diff mbox series

[3/3] trace: print address if symbol not found

Message ID 1513554812-13014-4-git-send-email-me@tobin.cc
State Not Applicable, archived
Delegated to: David Miller
Headers show
Series kallsyms: don't leak address | expand

Commit Message

Tobin C. Harding Dec. 17, 2017, 11:53 p.m. UTC 
Fixes behaviour modified by: commit bd6b239cdbb2 ("kallsyms: don't leak
address when symbol not found")

Previous patch changed behaviour of kallsyms function sprint_symbol() to
return an error code instead of printing the address if a symbol was not
found. Ftrace relies on the original behaviour. We should not break
tracing when applying the previous patch. We can maintain the original
behaviour by checking the return code on calls to sprint_symbol() and
friends.

Check return code and print actual address on error (i.e symbol not
found).

Signed-off-by: Tobin C. Harding <me@tobin.cc>
---
 kernel/trace/trace.h             | 24 ++++++++++++++++++++++++
 kernel/trace/trace_events_hist.c |  6 +++---
 2 files changed, 27 insertions(+), 3 deletions(-)

Comments

Steven Rostedt Dec. 18, 2017, 4:49 p.m. UTC | #1 
On Mon, 18 Dec 2017 10:53:32 +1100
"Tobin C. Harding" <me@tobin.cc> wrote:

> Fixes behaviour modified by: commit bd6b239cdbb2 ("kallsyms: don't leak
> address when symbol not found")
> 
> Previous patch changed behaviour of kallsyms function sprint_symbol() to
> return an error code instead of printing the address if a symbol was not
> found. Ftrace relies on the original behaviour. We should not break
> tracing when applying the previous patch. We can maintain the original
> behaviour by checking the return code on calls to sprint_symbol() and
> friends.
> 
> Check return code and print actual address on error (i.e symbol not
> found).
> 
> Signed-off-by: Tobin C. Harding <me@tobin.cc>
> ---
>  kernel/trace/trace.h             | 24 ++++++++++++++++++++++++
>  kernel/trace/trace_events_hist.c |  6 +++---
>  2 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index 2a6d0325a761..881b1a577d75 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -1814,4 +1814,28 @@ static inline void trace_event_eval_update(struct trace_eval_map **map, int len)
>  
>  extern struct trace_iterator *tracepoint_print_iter;
>  
> +static inline int
> +trace_sprint_symbol(char *buffer, unsigned long address)
> +{
> +	int ret;
> +
> +	ret = sprint_symbol(buffer, address);
> +	if (ret == -1)
> +		ret = sprintf(buffer, "0x%lx", address);
> +
> +	return ret;
> +}
> +
> +static inline int
> +trace_sprint_symbol_no_offset(char *buffer, unsigned long address)
> +{
> +	int ret;
> +
> +	ret = sprint_symbol_no_offset(buffer, address);
> +	if (ret == -1)
> +		ret = sprintf(buffer, "0x%lx", address);
> +
> +	return ret;
> +}
> +
>  #endif /* _LINUX_KERNEL_TRACE_H */
> diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> index 1e1558c99d56..3e28522a76f4 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
>  			return;
>  
>  		seq_printf(m, "%*c", 1 + spaces, ' ');
> -		sprint_symbol(str, stacktrace_entries[i]);
> +		trace_sprint_symbol_addr(str, stacktrace_entries[i]);

Hmm, where is trace_sprint_symbol_addr() defined?

