[Crash-utility] [PATCH] s390: Print pt_regs for interrupt stack frames

[Dave Anderson]

----- Original Message -----
> Hi Dave,
> 
> With this patch instead of just printing the string " - Interrupt -",
> we print the pt_regs for interrupts. The pt_regs contain all the current
> registers and PSW of the interrupted CPU. This is very useful information
> for debugging.
> 
> Old output:
> -----------
> #4 [00017ea0] do_restart at 111c18
> #5 [00017eb8] psw_restart_int_handler at 5c1194
> - Interrupt -
> #6 [00017f58] vtime_stop_cpu at 5c043e
> #0 [00907eb0] cpu_idle at 106026
> #1 [00907ef8] start_kernel at 9799e8
> 
> New output:
> -----------
> #4 [00017ea0] do_restart at 111c18
> #5 [00017eb8] psw_restart_int_handler at 5c1194
> PSW: 0706000180000000 00000000005c043e (vtime_stop_cpu+134)
> GPRS: 0000000000000000 00000000005c043e 00000000011e5228 00000000011e5248
> 0000000000907f08 00000000011e5b40 0000000000979324 0000000000000000
> 00000000009c0000 00000000009c0010 00000000009ab024 00000000011e5200
> 00000000011e5238 00000000005c6a00 0000000000106026 0000000000907e68
> #0 [00907eb0] cpu_idle at 106026
> #1 [00907ef8] start_kernel at 9799e
> 
> Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
> ---

Queued for the next release (crash-5.1.8).

Thanks,
  Dave

> s390x.c | 71
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++----------
> 1 file changed, 60 insertions(+), 11 deletions(-)
> 
> --- a/s390x.c
> +++ b/s390x.c
> @@ -878,6 +878,24 @@ static void print_frame_data(unsigned lo
> }
> 
> /*
> + * Do reference check and set flags
> + */
> +static int bt_reference_check(struct bt_info *bt, unsigned long addr)
> +{
> + if (!BT_REFERENCE_CHECK(bt))
> + return 0;
> +
> + if (bt->ref->cmdflags & BT_REF_HEXVAL) {
> + if (addr == bt->ref->hexval)
> + bt->ref->cmdflags |= BT_REF_FOUND;
> + } else {
> + if (STREQ(closest_symbol(addr), bt->ref->str))
> + bt->ref->cmdflags |= BT_REF_FOUND;
> + }
> + return 1;
> +}
> +
> +/*
> * Print stack frame
> */
> static void print_frame(struct bt_info *bt, int cnt, unsigned long sp,
> @@ -886,16 +904,8 @@ static void print_frame(struct bt_info *
> struct load_module *lm;
> char *sym;
> 
> - if (BT_REFERENCE_CHECK(bt)) {
> - if (bt->ref->cmdflags & BT_REF_HEXVAL) {
> - if (r14 == bt->ref->hexval)
> - bt->ref->cmdflags |= BT_REF_FOUND;
> - } else {
> - if (STREQ(closest_symbol(r14), bt->ref->str))
> - bt->ref->cmdflags |= BT_REF_FOUND;
> - }
> + if (bt_reference_check(bt, r14))
> return;
> - }
> fprintf(fp, "%s#%d [%08lx] ", cnt < 10 ? " " : "", cnt, sp);
> sym = closest_symbol(r14);
> fprintf(fp, "%s at %lx", sym, r14);
> @@ -907,6 +917,46 @@ static void print_frame(struct bt_info *
> }
> 
> /*
> + * Print pt_regs structure
> + */
> +static void print_ptregs(struct bt_info *bt, unsigned long sp)
> +{
> + unsigned long addr, psw_flags, psw_addr, offs;
> + struct load_module *lm;
> + char *sym;
> + int i;
> +
> + addr = sp + MEMBER_OFFSET("pt_regs", "psw");
> + psw_flags = readmem_ul(addr);
> + psw_addr = readmem_ul(addr + sizeof(long));
> + if (bt_reference_check(bt, psw_addr))
> + return;
> +
> + fprintf(fp, " PSW: %016lx %016lx ", psw_flags, psw_addr);
> + sym = closest_symbol(psw_addr);
> + offs = psw_addr - closest_symbol_value(psw_addr);
> + if (module_symbol(psw_addr, NULL, &lm, NULL, 0))
> + fprintf(fp, "(%s+%ld [%s])\n", sym, offs, lm->mod_name);
> + else
> + fprintf(fp, "(%s+%ld)\n", sym, offs);
> +
> + addr = sp + MEMBER_OFFSET("pt_regs", "gprs");
> + for (i = 0; i < 16; i++) {
> + if (i != 0 && i % 4 == 0)
> + fprintf(fp, "\n");
> + if (i % 4 == 0) {
> + if (i == 0)
> + fprintf(fp, " GPRS: ");
> + else
> + fprintf(fp, " ");
> + }
> + fprintf(fp, "%016lx ", readmem_ul(addr + i * sizeof(long)));
> + }
> + fprintf(fp, "\n");
> +}
> +
> +
> +/*
> * Print back trace for one stack
> */
> static unsigned long show_trace(struct bt_info *bt, int cnt, unsigned
> long sp,
> @@ -955,8 +1005,7 @@ static unsigned long show_trace(struct b
> /* Check for loop (kernel_thread_starter) of second zero bc */
> if (low == reg || reg == 0)
> return reg;
> - fprintf(fp, " - Interrupt -\n");
> - print_frame(bt, cnt++, sp, psw_addr);
> + print_ptregs(bt, sp);
> low = sp;
> sp = reg;
> cnt = 0;