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 v2 bpf-next 05/10] selftests/bpf: validate STACK_ZERO is preserved on subreg spill
Date: Mon, 20 Nov 2023 16:22:16 -0800 [thread overview]
Message-ID: <20231121002221.3687787-6-andrii@kernel.org> (raw)
In-Reply-To: <20231121002221.3687787-1-andrii@kernel.org>
Add tests validating that STACK_ZERO slots are preserved when slot is
partially overwritten with subregister spill.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
.../selftests/bpf/progs/verifier_spill_fill.c | 36 +++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
index 6115520154e3..899a74ac9093 100644
--- a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
+++ b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
@@ -450,4 +450,40 @@ l0_%=: r1 >>= 16; \
: __clobber_all);
}
+SEC("raw_tp")
+__log_level(2)
+__success
+__msg("fp-8=0m??mmmm")
+__msg("fp-16=00mm??mm")
+__msg("fp-24=00mm???m")
+__naked void spill_subregs_preserve_stack_zero(void)
+{
+ asm volatile (
+ "call %[bpf_get_prandom_u32];"
+
+ /* 32-bit subreg spill with ZERO, MISC, and INVALID */
+ "*(u8 *)(r10 -1) = 0;" /* ZERO */
+ "*(u8 *)(r10 -2) = r0;" /* MISC */
+ /* fp-3 and fp-4 stay INVALID */
+ "*(u32 *)(r10 -8) = r0;"
+
+ /* 16-bit subreg spill with ZERO, MISC, and INVALID */
+ "*(u16 *)(r10 -10) = 0;" /* ZERO */
+ "*(u16 *)(r10 -12) = r0;" /* MISC */
+ /* fp-13 and fp-14 stay INVALID */
+ "*(u16 *)(r10 -16) = r0;"
+
+ /* 8-bit subreg spill with ZERO, MISC, and INVALID */
+ "*(u16 *)(r10 -18) = 0;" /* ZERO */
+ "*(u16 *)(r10 -20) = r0;" /* MISC */
+ /* fp-21, fp-22, and fp-23 stay INVALID */
+ "*(u8 *)(r10 -24) = r0;"
+
+ "r0 = 0;"
+ "exit;"
+ :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all);
+}
+
char _license[] SEC("license") = "GPL";
--
2.34.1
next prev parent reply other threads:[~2023-11-21 0:23 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-21 0:22 [PATCH v2 bpf-next 00/10] Complete BPF verifier precision tracking support for register spills Andrii Nakryiko
2023-11-21 0:22 ` [PATCH v2 bpf-next 01/10] bpf: support non-r10 register spill/fill to/from stack in precision tracking Andrii Nakryiko
2023-11-21 0:22 ` [PATCH v2 bpf-next 02/10] selftests/bpf: add stack access precision test Andrii Nakryiko
2023-11-21 0:42 ` Eduard Zingerman
2023-11-21 0:22 ` [PATCH v2 bpf-next 03/10] bpf: fix check for attempt to corrupt spilled pointer Andrii Nakryiko
2023-11-21 0:22 ` [PATCH v2 bpf-next 04/10] bpf: preserve STACK_ZERO slots on partial reg spills Andrii Nakryiko
2023-11-21 0:22 ` Andrii Nakryiko [this message]
2023-11-21 0:55 ` [PATCH v2 bpf-next 05/10] selftests/bpf: validate STACK_ZERO is preserved on subreg spill Eduard Zingerman
2023-11-21 0:22 ` [PATCH v2 bpf-next 06/10] bpf: preserve constant zero when doing partial register restore Andrii Nakryiko
2023-11-21 16:20 ` Eduard Zingerman
2023-11-21 18:14 ` Andrii Nakryiko
2023-11-21 20:22 ` Eduard Zingerman
2023-11-21 0:22 ` [PATCH v2 bpf-next 07/10] selftests/bpf: validate zero preservation for sub-slot loads Andrii Nakryiko
2023-11-21 16:20 ` Eduard Zingerman
2023-11-21 18:15 ` Andrii Nakryiko
2023-11-21 0:22 ` [PATCH v2 bpf-next 08/10] bpf: track aligned STACK_ZERO cases as imprecise spilled registers Andrii Nakryiko
2023-11-21 20:38 ` Alexei Starovoitov
2023-11-21 22:01 ` Andrii Nakryiko
2023-11-21 0:22 ` [PATCH v2 bpf-next 09/10] selftests/bpf: validate precision logic in partial_stack_load_preserves_zeros Andrii Nakryiko
2023-11-21 16:20 ` Eduard Zingerman
2023-11-21 0:22 ` [PATCH v2 bpf-next 10/10] bpf: use common instruction history across all states Andrii Nakryiko
2023-11-21 16:20 ` Eduard Zingerman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231121002221.3687787-6-andrii@kernel.org \
--to=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=kernel-team@meta.com \
--cc=martin.lau@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox