4:09 p.m.
From: Rabin Vincent <rabinv(a)axis.com>
Set a default value for machdep->hz to 100, which will be used if the in
kernel config data is unavailable.
---
mips.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mips.c b/mips.c
index a4fc8b6..7ad6f61 100644
--- a/mips.c
+++ b/mips.c
@@ -57,6 +57,7 @@ static struct machine_specific mips_machine_specific = { 0 };
static void
mips_display_machine_stats(void)
{
+ fprintf(fp, " HZ: %d\n", machdep->hz);
fprintf(fp, " PAGE SIZE: %d\n", PAGESIZE());
fprintf(fp, "\n");
@@ -776,6 +777,7 @@ mips_dump_machdep_table(ulong arg)
fprintf(fp, " ptrs_per_pgd: %lu\n", PTRS_PER_PGD);
fprintf(fp, " ptrs_per_pte: %d\n", PTRS_PER_PTE);
fprintf(fp, " stacksize: %ld\n", machdep->stacksize);
+ fprintf(fp, " hz: %d\n", machdep->hz);
fprintf(fp, " memsize: %lld (0x%llx)\n",
machdep->memsize, machdep->memsize);
fprintf(fp, " bits: %d\n", machdep->bits);
@@ -904,6 +906,9 @@ mips_init(int when)
ARRAY_LENGTH_INIT(machdep->nr_irqs, irq_desc,
"irq_desc", NULL, 0);
mips_stackframe_init();
+
+ if (!machdep->hz)
+ machdep->hz = 100;
break;
}
}
--
2.1.4
4:09 p.m.
New subject: [PATCH 2/3] mips: set section_size_bits and max_physmem_bits
From: Rabin Vincent <rabinv(a)axis.com>
Enable SPARSEMEM support by setting this two values. It's not clear to
me if they'll work on all MIPS platforms, but they do on the ones I have
access to and should provide reasonable defaults.
---
defs.h | 3 +++
mips.c | 2 ++
2 files changed, 5 insertions(+)
diff --git a/defs.h b/defs.h
index 85300cc..d64db92 100644
--- a/defs.h
+++ b/defs.h
@@ -3125,6 +3125,9 @@ struct arm64_stackframe {
#define __swp_offset(entry) SWP_OFFSET(entry)
#define TIF_SIGPENDING (2)
+
+#define _SECTION_SIZE_BITS 26
+#define _MAX_PHYSMEM_BITS 32
#endif /* MIPS */
#ifdef X86
diff --git a/mips.c b/mips.c
index 7ad6f61..cf3e1ae 100644
--- a/mips.c
+++ b/mips.c
@@ -903,6 +903,8 @@ mips_init(int when)
machdep->dump_irq = generic_dump_irq;
machdep->show_interrupts = generic_show_interrupts;
machdep->get_irq_affinity = generic_get_irq_affinity;
+ machdep->section_size_bits = _SECTION_SIZE_BITS;
+ machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;
ARRAY_LENGTH_INIT(machdep->nr_irqs, irq_desc,
"irq_desc", NULL, 0);
mips_stackframe_init();
--
2.1.4
8:53 a.m.
New subject: [PATCH 2/3] mips: set section_size_bits and max_physmem_bits
----- Original Message -----
From: Rabin Vincent <rabinv(a)axis.com>
Enable SPARSEMEM support by setting this two values. It's not clear to
me if they'll work on all MIPS platforms, but they do on the ones I have
access to and should provide reasonable defaults.
Queued for crash-7.1.7:
https://github.com/crash-utility/crash/commit/fb5713c86f256dd4f948f0bfdc2...
Thanks,
Dave
---
defs.h | 3 +++
mips.c | 2 ++
2 files changed, 5 insertions(+)
diff --git a/defs.h b/defs.h
index 85300cc..d64db92 100644
--- a/defs.h
+++ b/defs.h
@@ -3125,6 +3125,9 @@ struct arm64_stackframe {
#define __swp_offset(entry) SWP_OFFSET(entry)
#define TIF_SIGPENDING (2)
+
+#define _SECTION_SIZE_BITS 26
+#define _MAX_PHYSMEM_BITS 32
#endif /* MIPS */
#ifdef X86
diff --git a/mips.c b/mips.c
index 7ad6f61..cf3e1ae 100644
--- a/mips.c
+++ b/mips.c
@@ -903,6 +903,8 @@ mips_init(int when)
machdep->dump_irq = generic_dump_irq;
machdep->show_interrupts = generic_show_interrupts;
machdep->get_irq_affinity = generic_get_irq_affinity;
+ machdep->section_size_bits = _SECTION_SIZE_BITS;
+ machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;
ARRAY_LENGTH_INIT(machdep->nr_irqs, irq_desc,
"irq_desc", NULL, 0);
mips_stackframe_init();
--
2.1.4
--
Crash-utility mailing list
Crash-utility(a)redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
4:09 p.m.
