On Thu, Mar 14, 2024 at 3:33 AM Alexey Makhalov <alexey.makhalov@broadcom.com> wrote:

Support for GDB debugging of all tasks active and inactive.
Before this commit only active tasks were listed by "info threads"
with "CPU #" as a Target Id.

"info threads" will now show all tasks, similar to "ps", example:
crash> info threads
Id Target Id Frame
* 1 0 swapper/0 0xffffffffadba19d4 in default_idle () at arch/x86/kernel/process.c:731
2 0 swapper/1 0xffffffffadba19d4 in default_idle () at arch/x86/kernel/process.c:731
3 0 swapper/2 0xffffffffadba19d4 in default_idle () at arch/x86/kernel/process.c:731
4 0 swapper/3 0xffffffffadba19d4 in default_idle () at arch/x86/kernel/process.c:731
5 0 swapper/4 0xffffffffadb97292 in context_switch (rf=0xffffbaf0000f3e88, next=0xffff9ecb04908000, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
...
730 970325 taskset 0xffffffffadb97292 in context_switch (rf=0xffffbaf006a0fd18, next=0xffff9ecb0aec0000, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
731 975217 sleep 0xffffffffadb97292 in context_switch (rf=0xffffbaf005743c20, next=0xffff9ecac0692880, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
732 975228 sleep 0xffffffffadb97292 in context_switch (rf=0xffffbaf00696fb58, next=0xffff9ecac0690000, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
...
876 976084 docker 0xffffffffadb97292 in context_switch (rf=0xffffbaf0153dbd10, next=0xffff9ecac0645100, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
877 976085 systemd-userwor 0xffffffffadb97292 in context_switch (rf=0xffffbaf0153cbc58, next=0xffff9ecac0645100, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
878 976086 systemd-userwor 0xffffffffadb97292 in context_switch (rf=0xffffbaf0153e3c58, next=0xffffffffaec15a40 <init_task>, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
879 976087 systemd-userwor 0xffffffffadb97292 in context_switch (rf=0xffffbaf0153ebc58, next=0xffffffffaec15a40 <init_task>, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
Where "Target ID" contains "PID COMM" of the task

Example of "731 975217 sleep" debugging, real case, trying to
figure out why sleep was stuck in uninterruptable sleep.
Backtrace using crash:
crash> ps | grep 975217
975217 969797 3 ffff9ecb3956a880 UN 0.0 0 0 sleep
crash> bt 975217
PID: 975217 TASK: ffff9ecb3956a880 CPU: 3 COMMAND: "sleep"
#0 [ffffbaf005743ba0] __schedule at ffffffffadb97292
#1 [ffffbaf005743c60] schedule at ffffffffadb982b8
#2 [ffffbaf005743c80] rwbase_write_lock at ffffffffadb9aed7
#3 [ffffbaf005743cc0] down_write at ffffffffadb9b133
#4 [ffffbaf005743cd0] unlink_file_vma at ffffffffad2b0e2e
#5 [ffffbaf005743cf8] free_pgtables at ffffffffad2a47b0
#6 [ffffbaf005743d88] exit_mmap at ffffffffad2b3b8d
#7 [ffffbaf005743e80] mmput at ffffffffad08c81f
#8 [ffffbaf005743e98] do_exit at ffffffffad09636c
#9 [ffffbaf005743ef8] do_group_exit at ffffffffad096c78
RIP: 00007f111c70ddf9 RSP: 00007fff451817e8 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 00007f111c8089e0 RCX: 00007f111c70ddf9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R8: ffffffffffffff80 R9: 0000000000000000
R10: 00007fff451817b0 R11: 0000000000000246 R12: 00007f111c8089e0
R13: 00007f111c80e2e0 R14: 0000000000000002 R15: 00007f111c80e2c8
ORIG_RAX: 00000000000000e7 CS: 0033 SS: 002b

