Only older kernel (v2.4) used h/w interrupt stack to store frames when CPU received IPI. Memory used for this in 'struct machine_specific' is useless for later kernels. For the sake of backward compatibility keep h/w interrupt stack but dynamically allocate memory for it and save some bytes from being wasted.
Signed-off-by: Hari Bathini <[email protected]> --- defs.h | 2 +- ppc64.c | 48 +++++++++++++++++++----------------------------- 2 files changed, 20 insertions(+), 30 deletions(-) diff --git a/defs.h b/defs.h index 7d3b734..d1d3ea9 100644 --- a/defs.h +++ b/defs.h @@ -6303,7 +6303,7 @@ struct ppc64_vmemmap { * Used to store the HW interrupt stack. It is only for 2.4. */ struct machine_specific { - ulong hwintrstack[NR_CPUS]; + ulong *hwintrstack; char *hwstackbuf; uint hwstacksize; diff --git a/ppc64.c b/ppc64.c index 0e1d867..fe96cfa 100644 --- a/ppc64.c +++ b/ppc64.c @@ -256,7 +256,7 @@ static int set_ppc64_max_physmem_bits(void) } struct machine_specific ppc64_machine_specific = { - .hwintrstack = { 0 }, + .hwintrstack = NULL, .hwstackbuf = 0, .hwstacksize = 0, .pte_rpn_shift = PTE_RPN_SHIFT_DEFAULT, @@ -275,7 +275,7 @@ struct machine_specific ppc64_machine_specific = { }; struct machine_specific book3e_machine_specific = { - .hwintrstack = { 0 }, + .hwintrstack = NULL, .hwstackbuf = 0, .hwstacksize = 0, .pte_rpn_shift = PTE_RPN_SHIFT_L4_BOOK3E_64K, @@ -676,6 +676,9 @@ ppc64_init(int when) */ offset = MEMBER_OFFSET("paca_struct", "xHrdIntStack"); paca_sym = symbol_value("paca"); + if (!(machdep->machspec->hwintrstack = + (ulong *)calloc(NR_CPUS, sizeof(ulong)))) + error(FATAL, "cannot malloc hwintrstack space."); for (cpu = 0; cpu < kt->cpus; cpu++) { readmem(paca_sym + (paca_size * cpu) + offset, KVADDR, @@ -686,14 +689,9 @@ ppc64_init(int when) machdep->machspec->hwstacksize = 8 * machdep->pagesize; if ((machdep->machspec->hwstackbuf = (char *) malloc(machdep->machspec->hwstacksize)) == NULL) - error(FATAL, "cannot malloc hwirqstack space."); - } else - /* - * 'xHrdIntStack' member in "paca_struct" is not - * available for 2.6 kernel. - */ - BZERO(&machdep->machspec->hwintrstack, - NR_CPUS*sizeof(ulong)); + error(FATAL, "cannot malloc hwirqstack buffer space."); + } + if (!machdep->hz) { machdep->hz = HZ; if (THIS_KERNEL_VERSION >= LINUX(2,6,0)) @@ -846,22 +844,13 @@ ppc64_dump_machdep_table(ulong arg) fprintf(fp, " is_vmaddr: %s\n", machdep->machspec->is_vmaddr == book3e_is_vmaddr ? "book3e_is_vmaddr()" : "ppc64_is_vmaddr()"); - fprintf(fp, " hwintrstack[%d]: ", NR_CPUS); - for (c = 0; c < NR_CPUS; c++) { - for (others = 0, i = c; i < NR_CPUS; i++) { - if (machdep->machspec->hwintrstack[i]) - others++; + if (machdep->machspec->hwintrstack) { + fprintf(fp, " hwintrstack[%d]: ", NR_CPUS); + for (c = 0; c < NR_CPUS; c++) { + fprintf(fp, "%s%016lx ", + ((c % 4) == 0) ? "\n " : "", + machdep->machspec->hwintrstack[c]); } - if (!others) { - fprintf(fp, "%s%s", - c && ((c % 4) == 0) ? "\n " : "", - c ? "(remainder unused)" : "(unused)"); - break; - } - - fprintf(fp, "%s%016lx ", - ((c % 4) == 0) ? "\n " : "", - machdep->machspec->hwintrstack[c]); } fprintf(fp, "\n"); fprintf(fp, " hwstackbuf: %lx\n", (ulong)machdep->machspec->hwstackbuf); @@ -1683,9 +1672,10 @@ ppc64_check_sp_in_HWintrstack(ulong sp, struct bt_info *bt) * * Note: HW Interrupt stack is used only in 2.4 kernel. */ - if (is_task_active(bt->task) && (tt->panic_task != bt->task) && - machdep->machspec->hwintrstack[bt->tc->processor]) { + if (machdep->machspec->hwintrstack && is_task_active(bt->task) && + (bt->task != tt->panic_task)) { ulong newsp; + readmem(machdep->machspec->hwintrstack[bt->tc->processor], KVADDR, &newsp, sizeof(ulong), "stack pointer", FAULT_ON_ERROR); @@ -1958,7 +1948,7 @@ ppc64_back_trace(struct gnu_request *req, struct bt_info *bt) bt->stackbase = irqstack; bt->stacktop = bt->stackbase + STACKSIZE(); alter_stackbuf(bt); - } else if (ms->hwintrstack[bt->tc->processor]) { + } else if (ms->hwintrstack) { bt->stacktop = ms->hwintrstack[bt->tc->processor] + sizeof(ulong); bt->stackbase = ms->hwintrstack[bt->tc->processor] - @@ -2555,7 +2545,7 @@ retry: goto retry; } - if (check_intrstack && ms->hwintrstack[bt->tc->processor]) { + if (check_intrstack && ms->hwintrstack) { bt->stacktop = ms->hwintrstack[bt->tc->processor] + sizeof(ulong); bt->stackbase = ms->hwintrstack[bt->tc->processor] - -- 2.35.3 -- Crash-utility mailing list [email protected] https://listman.redhat.com/mailman/listinfo/crash-utility Contribution Guidelines: https://github.com/crash-utility/crash/wiki
