[Qemu-devel] [PATCH v2] trace: tighten up trace-events regex to fix bad parse

[Qemu-devel] [PATCH v2] trace: tighten up trace-events regex to fix bad parse

[Stefan Hajnoczi]

Use \w for properties and trace event names since they are both drawn
from [a-zA-Z0-9_] character sets.

The .* for matching properties was too aggressive and caused the
following failure with foo(int rc) "(this is a test)":

  Traceback (most recent call last):
    File "scripts/tracetool.py", line 139, in <module>
      main(sys.argv)
    File "scripts/tracetool.py", line 134, in main
      binary=binary, probe_prefix=probe_prefix)
    File "scripts/tracetool/__init__.py", line 334, in generate
      events = _read_events(fevents)
    File "scripts/tracetool/__init__.py", line 262, in _read_events
      res.append(Event.build(line))
    File "scripts/tracetool/__init__.py", line 225, in build
      return Event(name, props, fmt, args, arg_fmts)
    File "scripts/tracetool/__init__.py", line 185, in __init__
      % ", ".join(unknown_props))
  ValueError: Unknown properties: foo(int, rc)

Cc: Lluís Vilanova <vilanova@ac.upc.edu>
Reported-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
v2:
 * Fix regex to allow multiple properties [Lluís]

 scripts/tracetool/__init__.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index 36c789d..6ee6af7 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -140,8 +140,8 @@ class Event(object):
         The format strings for each argument.
     """
 
-    _CRE = re.compile("((?P<props>.*)\s+)?"
-                      "(?P<name>[^(\s]+)"
+    _CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
+                      "(?P<name>\w+)"
                       "\((?P<args>[^)]*)\)"
                       "\s*"
                       "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
-- 
1.9.3

Re: [Qemu-devel] [PATCH v2] trace: tighten up trace-events regex to fix bad parse

[Stefan Hajnoczi]

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On Tue, Sep 23, 2014 at 11:37:06AM +0100, Stefan Hajnoczi wrote:
> Use \w for properties and trace event names since they are both drawn
> from [a-zA-Z0-9_] character sets.
> 
> The .* for matching properties was too aggressive and caused the
> following failure with foo(int rc) "(this is a test)":
> 
>   Traceback (most recent call last):
>     File "scripts/tracetool.py", line 139, in <module>
>       main(sys.argv)
>     File "scripts/tracetool.py", line 134, in main
>       binary=binary, probe_prefix=probe_prefix)
>     File "scripts/tracetool/__init__.py", line 334, in generate
>       events = _read_events(fevents)
>     File "scripts/tracetool/__init__.py", line 262, in _read_events
>       res.append(Event.build(line))
>     File "scripts/tracetool/__init__.py", line 225, in build
>       return Event(name, props, fmt, args, arg_fmts)
>     File "scripts/tracetool/__init__.py", line 185, in __init__
>       % ", ".join(unknown_props))
>   ValueError: Unknown properties: foo(int, rc)
> 
> Cc: Lluís Vilanova <vilanova@ac.upc.edu>
> Reported-by: Eric Auger <eric.auger@linaro.org>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> v2:
>  * Fix regex to allow multiple properties [Lluís]
> 
>  scripts/tracetool/__init__.py | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Applied to my tracing tree:
https://github.com/stefanha/qemu/commits/tracing

Stefan

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Re: [Qemu-devel] [PATCH v2] trace: tighten up trace-events regex to fix bad parse

[Eric Auger]

Dear all,

this patch fixes the issues I reported (related to VFIO trace points).

Many thanks for that.

Best Regards

Eric

On 09/23/2014 12:37 PM, Stefan Hajnoczi wrote:
> Use \w for properties and trace event names since they are both drawn
> from [a-zA-Z0-9_] character sets.
> 
> The .* for matching properties was too aggressive and caused the
> following failure with foo(int rc) "(this is a test)":
> 
>   Traceback (most recent call last):
>     File "scripts/tracetool.py", line 139, in <module>
>       main(sys.argv)
>     File "scripts/tracetool.py", line 134, in main
>       binary=binary, probe_prefix=probe_prefix)
>     File "scripts/tracetool/__init__.py", line 334, in generate
>       events = _read_events(fevents)
>     File "scripts/tracetool/__init__.py", line 262, in _read_events
>       res.append(Event.build(line))
>     File "scripts/tracetool/__init__.py", line 225, in build
>       return Event(name, props, fmt, args, arg_fmts)
>     File "scripts/tracetool/__init__.py", line 185, in __init__
>       % ", ".join(unknown_props))
>   ValueError: Unknown properties: foo(int, rc)
> 
> Cc: Lluís Vilanova <vilanova@ac.upc.edu>
> Reported-by: Eric Auger <eric.auger@linaro.org>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> v2:
>  * Fix regex to allow multiple properties [Lluís]
> 
>  scripts/tracetool/__init__.py | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
> index 36c789d..6ee6af7 100644
> --- a/scripts/tracetool/__init__.py
> +++ b/scripts/tracetool/__init__.py
> @@ -140,8 +140,8 @@ class Event(object):
>          The format strings for each argument.
>      """
>  
> -    _CRE = re.compile("((?P<props>.*)\s+)?"
> -                      "(?P<name>[^(\s]+)"
> +    _CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
> +                      "(?P<name>\w+)"
>                        "\((?P<args>[^)]*)\)"
>                        "\s*"
>                        "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
>