Backtrace using gdb (pay attention, task must be selected by thread Id):
crash> thread 731
[Switching to thread 731 ( 975217 sleep)]
5372 switch_to(prev, next, prev);
crash> gdb bt
#0 0xffffffffadb97292 in context_switch (rf=0xffffbaf005743c20, next=0xffff9ecac0692880, prev=<optimized out>, rq=<optimized out>) at kernel/sched/core.c:5372
#1 __schedule (sched_mode=sched_mode@entry=0) at kernel/sched/core.c:6696
#2 0xffffffffadb982b8 in schedule () at kernel/sched/core.c:6772
#3 0xffffffffadb9aed7 in rwbase_write_lock (rwb=rwb@entry=0xffff9ecaf1831430, state=state@entry=2) at kernel/locking/rwbase_rt.c:259
#4 0xffffffffadb9b133 in __down_write (sem=sem@entry=0xffff9ecaf1831430) at kernel/locking/rwsem.c:1474
#5 down_write (sem=sem@entry=0xffff9ecaf1831430) at kernel/locking/rwsem.c:1574
#6 0xffffffffad2b0e2e in i_mmap_lock_write (mapping=<optimized out>) at ./include/linux/fs.h:466
#7 unlink_file_vma (vma=vma@entry=0xffff9ecadd566090) at mm/mmap.c:127
#8 0xffffffffad2a47b0 in free_pgtables (tlb=tlb@entry=0xffffbaf005743dd0, mt=mt@entry=0xffff9ecb28e3b180, vma=0xffff9ecadd566090, vma@entry=0xffff9ecadd566000, floor=floor@entry=0, ceiling=ceiling@entry=0) at mm/memory.c:431
#9 0xffffffffad2b3b8d in exit_mmap (mm=mm@entry=0xffff9ecb28e3b180) at mm/mmap.c:3237
#10 0xffffffffad08c81f in __mmput (mm=0xffff9ecb28e3b180) at kernel/fork.c:1204
#11 mmput (mm=mm@entry=0xffff9ecb28e3b180) at kernel/fork.c:1226
#12 0xffffffffad09636c in exit_mm () at kernel/exit.c:563
#13 do_exit (code=code@entry=0) at kernel/exit.c:856
#14 0xffffffffad096c78 in do_group_exit (exit_code=0) at kernel/exit.c:1019
#15 0xffffffffad096cf8 in __do_sys_exit_group (error_code=<optimized out>) at kernel/exit.c:1030
#16 __se_sys_exit_group (error_code=<optimized out>) at kernel/exit.c:1028
#17 __x64_sys_exit_group (regs=<optimized out>) at kernel/exit.c:1028
#18 0xffffffffadb8a327 in do_syscall_x64 (nr=<optimized out>, regs=0xffffbaf005743f58) at arch/x86/entry/common.c:51
#19 do_syscall_64 (regs=0xffffbaf005743f58, nr=<optimized out>) at arch/x86/entry/common.c:81
#20 0xffffffffadc000dc in entry_SYSCALL_64 () at arch/x86/entry/entry_64.S:120
#21 0x00007f111c80e2c8 in ?? ()
#22 0x0000000000000002 in ?? ()
#23 0x00007f111c80e2e0 in ?? ()
#24 0x00007f111c8089e0 in ?? ()
#25 0x0000000000000000 in ?? ()
crash> f 3
259 rwbase_schedule();
crash> p *rwb
$1 = {
readers = {
counter = 1
},
rtmutex = {
wait_lock = {
raw_lock = {
{
val = {
counter = 0
},
{
locked = 0 '\000',
pending = 0 '\000'
},
{
locked_pending = 0,
tail = 0
}
}
}
},
waiters = {
rb_root = {
rb_node = 0xffffbaf006977be0
},
rb_leftmost = 0xffffbaf00696fbe0
},
owner = 0xffff9ecb3956a881
}
}

Additional changes:
1. Allow gdb "frame" command.
2. Blacklist useless gdb "gcore" command. Use gcore plugin instead.
3. Move crash_target_init() to later time as crash target requires a list of
tasks to be initialized.

