From: Rong Tao <[email protected]>
move libbpf_strlcpy() to bpf_util.h, and replace strncpy() with
libbpf_strlcpy(), fix compile warning.
Compile samples/bpf, warning:
$ cd samples/bpf
$ make
...
cgroup_helpers.c: In function ‘__enable_controllers’:
cgroup_helpers.c:80:17: warning: ‘strncpy’ specified bound 4097 equals destination size [-Wstringop-truncation]
80 | strncpy(enable, controllers, sizeof(enable));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Rong Tao <[email protected]>
---
tools/testing/selftests/bpf/bpf_util.h | 19 +++++++++++++++++++
tools/testing/selftests/bpf/cgroup_helpers.c | 3 ++-
tools/testing/selftests/bpf/xsk.c | 20 +-------------------
3 files changed, 22 insertions(+), 20 deletions(-)
diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h
index a3352a64c067..bf78212ff6e9 100644
--- a/tools/testing/selftests/bpf/bpf_util.h
+++ b/tools/testing/selftests/bpf/bpf_util.h
@@ -20,6 +20,25 @@ static inline unsigned int bpf_num_possible_cpus(void)
return possible_cpus;
}
+/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
+ * is zero-terminated string no matter what (unless sz == 0, in which case
+ * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
+ * in what is returned. Given this is internal helper, it's trivial to extend
+ * this, when necessary. Use this instead of strncpy inside libbpf source code.
+ */
+static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
+{
+ size_t i;
+
+ if (sz == 0)
+ return;
+
+ sz--;
+ for (i = 0; i < sz && src[i]; i++)
+ dst[i] = src[i];
+ dst[i] = '\0';
+}
+
#define __bpf_percpu_val_align __attribute__((__aligned__(8)))
#define BPF_DECLARE_PERCPU(type, name) \
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index e914cc45b766..e33b70e509da 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -13,6 +13,7 @@
#include <ftw.h>
#include "cgroup_helpers.h"
+#include "bpf_util.h"
/*
* To avoid relying on the system setup, when setup_cgroup_env is called
@@ -77,7 +78,7 @@ static int __enable_controllers(const char *cgroup_path, const char *controllers
enable[len] = 0;
close(fd);
} else {
- strncpy(enable, controllers, sizeof(enable));
+ libbpf_strlcpy(enable, controllers, sizeof(enable));
}
snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path);
diff --git a/tools/testing/selftests/bpf/xsk.c b/tools/testing/selftests/bpf/xsk.c
index 0b3ff49c740d..cf6e9ab37b1b 100644
--- a/tools/testing/selftests/bpf/xsk.c
+++ b/tools/testing/selftests/bpf/xsk.c
@@ -33,6 +33,7 @@
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "xsk.h"
+#include "bpf_util.h"
#ifndef SOL_XDP
#define SOL_XDP 283
@@ -521,25 +522,6 @@ static int xsk_create_bpf_link(struct xsk_socket *xsk)
return 0;
}
-/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
- * is zero-terminated string no matter what (unless sz == 0, in which case
- * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
- * in what is returned. Given this is internal helper, it's trivial to extend
- * this, when necessary. Use this instead of strncpy inside libbpf source code.
- */
-static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
-{
- size_t i;
-
- if (sz == 0)
- return;
-
- sz--;
- for (i = 0; i < sz && src[i]; i++)
- dst[i] = src[i];
- dst[i] = '\0';
-}
-
static int xsk_get_max_queues(struct xsk_socket *xsk)
{
struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
--
2.31.1
On 11/1/22 3:23 PM, Rong Tao wrote:
> From: Rong Tao <[email protected]>
>
> move libbpf_strlcpy() to bpf_util.h, and replace strncpy() with
> libbpf_strlcpy(), fix compile warning.
>
> Compile samples/bpf, warning:
> $ cd samples/bpf
> $ make
> ...
> cgroup_helpers.c: In function ‘__enable_controllers’:
> cgroup_helpers.c:80:17: warning: ‘strncpy’ specified bound 4097 equals destination size [-Wstringop-truncation]
> 80 | strncpy(enable, controllers, sizeof(enable));
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Signed-off-by: Rong Tao <[email protected]>
Nope, BPF CI fails once again with:
https://github.com/kernel-patches/bpf/actions/runs/3370230622/jobs/5590876906
[...]
