diff options
| -rw-r--r-- | src/plugins/unittest/util_test.c | 62 | ||||
| -rw-r--r-- | src/vppinfra/hash.c | 51 |
2 files changed, 109 insertions, 4 deletions
diff --git a/src/plugins/unittest/util_test.c b/src/plugins/unittest/util_test.c index d2f2715d763..67fe0093ab8 100644 --- a/src/plugins/unittest/util_test.c +++ b/src/plugins/unittest/util_test.c @@ -14,6 +14,7 @@ */ #include <vlib/vlib.h> +#include <sys/mman.h> static clib_error_t * test_crash_command_fn (vlib_main_t * vm, @@ -45,6 +46,67 @@ VLIB_CLI_COMMAND (test_crash_command, static) = }; /* *INDENT-ON* */ +static clib_error_t * +test_hash_command_fn (vlib_main_t * vm, + unformat_input_t * input, vlib_cli_command_t * cmd) +{ + uword hash1, hash2; + u8 *baseaddr; + u8 *key_loc; + + baseaddr = mmap (NULL, 8192, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0 /* offset */ ); + + if (baseaddr == 0) + { + clib_unix_warning ("mmap"); + return 0; + } + + if (mprotect (baseaddr + (4 << 10), (4 << 10), PROT_NONE) < 0) + { + clib_unix_warning ("mprotect"); + return 0; + } + + key_loc = baseaddr + (4 << 10) - 4; + key_loc[0] = 0xde; + key_loc[1] = 0xad; + key_loc[2] = 0xbe; + key_loc[3] = 0xef; + + hash1 = hash_memory (key_loc, 4, 0ULL); + + vlib_cli_output (vm, "hash1 is %llx", hash1); + + key_loc = baseaddr; + + key_loc[0] = 0xde; + key_loc[1] = 0xad; + key_loc[2] = 0xbe; + key_loc[3] = 0xef; + + hash2 = hash_memory (key_loc, 4, 0ULL); + + vlib_cli_output (vm, "hash2 is %llx", hash2); + + if (hash1 == hash2) + vlib_cli_output (vm, "PASS..."); + else + vlib_cli_output (vm, "FAIL..."); + + return 0; +} + +/* *INDENT-OFF* */ +VLIB_CLI_COMMAND (test_hash_command, static) = +{ + .path = "test hash_memory", + .short_help = "page boundary crossing test", + .function = test_hash_command_fn, +}; +/* *INDENT-ON* */ + /* * fd.io coding-style-patch-verification: ON * diff --git a/src/vppinfra/hash.c b/src/vppinfra/hash.c index eae79d48592..b6f0901dd68 100644 --- a/src/vppinfra/hash.c +++ b/src/vppinfra/hash.c @@ -103,14 +103,32 @@ zap64 (u64 x, word n) * Therefore all the 8 Bytes of the u64 are systematically read, which * rightfully causes address-sanitizer to raise an error on smaller inputs. * - * However the invalid Bytes are discarded within zap64(), whicj is why + * However the invalid Bytes are discarded within zap64(), which is why * this can be silenced safely. + * + * The above is true *unless* the extra bytes cross a page boundary + * into unmapped or no-access space, hence the boundary crossing check. */ static inline u64 __attribute__ ((no_sanitize_address)) hash_memory64 (void *p, word n_bytes, u64 state) { u64 *q = p; u64 a, b, c, n; + int page_boundary_crossing; + u64 start_addr, end_addr; + union + { + u8 as_u8[8]; + u64 as_u64; + } tmp; + + /* + * If the request crosses a 4k boundary, it's not OK to assume + * that the zap64 game is safe. 4k is the minimum known page size. + */ + start_addr = (u64) p; + end_addr = start_addr + n_bytes + 7; + page_boundary_crossing = (start_addr >> 12) != (end_addr >> 12); a = b = 0x9e3779b97f4a7c13LL; c = state; @@ -133,18 +151,43 @@ hash_memory64 (void *p, word n_bytes, u64 state) a += clib_mem_unaligned (q + 0, u64); b += clib_mem_unaligned (q + 1, u64); if (n % sizeof (u64)) - c += zap64 (clib_mem_unaligned (q + 2, u64), n % sizeof (u64)) << 8; + { + if (PREDICT_TRUE (page_boundary_crossing == 0)) + c += + zap64 (clib_mem_unaligned (q + 2, u64), n % sizeof (u64)) << 8; + else + { + clib_memcpy_fast (tmp.as_u8, q + 2, n % sizeof (u64)); + c += zap64 (tmp.as_u64, n % sizeof (u64)) << 8; + } + } break; case 1: a += clib_mem_unaligned (q + 0, u64); if (n % sizeof (u64)) - b += zap64 (clib_mem_unaligned (q + 1, u64), n % sizeof (u64)); + { + if (PREDICT_TRUE (page_boundary_crossing == 0)) + b += zap64 (clib_mem_unaligned (q + 1, u64), n % sizeof (u64)); + else + { + clib_memcpy_fast (tmp.as_u8, q + 1, n % sizeof (u64)); + b += zap64 (tmp.as_u64, n % sizeof (u64)); + } + } break; case 0: if (n % sizeof (u64)) - a += zap64 (clib_mem_unaligned (q + 0, u64), n % sizeof (u64)); + { + if (PREDICT_TRUE (page_boundary_crossing == 0)) + a += zap64 (clib_mem_unaligned (q + 0, u64), n % sizeof (u64)); + else + { + clib_memcpy_fast (tmp.as_u8, q, n % sizeof (u64)); + a += zap64 (tmp.as_u64, n % sizeof (u64)); + } + } break; } |