Re: [PATCH] scripts/gdb: fix 'lx-timerlist' on newer kernel

[Lin Ma]

Hi Jan,

> > After commit 511885d7061e ("lib/timerqueue: Rely on rbtree semantics for
> > next timer"), the struct timerqueue_head changes internal field hence
> > causes the old lx-timerlist command keeps reporting errors.
> > 
> > This fix addes a simple version comparison and necessary code for
> 
> typo: "adds"

Thanks, my bad. dx

> 
> > traversing timerqueue on a newer kernel. Moreover, it fixes some
> > python 3.X compatibility bugs.
> 
> The gdb scripts are in lock-step with the kernel version they can
> inspect. So just move the logic to the current kernel and drop support
> for older versions.

Okay, roger that. Will send another version soon.

Regards
Lin

> 
> Jan
> 
> > 
> > Test with python 2.7 and python 3.6
> > Test with 
> > * commit 442284a89a65 ("scripts/gdb: add a timer list command") and 
> > * commit 88603b6dc419 ("Linux 6.2-rc2") kernel
> > 
> > Signed-off-by: Lin Ma <linma@xxxxxxxxxx>
> > ---
> >  scripts/gdb/linux/timerlist.py | 41 ++++++++++++++++++++++------------
> >  1 file changed, 27 insertions(+), 14 deletions(-)
> > 
> > diff --git a/scripts/gdb/linux/timerlist.py b/scripts/gdb/linux/timerlist.py
> > index 071d0dd5a634..65d035df253d 100644
> > --- a/scripts/gdb/linux/timerlist.py
> > +++ b/scripts/gdb/linux/timerlist.py
> > @@ -4,6 +4,7 @@
> >  
> >  import binascii
> >  import gdb
> > +import re
> >  
> >  from linux import constants
> >  from linux import cpus
> > @@ -42,9 +43,15 @@ def print_timer(rb_node, idx):
> >      return text
> >  
> >  
> > -def print_active_timers(base):
> > -    curr = base['active']['next']['node']
> > -    curr = curr.address.cast(rbtree.rb_node_type.get_type().pointer())
> > +def print_active_timers(base, oldver):
> > +    # 511885d7061e ("lib/timerqueue: Rely on rbtree semantics for next timer")
> > +    if oldver:
> > +        curr = base['active']['next']['node']
> > +        curr = curr.address.cast(rbtree.rb_node_type.get_type().pointer())
> > +    else:
> > +        leftmost = base['active']['rb_root']['rb_leftmost']
> > +        curr = leftmost.cast(rbtree.rb_node_type.get_type().pointer())
> > +
> >      idx = 0
> >      while curr:
> >          yield print_timer(curr, idx)
> > @@ -52,7 +59,7 @@ def print_active_timers(base):
> >          idx += 1
> >  
> >  
> > -def print_base(base):
> > +def print_base(base, oldver):
> >      text = " .base:       {}\n".format(base.address)
> >      text += " .index:      {}\n".format(base['index'])
> >  
> > @@ -62,21 +69,20 @@ def print_base(base):
> >      if constants.LX_CONFIG_HIGH_RES_TIMERS:
> >          text += "  .offset:     {} nsecs\n".format(base['offset'])
> >      text += "active timers:\n"
> > -    text += "".join([x for x in print_active_timers(base)])
> > +    text += "".join([x for x in print_active_timers(base, oldver)])
> >      return text
> >  
> >  
> > -def print_cpu(hrtimer_bases, cpu, max_clock_bases):
> > +def print_cpu(hrtimer_bases, cpu, max_clock_bases, oldver):
> >      cpu_base = cpus.per_cpu(hrtimer_bases, cpu)
> >      jiffies = gdb.parse_and_eval("jiffies_64")
> >      tick_sched_ptr = gdb.parse_and_eval("&tick_cpu_sched")
> >      ts = cpus.per_cpu(tick_sched_ptr, cpu)
> >  
> >      text = "cpu: {}\n".format(cpu)
> > -    for i in xrange(max_clock_bases):
> > +    for i in range(max_clock_bases):
> >          text += " clock {}:\n".format(i)
> > -        text += print_base(cpu_base['clock_base'][i])
> > -
> > +        text += print_base(cpu_base['clock_base'][i], oldver)
> >          if constants.LX_CONFIG_HIGH_RES_TIMERS:
> >              fmts = [("  .{}   : {} nsecs", 'expires_next'),
> >                      ("  .{}    : {}", 'hres_active'),
> > @@ -165,7 +171,7 @@ def pr_cpumask(mask):
> >          i -= 1
> >          start = i * 2
> >          end = start + 2
> > -        chunks.append(buf[start:end])
> > +        chunks.append(str(buf[start:end]))
> >          if i != 0 and i % 4 == 0:
> >              chunks.append(',')
> >  
> > @@ -184,14 +190,21 @@ class LxTimerList(gdb.Command):
> >  
> >      def invoke(self, arg, from_tty):
> >          hrtimer_bases = gdb.parse_and_eval("&hrtimer_bases")
> > -        max_clock_bases = gdb.parse_and_eval("HRTIMER_MAX_CLOCK_BASES")
> > -
> > -        text = "Timer List Version: gdb scripts\n"
> > +        max_clock_bases = gdb.parse_and_eval("(int)HRTIMER_MAX_CLOCK_BASES")
> > +        banner = gdb.parse_and_eval("(char *)linux_banner").string()
> > +        r = re.match(r"^Linux version (.+) \(.*@.*$", banner)
> > +        if not r:
> > +            gdb.write("failed to load image version")
> > +            return
> > +        lver = r.group(1)
> > +        oldver = lver < '5.3.0-rc1'
> > +
> > +        text = "Timer List Version: gdb scripts, old version: {}\n".format(oldver)
> >          text += "HRTIMER_MAX_CLOCK_BASES: {}\n".format(max_clock_bases)
> >          text += "now at {} nsecs\n".format(ktime_get())
> >  
> >          for cpu in cpus.each_online_cpu():
> > -            text += print_cpu(hrtimer_bases, cpu, max_clock_bases)
> > +            text += print_cpu(hrtimer_bases, cpu, max_clock_bases, oldver)
> >  
> >          if constants.LX_CONFIG_GENERIC_CLOCKEVENTS:
> >              if constants.LX_CONFIG_GENERIC_CLOCKEVENTS_BROADCAST:
> 
> -- 
> Siemens AG, Technology
> Competence Center Embedded Linux