On Wed, Mar 21, 2018 at 02:28:48AM +0300, Dmitry V. Levin wrote: > On Sun, Mar 18, 2018 at 01:43:23AM +0100, Mark Wielaard wrote: > > + /* Let the ptrace fallback deal with the corner case of the address > > + possibly crossing a page boundery. */ > > + if ((addr & ((Dwarf_Addr)__LIBDWFL_REMOTE_MEM_CACHE_SIZE - 1)) > > + > (Dwarf_Addr)__LIBDWFL_REMOTE_MEM_CACHE_SIZE - sizeof (unsigned > > long)) > > It looks odd that the variable that is going to be assigned has type > Dwarf_Word, while the size being checked has type unsigned long. > Shouldn't it be sizeof(*result) instead? > > > + d = &mem_cache->buf[addr - mem_cache->addr]; > > + *result = *(unsigned long *) d; > > Likewise, shouldn't it be memcpy(result, d, sizeof(*result)) instead?
That is indeed not immediately clear. I'll add some documentation. Although the functions do use Dwarf_Word (which is always 64bits) they actually return the result of an unsigned long/address. This is true for both the pid based and core based memory read functions. I am not completely sure if this was originally deliberate, or if this was the accidental result of the ptrace interface returning a long (target word) for PTRACE_PEEKDATA. Thanks for reviewing. Cheers, Mark