New subject: [PATCH 3/3] mips: use get_stackframe() implementation from ARM
From: Rabin Vincent <rabinv(a)axis.com>
The mips stackframe handling has two problems:
(1) It does not read the registers from the kernel's crash_notes if ELF
notes are not available for some reason. This is important when
debugging raw memory dumps.
(2) If one of the online CPUs did not save the ELF notes, then the
mapping of ELF notes to CPUs may be incorrect.
ARM has an implementation which handles both these cases, so we borrow
it. Note that this code is entirely copy/pasted from arm, so perhaps
we could make a common function out of this which could be shared
between the two architectures?
---
defs.h | 2 +
mips.c | 187 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
netdump.c | 9 ++-
3 files changed, 187 insertions(+), 11 deletions(-)
diff --git a/defs.h b/defs.h
index d64db92..0384f4e 100644
--- a/defs.h
+++ b/defs.h
@@ -5990,6 +5990,8 @@ struct machine_specific {
#define _PAGE_NO_EXEC (machdep->machspec->_page_no_exec)
#define _PAGE_DIRTY (machdep->machspec->_page_dirty)
#define _PFN_SHIFT (machdep->machspec->_pfn_shift)
+
+ struct mips_regset *crash_task_regs;
};
#endif /* MIPS */
diff --git a/mips.c b/mips.c
index cf3e1ae..e3f1569 100644
--- a/mips.c
+++ b/mips.c
@@ -54,6 +54,11 @@ typedef ulong pte_t;
static struct machine_specific mips_machine_specific = { 0 };
+/*
+ * Holds registers during the crash.
+ */
+static struct mips_regset *panic_task_regs;
+
static void
mips_display_machine_stats(void)
{
@@ -533,6 +538,9 @@ mips_back_trace_cmd(struct bt_info *bt)
struct mips_unwind_frame current, previous;
int level = 0;
+ if (bt->flags & BT_REGS_NOT_FOUND)
+ return;
+
previous.sp = previous.pc = previous.ra = 0;
current.pc = bt->instptr;
@@ -629,22 +637,35 @@ mips_back_trace_cmd(struct bt_info *bt)
}
}
-static void
+static int
mips_dumpfile_stack_frame(struct bt_info *bt, ulong *nip, ulong *ksp)
{
+ const struct machine_specific *ms = machdep->machspec;
struct mips_regset *regs;
+ ulong epc, r29;
- regs = bt->machdep;
- if (!regs) {
- fprintf(fp, "0%lx: Register values not available\n",
- bt->task);
- return;
+ if (!ms->crash_task_regs) {
+ bt->flags |= BT_REGS_NOT_FOUND;
+ return FALSE;
+ }
+
+ regs = &ms->crash_task_regs[bt->tc->processor];
+ epc = regs->regs[MIPS32_EF_CPU0_EPC];
+ r29 = regs->regs[MIPS32_EF_R29];
+
+ if (!epc && !r29) {
+ bt->flags |= BT_REGS_NOT_FOUND;
+ return FALSE;
}
if (nip)
- *nip = regs->regs[MIPS32_EF_CPU0_EPC];
+ *nip = epc;
if (ksp)
- *ksp = regs->regs[MIPS32_EF_R29];
+ *ksp = r29;
+
+ bt->machdep = regs;
+
+ return TRUE;
}
static int
@@ -698,14 +719,20 @@ mips_stackframe_init(void)
static void
mips_get_stack_frame(struct bt_info *bt, ulong *pcp, ulong *spp)
{
+ int ret;
+
*pcp = 0;
*spp = 0;
+ bt->machdep = NULL;
if (DUMPFILE() && is_task_active(bt->task))
- mips_dumpfile_stack_frame(bt, pcp, spp);
+ ret = mips_dumpfile_stack_frame(bt, pcp, spp);
else
- mips_get_frame(bt, pcp, spp);
+ ret = mips_get_frame(bt, pcp, spp);
+ if (!ret)
+ error(WARNING, "cannot determine starting stack frame for task %lx\n",
+ bt->task);
}
static int
@@ -747,6 +774,130 @@ mips_vmalloc_start(void)
return first_vmalloc_address();
}
+/*
+ * Retrieve task registers for the time of the crash.
