bpf: fix _htons occurences in test_progs

Dave reported that on sparc test_progs generates buggy swapped
eth->h_proto protocol comparisons:

  10: (15) if r3 == 0xdd86 goto pc+9
   R0=imm2,min_value=2,max_value=2 R1=pkt(id=0,off=0,r=14) R2=pkt_end R3=inv
   R4=pkt(id=0,off=14,r=14) R5=inv56 R10=fp

This is due to the unconditional ...

  #define htons __builtin_bswap16
  #define ntohs __builtin_bswap16

... in test_progs that causes this. Make use of asm/byteorder.h
and use __constant_htons() where possible and only perform the
bswap16 when on little endian in non-constant case.

Fixes: 6882804c91 ("selftests/bpf: add a test for overlapping packet range checks")
Fixes: 3782161362 ("selftests/bpf: add l4 load balancer test based on sched_cls")
Reported-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann
2017-04-27 01:39:34 +02:00
committed by David S. Miller
parent d24f7c7fb9
commit 43bcf707cc
4 changed files with 31 additions and 15 deletions

View File

@@ -6,6 +6,25 @@
#include <string.h>
#include <errno.h>
#include <asm/byteorder.h>
#if __BYTE_ORDER == __LITTLE_ENDIAN
# define __bpf_ntohs(x) __builtin_bswap16(x)
# define __bpf_htons(x) __builtin_bswap16(x)
#elif __BYTE_ORDER == __BIG_ENDIAN
# define __bpf_ntohs(x) (x)
# define __bpf_htons(x) (x)
#else
# error "Fix your __BYTE_ORDER?!"
#endif
#define bpf_htons(x) \
(__builtin_constant_p(x) ? \
__constant_htons(x) : __bpf_htons(x))
#define bpf_ntohs(x) \
(__builtin_constant_p(x) ? \
__constant_ntohs(x) : __bpf_ntohs(x))
static inline unsigned int bpf_num_possible_cpus(void)
{
static const char *fcpu = "/sys/devices/system/cpu/possible";