public inbox for bpf@vger.kernel.org
 help / color / mirror / Atom feed
From: Song Liu <song@kernel.org>
To: bpf@vger.kernel.org, netdev@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	kernel-team@meta.com, song@kernel.org,
	Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH bpf-next] selftests/bpf: Fix verifier_bpf_fastcall
Date: Fri, 28 Mar 2025 12:31:24 -0700	[thread overview]
Message-ID: <20250328193124.808784-1-song@kernel.org> (raw)

Commit [1] moves percpu data on x86 from address 0x000... to address
0xfff...

Before [1]:

159020: 0000000000030700     0 OBJECT  GLOBAL DEFAULT   23 pcpu_hot

After [1]:

152602: ffffffff83a3e034     4 OBJECT  GLOBAL DEFAULT   35 pcpu_hot

As a result, verifier_bpf_fastcall tests should now expect a negative
value for pcpu_hot, IOW, the disassemble should show "r=" instead of
"w=".

Fix this in the test.

Note that, a later change created a new variable "cpu_number" for
bpf_get_smp_processor_id() [2]. The inlining logic is updated properly
as part of this change, so there is no need to fix anything on the
kernel side.

[1] commit 9d7de2aa8b41 ("x86/percpu/64: Use relative percpu offsets")
[2] commit 01c7bc5198e9 ("x86/smp: Move cpu number to percpu hot section")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
---
 tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c b/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
index a9be6ae49454..c258b0722e04 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
@@ -12,7 +12,7 @@ SEC("raw_tp")
 __arch_x86_64
 __log_level(4) __msg("stack depth 8")
 __xlated("4: r5 = 5")
-__xlated("5: w0 = ")
+__xlated("5: r0 = ")
 __xlated("6: r0 = &(void __percpu *)(r0)")
 __xlated("7: r0 = *(u32 *)(r0 +0)")
 __xlated("8: exit")
@@ -704,7 +704,7 @@ SEC("raw_tp")
 __arch_x86_64
 __log_level(4) __msg("stack depth 32+0")
 __xlated("2: r1 = 1")
-__xlated("3: w0 =")
+__xlated("3: r0 =")
 __xlated("4: r0 = &(void __percpu *)(r0)")
 __xlated("5: r0 = *(u32 *)(r0 +0)")
 /* bpf_loop params setup */
@@ -753,7 +753,7 @@ __arch_x86_64
 __log_level(4) __msg("stack depth 40+0")
 /* call bpf_get_smp_processor_id */
 __xlated("2: r1 = 42")
-__xlated("3: w0 =")
+__xlated("3: r0 =")
 __xlated("4: r0 = &(void __percpu *)(r0)")
 __xlated("5: r0 = *(u32 *)(r0 +0)")
 /* call bpf_get_prandom_u32 */
-- 
2.47.1


             reply	other threads:[~2025-03-28 19:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-28 19:31 Song Liu [this message]
2025-03-30 23:40 ` [PATCH bpf-next] selftests/bpf: Fix verifier_bpf_fastcall patchwork-bot+netdevbpf

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=20250328193124.808784-1-song@kernel.org \
    --to=song@kernel.org \
    --cc=andrii@kernel.org \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=kernel-team@meta.com \
    --cc=kuba@kernel.org \
    --cc=netdev@vger.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