TEST-OBJ [test_progs-no_alu32] connect_ping.test.o
TEST-OBJ [test_progs-no_alu32] map_kptr.test.o
In file included from /tmp/work/bpf/bpf/tools/testing/selftests/bpf/prog_tests/perf_branches.c:7:
/tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/libbpf_internal.h:200:20: error: redefinition of 'libbpf_strlcpy'
static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
^
/tmp/work/bpf/bpf/tools/testing/selftests/bpf/bpf_util.h:29:20: note: previous definition is here
static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
^
1 error generated.
TEST-OBJ [test_progs-no_alu32] hash_large_key.test.o
make: *** [Makefile:539: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/no_alu32/perf_branches.test.o] Error 1
make: *** Waiting for unfinished jobs....
make: Leaving directory '/tmp/work/bpf/bpf/tools/testing/selftests/bpf'
Error: Process completed with exit code 2.
Please do not send broken stuff that was not even compile tested.
Here's a small howto for running BPF selftests:
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/tools/testing/selftests/bpf/README.rst#n48
From: Rong Tao <[email protected]>
Move libbpf_strlcpy() to libbpf_common.h, and replace strncpy() with
libbpf_strlcpy(), fix compile warning.
We can't use libbpf_internal.h directly, because it introduces a lot of
header dependency issues. So move libbpf_strlcpy() into libbpf_common.h,
and if you need to use the libbpf_strlcpy() function, you need to include
the header file libbpf.h
How to reproduce this compilation warning:
$ make -C samples/bpf
cgroup_helpers.c: In function ‘__enable_controllers’:
cgroup_helpers.c:80:17: warning: ‘strncpy’ specified bound 4097 equals destination size [-Wstringop-truncation]
80 | strncpy(enable, controllers, sizeof(enable));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Rong Tao <[email protected]>
---
tools/lib/bpf/libbpf_common.h | 19 +++++++++++++++++++
tools/lib/bpf/libbpf_internal.h | 19 -------------------
tools/testing/selftests/bpf/cgroup_helpers.c | 3 ++-
tools/testing/selftests/bpf/xsk.c | 19 -------------------
4 files changed, 21 insertions(+), 39 deletions(-)
diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
index 9a7937f339df..9d5132e0bec9 100644
--- a/tools/lib/bpf/libbpf_common.h
+++ b/tools/lib/bpf/libbpf_common.h
@@ -70,4 +70,23 @@
}; \
})
+/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
+ * is zero-terminated string no matter what (unless sz == 0, in which case
+ * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
+ * in what is returned. Given this is internal helper, it's trivial to extend
+ * this, when necessary. Use this instead of strncpy inside libbpf source code.
+ */
+static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
+{
+ size_t i;
+
+ if (sz == 0)
+ return;
+
+ sz--;
+ for (i = 0; i < sz && src[i]; i++)
+ dst[i] = src[i];
+ dst[i] = '\0';
+}
+
#endif /* __LIBBPF_LIBBPF_COMMON_H */
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 377642ff51fc..902110ffb7a6 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -191,25 +191,6 @@ static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size)
return realloc(ptr, total);
}
-/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
- * is zero-terminated string no matter what (unless sz == 0, in which case
- * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
- * in what is returned. Given this is internal helper, it's trivial to extend
- * this, when necessary. Use this instead of strncpy inside libbpf source code.
- */
-static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
-{
- size_t i;
-
- if (sz == 0)
- return;
-
- sz--;
- for (i = 0; i < sz && src[i]; i++)
- dst[i] = src[i];
- dst[i] = '\0';
-}
-
__u32 get_kernel_version(void);
struct btf;
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index e914cc45b766..e3bfe2b13018 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -11,6 +11,7 @@
#include <fcntl.h>
#include <unistd.h>
#include <ftw.h>
+#include <bpf/libbpf.h>
#include "cgroup_helpers.h"
@@ -77,7 +78,7 @@ static int __enable_controllers(const char *cgroup_path, const char *controllers
enable[len] = 0;
close(fd);
} else {
- strncpy(enable, controllers, sizeof(enable));
+ libbpf_strlcpy(enable, controllers, sizeof(enable));
}
snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path);
diff --git a/tools/testing/selftests/bpf/xsk.c b/tools/testing/selftests/bpf/xsk.c
index 0b3ff49c740d..4b6890e2a0a9 100644
--- a/tools/testing/selftests/bpf/xsk.c
+++ b/tools/testing/selftests/bpf/xsk.c
@@ -521,25 +521,6 @@ static int xsk_create_bpf_link(struct xsk_socket *xsk)
return 0;
}
-/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
- * is zero-terminated string no matter what (unless sz == 0, in which case
- * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
- * in what is returned. Given this is internal helper, it's trivial to extend
- * this, when necessary. Use this instead of strncpy inside libbpf source code.
