[OE-core][dunfell 3/4] classes/reproducible_build: Use atomic rename for SDE file
From: Steve Sakoman <hidden>
Date: 2021-10-25 23:32:04
Subsystem:
the rest · Maintainer:
Linus Torvalds
From: Joshua Watt <redacted> If an existing source date epoch file was found during do_unpack, it was deleted and a new one would be written in its place. This causes a race with check-before-use code in get_source_date_epoch_value. Resolve the problem by making do_unpack write the new source date epoch to a temporary file, then do an atomic rename to ensure it's always present, and change the check-before-use code to use a EAFP exception instead of checking for file existence. [YOCTO #14384] Signed-off-by: Joshua Watt <redacted> Signed-off-by: Richard Purdie <redacted> (cherry picked from commit 0b5e3b33187bf78a2d62cc886463e4b27d6bd228) Signed-off-by: Steve Sakoman <redacted> --- meta/classes/reproducible_build.bbclass | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/meta/classes/reproducible_build.bbclass b/meta/classes/reproducible_build.bbclass
index 43cf9dc894..62655c2a5b 100644
--- a/meta/classes/reproducible_build.bbclass
+++ b/meta/classes/reproducible_build.bbclass@@ -77,17 +77,16 @@ python create_source_date_epoch_stamp() { import oe.reproducible epochfile = d.getVar('SDE_FILE') - # If it exists we need to regenerate as the sources may have changed - if os.path.isfile(epochfile): - bb.debug(1, "Deleting existing SOURCE_DATE_EPOCH from: %s" % epochfile) - os.remove(epochfile) + tmp_file = "%s.new" % epochfile source_date_epoch = oe.reproducible.get_source_date_epoch(d, d.getVar('S')) bb.debug(1, "SOURCE_DATE_EPOCH: %d" % source_date_epoch) bb.utils.mkdirhier(d.getVar('SDE_DIR')) - with open(epochfile, 'w') as f: + with open(tmp_file, 'w') as f: f.write(str(source_date_epoch)) + + os.rename(tmp_file, epochfile) } def get_source_date_epoch_value(d):
@@ -100,7 +99,7 @@ def get_source_date_epoch_value(d): bb.debug(1, "Epoch file changed from %s to %s" % (efile, epochfile)) source_date_epoch = int(d.getVar('SOURCE_DATE_EPOCH_FALLBACK')) - if os.path.isfile(epochfile): + try: with open(epochfile, 'r') as f: s = f.read() try:
@@ -113,7 +112,7 @@ def get_source_date_epoch_value(d): bb.warn("SOURCE_DATE_EPOCH value '%s' is invalid. Reverting to SOURCE_DATE_EPOCH_FALLBACK" % s) source_date_epoch = int(d.getVar('SOURCE_DATE_EPOCH_FALLBACK')) bb.debug(1, "SOURCE_DATE_EPOCH: %d" % source_date_epoch) - else: + except FileNotFoundError: bb.debug(1, "Cannot find %s. SOURCE_DATE_EPOCH will default to %d" % (epochfile, source_date_epoch)) d.setVar('__CACHED_SOURCE_DATE_EPOCH', (str(source_date_epoch), epochfile))
--
2.25.1