On 10/10/24 06:16, zhouyuhang wrote:
From: zhouyuhang <zhouyuhang@xxxxxxxxxx>
The libcap commit aca076443591 ("Make cap_t operations thread safe.") added a
__u8 mutex at the beginning of the struct _cap_struct,it changes the offset of
the members in the structure that breaks the assumption made in the "struct libcap"
definition in clone3_cap_checkpoint_restore.c.So use the capget and capset syscall
directly and remove the libcap library dependency like the commit 663af70aabb7
("bpf: selftests: Add helpers to directly use the capget and capset syscall") does.
NIT: grammar and comma spacing. Please fix those for readability.
e.g: Change "struct _cap_struct,it" to "struct _cap_struct, it"
Fix others as well.
Signed-off-by: zhouyuhang <zhouyuhang@xxxxxxxxxx>
---
tools/testing/selftests/clone3/Makefile | 1 -
.../clone3/clone3_cap_checkpoint_restore.c | 60 +++++++++----------
2 files changed, 28 insertions(+), 33 deletions(-)
diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
index 84832c369a2e..59d26e8da8d2 100644
--- a/tools/testing/selftests/clone3/Makefile
+++ b/tools/testing/selftests/clone3/Makefile
@@ -1,6 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
CFLAGS += -g -std=gnu99 $(KHDR_INCLUDES)
-LDLIBS += -lcap
TEST_GEN_PROGS := clone3 clone3_clear_sighand clone3_set_tid \
clone3_cap_checkpoint_restore
diff --git a/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c b/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c
index 3c196fa86c99..111912e2aead 100644
--- a/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c
+++ b/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c
@@ -15,7 +15,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
-#include <sys/capability.h>
+#include <linux/capability.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/types.h>
@@ -27,6 +27,13 @@
#include "../kselftest_harness.h"
#include "clone3_selftests.h"
+#ifndef CAP_CHECKPOINT_RESTORE
+#define CAP_CHECKPOINT_RESTORE 40
+#endif
+
Why is this necessary? This is defined in linux/capability.h.
+int capget(cap_user_header_t header, cap_user_data_t data);
+int capset(cap_user_header_t header, const cap_user_data_t data);
In general prototypes such as these should be defined in header
file. Why are we defining these here?
These are defined in sys/capability.h
I don't understand this change. You are removing sys/capability.h
which requires you to add these defines here. This doesn't
sound like a correct solution to me.
+
static void child_exit(int ret)
{
fflush(stdout);
@@ -87,47 +94,36 @@ static int test_clone3_set_tid(struct __test_metadata *_metadata,
return ret;
}
-struct libcap {
- struct __user_cap_header_struct hdr;
- struct __user_cap_data_struct data[2];
-};
-
static int set_capability(void)
{
- cap_value_t cap_values[] = { CAP_SETUID, CAP_SETGID };
- struct libcap *cap;
- int ret = -1;
- cap_t caps;
-
- caps = cap_get_proc();
- if (!caps) {
- perror("cap_get_proc");
+ struct __user_cap_data_struct data[2];
+ struct __user_cap_header_struct hdr = {
+ .version = _LINUX_CAPABILITY_VERSION_3,
+ };
+ __u32 cap0 = 1 << CAP_SETUID | 1 << CAP_SETGID;
+ __u32 cap1 = 1 << (CAP_CHECKPOINT_RESTORE - 32);
+ int ret;
+
+ ret = capget(&hdr, data);
+ if (ret) {
+ perror("capget");
return -1;
}
/* Drop all capabilities */
- if (cap_clear(caps)) {
- perror("cap_clear");
- goto out;
- }
+ memset(&data, 0, sizeof(data));
- cap_set_flag(caps, CAP_EFFECTIVE, 2, cap_values, CAP_SET);
- cap_set_flag(caps, CAP_PERMITTED, 2, cap_values, CAP_SET);
+ data[0].effective |= cap0;
+ data[0].permitted |= cap0;
- cap = (struct libcap *) caps;
+ data[1].effective |= cap1;
+ data[1].permitted |= cap1;
- /* 40 -> CAP_CHECKPOINT_RESTORE */
- cap->data[1].effective |= 1 << (40 - 32);
- cap->data[1].permitted |= 1 << (40 - 32);
-
- if (cap_set_proc(caps)) {
- perror("cap_set_proc");
- goto out;
+ ret = capset(&hdr, data);
+ if (ret) {
+ perror("capset");
+ return -1;
}
- ret = 0;
-out:
- if (cap_free(caps))
- perror("cap_free");
return ret;
}
thanks,
-- Shuah