- */
-static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
-{
- size_t i;
-
- if (sz == 0)
- return;
-
- sz--;
- for (i = 0; i < sz && src[i]; i++)
- dst[i] = src[i];
- dst[i] = '\0';
-}
-
static int xsk_get_max_queues(struct xsk_socket *xsk)
{
struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
--
2.31.1
On Wed, Nov 2, 2022 at 5:59 AM Rong Tao <[email protected]> wrote:
>
> From: Rong Tao <[email protected]>
>
> Move libbpf_strlcpy() to libbpf_common.h, and replace strncpy() with
> libbpf_strlcpy(), fix compile warning.
>
> We can't use libbpf_internal.h directly, because it introduces a lot of
> header dependency issues. So move libbpf_strlcpy() into libbpf_common.h,
> and if you need to use the libbpf_strlcpy() function, you need to include
> the header file libbpf.h
well, no, we should make libbpf_strlcpy as a public API, it's internal
helper. libbpf_common.h is part of libbpf's UAPI.
So don't touch libbpf, please. Name the function as _strlcpy or
something like that, put it into bpf_util.h and use that from
selftests.
>
> How to reproduce this compilation warning:
>
> $ make -C samples/bpf
> cgroup_helpers.c: In function ‘__enable_controllers’:
> cgroup_helpers.c:80:17: warning: ‘strncpy’ specified bound 4097 equals destination size [-Wstringop-truncation]
> 80 | strncpy(enable, controllers, sizeof(enable));
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Signed-off-by: Rong Tao <[email protected]>
> ---
> tools/lib/bpf/libbpf_common.h | 19 +++++++++++++++++++
> tools/lib/bpf/libbpf_internal.h | 19 -------------------
> tools/testing/selftests/bpf/cgroup_helpers.c | 3 ++-
> tools/testing/selftests/bpf/xsk.c | 19 -------------------
> 4 files changed, 21 insertions(+), 39 deletions(-)
>
[...]
From: Rong Tao <[email protected]>
Copy libbpf_strlcpy() from libbpf_internal.h to bpf_util.h, and rename it
to bpf_strlcpy(), then replace selftests strncpy()/libbpf_strlcpy() with
bpf_strlcpy(), fix compile warning.
The libbpf_internal.h header cannot be used directly here, because
references to cgroup_helpers.c in samples/bpf will generate compilation
errors. We also can't add libbpf_strlcpy() directly to bpf_util.h,
because the definition of libbpf_strlcpy() in libbpf_internal.h is
duplicated. In order not to modify the libbpf code, add a new function
bpf_strlcpy() to selftests bpf_util.h.
How to reproduce this compilation warning:
$ make -C samples/bpf
cgroup_helpers.c: In function ‘__enable_controllers’:
cgroup_helpers.c:80:17: warning: ‘strncpy’ specified bound 4097 equals destination size [-Wstringop-truncation]
80 | strncpy(enable, controllers, sizeof(enable));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Rong Tao <[email protected]>
---
tools/testing/selftests/bpf/bpf_util.h | 19 ++++++++++++++
tools/testing/selftests/bpf/cgroup_helpers.c | 3 ++-
tools/testing/selftests/bpf/xsk.c | 26 +++-----------------
3 files changed, 25 insertions(+), 23 deletions(-)
diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h
index a3352a64c067..10587a29b967 100644
--- a/tools/testing/selftests/bpf/bpf_util.h
+++ b/tools/testing/selftests/bpf/bpf_util.h
@@ -20,6 +20,25 @@ static inline unsigned int bpf_num_possible_cpus(void)
return possible_cpus;
}
+/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
+ * is zero-terminated string no matter what (unless sz == 0, in which case
+ * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
+ * in what is returned. Given this is internal helper, it's trivial to extend
+ * this, when necessary. Use this instead of strncpy inside libbpf source code.
