diff options
| -rw-r--r-- | util/cbmem/cbmem.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/util/cbmem/cbmem.c b/util/cbmem/cbmem.c index 7b434d874c..e60505222a 100644 --- a/util/cbmem/cbmem.c +++ b/util/cbmem/cbmem.c @@ -61,6 +61,36 @@ static uint64_t lbtable_address; static size_t lbtable_size; /* + * Some architectures map /dev/mem memory in a way that doesn't support + * unaligned accesses. Most normal libc memcpy()s aren't safe to use in this + * case, so build our own which makes sure to never do unaligned accesses on + * *src (*dest is fine since we never map /dev/mem for writing). + */ +static void *aligned_memcpy(void *dest, const void *src, size_t n) +{ + u8 *d = dest; + const volatile u8 *s = src; /* volatile to prevent optimization */ + + while ((uintptr_t)s & (sizeof(size_t) - 1)) { + if (n-- == 0) + return dest; + *d++ = *s++; + } + + while (n >= sizeof(size_t)) { + *(size_t *)d = *(const volatile size_t *)s; + d += sizeof(size_t); + s += sizeof(size_t); + n -= sizeof(size_t); + } + + while (n-- > 0) + *d++ = *s++; + + return dest; +} + +/* * calculate ip checksum (16 bit quantities) on a passed in buffer. In case * the buffer length is odd last byte is excluded from the calculation */ @@ -608,7 +638,7 @@ static void dump_console(void) console_p = map_memory_size((unsigned long)console.cbmem_addr, size + sizeof(size) + sizeof(cursor), 1); - memcpy(console_c, console_p + 8, size); + aligned_memcpy(console_c, console_p + 8, size); printf("%s\n", console_c); if (size < cursor) |