x86/crash: Correct the address boundary of function parameters

Let's carefully handle the boundary of the function parameter to make
sure that the arguments passed doesn't exceed the address range.
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Young <dyoung@redhat.com>
Link: https://lore.kernel.org/r/20200804044933.1973-2-lijiang@redhat.com

arch/x86/kernel/crash.c

@@ -230,7 +230,7 @@ static int elf_header_exclude_ranges(struct crash_mem *cmem)
 	int ret = 0;
 
 	/* Exclude the low 1M because it is always reserved */
-	ret = crash_exclude_mem_range(cmem, 0, 1<<20);
+	ret = crash_exclude_mem_range(cmem, 0, (1<<20)-1);
 	if (ret)
 		return ret;