[PATCH 1/3] classes/insane: increase shebang size limit

[PATCH 1/3] classes/insane: increase shebang size limit

[Ross Burton]

Since Linux 5.1 the shebang buffer has been 256 bytes[1], so update the
check to match.

Also rewrite the test, create a variable for the magic number (that has
the same name as the kernel #define), don't pointlessly try to decode
the bytes as UTF-8, and consolidate the test logic to entirely inside
the try block.

[1] linux 6eb3c3d0a52dc ("exec: increase BINPRM_BUF_SIZE to 256")
---
 meta/classes-global/insane.bbclass | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/meta/classes-global/insane.bbclass b/meta/classes-global/insane.bbclass
index 4250331af12..08bff7dca45 100644
--- a/meta/classes-global/insane.bbclass
+++ b/meta/classes-global/insane.bbclass
@@ -83,25 +83,22 @@ QAPATHTEST[shebang-size] = "package_qa_check_shebang_size"
 def package_qa_check_shebang_size(path, name, d, elf):
     global cpath
 
+    # From kernel 5.1 onwards (specifically linux 6eb3c3d0a52dc ("exec: increase
+    # BINPRM_BUF_SIZE to 256")) the shebang buffer is was increased from 128 bytes
+    # to 256 bytes.
+    BINPRM_BUF_SIZE = 256
+
     if elf or cpath.islink(path) or not cpath.isfile(path):
         return
 
     try:
         with open(path, 'rb') as f:
-            stanza = f.readline(130)
+            stanza = f.readline(BINPRM_BUF_SIZE)
+            if stanza.startswith(b'#!') and len(stanza) > BINPRM_BUF_SIZE:
+                oe.qa.handle_error("shebang-size", "%s: %s maximum shebang size exceeded, the maximum size is %d" % (name, package_qa_clean_path(path, d, name), BINPRM_BUF_SIZE), d)
+                return
     except IOError:
-        return
-
-    if stanza.startswith(b'#!'):
-        try:
-            stanza.decode("utf-8")
-        except UnicodeDecodeError:
-            #If it is not a text file, it is not a script
-            return
-
-        if len(stanza) > 129:
-            oe.qa.handle_error("shebang-size", "%s: %s maximum shebang size exceeded, the maximum size is 128." % (name, package_qa_clean_path(path, d, name)), d)
-            return
+        pass
 
 QAPATHTEST[libexec] = "package_qa_check_libexec"
 def package_qa_check_libexec(path,name, d, elf):
-- 
2.43.0

[PATCH 2/3] classes/insane: create one CachedPath instance in qa_check_staged

[Ross Burton]

There's no need to create a new CachedPath instance for every file that
we want to scan, just create one at the beginning of the function.

Signed-off-by: Ross Burton <ross.burton@arm.com>
---
 meta/classes-global/insane.bbclass | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/meta/classes-global/insane.bbclass b/meta/classes-global/insane.bbclass
index 08bff7dca45..68ad78c39d6 100644
--- a/meta/classes-global/insane.bbclass
+++ b/meta/classes-global/insane.bbclass
@@ -729,6 +729,10 @@ def qa_check_staged(path,d):
     workdir = os.path.join(tmpdir, "work")
     recipesysroot = d.getVar("RECIPE_SYSROOT")
 
+    # package_qa_check_shebang_size needs the global cpath to be already created
+    global cpath
+    cpath = oe.cachedpath.CachedPath()
+
     if bb.data.inherits_class("native", d) or bb.data.inherits_class("cross", d):
         pkgconfigcheck = workdir
     else:
@@ -772,10 +776,7 @@ def qa_check_staged(path,d):
                         oe.qa.handle_error("pkgconfig", error_msg, d)
 
             if not skip_shebang_size:
-                global cpath
-                cpath = oe.cachedpath.CachedPath()
                 package_qa_check_shebang_size(path, "", d, None)
-                cpath = None
 
 # Walk over all files in a directory and call func
 def package_qa_walk(checkfuncs, package, d):
-- 
2.43.0

[PATCH 3/3] classes/insane: clean up do_qa_sysroot

[Ross Burton]

do_populate_sysroot copies SYSROOT_DIRS into SYSROOT_DESTDIR, so there's
no need to loop over SYSROOT_DIRS when checking files: qa_check_staged
can just recurse down the entire tree.

Signed-off-by: Ross Burton <ross.burton@arm.com>
---
 meta/classes-global/insane.bbclass | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/meta/classes-global/insane.bbclass b/meta/classes-global/insane.bbclass
index 68ad78c39d6..9640738f49f 100644
--- a/meta/classes-global/insane.bbclass
+++ b/meta/classes-global/insane.bbclass
@@ -1222,9 +1222,7 @@ addtask do_package_qa_setscene
 
 python do_qa_sysroot() {
     bb.note("QA checking do_populate_sysroot")
-    sysroot_destdir = d.expand('${SYSROOT_DESTDIR}')
-    for sysroot_dir in d.expand('${SYSROOT_DIRS}').split():
-        qa_check_staged(sysroot_destdir + sysroot_dir, d)
+    qa_check_staged(d.getVar("SYSROOT_DESTDIR"), d)
     oe.qa.exit_with_message_if_errors("do_populate_sysroot for this recipe installed files with QA issues", d)
 }
 do_populate_sysroot[postfuncs] += "do_qa_sysroot"
-- 
2.43.0

