linux/tools
Daniel Borkmann 36f9814a49 bpf: fix uapi hole for 32 bit compat applications
In 64 bit, we have a 4 byte hole between ifindex and netns_dev in the
case of struct bpf_map_info but also struct bpf_prog_info. In net-next
commit b85fab0e67 ("bpf: Add gpl_compatible flag to struct bpf_prog_info")
added a bitfield into it to expose some flags related to programs. Thus,
add an unnamed __u32 bitfield for both so that alignment keeps the same
in both 32 and 64 bit cases, and can be naturally extended from there
as in b85fab0e67.

Before:

  # file test.o
  test.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped
  # pahole test.o
  struct bpf_map_info {
	__u32                      type;                 /*     0     4 */
	__u32                      id;                   /*     4     4 */
	__u32                      key_size;             /*     8     4 */
	__u32                      value_size;           /*    12     4 */
	__u32                      max_entries;          /*    16     4 */
	__u32                      map_flags;            /*    20     4 */
	char                       name[16];             /*    24    16 */
	__u32                      ifindex;              /*    40     4 */
	__u64                      netns_dev;            /*    44     8 */
	__u64                      netns_ino;            /*    52     8 */

	/* size: 64, cachelines: 1, members: 10 */
	/* padding: 4 */
  };

After (same as on 64 bit):

  # file test.o
  test.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped
  # pahole test.o
  struct bpf_map_info {
	__u32                      type;                 /*     0     4 */
	__u32                      id;                   /*     4     4 */
	__u32                      key_size;             /*     8     4 */
	__u32                      value_size;           /*    12     4 */
	__u32                      max_entries;          /*    16     4 */
	__u32                      map_flags;            /*    20     4 */
	char                       name[16];             /*    24    16 */
	__u32                      ifindex;              /*    40     4 */

	/* XXX 4 bytes hole, try to pack */

	__u64                      netns_dev;            /*    48     8 */
	__u64                      netns_ino;            /*    56     8 */
	/* --- cacheline 1 boundary (64 bytes) --- */

	/* size: 64, cachelines: 1, members: 10 */
	/* sum members: 60, holes: 1, sum holes: 4 */
  };

Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Reported-by: Eugene Syromiatnikov <esyr@redhat.com>
Fixes: 52775b33bb ("bpf: offload: report device information about offloaded maps")
Fixes: 675fc275a3 ("bpf: offload: report device information for offloaded programs")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-06-01 20:41:35 -07:00
..
accounting License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
arch tools headers kvm: Sync ARM UAPI headers with the kernel sources 2018-05-07 15:23:46 -03:00
bpf bpf: fix uninitialized variable in bpf tools 2018-04-26 22:23:02 +02:00
build Kbuild: fix # escaping in .cmd files for future Make 2018-04-11 00:03:02 +09:00
cgroup tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
firewire License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
gpio Linux 4.16-rc5 2018-03-18 17:48:59 +01:00
hv tools: hv: include string.h in hv_fcopy_daemon 2018-03-06 09:57:16 -08:00
iio tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
include bpf: fix uapi hole for 32 bit compat applications 2018-06-01 20:41:35 -07:00
kvm/kvm_stat tools/kvm_stat: Remove unused function 2018-03-28 22:47:06 +02:00
laptop tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
leds tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
lib tools: bpf: handle NULL return in bpf_prog_load_xattr() 2018-05-11 00:20:53 +02:00
memory-model tools/memory-model: Finish the removal of rb-dep, smp_read_barrier_depends(), and lockless_dereference() 2018-03-10 10:22:23 +01:00
nfsd License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
objtool objtool: Detect RIP-relative switch table references, part 2 2018-05-19 08:10:04 +02:00
pci License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pcmcia License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
perf perf tools: Add missing newline when parsing empty BPF proggie 2018-05-11 12:10:02 -03:00
power tools: power/acpi, revert to LD = gcc 2018-05-04 11:24:22 +02:00
scripts Kbuild: fix # escaping in .cmd files for future Make 2018-04-11 00:03:02 +09:00
spi tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
testing Merge branch 'akpm' (patches from Andrew) 2018-05-25 20:24:28 -07:00
thermal/tmon tools/thermal: tmon: fix for segfault 2018-03-27 09:51:23 +02:00
time
usb usbip: tools: usbipd: exclude exported devices from exportable device list 2018-03-22 13:08:20 +01:00
virtio ptr_ring: fix build 2018-03-20 03:17:37 +02:00
vm tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
wmi tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
Makefile platform-drivers-x86 for v4.15-1 2017-11-18 10:26:57 -08:00