+ */
+static inline void bpf_strlcpy(char *dst, const char *src, size_t sz)
+{
+ size_t i;
+
+ if (sz == 0)
+ return;
+
+ sz--;
+ for (i = 0; i < sz && src[i]; i++)
+ dst[i] = src[i];
+ dst[i] = '\0';
+}
+
#define __bpf_percpu_val_align __attribute__((__aligned__(8)))
#define BPF_DECLARE_PERCPU(type, name) \
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index e914cc45b766..dd1aa5afcf5a 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -13,6 +13,7 @@
#include <ftw.h>
#include "cgroup_helpers.h"
+#include "bpf_util.h"
/*
* To avoid relying on the system setup, when setup_cgroup_env is called
@@ -77,7 +78,7 @@ static int __enable_controllers(const char *cgroup_path, const char *controllers
enable[len] = 0;
close(fd);
} else {
- strncpy(enable, controllers, sizeof(enable));
+ bpf_strlcpy(enable, controllers, sizeof(enable));
}
snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path);
diff --git a/tools/testing/selftests/bpf/xsk.c b/tools/testing/selftests/bpf/xsk.c
index 0b3ff49c740d..39d349509ba4 100644
--- a/tools/testing/selftests/bpf/xsk.c
+++ b/tools/testing/selftests/bpf/xsk.c
@@ -33,6 +33,7 @@
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "xsk.h"
+#include "bpf_util.h"
#ifndef SOL_XDP
#define SOL_XDP 283
@@ -521,25 +522,6 @@ static int xsk_create_bpf_link(struct xsk_socket *xsk)
return 0;
}
-/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
- * is zero-terminated string no matter what (unless sz == 0, in which case
- * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
- * in what is returned. Given this is internal helper, it's trivial to extend
- * this, when necessary. Use this instead of strncpy inside libbpf source code.
- */
-static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
-{
- size_t i;
-
- if (sz == 0)
- return;
-
- sz--;
- for (i = 0; i < sz && src[i]; i++)
- dst[i] = src[i];
- dst[i] = '\0';
-}
-
static int xsk_get_max_queues(struct xsk_socket *xsk)
{
struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
@@ -552,7 +534,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk)
return -errno;
ifr.ifr_data = (void *)&channels;
- libbpf_strlcpy(ifr.ifr_name, ctx->ifname, IFNAMSIZ);
+ bpf_strlcpy(ifr.ifr_name, ctx->ifname, IFNAMSIZ);
err = ioctl(fd, SIOCETHTOOL, &ifr);
if (err && errno != EOPNOTSUPP) {
ret = -errno;
@@ -771,7 +753,7 @@ static int xsk_create_xsk_struct(int ifindex, struct xsk_socket *xsk)
}
ctx->ifindex = ifindex;
- libbpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
+ bpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
xsk->ctx = ctx;
xsk->ctx->has_bpf_link = xsk_probe_bpf_link();
@@ -958,7 +940,7 @@ static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk,
ctx->refcount = 1;
ctx->umem = umem;
ctx->queue_id = queue_id;
- libbpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
+ bpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
ctx->fill = fill;
ctx->comp = comp;
--
2.31.1
Hello:
This patch was applied to bpf/bpf-next.git (master)
by Andrii Nakryiko <[email protected]>:
On Fri, 4 Nov 2022 09:27:54 +0800 you wrote:
> From: Rong Tao <[email protected]>
>
> Copy libbpf_strlcpy() from libbpf_internal.h to bpf_util.h, and rename it
> to bpf_strlcpy(), then replace selftests strncpy()/libbpf_strlcpy() with
> bpf_strlcpy(), fix compile warning.
>
> The libbpf_internal.h header cannot be used directly here, because
> references to cgroup_helpers.c in samples/bpf will generate compilation
> errors. We also can't add libbpf_strlcpy() directly to bpf_util.h,
> because the definition of libbpf_strlcpy() in libbpf_internal.h is
> duplicated. In order not to modify the libbpf code, add a new function
> bpf_strlcpy() to selftests bpf_util.h.
>
> [...]
Here is the summary with links:
- [bpf-next] selftests/bpf: cgroup_helpers.c: Fix strncpy() fortify warning
https://git.kernel.org/bpf/bpf-next/c/b3c09fdca113
You are awesome, thank you!
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