On Tuesday 10 January 2012 17:28:05 Wolfgang Denk wrote:
Doug Anderson wrote:
This makes fixup_silent_linux() use malloc() to allocate its working space, meaning that our maximum kernel command line should only be limited by malloc(). Previously it was silently overflowing the stack.
...
static void fixup_silent_linux(void) {
- char buf[256], *start, *end;
Are you sure that the kernel's buffer is long enough?
For example on PowerPC, there is a current hard limit on 512 characters:
arch/powerpc/boot/ops.h:#define COMMAND_LINE_SIZE 512 arch/powerpc/kernel/setup-common.c:char cmd_line[COMMAND_LINE_SIZE];
On SPARC, we have 256 bytes hard limit, see arch/sparc/prom/bootstr_64.c:
#define BARG_LEN 256 ... prom_getstring(prom_chosen_node, "bootargs", bootstr_info.bootstr_buf, BARG_LEN);
i think this does len checking ...
I think your patch is likely to break all these architectures?
i don't know about others, but on Blackfin, we don't care. we just copy the first COMMAND_LINE_SIZE bytes out and ignore the rest. -mike