[Crash-utility] [PATCH] ppc64: rework bt command
Hari Bathini
hbathini at linux.ibm.com
Fri Sep 7 19:34:11 UTC 2018
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 at linux.ibm.com>
---
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");
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