Re: [Crash-utility] Problem in bt for ARM64

On Tue, Oct 17, 2017 at 03:44:36PM -0400, Dave Anderson wrote: Oops, I've made small changes, nothing essential but some sort of clean-ups/readability improvements with deleting incomplete fixes against "bt -o." Thanks, -Takahiro AKASHI ===8<=== From: AKASHI Takahiro <takahiro.akashi(a)linaro.org&gt; Date: Thu, 12 Oct 2017 10:46:34 +0900 Subject: [PATCH v2] arm64: backtrace for v4.14 --- arm64.c | 212 +++++++++++++++++++++++++++++++++++++++++++++++----------------- defs.h | 3 + task.c | 2 + 3 files changed, 161 insertions(+), 56 deletions(-) diff --git a/arm64.c b/arm64.c index 20c5d34..80cb476 100644 --- a/arm64.c +++ b/arm64.c @@ -72,6 +72,7 @@ static void arm64_cmd_mach(void); static void arm64_display_machine_stats(void); static int arm64_get_smp_cpus(void); static void arm64_clear_machdep_cache(void); +static int arm64_on_process_stack(struct bt_info *, ulong); static int arm64_in_alternate_stack(int, ulong); static int arm64_on_irq_stack(int, ulong); static void arm64_set_irq_stack(struct bt_info *); @@ -611,6 +612,7 @@ arm64_dump_machdep_table(ulong arg) fprintf(fp, " exp_entry2_end: %lx\n", ms->exp_entry2_end); fprintf(fp, " panic_task_regs: %lx\n", (ulong)ms->panic_task_regs); fprintf(fp, " user_eframe_offset: %ld\n", ms->user_eframe_offset); + fprintf(fp, " kern_eframe_offset: %ld\n", ms->kern_eframe_offset); fprintf(fp, " PTE_PROT_NONE: %lx\n", ms->PTE_PROT_NONE); fprintf(fp, " PTE_FILE: "); if (ms->PTE_FILE) @@ -1336,31 +1338,64 @@ arm64_irq_stack_init(void) req = &request; struct machine_specific *ms = machdep->machspec; - if (!symbol_exists("irq_stack") || - !(sp = per_cpu_symbol_search("irq_stack")) || - !get_symbol_type("irq_stack", NULL, req) || - (req->typecode != TYPE_CODE_ARRAY) || - (req->target_typecode != TYPE_CODE_INT)) - return; + if (!(ms->irq_stacks = (ulong *)malloc((size_t)(kt->cpus + * sizeof(ulong))))) + error(FATAL, "cannot malloc irq_stack addresses\n"); - if (CRASHDEBUG(1)) { - fprintf(fp, "irq_stack: \n"); - fprintf(fp, " type: %s\n", - (req->typecode == TYPE_CODE_ARRAY) ? "TYPE_CODE_ARRAY" : "other"); - fprintf(fp, " target_typecode: %s\n", - req->target_typecode == TYPE_CODE_INT ? "TYPE_CODE_INT" : "other"); - fprintf(fp, " target_length: %ld\n", req->target_length); - fprintf(fp, " length: %ld\n", req->length); - } + if (symbol_exists("irq_stack") && + (sp = per_cpu_symbol_search("irq_stack")) && + get_symbol_type("irq_stack", NULL, req)) { + /* before v4.14 or CONFIG_VMAP_STACK disabled */ + if (CRASHDEBUG(1)) { + fprintf(fp, "irq_stack: \n"); + fprintf(fp, " type: %s\n", + (req->typecode == TYPE_CODE_ARRAY) ? + "TYPE_CODE_ARRAY" : "other"); + fprintf(fp, " target_typecode: %s\n", + req->target_typecode == TYPE_CODE_INT ? + "TYPE_CODE_INT" : "other"); + fprintf(fp, " target_length: %ld\n", + req->target_length); + fprintf(fp, " length: %ld\n", req->length); + } - ms->irq_stack_size = req->length; - if (!