This is the mail archive of the
gdb@sourceware.org
mailing list for the GDB project.
Linux Kernel GDB tracepoint module support most collect now
- From: Hui Zhu <teawater at gmail dot com>
- To: "gdb at sourceware dot org" <gdb at sourceware dot org>, linux-kernel at vger dot kernel dot org
- Cc: Michael Snyder <msnyder at vmware dot com>, Marc Khouzam <marc dot khouzam at ericsson dot com>, Thiago Jung Bauermann <thiago dot bauermann at gmail dot com>
- Date: Sun, 22 Aug 2010 23:16:29 +0800
- Subject: Linux Kernel GDB tracepoint module support most collect now
Linux Kernel GDB tracepoint module support action X and all agent
expression except the trace state variable codes. So KGTP can support
a lot of collect command of tracepoint in x86-64 and x86-32.
To get the new KGTP please goto http://code.google.com/p/kgtp/downloads/list
To get more message about GDB tracepoint please goto
http://sourceware.org/gdb/current/onlinedocs/gdb/Tracepoints.html
For example:
make
sudo insmod gtp.ko
sudo gdb ./vmlinux
(gdb) trace vfs_readdir
Tracepoint 1 at 0xffffffff8113f7fc: file
/home/teawater/kernel/linux-2.6/fs/readdir.c, line 24.
(gdb) actions
Enter actions for tracepoint 1, one per line.
End with a line saying just "end".
>collect *(unsigned char *)$rsp@512
>collect *file
>end
(gdb) target remote /proc/gtp
Remote debugging using /proc/gtp
0x0000000000000000 in ?? ()
(gdb) tstart
(gdb) shell ls
2 block firmware i ipc Makefile
modules.order scripts source t~ vmlinux
a.out crypto fs include kernel mm
Module.symvers security System.map usr vmlinux.o
arch drivers gdb.txt init lib modules.builtin net
sound t virt
(gdb) tstop
(gdb) tfind
Found trace frame 0, tracepoint 1
#0 0xffffffff8113f7fd in vfs_readdir (file=0xffff880075f00780,
filler=0xffffffff8113f630 <filldir>, buf=0xffff880005785f38)
at /home/teawater/kernel/linux-2.6/fs/readdir.c:24
24 {
(gdb) bt
#0 0xffffffff8113f7fd in vfs_readdir (file=0xffff880075f00780,
filler=0xffffffff8113f630 <filldir>, buf=0xffff880005785f38)
at /home/teawater/kernel/linux-2.6/fs/readdir.c:24
#1 0xffffffff8113fa14 in sys_getdents (fd=<value optimized out>,
dirent=0x801108, count=32768)
at /home/teawater/kernel/linux-2.6/fs/readdir.c:214
#2 0xffffffff8100af42 in ?? () at
/home/teawater/kernel/linux-2.6/arch/x86/kernel/entry_64.S:487
#3 0x00007f3249a81765 in ?? ()
#4 0x00000018555503f7 in ?? ()
#5 0x0000015400000000 in ?? ()
#6 0x0000000000bf5048 in ?? ()
#7 0x0000000000000000 in ?? ()
(gdb) p file
$1 = (struct file *) 0xffff880075f00780
(gdb) p *file
$2 = {f_u = {fu_list = {next = 0xffff880075f00480, prev =
0xffffe8ffffc06948}, fu_rcuhead = {next = 0xffff880075f00480,
func = 0xffffe8ffffc06948}}, f_path = {mnt = 0xffff880037d92e00,
dentry = 0xffff8800353239c0}, f_op = 0xffffffff81622a60, f_lock = {{
rlock = {raw_lock = {slock = 0}}}}, f_sb_list_cpu = 0, f_count =
{counter = 2}, f_flags = 624640, f_mode = 29, f_pos = 0, f_owner = {
lock = {raw_lock = {lock = 16777216}}, pid = 0x0, pid_type =
PIDTYPE_PID, uid = 0, euid = 0, signum = 0}, f_cred =
0xffff880079b40a80,
f_ra = {start = 0, size = 0, async_size = 0, ra_pages = 32,
mmap_miss = 0, prev_pos = -1}, f_version = 0, f_security = 0x0,
private_data = 0x0, f_ep_links = {next = 0xffff880075f00828, prev =
0xffff880075f00828}, f_mapping = 0xffff88003539d6b8}
(gdb) tfind
Found trace frame 1, tracepoint 1
0xffffffff8113f7fd 24 {
(gdb) bt
#0 0xffffffff8113f7fd in vfs_readdir (file=0xffff880075f00780,
filler=0xffffffff8113f630 <filldir>, buf=0xffff880005785f38)
at /home/teawater/kernel/linux-2.6/fs/readdir.c:24
#1 0xffffffff8113fa14 in sys_getdents (fd=<value optimized out>,
dirent=0x801108, count=32768)
at /home/teawater/kernel/linux-2.6/fs/readdir.c:214
#2 0xffffffff8100af42 in ?? () at
/home/teawater/kernel/linux-2.6/arch/x86/kernel/entry_64.S:487
#3 0x00007f3249a81765 in ?? ()
#4 0x00000018555503f7 in ?? ()
#5 0x0000015400000000 in ?? ()
#6 0x0000000000bf5048 in ?? ()
#7 0x0000000000000000 in ?? ()
(gdb) p *file
$3 = {f_u = {fu_list = {next = 0xffff880075f00480, prev =
0xffffe8ffffc06948}, fu_rcuhead = {next = 0xffff880075f00480,
func = 0xffffe8ffffc06948}}, f_path = {mnt = 0xffff880037d92e00,
dentry = 0xffff8800353239c0}, f_op = 0xffffffff81622a60, f_lock = {{
rlock = {raw_lock = {slock = 0}}}}, f_sb_list_cpu = 0, f_count =
{counter = 2}, f_flags = 624640, f_mode = 29, f_pos = 2147483647,
f_owner = {lock = {raw_lock = {lock = 16777216}}, pid = 0x0,
pid_type = PIDTYPE_PID, uid = 0, euid = 0, signum = 0},
f_cred = 0xffff880079b40a80, f_ra = {start = 0, size = 0, async_size
= 0, ra_pages = 32, mmap_miss = 0, prev_pos = -1}, f_version = 16,
f_security = 0x0, private_data = 0xffff8800755d5600, f_ep_links =
{next = 0xffff880075f00828, prev = 0xffff880075f00828},
f_mapping = 0xffff88003539d6b8}