Re: [Crash-utility] [PATCH] ppc64: rework bt command

Commit 3db3d3992d78 was aimed at making 'bt' work for dumpfiles saved with fadump but it introduced a bit of unwarranted complexity in 'bt' command processing. Rework 'bt' command processing for PPC64 arch to make it a little less compilated and also, print symbols for NIP and LR registers on exception frames. Signed-off-by: Hari Bathini <hbathini(a)linux.ibm.com&gt;

--- ppc64.c | 140 +++++++++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 99 insertions(+), 41 deletions(-) diff --git a/ppc64.c b/ppc64.c index f5d0dac..03fecd3 100644 --- a/ppc64.c +++ b/ppc64.c @@ -2093,15 +2093,10 @@ ppc64_print_stack_entry(int frame, lr); return; } - if (req->pc != lr) { - fprintf(fp, "\n%s[Link Register] ", - frame < 10 ? " " : ""); - fprintf(fp, "[%lx] %s at %lx", - req->sp, lrname, lr); - } req->ra = lr; } - if (!req->name || STREQ(req->name,lrname)) + if (!req->name || STREQ(req->name, lrname) || + !is_kernel_text(req->pc)) fprintf(fp, " (unreliable)"); fprintf(fp, "\n"); @@ -2219,6 +2214,22 @@ ppc64_print_regs(struct ppc64_pt_regs *regs) fprintf(fp, " Syscall Result: %016lx\n", regs->result); } +static void ppc64_print_nip_lr(struct ppc64_pt_regs *regs, int print_lr) +{ + char buf[BUFSIZE]; + char *sym_buf; + + sym_buf = value_to_symstr(regs->nip, buf, 0); + if (sym_buf[0] != NULLCHAR) + fprintf(fp, " [NIP : %s]\n", sym_buf); + + if (print_lr) { + sym_buf = value_to_symstr(regs->link, buf, 0); + if (sym_buf[0] != NULLCHAR) + fprintf(fp, " [LR : %s]\n", sym_buf); + } +} + /* * Print the exception frame information */ @@ -2231,6 +2242,59 @@ ppc64_print_eframe(char *efrm_str, struct ppc64_pt_regs *regs, fprintf(fp, " %s [%lx] exception frame:\n", efrm_str, regs->trap); ppc64_print_regs(regs); + ppc64_print_nip_lr(regs, 1); +} + +/* + * For vmcore typically saved with KDump or FADump, get SP and IP values + * from the saved ptregs. + */ +static int +ppc64_vmcore_stack_frame(struct bt_info *bt_in, ulong *nip, ulong *ksp) +{ + struct ppc64_pt_regs *pt_regs; + unsigned long unip; + + pt_regs = (struct ppc64_pt_regs *)bt_in->machdep; + if (!pt_regs || !pt_regs->gpr[1]) { + /* + * Not collected regs. May be the corresponding CPU not + * responded to an IPI in case of KDump OR f/w has not + * not provided the register info in case of FADump. + */ + fprintf(fp, "%0lx: GPR1 register value (SP) was not saved\n", + bt_in->task); + return FALSE; + } + *ksp = pt_regs->gpr[1]; + if (IS_KVADDR(*ksp)) { + readmem(*ksp+16, KVADDR, &unip, sizeof(ulong), "Regs NIP value", + FAULT_ON_ERROR); + *nip = unip; + } else { + if (IN_TASK_VMA(bt_in->task, *ksp)) + fprintf(fp, "%0lx: Task is running in user space\n", + bt_in->task); + else + fprintf(fp, "%0lx: Invalid Stack Pointer %0lx\n", + bt_in->task, *ksp); + *nip = pt_regs->nip; + } + + if (bt_in->flags && + ((BT_TEXT_SYMBOLS|BT_TEXT_SYMBOLS_PRINT|BT_TEXT_SYMBOLS_NOPRINT))) + return TRUE; + + /* + * Print the collected regs for the active task + */ + ppc64_print_regs(pt_regs); + if (!IS_KVADDR(*ksp)) + return FALSE; + + ppc64_print_nip_lr(pt_regs, (unip != pt_regs->link) ? 1 : 0); + + return TRUE; } /* @@ -2239,7 +2303,7 @@ ppc64_print_eframe(char *efrm_str, struct ppc64_pt_regs *regs, static int ppc64_get_dumpfile_stack_frame(struct bt_info *bt_in, ulong *nip, ulong *ksp) { - int i; + int i, ret, panic_task; char *sym; ulong *up; struct bt_info bt_local, *bt; @@ -2251,11 +2315,29 @@ ppc64_get_dumpfile_stack_frame(struct bt_info *bt_in, ulong *nip, ulong *ksp) struct ppc64_pt_regs *pt_regs; struct syment *sp; - bt = &bt_local; - BCOPY(bt_in, bt, sizeof(struct bt_info)); - ms = machdep->machspec; + bt = &bt_local; + BCOPY(bt_in, bt, sizeof(struct bt_info)); + ms = machdep->machspec; + ur_nip = ur_ksp = 0; + + panic_task = tt->panic_task == bt->task ? TRUE : FALSE; check_hardirq = check_softirq = tt->flags & IRQSTACKS ? TRUE : FALSE; + if (panic_task && bt->machdep) { + pt_regs = (struct ppc64_pt_regs *)bt->machdep; + ur_nip = pt_regs->nip; + ur_ksp = pt_regs->gpr[1]; + } else if ((pc->flags & KDUMP) || + ((pc->flags & DISKDUMP) && + (*diskdump_flags & KDUMP_CMPRS_LOCAL))) { + /* + * For the KDump or FADump vmcore, use SP and IP values + * that are saved in ptregs. + */ + ret = ppc64_vmcore_stack_frame(bt_in, nip, ksp); + if (ret) + return TRUE; + } if (bt->task != tt->panic_task) { char cpu_frozen = FALSE; @@ -2385,38 +2467,14 @@ retry: check_intrstack = FALSE; goto retry; } - /* - * We didn't find what we were looking for, so try to use - * the SP and IP values saved in ptregs. + * We didn't find what we were looking for, so just use what was + * passed in the ELF header. */ - pt_regs = (struct ppc64_pt_regs *)bt_in->machdep; - if (!pt_regs || !pt_regs->gpr[1]) { - /* - * Not collected regs. May be the corresponding CPU did not - * respond to an IPI. - */ - if (CRASHDEBUG(1)) - fprintf(fp, "%0lx: GPR1(SP) register value not saved\n", - bt_in->task); - } else { - *ksp = pt_regs->gpr[1]; - if (IS_KVADDR(*ksp)) { - readmem(*ksp+16, KVADDR, nip, sizeof(ulong), - "Regs NIP value", FAULT_ON_ERROR); - ppc64_print_regs(pt_regs); - return TRUE; - } else { - if (IN_TASK_VMA(bt_in->task, *ksp)) - fprintf(fp, "%0lx: Task is running in user space\n", - bt_in->task); - else - fprintf(fp, "%0lx: Invalid Stack Pointer %0lx\n", - bt_in->task, *ksp); - *nip = pt_regs->nip; - ppc64_print_regs(pt_regs); - return FALSE; - } + if (ur_nip && ur_ksp) { + *nip = ur_nip; + *ksp = ur_ksp; + return TRUE; } console("ppc64_get_dumpfile_stack_frame: cannot find SP for panic task\n");