From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001
From: root <root@artemis.panaceas.org>
Date: Fri, 25 Dec 2015 04:40:36 +0000
Subject: initial_commit

---
 Documentation/kdump/gdbmacros.txt | 201 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 201 insertions(+)
 create mode 100644 Documentation/kdump/gdbmacros.txt

(limited to 'Documentation/kdump/gdbmacros.txt')

diff --git a/Documentation/kdump/gdbmacros.txt b/Documentation/kdump/gdbmacros.txt
new file mode 100644
index 00000000..9b9b454b
--- /dev/null
+++ b/Documentation/kdump/gdbmacros.txt
@@ -0,0 +1,201 @@
+#
+# This file contains a few gdb macros (user defined commands) to extract
+# useful information from kernel crashdump (kdump) like stack traces of
+# all the processes or a particular process and trapinfo.
+#
+# These macros can be used by copying this file in .gdbinit (put in home
+# directory or current directory) or by invoking gdb command with
+# --command=<command-file-name> option
+#
+# Credits:
+# Alexander Nyberg <alexn@telia.com>
+# V Srivatsa <vatsa@in.ibm.com>
+# Maneesh Soni <maneesh@in.ibm.com>
+#
+
+define bttnobp
+	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
+	set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
+	set $init_t=&init_task
+	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
+	while ($next_t != $init_t)
+		set $next_t=(struct task_struct *)$next_t
+		printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
+		printf "===================\n"
+		set var $stackp = $next_t.thread.esp
+		set var $stack_top = ($stackp & ~4095) + 4096
+
+		while ($stackp < $stack_top)
+			if (*($stackp) > _stext && *($stackp) < _sinittext)
+				info symbol *($stackp)
+			end
+			set $stackp += 4
+		end
+		set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
+		while ($next_th != $next_t)
+			set $next_th=(struct task_struct *)$next_th
+			printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
+			printf "===================\n"
+			set var $stackp = $next_t.thread.esp
+			set var $stack_top = ($stackp & ~4095) + 4096
+
+			while ($stackp < $stack_top)
+				if (*($stackp) > _stext && *($stackp) < _sinittext)
+					info symbol *($stackp)
+				end
+				set $stackp += 4
+			end
+			set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
+		end
+		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
+	end
+end
+document bttnobp
+	dump all thread stack traces on a kernel compiled with !CONFIG_FRAME_POINTER
+end
+
+define btt
+	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
+	set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
+	set $init_t=&init_task
+	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
+	while ($next_t != $init_t)
+		set $next_t=(struct task_struct *)$next_t
+		printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
+		printf "===================\n"
+		set var $stackp = $next_t.thread.esp
+		set var $stack_top = ($stackp & ~4095) + 4096
+		set var $stack_bot = ($stackp & ~4095)
+
+		set $stackp = *($stackp)
+		while (($stackp < $stack_top) && ($stackp > $stack_bot))
+			set var $addr = *($stackp + 4)
+			info symbol $addr
+			set $stackp = *($stackp)
+		end
+
+		set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
+		while ($next_th != $next_t)
+			set $next_th=(struct task_struct *)$next_th
+			printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
+			printf "===================\n"
+			set var $stackp = $next_t.thread.esp
+			set var $stack_top = ($stackp & ~4095) + 4096
+			set var $stack_bot = ($stackp & ~4095)
+
+			set $stackp = *($stackp)
+			while (($stackp < $stack_top) && ($stackp > $stack_bot))
+				set var $addr = *($stackp + 4)
+				info symbol $addr
+				set $stackp = *($stackp)
+			end
+			set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
+		end
+		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
+	end
+end
+document btt
+	dump all thread stack traces on a kernel compiled with CONFIG_FRAME_POINTER
+end
+
+define btpid
+	set var $pid = $arg0
+	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
+	set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
+	set $init_t=&init_task
+	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
+	set var $pid_task = 0
+
+	while ($next_t != $init_t)
+		set $next_t=(struct task_struct *)$next_t
+
+		if ($next_t.pid == $pid)
+			set $pid_task = $next_t
+		end
+
+		set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
+		while ($next_th != $next_t)
+			set $next_th=(struct task_struct *)$next_th
+			if ($next_th.pid == $pid)
+				set $pid_task = $next_th
+			end
+			set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
+		end
+		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
+	end
+
+	printf "\npid %d; comm %s:\n", $pid_task.pid, $pid_task.comm
+	printf "===================\n"
+	set var $stackp = $pid_task.thread.esp
+	set var $stack_top = ($stackp & ~4095) + 4096
+	set var $stack_bot = ($stackp & ~4095)
+
+	set $stackp = *($stackp)
+	while (($stackp < $stack_top) && ($stackp > $stack_bot))
+		set var $addr = *($stackp + 4)
+		info symbol $addr
+		set $stackp = *($stackp)
+	end
+end
+document btpid
+	backtrace of pid
+end
+
+
+define trapinfo
+	set var $pid = $arg0
+	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
+	set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
+	set $init_t=&init_task
+	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
+	set var $pid_task = 0
+
+	while ($next_t != $init_t)
+		set $next_t=(struct task_struct *)$next_t
+
+		if ($next_t.pid == $pid)
+			set $pid_task = $next_t
+		end
+
+		set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
+		while ($next_th != $next_t)
+			set $next_th=(struct task_struct *)$next_th
+			if ($next_th.pid == $pid)
+				set $pid_task = $next_th
+			end
+			set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
+		end
+		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
+	end
+
+	printf "Trapno %ld, cr2 0x%lx, error_code %ld\n", $pid_task.thread.trap_no, \
+				$pid_task.thread.cr2, $pid_task.thread.error_code
+
+end
+document trapinfo
+	Run info threads and lookup pid of thread #1
+	'trapinfo <pid>' will tell you by which trap & possibly
+	address the kernel panicked.
+end
+
+
+define dmesg
+	set $i = 0
+	set $end_idx = (log_end - 1) & (log_buf_len - 1)
+
+	while ($i < logged_chars)
+		set $idx = (log_end - 1 - logged_chars + $i) & (log_buf_len - 1)
+
+		if ($idx + 100 <= $end_idx) || \
+		   ($end_idx <= $idx && $idx + 100 < log_buf_len)
+			printf "%.100s", &log_buf[$idx]
+			set $i = $i + 100
+		else
+			printf "%c", log_buf[$idx]
+			set $i = $i + 1
+		end
+	end
+end
+document dmesg
+	print the kernel ring buffer
+end
-- 
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