diff mbox series

[bpf-next,02/10] bpf: provide correct register name for exception callback retval check

Message ID 20231122011656.1105943-3-andrii@kernel.org (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series BPF verifier retval logic fixes | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
netdev/series_format success Posting correctly formatted
netdev/codegen success Generated files up to date
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1146 this patch: 1146
netdev/cc_maintainers warning 13 maintainers not CCed: mykolal@fb.com yonghong.song@linux.dev john.fastabend@gmail.com eddyz87@gmail.com sdf@google.com haoluo@google.com linux-kselftest@vger.kernel.org martin.lau@linux.dev shuah@kernel.org jolsa@kernel.org kpsingh@kernel.org memxor@gmail.com song@kernel.org
netdev/build_clang success Errors and warnings before: 1162 this patch: 1162
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1173 this patch: 1173
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns WARNING: line length of 92 exceeds 80 columns WARNING: line length of 95 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Validate matrix.py
bpf/vmtest-bpf-next-VM_Test-0 success Logs for Lint
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-3 success Logs for aarch64-gcc / build / build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for aarch64-gcc / veristat
bpf/vmtest-bpf-next-VM_Test-7 success Logs for aarch64-gcc / test (test_verifier, false, 360) / test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-5 success Logs for aarch64-gcc / test (test_progs, false, 360) / test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for aarch64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on aarch64 with gcc
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bpf/vmtest-bpf-next-VM_Test-19 success Logs for x86_64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-20 success Logs for x86_64-gcc / test (test_progs_no_alu32_parallel, true, 30) / test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-21 success Logs for x86_64-gcc / test (test_progs_parallel, true, 30) / test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-22 success Logs for x86_64-gcc / test (test_verifier, false, 360) / test_verifier on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-13 success Logs for s390x-gcc / test (test_verifier, false, 360) / test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for s390x-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on s390x with gcc
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Commit Message

Andrii Nakryiko Nov. 22, 2023, 1:16 a.m. UTC 
bpf_throw() is checking R1, so let's report R1 in the log.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 kernel/bpf/verifier.c                                | 12 ++++++------
 .../testing/selftests/bpf/progs/exceptions_assert.c  |  2 +-
 tools/testing/selftests/bpf/progs/exceptions_fail.c  |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

Comments

Eduard Zingerman Nov. 22, 2023, 3:12 p.m. UTC | #1 
On Tue, 2023-11-21 at 17:16 -0800, Andrii Nakryiko wrote:
> bpf_throw() is checking R1, so let's report R1 in the log.
> 
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> ---

Acked-by: Eduard Zingerman <eddyz87@gmail.com>

[...]
Alexei Starovoitov Nov. 23, 2023, 1:44 a.m. UTC | #2 
On Tue, Nov 21, 2023 at 05:16:48PM -0800, Andrii Nakryiko wrote:
>  SEC("?fentry/bpf_check")
> -__failure __msg("At program exit the register R0 has value (0x40; 0x0)")
> +__failure __msg("At program exit the register R1 has value (0x40; 0x0)")

While at it...
should we change tnum_strn() to print it as normal constant when mask==0 ?
Andrii Nakryiko Nov. 24, 2023, 3:39 a.m. UTC | #3 
On Wed, Nov 22, 2023 at 5:44 PM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Tue, Nov 21, 2023 at 05:16:48PM -0800, Andrii Nakryiko wrote:
> >  SEC("?fentry/bpf_check")
> > -__failure __msg("At program exit the register R0 has value (0x40; 0x0)")
> > +__failure __msg("At program exit the register R1 has value (0x40; 0x0)")
>
> While at it...
> should we change tnum_strn() to print it as normal constant when mask==0 ?

sure, I can add that as another patch, because I suspect even more
tests would have to be adjusted
diff mbox series

