Re: [Crash-utility] Why module's global symbol cannot be displayed in crash? [ARM]

> In this case the original PGD is lost forever. But we can certainly detect > that and bail out instead of confusing our users. Maybe something like the > patch below? > > Note that I have not tested it on 3.2+ dump (I have none) but it works on the > dumps I have. > > Per, Jan, any comments on this? > > diff --git a/arm.c b/arm.c > index a3a7c23..03f63e6 100644 > --- a/arm.c > +++ b/arm.c > @@ -265,6 +265,10 @@ arm_init(int when) > STRUCT_EXISTS("pteval_t")) > machdep->flags |= PGTABLE_V2; > > + if (THIS_KERNEL_VERSION >= LINUX(3,2,0) || > + symbol_exists("idmap_pgd")) > + machdep->flags |= IDMAP_PGD; > + > machdep->section_size_bits = _SECTION_SIZE_BITS; > machdep->max_physmem_bits = _MAX_PHYSMEM_BITS; > > @@ -352,6 +356,8 @@ arm_dump_machdep_table(ulong arg) > fprintf(fp, "%sPHYS_BASE", others++ ? "|" : ""); > if (machdep->flags & PGTABLE_V2) > fprintf(fp, "%sPGTABLE_V2", others++ ? "|" : ""); > + if (machdep->flags & IDMAP_PGD) > + fprintf(fp, "%sIDMAP_PGD", others++ ? "|" : ""); > fprintf(fp, ")\n"); > > fprintf(fp, " kvbase: %lx\n", machdep->kvbase); > @@ -1042,6 +1048,15 @@ arm_uvtop(struct task_context *tc, ulong > uvaddr, physaddr_t *paddr, int verbose) > if (!tc) > error(FATAL, "current context invalid\n"); > > + /* > + * Before idmap_pgd was introduced with upstream commit 2c8951ab0c > + * (ARM: idmap: use idmap_pgd when setting up mm for reboot), the > + * panic task pgd was overwritten by soft reboot code, so we can't do > + * any vtop translations. > + */ > + if (!(machdep->flags & IDMAP_PGD) && tc->task == tt->panic_task) > + error(FATAL, "panic task pgd is trashed by soft reboot code\n"); > + > *paddr = 0; > > if (is_kernel_thread(tc->task) && IS_KVADDR(uvaddr)) { > diff --git a/defs.h b/defs.h > index 1f693c3..8b8b9f3 100755 > --- a/defs.h > +++ b/defs.h > @@ -4649,6 +4649,7 @@ struct arm_pt_regs { > #define KSYMS_START (0x1) > #define PHYS_BASE (0x2) > #define PGTABLE_V2 (0x4) > +#define IDMAP_PGD (0x8) > > struct machine_specific { > ulong phys_base; > Unless NAK'd by Per or Jan, then consider it queued for crash-6.1.5. Thanks, Dave