tests/tcg/arm: account for pauth randomness

Pointer authentication isn't guaranteed to always detect a clash
between different keys. Take this into account in the test by running
several times and checking the percentage hit rate of the test.

Cc: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
This commit is contained in:
Alex Bennée 2019-03-12 15:42:21 +00:00
parent 8a2af7a70c
commit b640728151

View File

@ -1,5 +1,6 @@
#include <assert.h>
#include <sys/prctl.h>
#include <stdio.h>
asm(".arch armv8.4-a");
@ -8,16 +9,29 @@ asm(".arch armv8.4-a");
#define PR_PAC_APDAKEY (1 << 2)
#endif
#define TESTS 1000
int main()
{
int x;
int x, i, count = 0;
void *p0 = &x, *p1, *p2;
float perc;
asm volatile("pacdza %0" : "=r"(p1) : "0"(p0));
prctl(PR_PAC_RESET_KEYS, PR_PAC_APDAKEY, 0, 0, 0);
asm volatile("pacdza %0" : "=r"(p2) : "0"(p0));
for (i = 0; i < TESTS; i++) {
asm volatile("pacdza %0" : "=r"(p1) : "0"(p0));
prctl(PR_PAC_RESET_KEYS, PR_PAC_APDAKEY, 0, 0, 0);
asm volatile("pacdza %0" : "=r"(p2) : "0"(p0));
assert(p1 != p0);
assert(p1 != p2);
if (p1 != p0) {
count++;
}
if (p1 != p2) {
count++;
}
}
perc = (float) count / (float) (TESTS * 2);
printf("Ptr Check: %0.2f%%", perc * 100.0);
assert(perc > 0.95);
return 0;
}