Alexander Potapenko <glider@xxxxxxxxxx> writes:
> On Wed, Jul 28, 2021 at 9:03 PM Heiko Carstens <hca@xxxxxxxxxxxxx> wrote:
>>
>> From: Sven Schnelle <svens@xxxxxxxxxxxxx>
>>
>> s390 only reports the page address during a translation fault.
>> To make the kfence unit tests pass, add a function that might
>> be implemented by architectures to mask out address bits.
>>
>> Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
>> Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
>> ---
>> mm/kfence/kfence_test.c | 13 ++++++++++++-
>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
>> index 942cbc16ad26..eb6307c199ea 100644
>> --- a/mm/kfence/kfence_test.c
>> +++ b/mm/kfence/kfence_test.c
>> @@ -23,8 +23,15 @@
>> #include <linux/tracepoint.h>
>> #include <trace/events/printk.h>
>>
>> +#include <asm/kfence.h>
>> +
>> #include "kfence.h"
>>
>> +/* May be overridden by <asm/kfence.h>. */
>> +#ifndef arch_kfence_test_address
>> +#define arch_kfence_test_address(addr) (addr)
>> +#endif
>> +
>> /* Report as observed from console. */
>> static struct {
>> spinlock_t lock;
>> @@ -82,6 +89,7 @@ static const char *get_access_type(const struct expect_report *r)
>> /* Check observed report matches information in @r. */
>> static bool report_matches(const struct expect_report *r)
>> {
>> + unsigned long addr = (unsigned long)r->addr;
>> bool ret = false;
>> unsigned long flags;
>> typeof(observed.lines) expect;
>> @@ -131,22 +139,25 @@ static bool report_matches(const struct expect_report *r)
>> switch (r->type) {
>> case KFENCE_ERROR_OOB:
>> cur += scnprintf(cur, end - cur, "Out-of-bounds %s at", get_access_type(r));
>> + addr = arch_kfence_test_address(addr);
>
> Can we normalize addr once before (or after) this switch?
>
I don't think so. When reporing corrupted memory or an invalid free the
address is not generated by hardware but kfence itself, and therefore we
would strip valid bits.
>> break;
>> case KFENCE_ERROR_UAF:
>> cur += scnprintf(cur, end - cur, "Use-after-free %s at", get_access_type(r));
>> + addr = arch_kfence_test_address(addr);
>> break;
>> case KFENCE_ERROR_CORRUPTION:
>> cur += scnprintf(cur, end - cur, "Corrupted memory at");
>> break;
>> case KFENCE_ERROR_INVALID:
>> cur += scnprintf(cur, end - cur, "Invalid %s at", get_access_type(r));
>> + addr = arch_kfence_test_address(addr);
>> break;
>> case KFENCE_ERROR_INVALID_FREE:
>> cur += scnprintf(cur, end - cur, "Invalid free of");
>> break;
>> }
>>
>> - cur += scnprintf(cur, end - cur, " 0x%p", (void *)r->addr);
>> + cur += scnprintf(cur, end - cur, " 0x%p", (void *)addr);
>>
>> spin_lock_irqsave(&observed.lock, flags);
>> if (!report_available())
>> --
>> 2.25.1
>>