+ */
+static int
+mips_get_crash_notes(void)
+{
+ struct machine_specific *ms = machdep->machspec;
+ ulong crash_notes;
+ Elf32_Nhdr *note;
+ ulong offset;
+ char *buf, *p;
+ ulong *notes_ptrs;
+ ulong i;
+
+ if (!symbol_exists("crash_notes"))
+ return FALSE;
+
+ crash_notes = symbol_value("crash_notes");
+
+ notes_ptrs = (ulong *)GETBUF(kt->cpus*sizeof(notes_ptrs[0]));
+
+ /*
+ * Read crash_notes for the first CPU. crash_notes are in standard ELF
+ * note format.
+ */
+ if (!readmem(crash_notes, KVADDR, ¬es_ptrs[kt->cpus-1],
+ sizeof(notes_ptrs[kt->cpus-1]), "crash_notes",
+ RETURN_ON_ERROR)) {
+ error(WARNING, "cannot read crash_notes\n");
+ FREEBUF(notes_ptrs);
+ return FALSE;
+ }
+
+ if (symbol_exists("__per_cpu_offset")) {
+
+ /* Add __per_cpu_offset for each cpu to form the pointer to the notes */
+ for (i = 0; i<kt->cpus; i++)
+ notes_ptrs[i] = notes_ptrs[kt->cpus-1] + kt->__per_cpu_offset[i];
+ }
+
+ buf = GETBUF(SIZE(note_buf));
+
+ if (!(panic_task_regs = calloc((size_t)kt->cpus, sizeof(*panic_task_regs))))
+ error(FATAL, "cannot calloc panic_task_regs space\n");
+
+ for (i=0;i<kt->cpus;i++) {
+
+ if (!readmem(notes_ptrs[i], KVADDR, buf, SIZE(note_buf), "note_buf_t",
+ RETURN_ON_ERROR)) {
+ error(WARNING, "failed to read note_buf_t\n");
+ goto fail;
+ }
+
+ /*
+ * Do some sanity checks for this note before reading registers from it.
+ */
+ note = (Elf32_Nhdr *)buf;
+ p = buf + sizeof(Elf32_Nhdr);
+
+ /*
+ * dumpfiles created with qemu won't have crash_notes, but there will
+ * be elf notes; dumpfiles created by kdump do not create notes for
+ * offline cpus.
+ */
+ if (note->n_namesz == 0 && (DISKDUMP_DUMPFILE() || KDUMP_DUMPFILE())) {
+ if (DISKDUMP_DUMPFILE())
+ note = diskdump_get_prstatus_percpu(i);
+ else if (KDUMP_DUMPFILE())
+ note = netdump_get_prstatus_percpu(i);
+ if (note) {
+ /*
+ * SIZE(note_buf) accounts for a "final note", which is a
+ * trailing empty elf note header.
+ */
+ long notesz = SIZE(note_buf) - sizeof(Elf32_Nhdr);
+
+ if (sizeof(Elf32_Nhdr) + roundup(note->n_namesz, 4) +
+ note->n_descsz == notesz)
+ BCOPY((char *)note, buf, notesz);
+ } else {
+ error(WARNING,
+ "cannot find NT_PRSTATUS note for cpu: %d\n", i);
+ continue;
+ }
+ }
+
+ if (note->n_type != NT_PRSTATUS) {
+ error(WARNING, "invalid note (n_type != NT_PRSTATUS)\n");
+ goto fail;
+ }
+ if (p[0] != 'C' || p[1] != 'O' || p[2] != 'R' || p[3] !=
'E') {
+ error(WARNING, "invalid note (name != \"CORE\"\n");
+ goto fail;
+ }
+
+ /*
+ * Find correct location of note data. This contains elf_prstatus
+ * structure which has registers etc. for the crashed task.
+ */
+ offset = sizeof(Elf32_Nhdr);
+ offset = roundup(offset + note->n_namesz, 4);
+ p = buf + offset; /* start of elf_prstatus */
+
+ BCOPY(p + OFFSET(elf_prstatus_pr_reg), &panic_task_regs[i],
+ sizeof(panic_task_regs[i]));
+ }
+
+ /*
+ * And finally we have the registers for the crashed task. This is
+ * used later on when dumping backtrace.
+ */
+ ms->crash_task_regs = panic_task_regs;
+
+ FREEBUF(buf);
+ FREEBUF(notes_ptrs);
+ return TRUE;
+
+fail:
+ FREEBUF(buf);
+ FREEBUF(notes_ptrs);
+ free(panic_task_regs);
+ return FALSE;
+}
+
static int
mips_verify_symbol(const char *name, ulong value, char type)
{
@@ -911,7 +1062,23 @@ mips_init(int when)
if (!machdep->hz)
machdep->hz = 100;
+
+ MEMBER_OFFSET_INIT(elf_prstatus_pr_reg, "elf_prstatus",
+ "pr_reg");
+
+ STRUCT_SIZE_INIT(note_buf, "note_buf_t");
break;
+ case POST_VM:
+ /*
+ * crash_notes contains machine specific information about the
+ * crash. In particular, it contains CPU registers at the time
+ * of the crash. We need this information to extract correct
+ * backtraces from the panic task.
+ */
+ if (!ACTIVE() && !mips_get_crash_notes())
+ error(WARNING,
+ "cannot retrieve registers for active task%s\n\n",
+ kt->cpus > 1 ? "s" : "");
}
}
diff --git a/netdump.c b/netdump.c
index 2b7f1ce..3350c28 100644
--- a/netdump.c
+++ b/netdump.c
@@ -40,6 +40,7 @@ static void get_netdump_regs_ppc(struct bt_info *, ulong *, ulong *);
static void get_netdump_regs_ppc64(struct bt_info *, ulong *, ulong *);
static void get_netdump_regs_arm(struct bt_info *, ulong *, ulong *);
static void get_netdump_regs_arm64(struct bt_info *, ulong *, ulong *);
+static void get_netdump_regs_mips(struct bt_info *, ulong *, ulong *);
static void check_dumpfile_size(char *);
static int proc_kcore_init_32(FILE *fp);
static int proc_kcore_init_64(FILE *fp);
@@ -2436,7 +2437,7 @@ get_netdump_regs(struct bt_info *bt, ulong *eip, ulong *esp)
break;
case EM_MIPS:
- return get_netdump_regs_32(bt, eip, esp);
+ return get_netdump_regs_mips(bt, eip, esp);
break;
default:
@@ -3628,6 +3629,12 @@ get_netdump_regs_arm64(struct bt_info *bt, ulong *eip, ulong *esp)
machdep->get_stack_frame(bt, eip, esp);
}
+static void
+get_netdump_regs_mips(struct bt_info *bt, ulong *eip, ulong *esp)
+{
+ machdep->get_stack_frame(bt, eip, esp);
+}
+
int
is_partial_netdump(void)
{
--
2.1.4
8:56 a.m.
New subject: [PATCH 3/3] mips: use get_stackframe() implementation from ARM
----- Original Message -----
From: Rabin Vincent <rabinv(a)axis.com>
The mips stackframe handling has two problems:
(1) It does not read the registers from the kernel's crash_notes if ELF
notes are not available for some reason. This is important when
debugging raw memory dumps.
(2) If one of the online CPUs did not save the ELF notes, then the
mapping of ELF notes to CPUs may be incorrect.
ARM has an implementation which handles both these cases, so we borrow
it. Note that this code is entirely copy/pasted from arm, so perhaps
we could make a common function out of this which could be shared
between the two architectures?
Rabin,
The duplication is fine, so let's leave it at that.
However, when you originally did the mips port, you gave me two ELF kdumps
named "oops-sysrq" and "oops-module", which I've been testing with
a crash
binary built with "make target=MIPS".
Without this 3rd patch installed, both dumpfiles look OK:
$ crash vmlinux oops-sysrq
crash 7.1.6
Copyright (C) 2002-2016 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011 NEC Corporation
Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions. Enter "help copying" to see the conditions.
This program has absolutely no warranty. Enter "help warranty" for details.
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-unknown-linux-gnu
--target=mipsel-elf-linux"...