-- Steve

>  		seq_printf(m, "%s\n", str);
>  	}
>  }
> @@ -1014,12 +1014,12 @@ hist_trigger_entry_print(struct seq_file *m,
>  			seq_printf(m, "%s: %llx", field_name, uval);
>  		} else if (key_field->flags & HIST_FIELD_FL_SYM) {
>  			uval = *(u64 *)(key + key_field->offset);
> -			sprint_symbol_no_offset(str, uval);
> +			trace_sprint_symbol_no_offset(str, uval);
>  			seq_printf(m, "%s: [%llx] %-45s", field_name,
>  				   uval, str);
>  		} else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
>  			uval = *(u64 *)(key + key_field->offset);
> -			sprint_symbol(str, uval);
> +			trace_sprint_symbol(str, uval);
>  			seq_printf(m, "%s: [%llx] %-55s", field_name,
>  				   uval, str);
>  		} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
Tobin C. Harding Dec. 18, 2017, 9:16 p.m. UTC | #2 
On Mon, Dec 18, 2017 at 11:49:47AM -0500, Steven Rostedt wrote:
> On Mon, 18 Dec 2017 10:53:32 +1100
> "Tobin C. Harding" <me@tobin.cc> wrote:
> 
> > Fixes behaviour modified by: commit bd6b239cdbb2 ("kallsyms: don't leak
> > address when symbol not found")
> > 
> > Previous patch changed behaviour of kallsyms function sprint_symbol() to
> > return an error code instead of printing the address if a symbol was not
> > found. Ftrace relies on the original behaviour. We should not break
> > tracing when applying the previous patch. We can maintain the original
> > behaviour by checking the return code on calls to sprint_symbol() and
> > friends.
> > 
> > Check return code and print actual address on error (i.e symbol not
> > found).
> > 
> > Signed-off-by: Tobin C. Harding <me@tobin.cc>
> > ---
> >  kernel/trace/trace.h             | 24 ++++++++++++++++++++++++
> >  kernel/trace/trace_events_hist.c |  6 +++---
> >  2 files changed, 27 insertions(+), 3 deletions(-)
> > 
> > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> > index 2a6d0325a761..881b1a577d75 100644
> > --- a/kernel/trace/trace.h
> > +++ b/kernel/trace/trace.h
> > @@ -1814,4 +1814,28 @@ static inline void trace_event_eval_update(struct trace_eval_map **map, int len)
> >  
> >  extern struct trace_iterator *tracepoint_print_iter;
> >  
> > +static inline int
> > +trace_sprint_symbol(char *buffer, unsigned long address)
> > +{
> > +	int ret;
> > +
> > +	ret = sprint_symbol(buffer, address);
> > +	if (ret == -1)
> > +		ret = sprintf(buffer, "0x%lx", address);
> > +
> > +	return ret;
> > +}
> > +
> > +static inline int
> > +trace_sprint_symbol_no_offset(char *buffer, unsigned long address)
> > +{
> > +	int ret;
> > +
> > +	ret = sprint_symbol_no_offset(buffer, address);
> > +	if (ret == -1)
> > +		ret = sprintf(buffer, "0x%lx", address);
> > +
> > +	return ret;
> > +}
> > +
> >  #endif /* _LINUX_KERNEL_TRACE_H */
> > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > index 1e1558c99d56..3e28522a76f4 100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
> >  			return;
> >  
> >  		seq_printf(m, "%*c", 1 + spaces, ' ');
> > -		sprint_symbol(str, stacktrace_entries[i]);
> > +		trace_sprint_symbol_addr(str, stacktrace_entries[i]);
> 
> Hmm, where is trace_sprint_symbol_addr() defined?

Gee, seems I can't build a kernel and I can't read a diff - epic
fail. Sorry for wasting your time Steve I'll try to be more careful.

FTR This should have been 

-		sprint_symbol(str, stacktrace_entries[i]);
+		trace_sprint_symbol(str, stacktrace_entries[i]);

If you have the time to give me some brief pointers on how I should go
about testing this I'd love to test it before the next version. I know
very little about ftrace.