Patch

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 8c2d31aa3d31..a921dba4f603 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11663,7 +11663,7 @@  static int fetch_kfunc_meta(struct bpf_verifier_env *env,
 	return 0;
 }
 
-static int check_return_code(struct bpf_verifier_env *env, int regno);
+static int check_return_code(struct bpf_verifier_env *env, int regno, const char *reg_name);
 
 static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 			    int *insn_idx_p)
@@ -11799,7 +11799,7 @@  static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 		 * to bpf_throw becomes the return value of the program.
 		 */
 		if (!env->exception_callback_subprog) {
-			err = check_return_code(env, BPF_REG_1);
+			err = check_return_code(env, BPF_REG_1, "R1");
 			if (err < 0)
 				return err;
 		}
@@ -14818,7 +14818,7 @@  static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
 	return 0;
 }
 
-static int check_return_code(struct bpf_verifier_env *env, int regno)
+static int check_return_code(struct bpf_verifier_env *env, int regno, const char *reg_name)
 {
 	struct tnum enforce_attach_type_range = tnum_unknown;
 	const struct bpf_prog *prog = env->prog;
@@ -14872,7 +14872,7 @@  static int check_return_code(struct bpf_verifier_env *env, int regno)
 		}
 
 		if (!tnum_in(const_0, reg->var_off)) {
-			verbose_invalid_scalar(env, reg, &const_0, "async callback", "R0");
+			verbose_invalid_scalar(env, reg, &const_0, "async callback", reg_name);
 			return -EINVAL;
 		}
 		return 0;
@@ -14972,7 +14972,7 @@  static int check_return_code(struct bpf_verifier_env *env, int regno)
 	}
 
 	if (!tnum_in(range, reg->var_off)) {
-		verbose_invalid_scalar(env, reg, &range, "program exit", "R0");
+		verbose_invalid_scalar(env, reg, &range, "program exit", reg_name);
 		if (prog->expected_attach_type == BPF_LSM_CGROUP &&
 		    prog_type == BPF_PROG_TYPE_LSM &&
 		    !prog->aux->attach_func_proto->type)
@@ -17220,7 +17220,7 @@  static int do_check(struct bpf_verifier_env *env)
 					continue;
 				}
 
-				err = check_return_code(env, BPF_REG_0);
+				err = check_return_code(env, BPF_REG_0, "R0");
 				if (err)
 					return err;
 process_bpf_exit:
diff --git a/tools/testing/selftests/bpf/progs/exceptions_assert.c b/tools/testing/selftests/bpf/progs/exceptions_assert.c
index 49efaed143fc..575e7dd719c4 100644
--- a/tools/testing/selftests/bpf/progs/exceptions_assert.c
+++ b/tools/testing/selftests/bpf/progs/exceptions_assert.c
@@ -125,7 +125,7 @@  int check_assert_generic(struct __sk_buff *ctx)
 }
 
 SEC("?fentry/bpf_check")
-__failure __msg("At program exit the register R0 has value (0x40; 0x0)")
+__failure __msg("At program exit the register R1 has value (0x40; 0x0)")
 int check_assert_with_return(void *ctx)
 {
 	bpf_assert_with(!ctx, 64);
diff --git a/tools/testing/selftests/bpf/progs/exceptions_fail.c b/tools/testing/selftests/bpf/progs/exceptions_fail.c
index 4c39e920dac2..69a8fb53ea1d 100644
--- a/tools/testing/selftests/bpf/progs/exceptions_fail.c
+++ b/tools/testing/selftests/bpf/progs/exceptions_fail.c
@@ -306,7 +306,7 @@  int reject_set_exception_cb_bad_ret1(void *ctx)
 }
 
 SEC("?fentry/bpf_check")
-__failure __msg("At program exit the register R0 has value (0x40; 0x0) should")
+__failure __msg("At program exit the register R1 has value (0x40; 0x0) should")
 int reject_set_exception_cb_bad_ret2(void *ctx)
 {
 	bpf_throw(64);