KERNEL: vmlinux
DUMPFILE: oops-sysrq
CPUS: 1
DATE: Sun Jan 11 12:45:20 2015
UPTIME: 00:00:54
LOAD AVERAGE: 6.68, 1.62, 0.54
TASKS: 47
NODENAME: buildroot
RELEASE: 3.19.0-rc3-00169-geb74926-dirty
VERSION: #23 SMP Sun Jan 11 18:00:43 CET 2015
MACHINE: mips (unknown Mhz)
MEMORY: 128 MB
PANIC: "SysRq : Trigger a crash"
PID: 14
COMMAND: "kworker/u2:1"
TASK: 87d20e20 [THREAD_INFO: 87df6000]
CPU: 0
STATE: TASK_RUNNING (SYSRQ)
crash> bt
PID: 14 TASK: 87d20e20 CPU: 0 COMMAND: "kworker/u2:1"
#0 [87df78e8] __udelay at 803773f8
#1 [87df78e8] panic at 8054be58
#2 [87df7928] die at 8010bc10
#3 [87df7958] __do_page_fault at 8011638c
#4 [87df7a28] ret_from_exception at 80105aa0
$ 0 : 00000000 00000001 00000001 806d0000
$ 4 : 00000063 81103288 811045a0 806d8fa0
$ 8 : 00000001 00000000 80650000 000038b8
$12 : 000000bc 00000002 00000000 00000000
$16 : 8066c9e4 80650000 00000063 00000007
$20 : 80670000 00000001 80680740 80638400
$24 : 000000bc 00000001 80608ee4 87df7ae4
$28 : 87df6000 87df7ae0 00000000 803c8434
Hi : 00001644
Lo : 00005910
epc : 803c7c80 sysrq_handle_crash+0x10
ra : 803c8434 __handle_sysrq+0x144
Status: 1000a302
Cause : c080840c
BadVA : 00000000
#5 [87df7ae0] sysrq_handle_crash at 803c7c80
#6 [87df7ae0] __handle_sysrq at 803c8434
#7 [87df7b18] serial8250_rx_chars at 803dd678
#8 [87df7b50] serial8250_handle_irq at 803e0180
#9 [87df7b78] serial8250_interrupt at 803dda5c
#10 [87df7ba8] handle_irq_event_percpu at 8016b300
#11 [87df7be8] handle_irq_event at 8016b530
#12 [87df7c08] handle_level_irq at 8016eb50
#13 [87df7c28] generic_handle_irq at 8016a8ec
#14 [87df7c40] do_IRQ at 80107a8c
#15 [87df7c60] i8259_handler at 801013fc
#16 [87df7c78] handle_irq_event_percpu at 8016b300
#17 [87df7cb8] handle_percpu_irq at 8016f4c8
#18 [87df7cd8] generic_handle_irq at 8016a8ec
#19 [87df7cf0] do_IRQ at 80107a8c
#20 [87df7d10] plat_irq_dispatch at 8011358c
#21 [87df7d38] ret_from_irq at 80105ab0
$ 0 : 00000000 806d0000 00000000 876773bc
$ 4 : 0000000c 00000000 00000064 00000000
$ 8 : 0003d090 00000000 fffffffc 00000001
$12 : 811051f0 00000005 00000000 00000005
$16 : 00000000 87435e78 876773b0 00000000
$20 : 876774d8 876774dc 87677480 80680000
$24 : 00000010 80155448 00000000 8023d2a4
$28 : 87df6000 87df7df0 00000000 8023efe4
Hi : 00013880
Lo : 00011170
epc : 8023f000 bdi_writeback_workfn+0x168
ra : 8023efe4 bdi_writeback_workfn+0x14c
Status: 1000a703
Cause : 00800400
BadVA : 87435e78
#22 [87df7df0] bdi_writeback_workfn at 8023f000
#23 [87df7e58] process_one_work at 8013e1b8
#24 [87df7e98] worker_thread at 8013ed6c
#25 [87df7ed0] kthread at 801434ac
#26 [87df7f28] ret_from_kernel_thread at 80105af8
crash>
$ crash vmlinux oops-module
crash 7.1.6
Copyright (C) 2002-2016 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011 NEC Corporation
Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions. Enter "help copying" to see the conditions.
This program has absolutely no warranty. Enter "help warranty" for details.
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-unknown-linux-gnu
--target=mipsel-elf-linux"...