(ms->irq_stacks = (ulong *)malloc((size_t)(kt->cpus * sizeof(ulong))))) - error(FATAL, "cannot malloc irq_stack addresses\n"); + ms->irq_stack_size = req->length; + + for (i = 0; i < kt->cpus; i++) + ms->irq_stacks[i] = kt->__per_cpu_offset[i] + sp->value; + + machdep->flags |= IRQ_STACKS; + } else if (symbol_exists("irq_stack_ptr") && + (sp = per_cpu_symbol_search("irq_stack_ptr")) && + get_symbol_type("irq_stack_ptr", NULL, req)) { + /* v4.14 and later with CONFIG_VMAP_STACK enabled */ + if (CRASHDEBUG(1)) { + fprintf(fp, "irq_stack_ptr: \n"); + fprintf(fp, " type: %x, %s\n", + (int)req->typecode, + (req->typecode == TYPE_CODE_PTR) ? + "TYPE_CODE_PTR" : "other"); + fprintf(fp, " target_typecode: %x, %s\n", + (int)req->target_typecode, + req->target_typecode == TYPE_CODE_INT ? + "TYPE_CODE_INT" : "other"); + fprintf(fp, " target_length: %ld\n", + req->target_length); + fprintf(fp, " length: %ld\n", req->length); + } + + ms->irq_stack_size = ARM64_IRQ_STACK_SIZE; - for (i = 0; i < kt->cpus; i++) - ms->irq_stacks[i] = kt->__per_cpu_offset[i] + sp->value; + for (i = 0; i < kt->cpus; i++) { + ulong p; - machdep->flags |= IRQ_STACKS; + p = kt->__per_cpu_offset[i] + sp->value; + readmem(p, KVADDR, &(ms->irq_stacks[i]), sizeof(ulong), + "IRQ stack pointer", RETURN_ON_ERROR); + } + + machdep->flags |= IRQ_STACKS; + } } /* @@ -1379,10 +1414,13 @@ arm64_stackframe_init(void) MEMBER_OFFSET_INIT(elf_prstatus_pr_pid, "elf_prstatus", "pr_pid"); MEMBER_OFFSET_INIT(elf_prstatus_pr_reg, "elf_prstatus", "pr_reg"); - if (MEMBER_EXISTS("pt_regs", "stackframe")) + if (MEMBER_EXISTS("pt_regs", "stackframe")) { machdep->machspec->user_eframe_offset = SIZE(pt_regs); - else + machdep->machspec->kern_eframe_offset = SIZE(pt_regs) - 16; + } else { machdep->machspec->user_eframe_offset = SIZE(pt_regs) + 16; + machdep->machspec->kern_eframe_offset = SIZE(pt_regs); + } machdep->machspec->__exception_text_start = symbol_value("__exception_text_start"); @@ -1472,6 +1510,7 @@ arm64_stackframe_init(void) #define USER_MODE (2) #define USER_EFRAME_OFFSET (machdep->machspec->user_eframe_offset) +#define KERN_EFRAME_OFFSET (machdep->machspec->kern_eframe_offset) /* * PSR bits @@ -1747,14 +1786,23 @@ arm64_display_full_frame(struct bt_info *bt, ulong sp) ulong words, addr; char buf[BUFSIZE]; - if (bt->frameptr == sp) + if (bt->frameptr >= sp) return; - if (!INSTACK(sp, bt) || !INSTACK(bt->frameptr, bt)) { - if (sp == 0) - sp = bt->stacktop - USER_EFRAME_OFFSET; - else - return; + if (INSTACK(bt->frameptr, bt)) { + if (INSTACK(sp, bt)) { + /* normal case */; + } else { + if (sp == 0) + /* interrupt in user mode */ + sp = bt->stacktop - USER_EFRAME_OFFSET; + else + /* interrupt in kernel mode */ + sp = bt->stacktop; + } + } else { + /* This is a transition case from irq to process stack. */ + return; } words = (sp - bt->frameptr) / sizeof(ulong); @@ -1860,6 +1908,38 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame) if ((frame->fp == 0) && (frame->pc == 0)) return FALSE; + if (!