tracetool: also strip %l and %ll from systemtap format strings

[PATCH v2] tracetool: also strip %l and %ll from systemtap format strings

Posted by Daniel P. Berrangé 4 years, 10 months ago

All variables are 64-bit and so %l / %ll are not required, and the
latter is actually invalid:

  $ sudo stap -e 'probe begin{printf ("BEGIN")}'  -I .
  parse error: invalid or missing conversion specifier
          saw: operator ',' at ./qemu-system-x86_64-log.stp:15118:101
       source:     printf("%d@%d vhost_vdpa_set_log_base dev: %p base: 0x%x size: %llu
refcnt: %d fd: %d log: %p\n", pid(), gettimeofday_ns(), dev, base, size, refcnt, fd, log)

                       ^

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 scripts/tracetool/format/log_stap.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

In v2:

 - Change existing logic that stripped %z to handle %l/%ll too

diff --git a/scripts/tracetool/format/log_stap.py b/scripts/tracetool/format/log_stap.py
index b486beb672..fac911a0f4 100644
--- a/scripts/tracetool/format/log_stap.py
+++ b/scripts/tracetool/format/log_stap.py
@@ -77,7 +77,12 @@ def c_fmt_to_stap(fmt):
     elif state == STATE_LITERAL:
         bits.append(literal)
 
-    fmt = re.sub("%(\d*)z(x|u|d)", "%\\1\\2", "".join(bits))
+    # All variables in systemtap are 64-bit in size
+    # The "%l" integer size qualifier is thus redundant
+    # and "%ll" is not valid at all. Simiarly the size_t
+    # based "%z" size qualifier is not valid. We just
+    # strip all size qualifiers for sanity.
+    fmt = re.sub("%(\d*)(l+|z)(x|u|d)", "%\\1\\3", "".join(bits))
     return fmt
 
 def generate(events, backend, group):
-- 
2.29.2

Re: [PATCH v2] tracetool: also strip %l and %ll from systemtap format strings

Posted by Laurent Vivier 4 years, 10 months ago

On 06/01/2021 14:02, Daniel P. Berrangé wrote:
> All variables are 64-bit and so %l / %ll are not required, and the
> latter is actually invalid:
> 
>   $ sudo stap -e 'probe begin{printf ("BEGIN")}'  -I .
>   parse error: invalid or missing conversion specifier
>           saw: operator ',' at ./qemu-system-x86_64-log.stp:15118:101
>        source:     printf("%d@%d vhost_vdpa_set_log_base dev: %p base: 0x%x size: %llu
> refcnt: %d fd: %d log: %p\n", pid(), gettimeofday_ns(), dev, base, size, refcnt, fd, log)
> 
>                        ^
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  scripts/tracetool/format/log_stap.py | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> In v2:
> 
>  - Change existing logic that stripped %z to handle %l/%ll too
> 
> diff --git a/scripts/tracetool/format/log_stap.py b/scripts/tracetool/format/log_stap.py
> index b486beb672..fac911a0f4 100644
> --- a/scripts/tracetool/format/log_stap.py
> +++ b/scripts/tracetool/format/log_stap.py
> @@ -77,7 +77,12 @@ def c_fmt_to_stap(fmt):
>      elif state == STATE_LITERAL:
>          bits.append(literal)
>  
> -    fmt = re.sub("%(\d*)z(x|u|d)", "%\\1\\2", "".join(bits))
> +    # All variables in systemtap are 64-bit in size
> +    # The "%l" integer size qualifier is thus redundant
> +    # and "%ll" is not valid at all. Simiarly the size_t
> +    # based "%z" size qualifier is not valid. We just
> +    # strip all size qualifiers for sanity.
> +    fmt = re.sub("%(\d*)(l+|z)(x|u|d)", "%\\1\\3", "".join(bits))
>      return fmt
>  
>  def generate(events, backend, group):
> 

Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Laurent Vivier <lvivier@redhat.com>

