kernel.git/tools/lib/bpf/xsk.c, branch linux-5.2.y

libbpf: silence GCC8 warning about string truncation

2019-08-29T06:30:05Z

[ Upstream commit cb8ffde5694ae5fffb456eae932aac442aa3a207 ] Despite a proper NULL-termination after strncpy(..., ..., IFNAMSIZ - 1), GCC8 still complains about *expected* string truncation: xsk.c:330:2: error: 'strncpy' output may be truncated copying 15 bytes from a string of length 15 [-Werror=stringop-truncation] strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1); This patch gets rid of the issue altogether by using memcpy instead. There is no performance regression, as strncpy will still copy and fill all of the bytes anyway. v1->v2: - rebase against bpf tree. Cc: Magnus Karlsson Signed-off-by: Andrii Nakryiko Acked-by: Magnus Karlsson Acked-by: Song Liu Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: fix using uninitialized ioctl results

2019-08-29T06:30:04Z

[ Upstream commit decb705e01a5d325c9876b9674043cde4b54f0db ] 'channels.max_combined' initialized only on ioctl success and errno is only valid on ioctl failure. The code doesn't produce any runtime issues, but makes memory sanitizers angry: Conditional jump or move depends on uninitialised value(s) at 0x55C056F: xsk_get_max_queues (xsk.c:336) by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354) by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447) by 0x55C0E57: xsk_socket__create (xsk.c:601) Uninitialised value was created by a stack allocation at 0x55C04CD: xsk_get_max_queues (xsk.c:318) Additionally fixed warning on uninitialized bytes in ioctl arguments: Syscall param ioctl(SIOCETHTOOL) points to uninitialised byte(s) at 0x648D45B: ioctl (in /usr/lib64/libc-2.28.so) by 0x55C0546: xsk_get_max_queues (xsk.c:330) by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354) by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447) by 0x55C0E57: xsk_socket__create (xsk.c:601) Address 0x1ffefff378 is on thread 1's stack in frame #1, created by xsk_get_max_queues (xsk.c:318) Uninitialised value was created by a stack allocation at 0x55C04CD: xsk_get_max_queues (xsk.c:318) CC: Magnus Karlsson Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Ilya Maximets Acked-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: fix another GCC8 warning for strncpy

2019-07-26T07:10:47Z

[ Upstream commit 763ff0e7d9c72e7094b31e7fb84a859be9325635 ] Similar issue was fixed in cdfc7f888c2a ("libbpf: fix GCC8 warning for strncpy") already. This one was missed. Fixing now. Cc: Magnus Karlsson Signed-off-by: Andrii Nakryiko Acked-by: Magnus Karlsson Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: fix GCC8 warning for strncpy

2019-07-26T07:10:43Z

[ Upstream commit cdfc7f888c2a355b01308e97c6df108f1c2b64e8 ] GCC8 started emitting warning about using strncpy with number of bytes exactly equal destination size, which is generally unsafe, as can lead to non-zero terminated string being copied. Use IFNAMSIZ - 1 as number of bytes to ensure name is always zero-terminated. Signed-off-by: Andrii Nakryiko Cc: Magnus Karlsson Acked-by: Yonghong Song Acked-by: Magnus Karlsson Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

libbpf: move logging helpers into libbpf_internal.h

2019-05-16T19:47:47Z

libbpf_util.h header was recently exposed as public as a dependency of xsk.h. In addition to memory barriers, it contained logging helpers, which are not supposed to be exposed. This patch moves those into libbpf_internal.h, which is kept as an internal header. Cc: Stanislav Fomichev Cc: Daniel Borkmann Fixes: 7080da890984 ("libbpf: add libbpf_util.h to header install.") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov

libbpf: remove unnecessary cast-to-void

2019-05-06T09:35:17Z

The patches with fixes tags added a cast-to-void in the places when the return value of a function was ignored. This is not common practice in the kernel, and is therefore removed in this patch. Reported-by: Daniel Borkmann Fixes: 5750902a6e9b ("libbpf: proper XSKMAP cleanup") Fixes: 0e6741f09297 ("libbpf: fix invalid munmap call") Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann

libbpf: proper XSKMAP cleanup

2019-05-05T06:26:22Z

The bpf_map_update_elem() function, when used on an XSKMAP, will fail if not a valid AF_XDP socket is passed as value. Therefore, this is function cannot be used to clear the XSKMAP. Instead, the bpf_map_delete_elem() function should be used for that. This patch also simplifies the code by breaking up xsk_update_bpf_maps() into three smaller functions. Reported-by: William Tu Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Björn Töpel Tested-by: William Tu Signed-off-by: Alexei Starovoitov

libbpf: fix invalid munmap call

2019-05-05T06:26:22Z

When unmapping the AF_XDP memory regions used for the rings, an invalid address was passed to the munmap() calls. Instead of passing the beginning of the memory region, the descriptor region was passed to munmap. When the userspace application tried to tear down an AF_XDP socket, the operation failed and the application would still have a reference to socket it wished to get rid of. Reported-by: William Tu Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Björn Töpel Tested-by: William Tu Signed-off-by: Alexei Starovoitov

libbpf: fix crash in XDP socket part with new larger BPF_LOG_BUF_SIZE

2019-04-10T07:51:50Z

In commit da11b417583e ("libbpf: teach libbpf about log_level bit 2"), the BPF_LOG_BUF_SIZE was increased to 16M. The XDP socket part of libbpf allocated the log_buf on the stack, but for the new 16M buffer size this is not going to work. Change the code so it uses a 16K buffer instead. Fixes: da11b417583e ("libbpf: teach libbpf about log_level bit 2") Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann

libbpf: fix to reject unknown flags in xsk_socket__create()

2019-03-12T20:58:18Z

In xsk_socket__create(), the libbpf_flags field was not checked for setting currently unused/unknown flags. This patch fixes that by returning -EINVAL if the user has set any flag that is not in use at this point in time. Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Magnus Karlsson Reviewed-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann