On 8/13/21 10:40 AM, Claudio Imbrenda wrote:
> On Fri, 13 Aug 2021 07:36:10 +0000
> Janosch Frank <frankja@xxxxxxxxxxxxx> wrote:
>
>> Right now we only get told the kind of program exception as well as
>> the PSW at the point where it happened.
>>
>> For addressing exceptions the PSW is not always enough so let's print
>> the TEID which contains the failing address and flags that tell us
>> more about the kind of address exception.
>>
>> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
>> ---
>> lib/s390x/asm/arch_def.h | 4 +++
>> lib/s390x/interrupt.c | 72
>> ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 76
>> insertions(+)
>>
>> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
>> index 4ca02c1d..39c5ba99 100644
>> --- a/lib/s390x/asm/arch_def.h
>> +++ b/lib/s390x/asm/arch_def.h
>> @@ -41,6 +41,10 @@ struct psw {
>> uint64_t addr;
>> };
>>
>> +/* Let's ignore spaces we don't expect to use for now. */
>> +#define AS_PRIM 0
>> +#define AS_HOME 3
>> +
>> #define PSW_MASK_EXT 0x0100000000000000UL
>> #define PSW_MASK_IO 0x0200000000000000UL
>> #define PSW_MASK_DAT 0x0400000000000000UL
>> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
>> index 01ded49d..1248bceb 100644
>> --- a/lib/s390x/interrupt.c
>> +++ b/lib/s390x/interrupt.c
>> @@ -12,6 +12,7 @@
>> #include <sclp.h>
>> #include <interrupt.h>
>> #include <sie.h>
>> +#include <asm/page.h>
>>
>> static bool pgm_int_expected;
>> static bool ext_int_expected;
>> @@ -126,6 +127,73 @@ static void fixup_pgm_int(struct stack_frame_int
>> *stack) /* suppressed/terminated/completed point already at the next
>> address */ }
>>
>> +static void decode_pgm_prot(uint64_t teid)
>
> it is actually more complicated than this.
I know it hurts to look at the spec :)
>
> if you don't want to add all the possibilities because they are
> unlikely and/or not relevant, maybe add a comment
Will do!
>
>> +{
>> + /* Low-address protection exception, 100 */
>> + if (test_bit_inv(56, &teid) && !test_bit_inv(60, &teid) &&
>> !test_bit_inv(61, &teid)) {
>> + printf("Type: LAP\n");
>> + return;
>> + }
>> +
>> + /* Instruction execution prevention, i.e. no-execute, 101 */
>> + if (test_bit_inv(56, &teid) && !test_bit_inv(60, &teid) &&
>> test_bit_inv(61, &teid)) {
>> + printf("Type: IEP\n");
>> + return;
>> + }
>> +
>> + /* Standard DAT exception, 001 */
>> + if (!test_bit_inv(56, &teid) && !test_bit_inv(60, &teid) &&
>> test_bit_inv(61, &teid)) {
>> + printf("Type: DAT\n");
>> + return;
>> + }
>> +}
>> +
>> +static void decode_teid(uint64_t teid)
>> +{
>> + int asce_id = lc->trans_exc_id & 3;
>> + bool dat = lc->pgm_old_psw.mask & PSW_MASK_DAT;
>> +
>> + printf("Memory exception information:\n");
>> + printf("TEID: %lx\n", teid);
>> + printf("DAT: %s\n", dat ? "on" : "off");
>> + printf("AS: %s\n", asce_id == AS_PRIM ? "Primary" : "Home");
>> +
>> + if (lc->pgm_int_code == PGM_INT_CODE_PROTECTION)
>> + decode_pgm_prot(teid);
>> +
>> + /*
>> + * If teid bit 61 is off for these two exception the reported
>> + * address is unpredictable.
>> + */
>> + if ((lc->pgm_int_code == PGM_INT_CODE_SECURE_STOR_ACCESS ||
>> + lc->pgm_int_code == PGM_INT_CODE_SECURE_STOR_VIOLATION)
>> &&
>> + !test_bit_inv(61, &teid)) {
>> + printf("Address: %lx, unpredictable\n ", teid &
>> PAGE_MASK);
>> + return;
>> + }
>> + printf("Address: %lx\n\n", teid & PAGE_MASK);
>> +}
>> +
>> +static void print_storage_exception_information(void)
>> +{
>> + switch (lc->pgm_int_code) {
>> + case PGM_INT_CODE_PROTECTION:
>> + case PGM_INT_CODE_PAGE_TRANSLATION:
>> + case PGM_INT_CODE_SEGMENT_TRANSLATION:
>> + case PGM_INT_CODE_ASCE_TYPE:
>> + case PGM_INT_CODE_REGION_FIRST_TRANS:
>> + case PGM_INT_CODE_REGION_SECOND_TRANS:
>> + case PGM_INT_CODE_REGION_THIRD_TRANS:
>> + case PGM_INT_CODE_SECURE_STOR_ACCESS:
>> + case PGM_INT_CODE_NON_SECURE_STOR_ACCESS:
>> + case PGM_INT_CODE_SECURE_STOR_VIOLATION:
>> + decode_teid(lc->trans_exc_id);
>> + break;
>> + default:
>> + return;
>> + }
>> +}
>> +
>> static void print_int_regs(struct stack_frame_int *stack)
>> {
>> printf("\n");
>> @@ -155,6 +223,10 @@ static void print_pgm_info(struct
>> stack_frame_int *stack) lc->pgm_int_code, stap(),
>> lc->pgm_old_psw.addr, lc->pgm_int_id); print_int_regs(stack);
>> dump_stack();
>> +
>> + /* Dump stack doesn't end with a \n so we add it here
>> instead */
>> + printf("\n");
>> + print_storage_exception_information();
>> report_summary();
>> abort();
>> }
>