Re: [PATCH v2] tracetool: also strip %l and %ll from systemtap format strings

Posted by Stefan Hajnoczi 4 years, 10 months ago

On Wed, Jan 06, 2021 at 01:02:39PM +0000, Daniel P. Berrangé wrote:
> All variables are 64-bit and so %l / %ll are not required, and the
> latter is actually invalid:
> 
>   $ sudo stap -e 'probe begin{printf ("BEGIN")}'  -I .
>   parse error: invalid or missing conversion specifier
>           saw: operator ',' at ./qemu-system-x86_64-log.stp:15118:101
>        source:     printf("%d@%d vhost_vdpa_set_log_base dev: %p base: 0x%x size: %llu
> refcnt: %d fd: %d log: %p\n", pid(), gettimeofday_ns(), dev, base, size, refcnt, fd, log)
> 
>                        ^
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  scripts/tracetool/format/log_stap.py | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> In v2:
> 
>  - Change existing logic that stripped %z to handle %l/%ll too

Thanks, applied to my tracing tree with Laurent's typo fix:
https://gitlab.com/stefanha/qemu/commits/tracing

Stefan

Re: [PATCH v2] tracetool: also strip %l and %ll from systemtap format strings

Posted by Laurent Vivier 4 years, 10 months ago

On 06/01/2021 14:02, Daniel P. Berrangé wrote:
> All variables are 64-bit and so %l / %ll are not required, and the
> latter is actually invalid:
> 
>   $ sudo stap -e 'probe begin{printf ("BEGIN")}'  -I .
>   parse error: invalid or missing conversion specifier
>           saw: operator ',' at ./qemu-system-x86_64-log.stp:15118:101
>        source:     printf("%d@%d vhost_vdpa_set_log_base dev: %p base: 0x%x size: %llu
> refcnt: %d fd: %d log: %p\n", pid(), gettimeofday_ns(), dev, base, size, refcnt, fd, log)
> 
>                        ^
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  scripts/tracetool/format/log_stap.py | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> In v2:
> 
>  - Change existing logic that stripped %z to handle %l/%ll too
> 
> diff --git a/scripts/tracetool/format/log_stap.py b/scripts/tracetool/format/log_stap.py
> index b486beb672..fac911a0f4 100644
> --- a/scripts/tracetool/format/log_stap.py
> +++ b/scripts/tracetool/format/log_stap.py
> @@ -77,7 +77,12 @@ def c_fmt_to_stap(fmt):
>      elif state == STATE_LITERAL:
>          bits.append(literal)
>  
> -    fmt = re.sub("%(\d*)z(x|u|d)", "%\\1\\2", "".join(bits))
> +    # All variables in systemtap are 64-bit in size
> +    # The "%l" integer size qualifier is thus redundant
> +    # and "%ll" is not valid at all. Simiarly the size_t

Didn't see the typo the first time:

s/Simiarly/Similarly/

Thanks,
Laurent

Re: [PATCH v2] tracetool: also strip %l and %ll from systemtap format strings

Posted by Philippe Mathieu-Daudé 4 years, 10 months ago

On 1/6/21 3:36 PM, Laurent Vivier wrote:
> On 06/01/2021 14:02, Daniel P. Berrangé wrote:
>> All variables are 64-bit and so %l / %ll are not required, and the
>> latter is actually invalid:
>>
>>   $ sudo stap -e 'probe begin{printf ("BEGIN")}'  -I .
>>   parse error: invalid or missing conversion specifier
>>           saw: operator ',' at ./qemu-system-x86_64-log.stp:15118:101
>>        source:     printf("%d@%d vhost_vdpa_set_log_base dev: %p base: 0x%x size: %llu
>> refcnt: %d fd: %d log: %p\n", pid(), gettimeofday_ns(), dev, base, size, refcnt, fd, log)
>>
>>                        ^
>>
>> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
>> ---
>>  scripts/tracetool/format/log_stap.py | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> In v2:
>>
>>  - Change existing logic that stripped %z to handle %l/%ll too
>>
>> diff --git a/scripts/tracetool/format/log_stap.py b/scripts/tracetool/format/log_stap.py
>> index b486beb672..fac911a0f4 100644
>> --- a/scripts/tracetool/format/log_stap.py
>> +++ b/scripts/tracetool/format/log_stap.py
>> @@ -77,7 +77,12 @@ def c_fmt_to_stap(fmt):
>>      elif state == STATE_LITERAL:
>>          bits.append(literal)
>>  
>> -    fmt = re.sub("%(\d*)z(x|u|d)", "%\\1\\2", "".join(bits))
>> +    # All variables in systemtap are 64-bit in size
>> +    # The "%l" integer size qualifier is thus redundant
>> +    # and "%ll" is not valid at all. Simiarly the size_t
> 
> Didn't see the typo the first time:
> 
> s/Simiarly/Similarly/

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>