " R0=map_value(id=2,ks=4,vs=8)"
+ " R1_w=map_value(id=2,ks=4,vs=8)\n"
"[0-9]\\+: (85) call bpf_this_cpu_ptr#154\n"
"R1 type=map_value expected=percpu_ptr_" },
{ "lock_id_mismatch_kptr_kptr", "bpf_spin_unlock of different lock" },
diff --git a/tools/testing/selftests/bpf/progs/exceptions_assert.c b/tools/testing/selftests/bpf/progs/exceptions_assert.c
index e1e5c54a6a11..26f7d67432cc 100644
--- a/tools/testing/selftests/bpf/progs/exceptions_assert.c
+++ b/tools/testing/selftests/bpf/progs/exceptions_assert.c
@@ -59,7 +59,7 @@ check_assert(s64, ge, neg, INT_MIN);
SEC("?tc")
__log_level(2) __failure
-__msg(": R0=0 R1=ctx(off=0,imm=0) R2=scalar(smin=smin32=-2147483646,smax=smax32=2147483645) R10=fp0")
+__msg(": R0=0 R1=ctx() R2=scalar(smin=smin32=-2147483646,smax=smax32=2147483645) R10=fp0")
int check_assert_range_s64(struct __sk_buff *ctx)
{
struct bpf_sock *sk = ctx->sk;
@@ -75,7 +75,7 @@ int check_assert_range_s64(struct __sk_buff *ctx)
SEC("?tc")
__log_level(2) __failure
-__msg(": R1=ctx(off=0,imm=0) R2=scalar(smin=umin=smin32=umin32=4096,smax=umax=smax32=umax32=8192,var_off=(0x0; 0x3fff))")
+__msg(": R1=ctx() R2=scalar(smin=umin=smin32=umin32=4096,smax=umax=smax32=umax32=8192,var_off=(0x0; 0x3fff))")
int check_assert_range_u64(struct __sk_buff *ctx)
{
u64 num = ctx->len;
@@ -86,7 +86,7 @@ int check_assert_range_u64(struct __sk_buff *ctx)
SEC("?tc")
__log_level(2) __failure
-__msg(": R0=0 R1=ctx(off=0,imm=0) R2=4096 R10=fp0")
+__msg(": R0=0 R1=ctx() R2=4096 R10=fp0")
int check_assert_single_range_s64(struct __sk_buff *ctx)
{
struct bpf_sock *sk = ctx->sk;
@@ -103,7 +103,7 @@ int check_assert_single_range_s64(struct __sk_buff *ctx)
SEC("?tc")
__log_level(2) __failure
-__msg(": R1=ctx(off=0,imm=0) R2=4096 R10=fp0")
+__msg(": R1=ctx() R2=4096 R10=fp0")
int check_assert_single_range_u64(struct __sk_buff *ctx)
{
u64 num = ctx->len;
@@ -114,7 +114,7 @@ int check_assert_single_range_u64(struct __sk_buff *ctx)
SEC("?tc")
__log_level(2) __failure
-__msg(": R1=pkt(off=64,r=64,imm=0) R2=pkt_end(off=0,imm=0) R6=pkt(off=0,r=64,imm=0) R10=fp0")
+__msg(": R1=pkt(off=64,r=64) R2=pkt_end() R6=pkt(r=64) R10=fp0")
int check_assert_generic(struct __sk_buff *ctx)
{
u8 *data_end = (void *)(long)ctx->data_end;
--
2.34.1