Known issues and TBD items:
1. "info threads" may bail out first time throwing errors trying to access
userspace address during unwind process. Following "info threads"
invokations run without issues.
2. To unwind a stack of inactive task, only modern Linux versions, which use
inactive_task_frame, are supported and only x86_64 architecture.
3. gdb bt unwinder does not stop properly and may show invalid frames (21-25
on example above). Not a regression, existed before.
4. gdb bt unwinder does not work on active tasks in userspace. Not a regression,
existed before.
5. Only x86_64 architecture supported. machdep->get_task_reg() must be
implemented for others. Not a regression, existed before.
6. Active tasks registers fetching imlemented only for VMware dumps, see
x86_64_get_task_reg() for more details. Not a regression, existed before.

Signed-off-by: Alexey Makhalov <alexey.makhalov@broadcom.com>
---
Makefile | 16 ++++++------
crash_target.c | 39 ++++++++++++++++++++---------
defs.h | 10 ++++++--
gdb-10.2.patch | 7 ++----
gdb_interface.c | 62 ++++++++++++++++++++++++++++++----------------
help.c | 1 +
main.c | 1 +
task.c | 1 +
x86_64.c | 66 +++++++++++++++++++++++++++++++++++++++++++------
9 files changed, 147 insertions(+), 56 deletions(-)

diff --git a/Makefile b/Makefile
index 9e97313..63a5193 100644
--- a/Makefile
+++ b/Makefile
@@ -24,7 +24,7 @@ PROGRAM=crash
# Supported targets: X86 ALPHA PPC IA64 PPC64 SPARC64
# TARGET and GDB_CONF_FLAGS will be configured automatically by configure
#
-TARGET=
+TARGET=X86_64
GDB_CONF_FLAGS=

ARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ -e s/arm.*/arm/ -e s/sa110/arm/)
@@ -35,10 +35,10 @@ endif
#
# GDB, GDB_FILES, GDB_OFILES and GDB_PATCH_FILES will be configured automatically by configure
#
-GDB=
-GDB_FILES=
-GDB_OFILES=
-GDB_PATCH_FILES=
+GDB=gdb-10.2
+GDB_FILES=${GDB_10.2_FILES}
+GDB_OFILES=${GDB_10.2_OFILES}
+GDB_PATCH_FILES=gdb-10.2.patch

#
# Default installation directory
@@ -190,7 +190,7 @@ GDB_10.2_OFILES=${GDB}/gdb/symtab.o crash_target.o
#
# GDB_FLAGS is passed up from the gdb Makefile.
#
-GDB_FLAGS=
+GDB_FLAGS=-DGDB_10_2

#
# WARNING_OPTIONS and WARNING_ERROR are both applied on a per-file basis.
@@ -199,7 +199,7 @@ GDB_FLAGS=
# usefulness is also dependent upon the processor's compiler -- your mileage
# may vary.
#
-#WARNING_OPTIONS=-Wall -O2 -Wstrict-prototypes -Wmissing-prototypes -fstack-protector -Wformat-security
+WARNING_OPTIONS=-Wall -O2 -Wstrict-prototypes -Wmissing-prototypes -fstack-protector -Wformat-security
#WARNING_ERROR=-Werror

# TARGET_CFLAGS will be configured automatically by configure
@@ -207,7 +207,7 @@ TARGET_CFLAGS=

CRASH_CFLAGS=-g -D${TARGET} ${TARGET_CFLAGS} ${GDB_FLAGS} ${CFLAGS}

-GPL_FILES=
+GPL_FILES=COPYING3
TAR_FILES=${SOURCE_FILES} Makefile ${GPL_FILES} README .rh_rpm_package crash.8 \
${EXTENSION_SOURCE_FILES} ${MEMORY_DRIVER_FILES}
CSCOPE_FILES=${SOURCE_FILES}
diff --git a/crash_target.c b/crash_target.c
index 4554806..2fdf203 100644
--- a/crash_target.c
+++ b/crash_target.c
@@ -2,6 +2,8 @@
* crash_target.c
*
* Copyright (c) 2021 VMware, Inc.
+ * Copyright (c) 2024 Broadcom. All Rights Reserved. The term "Broadcom"
+ * refers to Broadcom Inc. and/or its subsidiaries.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -13,7 +15,7 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
- * Author: Alexey Makhalov <amakhalov@vmware.com>
+ * Author: Alexey Makhalov <alexey.makhalov@broadcom.com>
*/

