Hi Mikhail, Your patch is queued for crash-7.2.8: https://github.com/crash-utility/crash/commit/6664cb3f4ea2eac1b6d482e541b56d7792a4be04 Note that I made the s390x_lc_kaslr check gated upon a successful return from readmem(), just for the highly unlikely case of a failed read. Thanks, Dave ----- Original Message ----- > If the kernel crashes before vmcoreinfo initialization, there is > no way to extract KASLR offset for such early s390 dumps. With a new s390 > kernel patch, the KASLR offset will be stored in the lowcore memory during > early boot and then overwritten after vmcoreinfo is initialized. > This patch allows crash to identify the KASLR offset stored in the lowcore > memory for s390 dumps. > > Signed-off-by: Mikhail Zaslonko <zaslonko@xxxxxxxxxxxxx> > --- > s390x.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/s390x.c b/s390x.c > index 4a1a466..5e28ea4 100644 > --- a/s390x.c > +++ b/s390x.c > @@ -46,6 +46,8 @@ > > #define S390X_PSW_MASK_PSTATE 0x0001000000000000UL > > +#define S390X_LC_VMCORE_INFO 0xe0c > + > /* > * Flags for Region and Segment table entries. > */ > @@ -460,6 +462,8 @@ static void s390x_check_live(void) > void > s390x_init(int when) > { > + ulong s390x_lc_kaslr; > + > switch (when) > { > case SETUP_ENV: > @@ -486,6 +490,23 @@ s390x_init(int when) > machdep->verify_paddr = generic_verify_paddr; > machdep->get_kvaddr_ranges = s390x_get_kvaddr_ranges; > machdep->ptrs_per_pgd = PTRS_PER_PGD; > + if (DUMPFILE() && !(kt->flags & RELOC_SET)) { > + /* Read the value from well-known lowcore location*/ > + readmem(S390X_LC_VMCORE_INFO, PHYSADDR, &s390x_lc_kaslr, > + sizeof(s390x_lc_kaslr), "s390x_lc_kaslr", > + QUIET|RETURN_ON_ERROR); > + /* Check for explicit kaslr offset flag */ > + if (s390x_lc_kaslr & 0x1UL) { > + /* Drop the last bit to get an offset value */ > + s390x_lc_kaslr &= ~(0x1UL); > + /* Make sure the offset is aligned by 0x1000 */ > + if (s390x_lc_kaslr && !(s390x_lc_kaslr & 0xfff)) { > + kt->relocate = s390x_lc_kaslr * (-1); > + kt->flags |= RELOC_SET; > + kt->flags2 |= KASLR; > + } > + } > + } > break; > > case PRE_GDB: > -- > 2.17.1 > > -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
