fix system breakage window during make install due to permissions

install.sh was wrongly waiting until after atomically replacing the
old file to set the correct permissions on the new file. in the case
of the dynamic linker, this would cause a dynamic-linked chmod command
not to run (due to missing executable permissions on the dynamic
linker) and thus leave the system in an unusable state.

even if chmod is static-linked, the old behavior had a race window
where dynamic-linked programs could fail to run.

diff --git a/tools/install.sh b/tools/install.sh
index 4e5a8b9ff7e0c667c1f9e1561d61bf2c8f2afd02..d913b60bf24fc0589a211bc4f83dd0ce9d3c983a 100755 (executable)
--- a/tools/install.sh
+++ b/tools/install.sh
@@ -51,6 +51,7 @@ if test "$symlink" ; then
 ln -s "$1" "$tmp"
 else
 cat < "$1" > "$tmp"
+chmod "$mode" "$tmp"
 fi
 
 mv -f "$tmp" "$2"
@@ -60,6 +61,4 @@ printf "%s: %s is a directory\n" "$0" "$dst" 1>&2
 exit 1
 }
 
-test "$symlink" || chmod "$mode" "$2"
-
 exit 0