#include <defs.h>
@@ -23,11 +25,11 @@
#include "regcache.h"
#include "gdbarch.h"

-void crash_target_init (void);
-
+extern "C" void crash_target_init (void);
extern "C" int gdb_readmem_callback(unsigned long, void *, int, int);
-extern "C" int crash_get_nr_cpus(void);
-extern "C" int crash_get_cpu_reg (int cpu, int regno, const char *regname,
+extern "C" int crash_get_nr_tasks(void);
+extern "C" void crash_get_task_info(int task_nr, unsigned long *pid, char **comm);
+extern "C" int crash_get_task_reg (int task_nr, int regno, const char *regname,
int regsize, void *val);

@@ -60,7 +62,13 @@ public:
bool has_registers () override { return true; }
bool thread_alive (ptid_t ptid) override { return true; }
std::string pid_to_str (ptid_t ptid) override
- { return string_printf ("CPU %ld", ptid.tid ()); }
+ {
+ unsigned long pid;
+ char *comm;
+
+ crash_get_task_info(ptid.tid(), &pid, &comm);
+ return string_printf ("%7ld %s", pid, comm);
+ }

};

@@ -68,18 +76,25 @@ public:
void
crash_target::fetch_registers (struct regcache *regcache, int regno)
{
+ int r;
gdb_byte regval[16];
- int cpu = inferior_ptid.tid();
+ int task_nr = inferior_ptid.tid();
struct gdbarch *arch = regcache->arch ();

- for (int r = 0; r < gdbarch_num_regs (arch); r++)
+ if (regno >= 0) {
+ r = regno;
+ goto onetime;
+ }
+
+ for (r = 0; regno == -1 && r < gdbarch_num_regs (arch); r++)
{
+onetime:
const char *regname = gdbarch_register_name(arch, r);
int regsize = register_size (arch, r);
if (regsize > sizeof (regval))
error (_("fatal error: buffer size is not enough to fit register value"));

- if (crash_get_cpu_reg (cpu, r, regname, regsize, (void *)&regval))
+ if (crash_get_task_reg (task_nr, r, regname, regsize, (void *)&regval))
regcache->raw_supply (r, regval);
else
regcache->raw_supply (r, NULL);
@@ -107,10 +122,10 @@ crash_target::xfer_partial (enum target_object object, const char *annex,

#define CRASH_INFERIOR_PID 1

-void
+extern "C" void
crash_target_init (void)
{
- int nr_cpus = crash_get_nr_cpus();
+ int nr_tasks = crash_get_nr_tasks();
crash_target *target = new crash_target ();

/* Own the target until it is successfully pushed. */
@@ -119,7 +134,7 @@ crash_target_init (void)
push_target (std::move (target_holder));

inferior_appeared (current_inferior (), CRASH_INFERIOR_PID);
- for (int i = 0; i < nr_cpus; i++)
+ for (int i = 0; i < nr_tasks; i++)
{
thread_info *thread = add_thread_silent (target,
ptid_t(CRASH_INFERIOR_PID, 0, i));
diff --git a/defs.h b/defs.h
index 98650e8..2b3f247 100644
--- a/defs.h
+++ b/defs.h
@@ -1080,7 +1080,7 @@ struct machdep_table {
void (*get_irq_affinity)(int);
void (*show_interrupts)(int, ulong *);
int (*is_page_ptr)(ulong, physaddr_t *);
- int (*get_cpu_reg)(int, int, const char *, int, void *);
+ int (*get_task_reg)(struct task_context *, int, const char *, int, void *);
int (*is_cpu_prstatus_valid)(int cpu);
};

@@ -2263,6 +2263,7 @@ struct size_table { /* stash of commonly-used sizes */
long pt_regs;
long task_struct;
long thread_info;
+ long inactive_task_frame;
long softirq_state;
long desc_struct;
long umode_t;
@@ -8001,9 +8002,14 @@ extern int have_full_symbols(void);
#define XEN_HYPERVISOR_ARCH
#endif