KERNEL: vmlinux
DUMPFILE: oops-module
CPUS: 1
DATE: Sun Jan 11 12:47:40 2015
UPTIME: 00:00:41
LOAD AVERAGE: 6.63, 1.61, 0.54
TASKS: 48
NODENAME: buildroot
RELEASE: 3.19.0-rc3-00169-geb74926-dirty
VERSION: #23 SMP Sun Jan 11 18:00:43 CET 2015
MACHINE: mips (unknown Mhz)
MEMORY: 128 MB
PANIC: "CPU 0 Unable to handle kernel paging request at virtual address
0000deb0, epc == c003f4fc, ra == c003f4f4"
PID: 1009
COMMAND: "insmod"
TASK: 87f80710 [THREAD_INFO: 86870000]
CPU: 0
STATE: TASK_RUNNING (PANIC)
crash> bt
PID: 1009 TASK: 87f80710 CPU: 0 COMMAND: "insmod"
#0 [868716d0] __udelay at 803773f8
#1 [868716d0] panic at 8054be58
#2 [86871710] die at 8010bc30
#3 [86871740] __do_page_fault at 8011638c
#4 [86871810] ret_from_exception at 80105aa0
$ 0 : 00000000 00000001 0000dead 0000beef
$ 4 : 81103284 00000007 00000001 000003f8
$ 8 : 803de068 00000000 80650000 78302065
$12 : 000000c0 1dcd6500 00000000 00000000
$16 : 8054be68 87e22200 c0040000 00000000
$20 : 805e0000 ffffffff 80246d0c 00000001
$24 : 00000003 803dcf4c c003fda4 868718cc
$28 : 86870000 868718c8 00000000 c003f4f4
Hi : 00000bb8
Lo : 00002ee0
epc : c003f4fc free_cmd+0x70
ra : c003f4f4 free_cmd+0x68
Status: 1000a703
Cause : 0080000c
BadVA : 0000deb0
#5 [868718c8] free_cmd at c003f4fc [null_blk]
#6 [868718e8] generic_make_request at 8034a338
#7 [86871910] submit_bio at 8034a48c
#8 [86871970] _submit_bh at 802483cc
#9 [86871998] block_read_full_page at 8024894c
#10 [86871a08] do_read_cache_page at 801bf358
#11 [86871a48] read_cache_page at 801bf4d4
#12 [86871a68] read_dev_sector at 8035e6a8
#13 [86871a80] read_lba at 80360644
#14 [86871ac8] efi_partition at 80360b58
#15 [86871be0] check_partition at 8035f884
#16 [86871c08] rescan_partitions at 8035edc0
#17 [86871c58] __blkdev_get at 8024cfb8
#18 [86871c98] blkdev_get at 8024d234
#19 [86871ce8] add_disk at 8035c548
#20 [86871d38] init_module at c0042570 [null_blk]
#21 [86871d80] do_one_initcall at 8010058c
#22 [86871df8] load_module at 8019674c
#23 [86871ec8] sys_init_module at 80196f48
#24 [86871f28] handle_sys at 801139c8
$ 0 : 00000000 801105cc 00000fa0 773cc3ec
$ 4 : 772b1008 0002e480 00c4b008 004dd5f0
$ 8 : 00000000 00000203 fffffffc f8000000
$12 : 03ff0000 ac000000 03bd0000 03bf0000
$16 : 772b1008 00000003 7f898eb0 7f8988a8
$20 : 7f898a64 004d0000 004d0000 00000002
$24 : 24000000 773cc3ec 004dd5f0 00000000
$28 : 77469e20 7f898890 00a73404 00419e7c
Hi : 00000000
Lo : 0000000a
epc : 773cc400
ra : 00419e7c
Status: 0000a713
Cause : 00800020
BadVA : 772b1004
crash>
But with the patch installed, both dumpfiles show the "WARNING: cannot
retrieve registers for active task" during initialization, and "bt" fails
as expected:
$ crash vmlinux oops-sysrq
crash 7.1.6
Copyright (C) 2002-2016 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011 NEC Corporation
Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions. Enter "help copying" to see the conditions.
This program has absolutely no warranty. Enter "help warranty" for details.
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-unknown-linux-gnu
--target=mipsel-elf-linux"...
WARNING: cannot retrieve registers for active task
KERNEL: vmlinux
DUMPFILE: oops-sysrq
CPUS: 1
DATE: Sun Jan 11 12:45:20 2015
UPTIME: 00:00:54
LOAD AVERAGE: 6.68, 1.62, 0.54
TASKS: 47
NODENAME: buildroot
RELEASE: 3.19.0-rc3-00169-geb74926-dirty
VERSION: #23 SMP Sun Jan 11 18:00:43 CET 2015
MACHINE: mips (unknown Mhz)
MEMORY: 128 MB
PANIC: "SysRq : Trigger a crash"
PID: 14
COMMAND: "kworker/u2:1"
TASK: 87d20e20 [THREAD_INFO: 87df6000]
CPU: 0
STATE: TASK_RUNNING (SYSRQ)
crash> bt
PID: 14 TASK: 87d20e20 CPU: 0 COMMAND: "kworker/u2:1"
bt: WARNING: cannot determine starting stack frame for task 87d20e20
crash>
$ crash vmlinux oops-module
crash 7.1.6
Copyright (C) 2002-2016 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011 NEC Corporation
Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions. Enter "help copying" to see the conditions.
This program has absolutely no warranty. Enter "help warranty" for details.
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-unknown-linux-gnu
--target=mipsel-elf-linux"...
WARNING: cannot retrieve registers for active task
KERNEL: vmlinux
DUMPFILE: oops-module
CPUS: 1
DATE: Sun Jan 11 12:47:40 2015
UPTIME: 00:00:41
LOAD AVERAGE: 6.63, 1.61, 0.54
TASKS: 48
NODENAME: buildroot
RELEASE: 3.19.0-rc3-00169-geb74926-dirty
VERSION: #23 SMP Sun Jan 11 18:00:43 CET 2015
MACHINE: mips (unknown Mhz)
MEMORY: 128 MB
PANIC: "CPU 0 Unable to handle kernel paging request at virtual address
0000deb0, epc == c003f4fc, ra == c003f4f4"
PID: 1009
COMMAND: "insmod"
TASK: 87f80710 [THREAD_INFO: 86870000]
CPU: 0
STATE: TASK_RUNNING (PANIC)
crash> bt
PID: 1009 TASK: 87f80710 CPU: 0 COMMAND: "insmod"
bt: WARNING: cannot determine starting stack frame for task 87f80710
crash>
Just in case you don't have these two dumpfiles anymore, I've put
them here:
http://people.redhat.com/anderson/.rabin
Thanks,
Dave
4:15 p.m.
New subject: [PATCH 3/3] mips: use get_stackframe() implementation from ARM
On Wed, Oct 19, 2016 at 09:56:08AM -0400, Dave Anderson wrote:
But with the patch installed, both dumpfiles show the "WARNING:
cannot
retrieve registers for active task" during initialization, and "bt" fails
as expected:
Right, thanks for catching this. The code borrowed from ARM assumes
that the kernel was built with core dump support, which is not
necessarily the case if the dump was saved via some external means which
creates ELF dumps (QEMU in the case of my example dumps).
Folding in the following patch makes it work for both the example dumps
you have and dumps with crash_notes. Thanks.
8<----
From fd9cec4ae5e5f310e3de073e66825b7b9df07573 Mon Sep 17 00:00:00 2001
From: Rabin Vincent <rabinv(a)axis.com>
Date: Wed, 19 Oct 2016 21:18:31 +0200
Subject: [PATCH] mips: get regs from ELF notes if no crash_notes
---
mips.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/mips.c b/mips.c
index e3f1569..4eeab55 100644
--- a/mips.c
+++ b/mips.c
@@ -898,6 +898,54 @@ fail:
return FALSE;
}
+static int mips_get_elf_notes(void)
+{
+ struct machine_specific *ms = machdep->machspec;
+ int i;
+
+ if (!DISKDUMP_DUMPFILE() && !KDUMP_DUMPFILE())
+ return FALSE;
+
+ panic_task_regs = calloc(kt->cpus, sizeof(*panic_task_regs));
+ if (!panic_task_regs)
+ error(FATAL, "cannot calloc panic_task_regs space\n");
+
+ for (i = 0; i < kt->cpus; i++) {
+ Elf32_Nhdr *note = NULL;
+ size_t len;
+
+ if (DISKDUMP_DUMPFILE())
+ note = diskdump_get_prstatus_percpu(i);
+ else if (KDUMP_DUMPFILE())
+ note = netdump_get_prstatus_percpu(i);
+
+ if (!note)
+ error(WARNING,
+ "cannot find NT_PRSTATUS note for cpu: %d\n", i);
+
+ len = sizeof(Elf32_Nhdr);
+ len = roundup(len + note->n_namesz, 4);
+
+ BCOPY((char *)note + len + OFFSET(elf_prstatus_pr_reg),
+ &panic_task_regs[i], sizeof(panic_task_regs[i]));
+ }
+
+ ms->crash_task_regs = panic_task_regs;
+
+ return TRUE;
+}
+
+static int mips_init_active_task_regs(void)
+{
+ int retval;
+
+ retval = mips_get_crash_notes();
+ if (retval == TRUE)
+ return retval;
+
+ return mips_get_elf_notes();
+}
+
static int
mips_verify_symbol(const char *name, ulong value, char type)
{
@@ -1075,7 +1123,7 @@ mips_init(int when)
* of the crash. We need this information to extract correct
* backtraces from the panic task.
*/
- if (!ACTIVE() && !mips_get_crash_notes())
+ if (!ACTIVE() && !mips_init_active_task_regs())
error(WARNING,
"cannot retrieve registers for active task%s\n\n",
kt->cpus > 1 ? "s" : "");
--
2.1.4
1:16 p.m.
New subject: [PATCH 3/3] mips: use get_stackframe() implementation from ARM
----- Original Message -----
On Wed, Oct 19, 2016 at 09:56:08AM -0400, Dave Anderson wrote:
> But with the patch installed, both dumpfiles show the "WARNING: cannot
> retrieve registers for active task" during initialization, and "bt"
fails
> as expected:
Right, thanks for catching this. The code borrowed from ARM assumes
that the kernel was built with core dump support, which is not
necessarily the case if the dump was saved via some external means which
creates ELF dumps (QEMU in the case of my example dumps).
