[PATCH v2] drivers: gpu: drm: msm: registers: improve reproducibility

[Viswanath Kraleti]

From: Ryan Eatmon <reatmon at ti.com>

The files generated by gen_header.py capture the source path to the
input files and the date.  While that can be informative, it varies
based on where and when the kernel was built as the full path is
captured.

Since all of the files that this tool is run on is under the drivers
directory, this modifies the application to strip all of the path before
drivers.  Additionally it prints <stripped> instead of the date.

Signed-off-by: Ryan Eatmon <reatmon at ti.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield at gmail.com>
Signed-off-by: Viswanath Kraleti <viswanath.kraleti at oss.qualcomm.com>
---
The files generated by gen_header.py include the source path to the
input files and the build date. While this information can be useful,
it inadvertently exposes build system configuration details in the
binaries. This hinders binary reproducibility, as the output will
vary if the build environment changes.

This change was originally submitted to the linux-yocto-dev kernel [1]
to address binary reproducibility QA errors. However, the fix is generic 
enough to be applicable to the mainline kernel and would benefit other 
distributions as well. So proposing it here for broader inclusion.

[1] https://git.yoctoproject.org/linux-yocto-dev/commit/?id=f36faf0f9f8d8f5b4c43a68e5c6bd83a62253140
---
Changes in v2:
- Corrected author id
- Link to v1: https://lore.kernel.org/r/20250523-binrep-v1-1-c3a446518847@oss.qualcomm.com
---
 drivers/gpu/drm/msm/registers/gen_header.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/registers/gen_header.py b/drivers/gpu/drm/msm/registers/gen_header.py
index 3926485bb197b0992232447cb71bf1c1ebd0968c..a409404627c7180d5b0626f0ce6255d7d0df5113 100644
--- a/drivers/gpu/drm/msm/registers/gen_header.py
+++ b/drivers/gpu/drm/msm/registers/gen_header.py
@@ -11,6 +11,7 @@ import collections
 import argparse
 import time
 import datetime
+import re
 
 class Error(Exception):
 	def __init__(self, message):
@@ -877,13 +878,14 @@ The rules-ng-ng source files this header was generated from are:
 """)
 	maxlen = 0
 	for filepath in p.xml_files:
-		maxlen = max(maxlen, len(filepath))
+		new_filepath = re.sub("^.+drivers","drivers",filepath)
+		maxlen = max(maxlen, len(new_filepath))
 	for filepath in p.xml_files:
-		pad = " " * (maxlen - len(filepath))
+		pad = " " * (maxlen - len(new_filepath))
 		filesize = str(os.path.getsize(filepath))
 		filesize = " " * (7 - len(filesize)) + filesize
 		filetime = time.ctime(os.path.getmtime(filepath))
-		print("- " + filepath + pad + " (" + filesize + " bytes, from " + filetime + ")")
+		print("- " + new_filepath + pad + " (" + filesize + " bytes, from <stripped>)")
 	if p.copyright_year:
 		current_year = str(datetime.date.today().year)
 		print()

---
base-commit: fc5c669c902c3039aa41731b6c58c0960d0b1bbf
change-id: 20250523-binrep-f8c81fa0d31d

Best regards,
-- 
Viswanath Kraleti <viswanath.kraleti at oss.qualcomm.com>