(machdep->flags & IRQ_STACKS)) + return TRUE; + + if (machdep->flags & UNW_4_14) { + if ((bt->flags & BT_IRQSTACK) && + !arm64_on_irq_stack(bt->tc->processor, frame->fp)) { + if (arm64_on_process_stack(bt, frame->fp)) { + arm64_set_process_stack(bt); + + frame->sp = frame->fp - KERN_EFRAME_OFFSET; + /* + * for switch_stack + * fp still points to irq stack + */ + bt->bptr = fp; + /* + * for display_full_frame + * sp points to process stack + * + * If we want to see pt_regs, + * comment out the below. + * bt->frameptr = frame->sp; + */ + } else { + /* irq -> user */ + return FALSE; + } + } + + return TRUE; + } + /* * The kernel's manner of determining the end of the IRQ stack: * @@ -1872,29 +1952,27 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame) * irq_stack_ptr = IRQ_STACK_PTR(raw_smp_processor_id()); * orig_sp = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr); (pt_regs pointer on process stack) */ - if (machdep->flags & IRQ_STACKS) { - ms = machdep->machspec; - irq_stack_ptr = ms->irq_stacks[bt->tc->processor] + ms->irq_stack_size - 16; - - if (frame->sp == irq_stack_ptr) { - orig_sp = GET_STACK_ULONG(irq_stack_ptr - 8); - arm64_set_process_stack(bt); - if (INSTACK(orig_sp, bt) && (INSTACK(frame->fp, bt) || (frame->fp == 0))) { - ptregs = (struct arm64_pt_regs *)&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(orig_sp))]; - frame->sp = orig_sp; - frame->pc = ptregs->pc; - bt->bptr = fp; - if (CRASHDEBUG(1)) - error(INFO, - "arm64_unwind_frame: switch stacks: fp: %lx sp: %lx pc: %lx\n", - frame->fp, frame->sp, frame->pc); - } else { - error(WARNING, - "arm64_unwind_frame: on IRQ stack: oriq_sp: %lx%s fp: %lx%s\n", - orig_sp, INSTACK(orig_sp, bt) ? "" : " (?)", - frame->fp, INSTACK(frame->fp, bt) ? "" : " (?)"); - return FALSE; - } + ms = machdep->machspec; + irq_stack_ptr = ms->irq_stacks[bt->tc->processor] + ms->irq_stack_size - 16; + + if (frame->sp == irq_stack_ptr) { + orig_sp = GET_STACK_ULONG(irq_stack_ptr - 8); + arm64_set_process_stack(bt); + if (INSTACK(orig_sp, bt) && (INSTACK(frame->fp, bt) || (frame->fp == 0))) { + ptregs = (struct arm64_pt_regs *)&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(orig_sp))]; + frame->sp = orig_sp; + frame->pc = ptregs->pc; + bt->bptr = fp; + if (CRASHDEBUG(1)) + error(INFO, + "arm64_unwind_frame: switch stacks: fp: %lx sp: %lx pc: %lx\n", + frame->fp, frame->sp, frame->pc); + } else { + error(WARNING, + "arm64_unwind_frame: on IRQ stack: oriq_sp: %lx%s fp: %lx%s\n", + orig_sp, INSTACK(orig_sp, bt) ? "" : " (?)", + frame->fp, INSTACK(frame->fp, bt) ? "" : " (?)"); + return FALSE; } } @@ -2211,6 +2289,11 @@ arm64_back_trace_cmd(struct bt_info *bt) FILE *ofp; if (bt->flags & BT_OPT_BACK_TRACE) { + if (machdep->flags & UNW_4_14) { + error(WARNING, "\"-o\" is no longer supported for this version of kernel. Please use bt\n"); + return; + } + arm64_back_trace_cmd_v2(bt); return; } @@ -2272,7 +2355,7 @@ arm64_back_trace_cmd(struct bt_info *bt) goto complete_user; if (DUMPFILE() && is_task_active(bt->task)) { - exception_frame = stackframe.fp - SIZE(pt_regs); + exception_frame = stackframe.fp - KERN_EFRAME_OFFSET; if (arm64_is_kernel_exception_frame(bt, exception_frame)) arm64_print_exception_frame(bt, exception_frame, KERNEL_MODE, ofp); @@ -2304,11 +2387,12 @@ arm64_back_trace_cmd(struct bt_info *bt) if (arm64_in_exception_text(bt->instptr) && INSTACK(stackframe.fp, bt)) { if (!(bt->flags & BT_IRQSTACK) || (((stackframe.sp + SIZE(pt_regs)) < bt->stacktop))) - exception_frame = stackframe.fp - SIZE(pt_regs); + exception_frame = stackframe.fp + - KERN_EFRAME_OFFSET; } if ((bt->flags & BT_IRQSTACK) && - !arm64_on_irq_stack(bt->tc->processor, stackframe.sp)) { + !arm64_on_irq_stack(bt->tc->processor, stackframe.fp)) { bt->flags &= ~BT_IRQSTACK; if (arm64_switch_stack(bt, &stackframe, ofp) == USER_MODE) break; @@ -2669,7 +2753,9 @@ arm64_switch_stack(struct bt_info *bt, struct arm64_stackframe *frame, FILE *ofp if (frame->fp == 0) return USER_MODE; - arm64_print_exception_frame(bt, frame->sp, KERNEL_MODE, ofp); + if (!(machdep->flags & UNW_4_14)) + arm64_print_exception_frame(bt, frame->sp, KERNEL_MODE, ofp); + return KERNEL_MODE; } @@ -3362,6 +3448,20 @@ arm64_clear_machdep_cache(void) { return; } +static int +arm64_on_process_stack(struct bt_info *bt, ulong stkptr) +{ + ulong stackbase, stacktop; + + stackbase = GET_STACKBASE(bt->task); + stacktop = GET_STACKTOP(bt->task); + + if ((stkptr >= stackbase) && (stkptr < stacktop)) + return TRUE; + + return FALSE; +} + static int arm64_on_irq_stack(int cpu, ulong stkptr) { diff --git a/defs.h b/defs.h index 7768895..a694a66 100644 --- a/defs.h +++ b/defs.h @@ -3038,6 +3038,7 @@ typedef signed int s32; #define ARM64_VMEMMAP_END (ARM64_VMEMMAP_VADDR + GIGABYTES(8UL) - 1) #define ARM64_STACK_SIZE (16384) +#define ARM64_IRQ_STACK_SIZE ARM64_STACK_SIZE #define _SECTION_SIZE_BITS 30 #define _MAX_PHYSMEM_BITS 40 @@ -3117,6 +3118,8 @@ struct machine_specific { ulong kimage_text; ulong kimage_end; ulong user_eframe_offset; + /* for v4.14 or later */ + ulong kern_eframe_offset; }; struct arm64_stackframe { diff --git a/task.c b/task.c index 2b12af0..23c2b7b 100644 --- a/task.c +++ b/task.c @@ -6750,6 +6750,8 @@ panic_search(void) fd->keyword_array[0] = FOREACH_BT; if (machine_type("S390X")) fd->flags |= FOREACH_o_FLAG; + else if (machine_type("ARM64") && (machdep->flags & UNW_4_14)) + fd->flags |= FOREACH_t_FLAG; else fd->flags |= (FOREACH_t_FLAG|FOREACH_o_FLAG); -- 2.14.1