thanks,
Tobin.
Tobin C. Harding Dec. 18, 2017, 10:35 p.m. UTC | #3 
On Mon, Dec 18, 2017 at 11:49:47AM -0500, Steven Rostedt wrote:
> On Mon, 18 Dec 2017 10:53:32 +1100
> "Tobin C. Harding" <me@tobin.cc> wrote:
> 
> > Fixes behaviour modified by: commit bd6b239cdbb2 ("kallsyms: don't leak
> > address when symbol not found")
> > 
> > Previous patch changed behaviour of kallsyms function sprint_symbol() to
> > return an error code instead of printing the address if a symbol was not
> > found. Ftrace relies on the original behaviour. We should not break
> > tracing when applying the previous patch. We can maintain the original
> > behaviour by checking the return code on calls to sprint_symbol() and
> > friends.
> > 
> > Check return code and print actual address on error (i.e symbol not
> > found).
> > 
> > Signed-off-by: Tobin C. Harding <me@tobin.cc>
> > ---
> >  kernel/trace/trace.h             | 24 ++++++++++++++++++++++++
> >  kernel/trace/trace_events_hist.c |  6 +++---
> >  2 files changed, 27 insertions(+), 3 deletions(-)
> > 
> > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> > index 2a6d0325a761..881b1a577d75 100644
> > --- a/kernel/trace/trace.h
> > +++ b/kernel/trace/trace.h
> > @@ -1814,4 +1814,28 @@ static inline void trace_event_eval_update(struct trace_eval_map **map, int len)
> >  
> >  extern struct trace_iterator *tracepoint_print_iter;
> >  
> > +static inline int
> > +trace_sprint_symbol(char *buffer, unsigned long address)
> > +{
> > +	int ret;
> > +
> > +	ret = sprint_symbol(buffer, address);
> > +	if (ret == -1)
> > +		ret = sprintf(buffer, "0x%lx", address);
> > +
> > +	return ret;
> > +}
> > +
> > +static inline int
> > +trace_sprint_symbol_no_offset(char *buffer, unsigned long address)
> > +{
> > +	int ret;
> > +
> > +	ret = sprint_symbol_no_offset(buffer, address);
> > +	if (ret == -1)
> > +		ret = sprintf(buffer, "0x%lx", address);
> > +
> > +	return ret;
> > +}
> > +
> >  #endif /* _LINUX_KERNEL_TRACE_H */
> > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > index 1e1558c99d56..3e28522a76f4 100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
> >  			return;
> >  
> >  		seq_printf(m, "%*c", 1 + spaces, ' ');
> > -		sprint_symbol(str, stacktrace_entries[i]);
> > +		trace_sprint_symbol_addr(str, stacktrace_entries[i]);
> 
> Hmm, where is trace_sprint_symbol_addr() defined?
> 
> -- Steve

Also, I missed one in kernel/trace/trace_output.c

Added for next version.

thanks,
Tobin.
Steven Rostedt Dec. 18, 2017, 11:51 p.m. UTC | #4 
On Tue, 19 Dec 2017 08:16:14 +1100
"Tobin C. Harding" <me@tobin.cc> wrote:

> > >  #endif /* _LINUX_KERNEL_TRACE_H */
> > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > > index 1e1558c99d56..3e28522a76f4 100644
> > > --- a/kernel/trace/trace_events_hist.c
> > > +++ b/kernel/trace/trace_events_hist.c
> > > @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
> > >  			return;
> > >  
> > >  		seq_printf(m, "%*c", 1 + spaces, ' ');
> > > -		sprint_symbol(str, stacktrace_entries[i]);
> > > +		trace_sprint_symbol_addr(str, stacktrace_entries[i]);  
> > 

> 
> If you have the time to give me some brief pointers on how I should go
> about testing this I'd love to test it before the next version. I know
> very little about ftrace.

For hitting the histogram stacktrace trigger (this code path), make
sure you have CONFIG_HIST_TRIGGERS enabled. And then do:

 # cd /sys/kernel/debug/tracing
 # echo 'hist:keys=common_pid.execname,stacktrace:vals=prev_state' > \
     events/sched/sched_switch/trigger
 # cat events/sched/sched_switch/hist

For the "sym" part, you can do (from the same directory):

 # echo 'hist:keys=call_site.sym:vals=bytes_req' > \
     events/kmem/kmalloc/trigger
 # cat events/kmem/kmalloc/hist


And for sym-offset:

 # echo 'hist:keys=call_site.sym-offset:vals=bytes_req' > \
    events/kmem/kmalloc/trigger
 # cat events/kmem/kmalloc/hist

-- Steve
Tobin C. Harding Dec. 19, 2017, 12:22 a.m. UTC | #5 
On Mon, Dec 18, 2017 at 06:51:43PM -0500, Steven Rostedt wrote:
> On Tue, 19 Dec 2017 08:16:14 +1100
> "Tobin C. Harding" <me@tobin.cc> wrote:
> 
> > > >  #endif /* _LINUX_KERNEL_TRACE_H */
> > > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > > > index 1e1558c99d56..3e28522a76f4 100644
> > > > --- a/kernel/trace/trace_events_hist.c
> > > > +++ b/kernel/trace/trace_events_hist.c
> > > > @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
> > > >  			return;
> > > >  
> > > >  		seq_printf(m, "%*c", 1 + spaces, ' ');
> > > > -		sprint_symbol(str, stacktrace_entries[i]);
> > > > +		trace_sprint_symbol_addr(str, stacktrace_entries[i]);  
> > > 
> 
> > 
> > If you have the time to give me some brief pointers on how I should go
> > about testing this I'd love to test it before the next version. I know
> > very little about ftrace.
> 
> For hitting the histogram stacktrace trigger (this code path), make
> sure you have CONFIG_HIST_TRIGGERS enabled. And then do:
> 
>  # cd /sys/kernel/debug/tracing
>  # echo 'hist:keys=common_pid.execname,stacktrace:vals=prev_state' > \
>      events/sched/sched_switch/trigger
>  # cat events/sched/sched_switch/hist
> 
> For the "sym" part, you can do (from the same directory):
> 
>  # echo 'hist:keys=call_site.sym:vals=bytes_req' > \
>      events/kmem/kmalloc/trigger
>  # cat events/kmem/kmalloc/hist
> 
> 
> And for sym-offset:
> 
>  # echo 'hist:keys=call_site.sym-offset:vals=bytes_req' > \
>     events/kmem/kmalloc/trigger
>  # cat events/kmem/kmalloc/hist
> 
> -- Steve

Thanks, you're the man
Tobin C. Harding Dec. 19, 2017, 3 a.m. UTC | #6 
On Mon, Dec 18, 2017 at 06:51:43PM -0500, Steven Rostedt wrote:
> On Tue, 19 Dec 2017 08:16:14 +1100
> "Tobin C. Harding" <me@tobin.cc> wrote:
> 
> > > >  #endif /* _LINUX_KERNEL_TRACE_H */
> > > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > > > index 1e1558c99d56..3e28522a76f4 100644
> > > > --- a/kernel/trace/trace_events_hist.c
> > > > +++ b/kernel/trace/trace_events_hist.c
> > > > @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
> > > >  			return;
> > > >  
> > > >  		seq_printf(m, "%*c", 1 + spaces, ' ');
> > > > -		sprint_symbol(str, stacktrace_entries[i]);
> > > > +		trace_sprint_symbol_addr(str, stacktrace_entries[i]);  
> > > 
> 
> > 
> > If you have the time to give me some brief pointers on how I should go
> > about testing this I'd love to test it before the next version. I know
> > very little about ftrace.
> 
> For hitting the histogram stacktrace trigger (this code path), make
> sure you have CONFIG_HIST_TRIGGERS enabled. And then do:
> 
>  # cd /sys/kernel/debug/tracing
>  # echo 'hist:keys=common_pid.execname,stacktrace:vals=prev_state' > \
>      events/sched/sched_switch/trigger
>  # cat events/sched/sched_switch/hist
> 
> For the "sym" part, you can do (from the same directory):
> 
>  # echo 'hist:keys=call_site.sym:vals=bytes_req' > \
>      events/kmem/kmalloc/trigger
>  # cat events/kmem/kmalloc/hist
> 
> 
> And for sym-offset:
> 
>  # echo 'hist:keys=call_site.sym-offset:vals=bytes_req' > \
>     events/kmem/kmalloc/trigger
>  # cat events/kmem/kmalloc/hist

I ran through these as outlined here for the new version (v4). This hits
the modified code but doesn't test symbol look up failure.

I also configured kernel with 'Perform a startup test on ftrace' for
good luck.

Are you happy with this level of testing?

