[libcamera-devel,v1,2/4] test: v4l2_compat: Enable test with ASan

18049 diff mbox series

When libcamera is compiled with the address sanitizer enabled, the
v4l2_compat test generates failures in the link order runtime check, as
the host v4l2-ctl and v4l2-compliance tools are not (generally) linked
to ASan. For this reason, the test is disabled, which sadly shrinks test
coverage.

Fix this by loading the ASan runtime using LD_PRELOAD. This needs to be
done from within the v4l2_compat_test.py Python script, as the Python
interpreter itself leaks memory and would cause test failures if run
with ASan.

To LD_PRELOAD the ASan runtime, the path to the binary needs to be
known. gcc gives us a generic way to get the path, but that doesn't work
with clang as the ASan runtime file name depends on the clang version
and target architecture. We thus have to keep the v4l2_compat test
disabled with ASan is enabled and libcamera is compiled with clang.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 test/meson.build                     | 16 ++++++++++++++++
 test/v4l2_compat/meson.build         | 21 ++++++++++++++-------
 test/v4l2_compat/v4l2_compat_test.py | 18 +++++++++++++-----
 3 files changed, 43 insertions(+), 12 deletions(-)

Hi Laurent

Thank you for this patch

On 12/22/22 6:31 AM, Laurent Pinchart via libcamera-devel wrote:
> When libcamera is compiled with the address sanitizer enabled, the
> v4l2_compat test generates failures in the link order runtime check, as
> the host v4l2-ctl and v4l2-compliance tools are not (generally) linked
> to ASan. For this reason, the test is disabled, which sadly shrinks test
> coverage.
>
> Fix this by loading the ASan runtime using LD_PRELOAD. This needs to be
> done from within the v4l2_compat_test.py Python script, as the Python
> interpreter itself leaks memory and would cause test failures if run
> with ASan.
>
> To LD_PRELOAD the ASan runtime, the path to the binary needs to be
> known. gcc gives us a generic way to get the path, but that doesn't work
> with clang as the ASan runtime file name depends on the clang version
> and target architecture. We thus have to keep the v4l2_compat test
> disabled with ASan is enabled and libcamera is compiled with clang.
s/disabled with ASan/disabled when ASan/  probably?

Oh dear - quite a case to deal with`
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>   test/meson.build                     | 16 ++++++++++++++++
>   test/v4l2_compat/meson.build         | 21 ++++++++++++++-------
>   test/v4l2_compat/v4l2_compat_test.py | 18 +++++++++++++-----
>   3 files changed, 43 insertions(+), 12 deletions(-)
>
> diff --git a/test/meson.build b/test/meson.build
> index 05a54d5cad2f..19726f37421d 100644
> --- a/test/meson.build
> +++ b/test/meson.build
> @@ -7,6 +7,22 @@ endif
>   
>   test_enabled = true
>   
> +# When ASan is enabled, find the path to the ASan runtime needed by multiple
> +# tests. This currently works with gcc only, as clang uses different file names
> +# depending on the compiler version and target architecture.
> +asan_enabled = false
> +asan_runtime_missing = false
> +
> +if get_option('b_sanitize').contains('address')
> +    asan_enabled = true
> +
> +    if cc.get_id() == 'gcc'
> +        asan_runtime = run_command(cc, '-print-file-name=libasan.so', check : true).stdout().strip()
> +    else
> +        asan_runtime_missing = true
> +    endif
> +endif
> +
>   subdir('libtest')
>   
>   subdir('camera')
> diff --git a/test/v4l2_compat/meson.build b/test/v4l2_compat/meson.build
> index 10c4675286b3..da2e7a6d9045 100644
> --- a/test/v4l2_compat/meson.build
> +++ b/test/v4l2_compat/meson.build
> @@ -4,19 +4,26 @@ if not is_variable('v4l2_compat')
>       subdir_done()
>   endif
>   
> -# If ASan is enabled, the link order runtime check will fail as v4l2-ctl and
> -# v4l2-compliance are not linked to ASan. Skip the test in that case.
> -#
> -# TODO: Find a way to LD_PRELOAD the ASan dynamic library instead, in a
> -# cross-platform way with support for both gcc and clang.
> +# If ASan is enabled but the ASan runtime shared library missing,
> +# v4l2_compat_test.py won't be able to LD_PRELOAD it, resulting in a link order
> +# runtime check failure as v4l2-ctl and v4l2-compliance are not linked to ASan.
> +# Skip the test in that case.
>   
> -if get_option('b_sanitize').contains('address')
> +if asan_runtime_missing
> +    warning('Unable to get path to ASan runtime, v4l2_compat test disabled')
>       subdir_done()
>   endif
>   
>   v4l2_compat_test = files('v4l2_compat_test.py')
> +v4l2_compat_args = []
> +
> +if asan_enabled
> +    v4l2_compat_args += ['-s', asan_runtime]
> +endif
> +
> +v4l2_compat_args += [v4l2_compat]
>   
>   test('v4l2_compat_test', v4l2_compat_test,
> -     args : v4l2_compat,
> +     args : v4l2_compat_args,
>        suite : 'v4l2_compat',
>        timeout : 60)

Looks good till here, taking a break to review the python diffs below
> diff --git a/test/v4l2_compat/v4l2_compat_test.py b/test/v4l2_compat/v4l2_compat_test.py
> index a77585fc2f49..bd89d4962c16 100755
> --- a/test/v4l2_compat/v4l2_compat_test.py
> +++ b/test/v4l2_compat/v4l2_compat_test.py
> @@ -57,8 +57,8 @@ def extract_result(result):
>       return ret
>   
>   
> -def test_v4l2_compliance(v4l2_compliance, v4l2_compat, device, base_driver):
> -    ret, output = run_with_stdout(v4l2_compliance, '-s', '-d', device, env={'LD_PRELOAD': v4l2_compat})
> +def test_v4l2_compliance(v4l2_compliance, ld_preload, device, base_driver):
> +    ret, output = run_with_stdout(v4l2_compliance, '-s', '-d', device, env={'LD_PRELOAD': ld_preload})
>       if ret < 0:
>           output.append(f'Test for {device} terminated due to signal {signal.Signals(-ret).name}')
>           return TestFail, output
> @@ -82,13 +82,21 @@ def main(argv):
>       parser = argparse.ArgumentParser()
>       parser.add_argument('-a', '--all', action='store_true',
>                           help='Test all available cameras')
> +    parser.add_argument('-s', '--sanitizer', type=str,
> +                        help='Path to the address sanitizer (ASan) runtime')
>       parser.add_argument('-v', '--verbose', action='store_true',
>                           help='Make the output verbose')
>       parser.add_argument('v4l2_compat', type=str,
>                           help='Path to v4l2-compat.so')
>       args = parser.parse_args(argv[1:])
>   
> -    v4l2_compat = args.v4l2_compat
> +    # Compute the LD_PRELOAD value by first loading ASan (if specified) and
> +    # then the V4L2 compat layer.
> +    ld_preload = []
> +    if args.sanitizer:
> +        ld_preload.append(args.sanitizer)
> +    ld_preload.append(args.v4l2_compat)
> +    ld_preload = ':'.join(ld_preload)
>   
>       v4l2_compliance = shutil.which('v4l2-compliance')
>       if v4l2_compliance is None:
> @@ -118,7 +126,7 @@ def main(argv):
>       failed = []
>       drivers_tested = {}
>       for device in dev_nodes:
> -        ret, out = run_with_stdout(v4l2_ctl, '-D', '-d', device, env={'LD_PRELOAD': v4l2_compat})
> +        ret, out = run_with_stdout(v4l2_ctl, '-D', '-d', device, env={'LD_PRELOAD': ld_preload})
>           if ret < 0:
>               failed.append(device)
>               print(f'v4l2-ctl failed on {device} with v4l2-compat')
> @@ -144,7 +152,7 @@ def main(argv):
>               continue
>   
>           print(f'Testing {device} with {driver} driver... ', end='')
> -        ret, msg = test_v4l2_compliance(v4l2_compliance, v4l2_compat, device, driver)
> +        ret, msg = test_v4l2_compliance(v4l2_compliance, ld_preload, device, driver)
>           if ret == TestFail:
>               failed.append(device)
>               print('failed')

Looks good to me and adequately  documented

Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>

On Thu, Dec 22, 2022 at 03:01:30AM +0200, Laurent Pinchart via libcamera-devel wrote:
> When libcamera is compiled with the address sanitizer enabled, the
> v4l2_compat test generates failures in the link order runtime check, as
> the host v4l2-ctl and v4l2-compliance tools are not (generally) linked
> to ASan. For this reason, the test is disabled, which sadly shrinks test
> coverage.
> 
> Fix this by loading the ASan runtime using LD_PRELOAD. This needs to be
> done from within the v4l2_compat_test.py Python script, as the Python
> interpreter itself leaks memory and would cause test failures if run
> with ASan.
> 
> To LD_PRELOAD the ASan runtime, the path to the binary needs to be
> known. gcc gives us a generic way to get the path, but that doesn't work
> with clang as the ASan runtime file name depends on the clang version
> and target architecture. We thus have to keep the v4l2_compat test
> disabled with ASan is enabled and libcamera is compiled with clang.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  test/meson.build                     | 16 ++++++++++++++++
>  test/v4l2_compat/meson.build         | 21 ++++++++++++++-------
>  test/v4l2_compat/v4l2_compat_test.py | 18 +++++++++++++-----
>  3 files changed, 43 insertions(+), 12 deletions(-)
> 
> diff --git a/test/meson.build b/test/meson.build
> index 05a54d5cad2f..19726f37421d 100644
> --- a/test/meson.build
> +++ b/test/meson.build
> @@ -7,6 +7,22 @@ endif
>  
>  test_enabled = true
>  
> +# When ASan is enabled, find the path to the ASan runtime needed by multiple
> +# tests. This currently works with gcc only, as clang uses different file names
> +# depending on the compiler version and target architecture.
> +asan_enabled = false
> +asan_runtime_missing = false
> +
> +if get_option('b_sanitize').contains('address')
> +    asan_enabled = true
> +
> +    if cc.get_id() == 'gcc'
> +        asan_runtime = run_command(cc, '-print-file-name=libasan.so', check : true).stdout().strip()
> +    else
> +        asan_runtime_missing = true
> +    endif
> +endif
> +
>  subdir('libtest')
>  
>  subdir('camera')
> diff --git a/test/v4l2_compat/meson.build b/test/v4l2_compat/meson.build
> index 10c4675286b3..da2e7a6d9045 100644
> --- a/test/v4l2_compat/meson.build
> +++ b/test/v4l2_compat/meson.build
> @@ -4,19 +4,26 @@ if not is_variable('v4l2_compat')
>      subdir_done()
>  endif
>  
> -# If ASan is enabled, the link order runtime check will fail as v4l2-ctl and
> -# v4l2-compliance are not linked to ASan. Skip the test in that case.
> -#
> -# TODO: Find a way to LD_PRELOAD the ASan dynamic library instead, in a
> -# cross-platform way with support for both gcc and clang.
> +# If ASan is enabled but the ASan runtime shared library missing,

s/missing/is missing/


Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

> +# v4l2_compat_test.py won't be able to LD_PRELOAD it, resulting in a link order
> +# runtime check failure as v4l2-ctl and v4l2-compliance are not linked to ASan.
> +# Skip the test in that case.
>  
> -if get_option('b_sanitize').contains('address')
> +if asan_runtime_missing
> +    warning('Unable to get path to ASan runtime, v4l2_compat test disabled')
>      subdir_done()
>  endif
>  
>  v4l2_compat_test = files('v4l2_compat_test.py')
> +v4l2_compat_args = []
> +
> +if asan_enabled
> +    v4l2_compat_args += ['-s', asan_runtime]
> +endif
> +
> +v4l2_compat_args += [v4l2_compat]
>  
>  test('v4l2_compat_test', v4l2_compat_test,
> -     args : v4l2_compat,
> +     args : v4l2_compat_args,
>       suite : 'v4l2_compat',
>       timeout : 60)
> diff --git a/test/v4l2_compat/v4l2_compat_test.py b/test/v4l2_compat/v4l2_compat_test.py
> index a77585fc2f49..bd89d4962c16 100755
> --- a/test/v4l2_compat/v4l2_compat_test.py
> +++ b/test/v4l2_compat/v4l2_compat_test.py
> @@ -57,8 +57,8 @@ def extract_result(result):
>      return ret
>  
>  
> -def test_v4l2_compliance(v4l2_compliance, v4l2_compat, device, base_driver):
> -    ret, output = run_with_stdout(v4l2_compliance, '-s', '-d', device, env={'LD_PRELOAD': v4l2_compat})
> +def test_v4l2_compliance(v4l2_compliance, ld_preload, device, base_driver):
> +    ret, output = run_with_stdout(v4l2_compliance, '-s', '-d', device, env={'LD_PRELOAD': ld_preload})
>      if ret < 0:
>          output.append(f'Test for {device} terminated due to signal {signal.Signals(-ret).name}')
>          return TestFail, output
> @@ -82,13 +82,21 @@ def main(argv):
>      parser = argparse.ArgumentParser()
>      parser.add_argument('-a', '--all', action='store_true',
>                          help='Test all available cameras')
> +    parser.add_argument('-s', '--sanitizer', type=str,
> +                        help='Path to the address sanitizer (ASan) runtime')
>      parser.add_argument('-v', '--verbose', action='store_true',
>                          help='Make the output verbose')
>      parser.add_argument('v4l2_compat', type=str,
>                          help='Path to v4l2-compat.so')
>      args = parser.parse_args(argv[1:])
>  
> -    v4l2_compat = args.v4l2_compat
> +    # Compute the LD_PRELOAD value by first loading ASan (if specified) and
> +    # then the V4L2 compat layer.
> +    ld_preload = []
> +    if args.sanitizer:
> +        ld_preload.append(args.sanitizer)
> +    ld_preload.append(args.v4l2_compat)
> +    ld_preload = ':'.join(ld_preload)
>  
>      v4l2_compliance = shutil.which('v4l2-compliance')
>      if v4l2_compliance is None:
> @@ -118,7 +126,7 @@ def main(argv):
>      failed = []
>      drivers_tested = {}
>      for device in dev_nodes:
> -        ret, out = run_with_stdout(v4l2_ctl, '-D', '-d', device, env={'LD_PRELOAD': v4l2_compat})
> +        ret, out = run_with_stdout(v4l2_ctl, '-D', '-d', device, env={'LD_PRELOAD': ld_preload})
>          if ret < 0:
>              failed.append(device)
>              print(f'v4l2-ctl failed on {device} with v4l2-compat')
> @@ -144,7 +152,7 @@ def main(argv):
>              continue
>  
>          print(f'Testing {device} with {driver} driver... ', end='')
> -        ret, msg = test_v4l2_compliance(v4l2_compliance, v4l2_compat, device, driver)
> +        ret, msg = test_v4l2_compliance(v4l2_compliance, ld_preload, device, driver)
>          if ret == TestFail:
>              failed.append(device)
>              print('failed')