+/*
+ * crash_target.c
+ */
+extern void crash_target_init (void);
+
/*
* Register numbers must be in sync with gdb/features/i386/64bit-core.c
- * to make crash_target->fetch_registers() ---> machdep->get_cpu_reg()
+ * to make crash_target->fetch_registers() ---> machdep->get_task_reg()
* working properly.
*/
enum x86_64_regnum {
diff --git a/gdb-10.2.patch b/gdb-10.2.patch
index a7018a2..ecf673d 100644
--- a/gdb-10.2.patch
+++ b/gdb-10.2.patch
@@ -221,7 +221,7 @@ exit 0
warning (_("\
--- gdb-10.2/gdb/main.c.orig
+++ gdb-10.2/gdb/main.c
-@@ -392,6 +392,14 @@ start_event_loop ()
+@@ -392,6 +392,13 @@ start_event_loop ()
return;
}

@@ -230,7 +230,6 @@ exit 0
+extern "C" void main_loop(void);
+extern "C" unsigned long crash_get_kaslr_offset(void);
+extern "C" int console(const char *, ...);
-+void crash_target_init (void);
+#endif
+
/* Call command_loop. */
@@ -316,7 +315,7 @@ exit 0
}
}

-@@ -1242,6 +1274,16 @@ captured_main (void *data)
+@@ -1242,6 +1274,14 @@ captured_main (void *data)

captured_main_1 (context);

@@ -324,8 +323,6 @@ exit 0
+ /* Relocate the vmlinux. */
+ objfile_rebase (symfile_objfile, crash_get_kaslr_offset());
+
-+ crash_target_init();
-+
+ /* Back to crash. */
+ main_loop();
+#endif
diff --git a/gdb_interface.c b/gdb_interface.c
index b14319c..cbca296 100644
--- a/gdb_interface.c
+++ b/gdb_interface.c
@@ -3,6 +3,8 @@
* Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
* Copyright (C) 2002-2015,2018-2019 David Anderson
* Copyright (C) 2002-2015,2018-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (c) 2024 Broadcom. All Rights Reserved. The term "Broadcom"
+ * refers to Broadcom Inc. and/or its subsidiaries.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -711,7 +713,7 @@ static char *prohibited_list[] = {
"watch", "rwatch", "awatch", "attach", "continue", "c", "fg", "detach",
"finish", "handle", "interrupt", "jump", "kill", "next", "nexti",
"signal", "step", "s", "stepi", "target", "until", "delete",
- "clear", "disable", "enable", "condition", "ignore", "frame", "catch",
+ "clear", "disable", "enable", "condition", "ignore", "gcore", "catch",
"tcatch", "return", "file", "exec-file", "core-file", "symbol-file",
"load", "si", "ni", "shell", "sy",
NULL /* must be last */
@@ -1063,34 +1065,52 @@ get_frame_offset(ulong pc)
unsigned long crash_get_kaslr_offset(void);
unsigned long crash_get_kaslr_offset(void)
{
- return kt->relocate * -1;
+ return kt->relocate * -1;
}

/* Callbacks for crash_target */
-int crash_get_nr_cpus(void);
-int crash_get_cpu_reg (int cpu, int regno, const char *regname,
+int crash_get_nr_tasks(void);
+void crash_get_task_info(int task_nr, unsigned long *pid, char **comm);
+int crash_get_task_reg (int task_nr, int regno, const char *regname,
int regsize, void *val);

-int crash_get_nr_cpus(void)
+int crash_get_nr_tasks(void)
{
- if (SADUMP_DUMPFILE())
- return sadump_get_nr_cpus();
- else if (DISKDUMP_DUMPFILE())
- return diskdump_get_nr_cpus();
- else if (KDUMP_DUMPFILE())
- return kdump_get_nr_cpus();
- else if (VMSS_DUMPFILE())
- return vmware_vmss_get_nr_cpus();
-
- /* Just CPU #0 */
- return 1;
+ return RUNNING_TASKS();
}

-int crash_get_cpu_reg (int cpu, int regno, const char *regname,
- int regsize, void *value)
+/* Get task information by its index number in TT */
+void crash_get_task_info(int task_nr, unsigned long *pid, char **comm)
{
- if (!machdep->get_cpu_reg)
- return FALSE;
- return machdep->get_cpu_reg(cpu, regno, regname, regsize, value);
+ int i;
+ struct task_context *tc;
+
+ tc = FIRST_CONTEXT();
+ for (i = 0; i < RUNNING_TASKS(); i++, tc++)
+ if (i == task_nr) {
+ *pid = tc->pid;
+ *comm = tc->comm;
+ return;
+ }
+ *pid = 0;
+ *comm = NULL;
+ return;
+}
+
+int crash_get_task_reg (int task_nr, int regno, const char *regname,
+ int regsize, void *value)
+{
+ int i;
+ struct task_context *tc;
+
+ if (!machdep->get_task_reg)
+ return FALSE;
+
+ tc = FIRST_CONTEXT();
+ for (i = 0; i < RUNNING_TASKS(); i++, tc++)
+ if (i == task_nr) {
+ return machdep->get_task_reg(tc, regno, regname, regsize, value);
+ }
+ return FALSE;
}

diff --git a/help.c b/help.c
index a9c4d30..85dbda5 100644
--- a/help.c
+++ b/help.c
@@ -8520,6 +8520,7 @@ char *version_info[] = {
"Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.",
"Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.",
"Copyright (C) 2015, 2021 VMware, Inc.",
+"Copyright (C) 2024 Broadcom, 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.",
diff --git a/main.c b/main.c
index 0b6b927..13acd2d 100644
--- a/main.c
+++ b/main.c
@@ -794,6 +794,7 @@ main_loop(void)
} else
SIGACTION(SIGINT, restart, &pc->sigaction, NULL);

+ crash_target_init();
/*
* Display system statistics and current context.
*/
diff --git a/task.c b/task.c
index ebdb5be..5d26c52 100644
--- a/task.c
+++ b/task.c
@@ -298,6 +298,7 @@ task_init(void)
tt->flags |= THREAD_INFO;
}

+ STRUCT_SIZE_INIT(inactive_task_frame, "inactive_task_frame");
MEMBER_OFFSET_INIT(task_struct_state, "task_struct", "state");
MEMBER_SIZE_INIT(task_struct_state, "task_struct", "state");
if (INVALID_MEMBER(task_struct_state)) {
diff --git a/x86_64.c b/x86_64.c
index 502817d..b6e36a5 100644
--- a/x86_64.c
+++ b/x86_64.c
@@ -126,7 +126,7 @@ static int x86_64_get_framesize(struct bt_info *, ulong, ulong, char *);
static void x86_64_framesize_debug(struct bt_info *);
static void x86_64_get_active_set(void);
static int x86_64_get_kvaddr_ranges(struct vaddr_range *);
-static int x86_64_get_cpu_reg(int, int, const char *, int, void *);
+static int x86_64_get_task_reg(struct task_context *, int, const char *, int, void *);
static int x86_64_verify_paddr(uint64_t);
static void GART_init(void);
static void x86_64_exception_stacks_init(void);
@@ -195,7 +195,7 @@ x86_64_init(int when)
machdep->machspec->irq_eframe_link = UNINITIALIZED;
machdep->machspec->irq_stack_gap = UNINITIALIZED;
machdep->get_kvaddr_ranges = x86_64_get_kvaddr_ranges;
- machdep->get_cpu_reg = x86_64_get_cpu_reg;
+ machdep->get_task_reg = x86_64_get_task_reg;
if (machdep->cmdline_args[0])
parse_cmdline_args();
if ((string = pc->read_vmcoreinfo("relocate"))) {
@@ -891,7 +891,7 @@ x86_64_dump_machdep_table(ulong arg)
fprintf(fp, " is_page_ptr: x86_64_is_page_ptr()\n");
fprintf(fp, " verify_paddr: x86_64_verify_paddr()\n");
fprintf(fp, " get_kvaddr_ranges: x86_64_get_kvaddr_ranges()\n");
- fprintf(fp, " get_cpu_reg: x86_64_get_cpu_reg()\n");
+ fprintf(fp, " get_task_reg: x86_64_get_task_reg()\n");
fprintf(fp, " init_kernel_pgd: x86_64_init_kernel_pgd()\n");
fprintf(fp, "clear_machdep_cache: x86_64_clear_machdep_cache()\n");
fprintf(fp, " xendump_p2m_create: %s\n", PVOPS_XEN() ?
@@ -6398,6 +6398,9 @@ x86_64_ORC_init(void)
};
struct ORC_data *orc;