thanks,
Tobin.
Tobin C. Harding Dec. 19, 2017, 3:02 a.m. UTC | #7 
On Tue, Dec 19, 2017 at 02:00:11PM +1100, Tobin C. Harding wrote:
> On Mon, Dec 18, 2017 at 06:51:43PM -0500, Steven Rostedt wrote:
> > On Tue, 19 Dec 2017 08:16:14 +1100
> > "Tobin C. Harding" <me@tobin.cc> wrote:
> > 
> > > > >  #endif /* _LINUX_KERNEL_TRACE_H */
> > > > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > > > > index 1e1558c99d56..3e28522a76f4 100644
> > > > > --- a/kernel/trace/trace_events_hist.c
> > > > > +++ b/kernel/trace/trace_events_hist.c
> > > > > @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
> > > > >  			return;
> > > > >  
> > > > >  		seq_printf(m, "%*c", 1 + spaces, ' ');
> > > > > -		sprint_symbol(str, stacktrace_entries[i]);
> > > > > +		trace_sprint_symbol_addr(str, stacktrace_entries[i]);  
> > > > 
> > 
> > > 
> > > If you have the time to give me some brief pointers on how I should go
> > > about testing this I'd love to test it before the next version. I know
> > > very little about ftrace.
> > 
> > For hitting the histogram stacktrace trigger (this code path), make
> > sure you have CONFIG_HIST_TRIGGERS enabled. And then do:
> > 
> >  # cd /sys/kernel/debug/tracing
> >  # echo 'hist:keys=common_pid.execname,stacktrace:vals=prev_state' > \
> >      events/sched/sched_switch/trigger
> >  # cat events/sched/sched_switch/hist
> > 
> > For the "sym" part, you can do (from the same directory):
> > 
> >  # echo 'hist:keys=call_site.sym:vals=bytes_req' > \
> >      events/kmem/kmalloc/trigger
> >  # cat events/kmem/kmalloc/hist
> > 
> > 
> > And for sym-offset:
> > 
> >  # echo 'hist:keys=call_site.sym-offset:vals=bytes_req' > \
> >     events/kmem/kmalloc/trigger
> >  # cat events/kmem/kmalloc/hist
> 
> I ran through these as outlined here for the new version (v4). This hits

Should have been:

                                                            v2

thanks,
Tobin.
Steven Rostedt Dec. 19, 2017, 3:37 a.m. UTC | #8 
On Tue, 19 Dec 2017 14:00:11 +1100
"Tobin C. Harding" <me@tobin.cc> wrote:

> I ran through these as outlined here for the new version (v4). This hits
> the modified code but doesn't test symbol look up failure.

stacktrace shouldn't post non kernel values, unless there's a frame
pointer that isn't handled by kallsyms.

As for the other two, we could probably force a failure, like:

 # echo 'hist:keys=hrtimer.sym' > \
     events/timer/hrtimer_start/trigger
 # cat events/timer/hrtimer_start/hist

And then just add sym-offset too.

> 
> I also configured kernel with 'Perform a startup test on ftrace' for
> good luck.
> 
> Are you happy with this level of testing?

Can you try the above.

-- Steve
Tobin C. Harding Dec. 19, 2017, 4:20 a.m. UTC | #9 
On Mon, Dec 18, 2017 at 10:37:38PM -0500, Steven Rostedt wrote:
> On Tue, 19 Dec 2017 14:00:11 +1100
> "Tobin C. Harding" <me@tobin.cc> wrote:
> 
> > I ran through these as outlined here for the new version (v4). This hits
> > the modified code but doesn't test symbol look up failure.
> 
> stacktrace shouldn't post non kernel values, unless there's a frame
> pointer that isn't handled by kallsyms.
> 
> As for the other two, we could probably force a failure, like:
> 
>  # echo 'hist:keys=hrtimer.sym' > \
>      events/timer/hrtimer_start/trigger
>  # cat events/timer/hrtimer_start/hist
> 
> And then just add sym-offset too.
>
> > I also configured kernel with 'Perform a startup test on ftrace' for
> > good luck.
> > 
> > Are you happy with this level of testing?
> 
> Can you try the above.

Did both and in both cases we get the addresses as hoped :)

thanks,
Tobin.
kernel test robot Dec. 19, 2017, 11:19 p.m. UTC | #10 
Hi Tobin,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.15-rc4 next-20171219]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Tobin-C-Harding/kallsyms-don-t-leak-address/20171220-062707
config: i386-randconfig-x016-201751 (attached as .config)
compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   kernel/trace/trace_events_hist.c: In function 'hist_trigger_stacktrace_print':
>> kernel/trace/trace_events_hist.c:985:3: error: implicit declaration of function 'trace_sprint_symbol_addr'; did you mean 'trace_sprint_symbol'? [-Werror=implicit-function-declaration]
      trace_sprint_symbol_addr(str, stacktrace_entries[i]);
      ^~~~~~~~~~~~~~~~~~~~~~~~
      trace_sprint_symbol
   cc1: some warnings being treated as errors

