On 10/22/18 at 05:30am, Fan, Chao wrote: > >> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) > >> +{ > >> +#ifdef CONFIG_KEXEC > >> + unsigned long long res; > >> + int len = 0; > >> + char *val; > >> + > >> + val = malloc(20); > > > >Why is the length 20? Defined a macro? > > > > Not a calculation, if it's enough to store the address, that will be OK. Sorry, I didn't catch. It's 16 in setup_acpi_rsdp() of drivers/acpi/osl.c . What does 'that' mean? Wondering why not making it 200, it's also enough to store the address.