+ MEMBER_OFFSET_INIT(inactive_task_frame_bp, "inactive_task_frame", "bp");
+ MEMBER_OFFSET_INIT(inactive_task_frame_ret_addr, "inactive_task_frame", "ret_addr");
+
if (machdep->flags & FRAMEPOINTER)
return;

@@ -6455,9 +6458,6 @@ x86_64_ORC_init(void)
orc->__stop_orc_unwind = symbol_value("__stop_orc_unwind");
orc->orc_lookup = symbol_value("orc_lookup");

- MEMBER_OFFSET_INIT(inactive_task_frame_bp, "inactive_task_frame", "bp");
- MEMBER_OFFSET_INIT(inactive_task_frame_ret_addr, "inactive_task_frame", "ret_addr");
-
orc->has_signal = MEMBER_EXISTS("orc_entry", "signal"); /* added at 6.3 */
orc->has_end = MEMBER_EXISTS("orc_entry", "end"); /* removed at 6.4 */

@@ -9070,14 +9070,64 @@ x86_64_get_kvaddr_ranges(struct vaddr_range *vrp)
}

static int
-x86_64_get_cpu_reg(int cpu, int regno, const char *name,
+x86_64_get_task_reg(struct task_context *tc, int regno, const char *name,
int size, void *value)
{
if (regno >= LAST_REGNUM)
return FALSE;

+ /*
+ * For inactive task, grab rip, rbp, rbx, r12, r13, r14 and r15 from
+ * inactive_task_frame (see __switch_to_asm). Other regs saved on
+ * regular frame.
+ */
+ if (!is_task_active(tc->task)) {
+ int frame_size = STRUCT_SIZE("inactive_task_frame");
+
+ /* Only modern kernels supported. */
+ if (tt->flags & THREAD_INFO && frame_size == 7 * 8) {
+ ulong rsp;
+ int offset = 0;
+ switch (regno) {
+ case RSP_REGNUM:
+ readmem(tc->task + OFFSET(task_struct_thread) +
+ OFFSET(thread_struct_rsp), KVADDR,
+ &rsp, sizeof(void *),
+ "thread_struct rsp", FAULT_ON_ERROR);
+ rsp += frame_size;
+ memcpy(value, &rsp, size);
+ return TRUE;
+ case RIP_REGNUM:
+ offset += 8;
+ case RBP_REGNUM:
+ offset += 8;
+ case RBX_REGNUM:
+ offset += 8;
+ case R12_REGNUM:
+ offset += 8;
+ case R13_REGNUM:
+ offset += 8;
+ case R14_REGNUM:
+ offset += 8;
+ case R15_REGNUM:
+ readmem(tc->task + OFFSET(task_struct_thread) +
+ OFFSET(thread_struct_rsp), KVADDR,
+ &rsp, sizeof(void *),
+ "thread_struct rsp", FAULT_ON_ERROR);
+ readmem(rsp + offset, KVADDR, value, sizeof(void *),
+ "inactive_thread_frame saved regs", FAULT_ON_ERROR);
+ return TRUE;
+ }
+ }
+ /* TBD: older kernels support. */
+ return FALSE;
+ }
+
+ /*
+ * Task is active, grab CPU's registers
+ */
if (VMSS_DUMPFILE())
- return vmware_vmss_get_cpu_reg(cpu, regno, name, size, value);
+ return vmware_vmss_get_cpu_reg(tc->processor, regno, name, size, value);

return FALSE;
}
--
2.39.0