Fix a race condition in brp-strip

brp-strip script runs strip command on deliverables paralley and if deliverables are hard linked inside buildroot, it will create contention. One good example for such package is git. https://github.com/vmware/photon/blob/master/SPECS/git/git.spec ``` Sample output: $ rpm -ql git | grep libexec | xargs ls -li 668153 -rwxr-xr-x 137 root root 3401056 Aug 2 08:30 /usr/libexec/git-core/git 668153 -rwxr-xr-x 137 root root 3401056 Aug 2 08:30 /usr/libexec/git-core/git-add 787238 -rwxr-xr-x 1 root root 47770 Aug 2 08:30 /usr/libexec/git-core/git-add--interactive 668153 -rwxr-xr-x 137 root root 3401056 Aug 2 08:30 /usr/libexec/git-core/git-am ``` To overcome this, we run strip twice once for all files with no hardlinks, this is a parallel job, meaning multiple binaries will be stripped in parallel. And once for files with hardlinks, in this case we disable parallel processing and strip binaries in sequential order. RH bug link: https://bugzilla.redhat.com/show_bug.cgi?id=1959049 Co-authored-by: Dweep Advani <[email protected]> Signed-off-by: Shreenidhi Shedi <[email protected]>
rpm-software-management · Sep 13, 2022 · ae2e75a · ae2e75a
1 parent 2c63113
commit ae2e75a
Showing 1 changed file with 33 additions and 3 deletions.
diff --git a/scripts/brp-strip b/scripts/brp-strip
@@ -1,4 +1,5 @@
 #!/bin/sh
+
 # If using normal root, avoid changing anything.
 if [ -z "$RPM_BUILD_ROOT" ] || [ "$RPM_BUILD_ROOT" = "/" ]; then
  exit 0
@@ -7,11 +8,40 @@ fi
 STRIP=${1:-strip}
 NCPUS=${RPM_BUILD_NCPUS:-1}
 
+# 32 was chosen as a compromise between reducing the overhead of starting new
+# processes and distributing the work load evenly over as much processors as
+# possible
+MAX_ARGS=32
+
 case `uname -a` in
 Darwin*) exit 0 ;;
 *) ;;
 esac
 
-# Strip ELF binaries
-find "$RPM_BUILD_ROOT" -type f \! -regex "${RPM_BUILD_ROOT}/*usr/lib/debug.*" \! -name "*.go" -print0 | \
- xargs -0 -r -P$NCPUS -n32 sh -c "file \"\$@\" | sed -n -e 's/^\(.*\):[ ]*ELF.*, not stripped.*/\1/p' | grep -v 'no machine' | xargs -I\{\} $STRIP -g \{\}" ARG0
+# Below is the explanation of commands in the order of their appearance
+# Ignore /usr/lib/debug entries
+# Ignore all go(guile objects & golang) files
+# Consider files with only single link
+# Run the file command to find relevant non-stripped binaries, with bundle size of 32
+# Ignore all 'no machine' files
+# Only operate on non-stripped binaries
+
+strip_elf_binaries()
+{
+ local nlinks="${1}"
+ local nprocs="${2}"
+
+ find "$RPM_BUILD_ROOT" -type f \
+ ! -regex "${RPM_BUILD_ROOT}/*usr/lib/debug.*" \
+ ! -name "*.go" -links "${nlinks}" -print0 | \
+ xargs -0 -r -P${nprocs} -n${MAX_ARGS} sh -c "file \"\$@\" | \
+ sed -n -e 's/^\(.*\):[ ]*ELF.*, not stripped.*/\1/p' | \
+ grep -v 'no machine' | \
+ xargs -I\{\} $STRIP -g \{\}" ARG0
+}
+
+# strip all binaries with single link
+strip_elf_binaries "1" "${NCPUS}"
+
+# strip all binaries with more than 1 link
+strip_elf_binaries "+1" "1"