On Tue, Apr 26, 2011 at 1:54 PM, ratheesh kannoth <ratheesh.ksz@xxxxxxxxx> wrote: > On Tue, Apr 26, 2011 at 4:10 PM, Daniel Baluta <daniel.baluta@xxxxxxxxx> wrote: >> On Tue, Apr 26, 2011 at 1:33 PM, Randi Botse <nightdecoder@xxxxxxxxx> wrote: >>> Hi All, >>> >>> I want to ask malloc() behaviour, consider these codes; >>> >>> ... >>> char *ptr = malloc(1); >>> strcpy(ptr, "what"); >>> puts(ptr); >>> .... >>> >>> Confusingly, the strcpy() copied all bytes to ptr, but I just manage >>> to allocate ptr only for 1 byte, I guess I will have segfault here, >>> why this happen? why the string successfully copied into ptr? , is >>> those code legal? >> >> You didn't get segfault because you were lucky. >> >> Memory is allocated in multiples of page size (usually 4K). >> The memory after your allocated byte is valid in your case. >> >> thanks, >> Daniel. >> -- > > U could read a little more about vm_page_struct. ( virtual address > space to physical page ). Can you elaborate on this? Daniel. -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
