Fix randomizer
Relying on the system randomizer for unit tests leads to cases where we
don't get deterministic results, which causes inconsistent results.
These random results don't need to be secure, so reimplement as a simple
linear feedback shift register[1]. This makes our unit tests now
produce the same output every time we call generate.
Note, this change showed a weakness in our testing, where timestamps
relied on different rules for ir->cper versus cper->ir. hour 24 should
be allowed.
[1] https://en.wikipedia.org/wiki/Linear-feedback_shift_register
Change-Id: I0756b086c8ea5fb934e450f5d33e3ae0036868b3
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/generator/cper-generate.c b/generator/cper-generate.c
index b1b105b..2cee1e0 100644
--- a/generator/cper-generate.c
+++ b/generator/cper-generate.c
@@ -24,9 +24,6 @@
void generate_cper_record(char **types, UINT16 num_sections, FILE *out,
GEN_VALID_BITS_TEST_TYPE validBitsType)
{
- //Initialise randomiser.
- init_random(0);
-
//Generate the sections.
void *sections[num_sections];
size_t section_lengths[num_sections];
@@ -199,7 +196,7 @@
//If the section name is "unknown", simply generate a random bytes section.
int section_generated = 0;
if (strcmp(type, "unknown") == 0) {
- length = generate_random_section(location, rand() % 256);
+ length = generate_random_section(location, ALL_VALID);
section_generated = 1;
} else {
//Function defined section, switch on the type, generate accordingly.