Re: [OE-core] [PATCH 1/3] classes/insane: increase shebang size limit

[Jörg Sommer]

[-- Attachment #1: Type: text/plain, Size: 915 bytes --]

Ross Burton via lists.openembedded.org schrieb am Di 30. Jun, 15:07 (+0100):
> diff --git a/meta/classes-global/insane.bbclass b/meta/classes-global/insane.bbclass
> index 4250331af12..08bff7dca45 100644
> --- a/meta/classes-global/insane.bbclass
> +++ b/meta/classes-global/insane.bbclass
> @@ -83,25 +83,22 @@ QAPATHTEST[shebang-size] = "package_qa_check_shebang_size"
>  def package_qa_check_shebang_size(path, name, d, elf):
>      global cpath
>  
> +    # From kernel 5.1 onwards (specifically linux 6eb3c3d0a52dc ("exec: increase
> +    # BINPRM_BUF_SIZE to 256")) the shebang buffer is was increased from 128 bytes

The »is« is too much.


Regards, Jörg

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Re: [OE-core] [PATCH 1/3] classes/insane: increase shebang size limit

[Mathieu Dubois-Briand]

On Tue Jun 30, 2026 at 4:07 PM CEST, Ross Burton via lists.openembedded.org wrote:
> Since Linux 5.1 the shebang buffer has been 256 bytes[1], so update the
> check to match.
>
> Also rewrite the test, create a variable for the magic number (that has
> the same name as the kernel #define), don't pointlessly try to decode
> the bytes as UTF-8, and consolidate the test logic to entirely inside
> the try block.
>
> [1] linux 6eb3c3d0a52dc ("exec: increase BINPRM_BUF_SIZE to 256")
> ---

Hi Ross,

Thanks for your patch.

I believe you also need to update the test_sysroot_max_shebang selftest
/ sysroot-shebang-test-native recipe:

2026-07-01 11:25:35,511 - oe-selftest - INFO - FAIL: sysroot.SysrootTests.test_sysroot_max_shebang (subunit.RemotedTestCase)
2026-07-01 11:25:35,511 - oe-selftest - INFO - ----------------------------------------------------------------------
2026-07-01 11:25:35,511 - oe-selftest - INFO - testtools.testresult.real._StringException: Traceback (most recent call last):
  File "/srv/pokybuild/yocto-worker/oe-selftest-debian/build/layers/openembedded-core/meta/lib/oeqa/selftest/cases/sysroot.py", line 49, in test_sysroot_max_shebang
    self.assertTrue(expected in res.output, msg=res.output)
  File "/usr/lib/python3.12/unittest/case.py", line 727, in assertTrue
    raise self.failureException(msg)
AssertionError: False is not true : NOTE: Reconnecting to bitbake server...

https://autobuilder.yoctoproject.org/valkyrie/#/builders/35/builds/4183
https://autobuilder.yoctoproject.org/valkyrie/#/builders/48/builds/4010

Thanks,
Mathieu

-- 
Mathieu Dubois-Briand, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [OE-core] [PATCH 1/3] classes/insane: increase shebang size limit

[Ross Burton]

Hilariously, I was thinking I should write a test case and didn’t even think to check there was one already…

Sorry to break your build, v2 coming soon.

Ross

> On 1 Jul 2026, at 12:28, Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> wrote:
> 
> On Tue Jun 30, 2026 at 4:07 PM CEST, Ross Burton via lists.openembedded.org wrote:
>> Since Linux 5.1 the shebang buffer has been 256 bytes[1], so update the
>> check to match.
>> 
>> Also rewrite the test, create a variable for the magic number (that has
>> the same name as the kernel #define), don't pointlessly try to decode
>> the bytes as UTF-8, and consolidate the test logic to entirely inside
>> the try block.
>> 
>> [1] linux 6eb3c3d0a52dc ("exec: increase BINPRM_BUF_SIZE to 256")
>> ---
> 
> Hi Ross,
> 
> Thanks for your patch.
> 
> I believe you also need to update the test_sysroot_max_shebang selftest
> / sysroot-shebang-test-native recipe:
> 
> 2026-07-01 11:25:35,511 - oe-selftest - INFO - FAIL: sysroot.SysrootTests.test_sysroot_max_shebang (subunit.RemotedTestCase)
> 2026-07-01 11:25:35,511 - oe-selftest - INFO - ----------------------------------------------------------------------
> 2026-07-01 11:25:35,511 - oe-selftest - INFO - testtools.testresult.real._StringException: Traceback (most recent call last):
>  File "/srv/pokybuild/yocto-worker/oe-selftest-debian/build/layers/openembedded-core/meta/lib/oeqa/selftest/cases/sysroot.py", line 49, in test_sysroot_max_shebang
>    self.assertTrue(expected in res.output, msg=res.output)
>  File "/usr/lib/python3.12/unittest/case.py", line 727, in assertTrue
>    raise self.failureException(msg)
> AssertionError: False is not true : NOTE: Reconnecting to bitbake server...
> 
> https://autobuilder.yoctoproject.org/valkyrie/#/builders/35/builds/4183
> https://autobuilder.yoctoproject.org/valkyrie/#/builders/48/builds/4010
> 
> Thanks,
> Mathieu
> 
> -- 
> Mathieu Dubois-Briand, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com