vim +985 kernel/trace/trace_events_hist.c

   971	
   972	static void hist_trigger_stacktrace_print(struct seq_file *m,
   973						  unsigned long *stacktrace_entries,
   974						  unsigned int max_entries)
   975	{
   976		char str[KSYM_SYMBOL_LEN];
   977		unsigned int spaces = 8;
   978		unsigned int i;
   979	
   980		for (i = 0; i < max_entries; i++) {
   981			if (stacktrace_entries[i] == ULONG_MAX)
   982				return;
   983	
   984			seq_printf(m, "%*c", 1 + spaces, ' ');
 > 985			trace_sprint_symbol_addr(str, stacktrace_entries[i]);
   986			seq_printf(m, "%s\n", str);
   987		}
   988	}
   989	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kernel test robot Dec. 19, 2017, 11:39 p.m. UTC | #11 
Hi Tobin,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.15-rc4 next-20171219]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Tobin-C-Harding/kallsyms-don-t-leak-address/20171220-062707
config: i386-randconfig-s1-201751 (attached as .config)
compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   kernel/trace/trace_events_hist.c: In function 'hist_trigger_stacktrace_print':
>> kernel/trace/trace_events_hist.c:985:3: error: implicit declaration of function 'trace_sprint_symbol_addr' [-Werror=implicit-function-declaration]
      trace_sprint_symbol_addr(str, stacktrace_entries[i]);
      ^~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/trace_sprint_symbol_addr +985 kernel/trace/trace_events_hist.c

   971	
   972	static void hist_trigger_stacktrace_print(struct seq_file *m,
   973						  unsigned long *stacktrace_entries,
   974						  unsigned int max_entries)
   975	{
   976		char str[KSYM_SYMBOL_LEN];
   977		unsigned int spaces = 8;
   978		unsigned int i;
   979	
   980		for (i = 0; i < max_entries; i++) {
   981			if (stacktrace_entries[i] == ULONG_MAX)
   982				return;
   983	
   984			seq_printf(m, "%*c", 1 + spaces, ' ');
 > 985			trace_sprint_symbol_addr(str, stacktrace_entries[i]);
   986			seq_printf(m, "%s\n", str);
   987		}
   988	}
   989	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox series

Patch

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2a6d0325a761..881b1a577d75 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1814,4 +1814,28 @@  static inline void trace_event_eval_update(struct trace_eval_map **map, int len)
 
 extern struct trace_iterator *tracepoint_print_iter;
 
+static inline int
+trace_sprint_symbol(char *buffer, unsigned long address)
+{
+	int ret;
+
+	ret = sprint_symbol(buffer, address);
+	if (ret == -1)
+		ret = sprintf(buffer, "0x%lx", address);
+
+	return ret;
+}
+
+static inline int
+trace_sprint_symbol_no_offset(char *buffer, unsigned long address)
+{
+	int ret;
+
+	ret = sprint_symbol_no_offset(buffer, address);
+	if (ret == -1)
+		ret = sprintf(buffer, "0x%lx", address);
+
+	return ret;
+}
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 1e1558c99d56..3e28522a76f4 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -982,7 +982,7 @@  static void hist_trigger_stacktrace_print(struct seq_file *m,
 			return;
 
 		seq_printf(m, "%*c", 1 + spaces, ' ');
-		sprint_symbol(str, stacktrace_entries[i]);
+		trace_sprint_symbol_addr(str, stacktrace_entries[i]);
 		seq_printf(m, "%s\n", str);
 	}
 }
@@ -1014,12 +1014,12 @@  hist_trigger_entry_print(struct seq_file *m,
 			seq_printf(m, "%s: %llx", field_name, uval);
 		} else if (key_field->flags & HIST_FIELD_FL_SYM) {
 			uval = *(u64 *)(key + key_field->offset);
-			sprint_symbol_no_offset(str, uval);
+			trace_sprint_symbol_no_offset(str, uval);
 			seq_printf(m, "%s: [%llx] %-45s", field_name,
 				   uval, str);
 		} else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
 			uval = *(u64 *)(key + key_field->offset);
-			sprint_symbol(str, uval);
+			trace_sprint_symbol(str, uval);
 			seq_printf(m, "%s: [%llx] %-55s", field_name,
 				   uval, str);
 		} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {