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

----- Original Message ----- > 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; Thanks, Hari. As we discussed in the related bugzilla, this looks good. Queued for crash-7.2.4: https://github.com/crash-utility/crash/commit/5fe78861ea1589084f6a2956a6f... Dave > --- > 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"); > >