Folding in the following patch makes it work for both the example dumps
you have and dumps with crash_notes. Thanks.
That works -- queued for crash-7.1.7:
https://github.com/crash-utility/crash/commit/5bca61c0eb44729b541da02bcc4...
Thanks,
Dave
8<----
>From fd9cec4ae5e5f310e3de073e66825b7b9df07573 Mon Sep 17 00:00:00 2001
From: Rabin Vincent <rabinv(a)axis.com>
Date: Wed, 19 Oct 2016 21:18:31 +0200
Subject: [PATCH] mips: get regs from ELF notes if no crash_notes
---
mips.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/mips.c b/mips.c
index e3f1569..4eeab55 100644
--- a/mips.c
+++ b/mips.c
@@ -898,6 +898,54 @@ fail:
return FALSE;
}
+static int mips_get_elf_notes(void)
+{
+ struct machine_specific *ms = machdep->machspec;
+ int i;
+
+ if (!DISKDUMP_DUMPFILE() && !KDUMP_DUMPFILE())
+ return FALSE;
+
+ panic_task_regs = calloc(kt->cpus, sizeof(*panic_task_regs));
+ if (!panic_task_regs)
+ error(FATAL, "cannot calloc panic_task_regs space\n");
+
+ for (i = 0; i < kt->cpus; i++) {
+ Elf32_Nhdr *note = NULL;
+ size_t len;
+
+ if (DISKDUMP_DUMPFILE())
+ note = diskdump_get_prstatus_percpu(i);
+ else if (KDUMP_DUMPFILE())
+ note = netdump_get_prstatus_percpu(i);
+
+ if (!note)
+ error(WARNING,
+ "cannot find NT_PRSTATUS note for cpu: %d\n", i);
+
+ len = sizeof(Elf32_Nhdr);
+ len = roundup(len + note->n_namesz, 4);
+
+ BCOPY((char *)note + len + OFFSET(elf_prstatus_pr_reg),
+ &panic_task_regs[i], sizeof(panic_task_regs[i]));
+ }
+
+ ms->crash_task_regs = panic_task_regs;
+
+ return TRUE;
+}
+
+static int mips_init_active_task_regs(void)
+{
+ int retval;
+
+ retval = mips_get_crash_notes();
+ if (retval == TRUE)
+ return retval;
+
+ return mips_get_elf_notes();
+}
+
static int
mips_verify_symbol(const char *name, ulong value, char type)
{
@@ -1075,7 +1123,7 @@ mips_init(int when)
* of the crash. We need this information to extract correct
* backtraces from the panic task.
*/
- if (!ACTIVE() && !mips_get_crash_notes())
+ if (!ACTIVE() && !mips_init_active_task_regs())
error(WARNING,
"cannot retrieve registers for active task%s\n\n",
kt->cpus > 1 ? "s" : "");
--
2.1.4
--
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Crash-utility(a)redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
8:52 a.m.
----- Original Message -----
From: Rabin Vincent <rabinv(a)axis.com>
Set a default value for machdep->hz to 100, which will be used if the in
kernel config data is unavailable.
Queued for crash-7.1.7:
https://github.com/crash-utility/crash/commit/b240a8bfe2ef629ae7beb743c55...
Thanks,
Dave
---
mips.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mips.c b/mips.c
index a4fc8b6..7ad6f61 100644
--- a/mips.c
+++ b/mips.c
@@ -57,6 +57,7 @@ static struct machine_specific mips_machine_specific = { 0
};
static void
mips_display_machine_stats(void)
{
+ fprintf(fp, " HZ: %d\n", machdep->hz);
fprintf(fp, " PAGE SIZE: %d\n", PAGESIZE());
fprintf(fp, "\n");
@@ -776,6 +777,7 @@ mips_dump_machdep_table(ulong arg)
fprintf(fp, " ptrs_per_pgd: %lu\n", PTRS_PER_PGD);
fprintf(fp, " ptrs_per_pte: %d\n", PTRS_PER_PTE);
fprintf(fp, " stacksize: %ld\n", machdep->stacksize);
+ fprintf(fp, " hz: %d\n", machdep->hz);
fprintf(fp, " memsize: %lld (0x%llx)\n",
machdep->memsize, machdep->memsize);
fprintf(fp, " bits: %d\n", machdep->bits);
@@ -904,6 +906,9 @@ mips_init(int when)
ARRAY_LENGTH_INIT(machdep->nr_irqs, irq_desc,
"irq_desc", NULL, 0);
mips_stackframe_init();
+
+ if (!machdep->hz)
+ machdep->hz = 100;
break;
}
}
--
2.1.4
--
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Rabin Vincent