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From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>,
	<martin.lau@kernel.org>
Cc: <andrii@kernel.org>, <kernel-team@meta.com>
Subject: [PATCH v3 bpf-next 10/10] bpf: simplify tnum output if a fully known constant
Date: Wed, 29 Nov 2023 16:04:06 -0800	[thread overview]
Message-ID: <20231130000406.480870-11-andrii@kernel.org> (raw)
In-Reply-To: <20231130000406.480870-1-andrii@kernel.org>

Emit tnum representation as just a constant if all bits are known.
Use decimal-vs-hex logic to determine exact format of emitted
constant value, just like it's done for register range values.
For that move tnum_strn() to kernel/bpf/log.c to reuse decimal-vs-hex
determination logic and constants.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 kernel/bpf/log.c                                    | 13 +++++++++++++
 kernel/bpf/tnum.c                                   |  6 ------
 .../bpf/progs/verifier_direct_packet_access.c       |  2 +-
 .../testing/selftests/bpf/progs/verifier_int_ptr.c  |  2 +-
 .../selftests/bpf/progs/verifier_stack_ptr.c        |  4 ++--
 5 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c
index 3505f3e5ae96..55d019f30e91 100644
--- a/kernel/bpf/log.c
+++ b/kernel/bpf/log.c
@@ -539,6 +539,19 @@ static void verbose_snum(struct bpf_verifier_env *env, s64 num)
 		verbose(env, "%#llx", num);
 }
 
+int tnum_strn(char *str, size_t size, struct tnum a)
+{
+	/* print as a constant, if tnum is fully known */
+	if (a.mask == 0) {
+		if (is_unum_decimal(a.value))
+			return snprintf(str, size, "%llu", a.value);
+		else
+			return snprintf(str, size, "%#llx", a.value);
+	}
+	return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
+}
+EXPORT_SYMBOL_GPL(tnum_strn);
+
 static void print_scalar_ranges(struct bpf_verifier_env *env,
 				const struct bpf_reg_state *reg,
 				const char **sep)
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index f4c91c9b27d7..9dbc31b25e3d 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -172,12 +172,6 @@ bool tnum_in(struct tnum a, struct tnum b)
 	return a.value == b.value;
 }
 
-int tnum_strn(char *str, size_t size, struct tnum a)
-{
-	return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
-}
-EXPORT_SYMBOL_GPL(tnum_strn);
-
 int tnum_sbin(char *str, size_t size, struct tnum a)
 {
 	size_t n;
diff --git a/tools/testing/selftests/bpf/progs/verifier_direct_packet_access.c b/tools/testing/selftests/bpf/progs/verifier_direct_packet_access.c
index 99a23dea8233..be95570ab382 100644
--- a/tools/testing/selftests/bpf/progs/verifier_direct_packet_access.c
+++ b/tools/testing/selftests/bpf/progs/verifier_direct_packet_access.c
@@ -411,7 +411,7 @@ l0_%=:	r0 = 0;						\
 
 SEC("tc")
 __description("direct packet access: test17 (pruning, alignment)")
-__failure __msg("misaligned packet access off 2+(0x0; 0x0)+15+-4 size 4")
+__failure __msg("misaligned packet access off 2+0+15+-4 size 4")
 __flag(BPF_F_STRICT_ALIGNMENT)
 __naked void packet_access_test17_pruning_alignment(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_int_ptr.c b/tools/testing/selftests/bpf/progs/verifier_int_ptr.c
index b054f9c48143..74d9cad469d9 100644
--- a/tools/testing/selftests/bpf/progs/verifier_int_ptr.c
+++ b/tools/testing/selftests/bpf/progs/verifier_int_ptr.c
@@ -67,7 +67,7 @@ __naked void ptr_to_long_half_uninitialized(void)
 
 SEC("cgroup/sysctl")
 __description("ARG_PTR_TO_LONG misaligned")
-__failure __msg("misaligned stack access off (0x0; 0x0)+-20+0 size 8")
+__failure __msg("misaligned stack access off 0+-20+0 size 8")
 __naked void arg_ptr_to_long_misaligned(void)
 {
 	asm volatile ("					\
diff --git a/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
index e0f77e3e7869..417c61cd4b19 100644
--- a/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
+++ b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
@@ -37,7 +37,7 @@ __naked void ptr_to_stack_store_load(void)
 
 SEC("socket")
 __description("PTR_TO_STACK store/load - bad alignment on off")
-__failure __msg("misaligned stack access off (0x0; 0x0)+-8+2 size 8")
+__failure __msg("misaligned stack access off 0+-8+2 size 8")
 __failure_unpriv
 __naked void load_bad_alignment_on_off(void)
 {
@@ -53,7 +53,7 @@ __naked void load_bad_alignment_on_off(void)
 
 SEC("socket")
 __description("PTR_TO_STACK store/load - bad alignment on reg")
-__failure __msg("misaligned stack access off (0x0; 0x0)+-10+8 size 8")
+__failure __msg("misaligned stack access off 0+-10+8 size 8")
 __failure_unpriv
 __naked void load_bad_alignment_on_reg(void)
 {
-- 
2.34.1


  parent reply	other threads:[~2023-11-30  0:14 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-30  0:03 [PATCH v3 bpf-next 00/10] BPF verifier retval logic fixes Andrii Nakryiko
2023-11-30  0:03 ` [PATCH v3 bpf-next 01/10] bpf: provide correct register name for exception callback retval check Andrii Nakryiko
2023-11-30  5:41   ` Shung-Hsi Yu
2023-11-30  0:03 ` [PATCH v3 bpf-next 02/10] bpf: enforce precision of R0 on callback return Andrii Nakryiko
2023-11-30  5:43   ` Shung-Hsi Yu
2023-11-30  0:03 ` [PATCH v3 bpf-next 03/10] bpf: enforce exact retval range on subprog/callback exit Andrii Nakryiko
2023-11-30  5:49   ` Shung-Hsi Yu
2023-11-30  0:04 ` [PATCH v3 bpf-next 04/10] selftests/bpf: add selftest validating callback result is enforced Andrii Nakryiko
2023-11-30  5:52   ` Shung-Hsi Yu
2023-11-30  0:04 ` [PATCH v3 bpf-next 05/10] bpf: enforce precise retval range on program exit Andrii Nakryiko
2023-11-30  5:54   ` Shung-Hsi Yu
2023-11-30  0:04 ` [PATCH v3 bpf-next 06/10] bpf: unify async callback and program retval checks Andrii Nakryiko
2023-11-30  5:56   ` Shung-Hsi Yu
2023-11-30  0:04 ` [PATCH v3 bpf-next 07/10] bpf: enforce precision of R0 on program/async callback return Andrii Nakryiko
2023-11-30  6:33   ` Shung-Hsi Yu
2023-11-30  6:41     ` Andrii Nakryiko
2023-11-30  0:04 ` [PATCH v3 bpf-next 08/10] selftests/bpf: validate async callback return value check correctness Andrii Nakryiko
2023-11-30  0:04 ` [PATCH v3 bpf-next 09/10] selftests/bpf: adjust global_func15 test to validate prog exit precision Andrii Nakryiko
2023-11-30  0:04 ` Andrii Nakryiko [this message]
2023-11-30  6:34   ` [PATCH v3 bpf-next 10/10] bpf: simplify tnum output if a fully known constant Shung-Hsi Yu

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