From e99045bf493b3c54bab79f396b31ade2a8b20ee8 Mon Sep 17 00:00:00 2001
From: Jerome Marchand <jmarchan@redhat.com>
Date: Thu, 19 Jun 2025 16:06:02 +0200
Subject: [PATCH 1/2] bpf: Specify access type of bpf_sysctl_get_name args
The second argument of bpf_sysctl_get_name() helper is a pointer to a
buffer that is being written to. However that isn't specify in the
prototype.
Until commit 37cce22dbd51a ("bpf: verifier: Refactor helper access
type tracking"), all helper accesses were considered as a possible
write access by the verifier, so no big harm was done. However, since
then, the verifier might make wrong asssumption about the content of
that address which might lead it to make faulty optimizations (such as
removing code that was wrongly labeled dead). This is what happens in
test_sysctl selftest to the tests related to sysctl_get_name.
Add MEM_WRITE flag the second argument of bpf_sysctl_get_name().
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
---
kernel/bpf/cgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index ffbafbef5010d..cd220e861d678 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -2272,7 +2272,7 @@ static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_WRITE,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
};
From db9c9c28d886cf6c5980103dda801b9e782683ec Mon Sep 17 00:00:00 2001
From: Jerome Marchand <jmarchan@redhat.com>
Date: Thu, 19 Jun 2025 16:06:03 +0200
Subject: [PATCH 2/2] selftests/bpf: Convert test_sysctl to prog_tests
Convert test_sysctl test to prog_tests with minimal change to the
tests themselves.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
---
tools/testing/selftests/bpf/.gitignore | 1 -
tools/testing/selftests/bpf/Makefile | 5 +--
.../bpf/{ => prog_tests}/test_sysctl.c | 37 ++++---------------
3 files changed, 10 insertions(+), 33 deletions(-)
rename tools/testing/selftests/bpf/{ => prog_tests}/test_sysctl.c (98%)
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index e2a2c46c008b1..3d8378972d26c 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -21,7 +21,6 @@ test_lirc_mode2_user
flow_dissector_load
test_tcpnotify_user
test_libbpf
-test_sysctl
xdping
test_cpp
*.d
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index da868bb8c4215..4863106034dfb 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -73,7 +73,7 @@ endif
# Order correspond to 'make run_tests' order
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_progs \
test_sockmap \
- test_tcpnotify_user test_sysctl \
+ test_tcpnotify_user \
test_progs-no_alu32
TEST_INST_SUBDIRS := no_alu32
@@ -221,7 +221,7 @@ ifeq ($(VMLINUX_BTF),)
$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
endif
-# Define simple and short `make test_progs`, `make test_sysctl`, etc targets
+# Define simple and short `make test_progs`, `make test_maps`, etc targets
# to build individual tests.
# NOTE: Semicolon at the end is critical to override lib.mk's default static
# rule for binaries.
@@ -330,7 +330,6 @@ NETWORK_HELPERS := $(OUTPUT)/network_helpers.o
$(OUTPUT)/test_sockmap: $(CGROUP_HELPERS) $(TESTING_HELPERS)
$(OUTPUT)/test_tcpnotify_user: $(CGROUP_HELPERS) $(TESTING_HELPERS) $(TRACE_HELPERS)
$(OUTPUT)/test_sock_fields: $(CGROUP_HELPERS) $(TESTING_HELPERS)
-$(OUTPUT)/test_sysctl: $(CGROUP_HELPERS) $(TESTING_HELPERS)
$(OUTPUT)/test_tag: $(TESTING_HELPERS)
$(OUTPUT)/test_lirc_mode2_user: $(TESTING_HELPERS)
$(OUTPUT)/xdping: $(TESTING_HELPERS)
diff --git a/tools/testing/selftests/bpf/test_sysctl.c b/tools/testing/selftests/bpf/prog_tests/test_sysctl.c
similarity index 98%
rename from tools/testing/selftests/bpf/test_sysctl.c
rename to tools/testing/selftests/bpf/prog_tests/test_sysctl.c
index bcdbd27f22f08..273dd41ca09e4 100644
--- a/tools/testing/selftests/bpf/test_sysctl.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_sysctl.c
@@ -1,22 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
-#include <fcntl.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <linux/filter.h>
-
-#include <bpf/bpf.h>
-#include <bpf/libbpf.h>
-
-#include <bpf/bpf_endian.h>
-#include "bpf_util.h"
+#include "test_progs.h"
#include "cgroup_helpers.h"
-#include "testing_helpers.h"
#define CG_PATH "/foo"
#define MAX_INSNS 512
@@ -1608,26 +1594,19 @@ static int run_tests(int cgfd)
return fails ? -1 : 0;
}
-int main(int argc, char **argv)
+void test_sysctl(void)
{
- int cgfd = -1;
- int err = 0;
+ int cgfd;
cgfd = cgroup_setup_and_join(CG_PATH);
- if (cgfd < 0)
- goto err;
+ if (!ASSERT_OK_FD(cgfd < 0, "create_cgroup"))
+ goto out;
- /* Use libbpf 1.0 API mode */
- libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+ if (!ASSERT_OK(run_tests(cgfd), "run_tests"))
+ goto out;
- if (run_tests(cgfd))
- goto err;
-
- goto out;
-err:
- err = -1;
out:
close(cgfd);
cleanup_cgroup_environment();
- return err;
+ return;
}