Added basic support for FreeBSD.

Freebsd-support: Change bash shebang to use /usr/bin/env

Freebsd-support: Fix go vet "undefined" fixes when running make ci

freebsd: stub xattr functions

/proc/PID/fd does not exist on freebsd.

freebsd-support: modify FchmodatNofollow for FreeBSD

FreeBSD supports the Fchmodat system call, with the AT_SYMLINK_NOFOLLOW
flag. FchmodatNofollow has been modified to use this system call and
flag.

freebsd-support: PR changes and fixes

* Functions in fusefrontend_reverse/node_xattr_freebsd.go have been
  stubbed for now.

* asuser_freebsd.go updated to only run f() when context is nil;
  otherwise log a warning and return an error.

* emulate.go build flags updated, and FreeBSD specific version added.

* sys_freebsd.go bug in Renameat2 with RENAME_EXCHANGE flag fixed.
  FreeBSD does not support atomic file swapping, so this flag now
  returns an error.

* unix2syscall and atime is identical between FreeBSD and Darwin,
  updated filenames so Go will build the file for FreeBSD and Mac OS.

freebsd-support: Addressed more PR comments and fixed build tags

39 files changed, 327 insertions, 28 deletions

diff --git a/Documentation/MANPAGE-render.bash b/Documentation/MANPAGE-render.bash
index c141c1e..2f19355 100755
--- a/Documentation/MANPAGE-render.bash
+++ b/Documentation/MANPAGE-render.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -eu
 cd "$(dirname "$0")"
diff --git a/benchmark-reverse.bash b/benchmark-reverse.bash
index fad6bfe..ca3bc9b 100755
--- a/benchmark-reverse.bash
+++ b/benchmark-reverse.bash
@@ -1,7 +1,9 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
 
 # Benchmark gocryptfs' reverse mode
 
+set -eu
+
 cd "$(dirname "$0")"
 MYNAME=$(basename "$0")
 source tests/fuse-unmount.bash
diff --git a/benchmark.bash b/benchmark.bash
index fb99c65..f3d8a20 100755
--- a/benchmark.bash
+++ b/benchmark.bash
@@ -1,8 +1,10 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
 
 # Run the set of "canonical" benchmarks that are shown on
 # https://nuetzlich.net/gocryptfs/comparison/
 
+set -eu
+
 cd "$(dirname "$0")"
 MYNAME=$(basename "$0")
 source tests/fuse-unmount.bash
diff --git a/build-without-openssl.bash b/build-without-openssl.bash
index c09e7f3..388f823 100755
--- a/build-without-openssl.bash
+++ b/build-without-openssl.bash
@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
+
+set -eu
 
 cd "$(dirname "$0")"
 
diff --git a/build.bash b/build.bash
index 5e95c3e..e78188e 100755
--- a/build.bash
+++ b/build.bash
@@ -1,4 +1,4 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
 #
 # Compile gocryptfs and bake the git version string of itself and the go-fuse
 # library into the binary.
@@ -10,6 +10,8 @@
 #  SOURCE_DATE_EPOCH=1544192417 ./build.bash
 # .
 
+set -eu
+
 cd "$(dirname "$0")"
 
 # $0 does not work because we may have been sourced
diff --git a/contrib/gocryptfs-maybe.bash b/contrib/gocryptfs-maybe.bash
index daf3e60..d83dd91 100755
--- a/contrib/gocryptfs-maybe.bash
+++ b/contrib/gocryptfs-maybe.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Conditionally try to mount a gocryptfs filesystem. If either
 # * CIPHERDIR/gocryptfs.conf does not exist OR
diff --git a/contrib/maxlen.bash b/contrib/maxlen.bash
index be5f7a6..4cf5802 100755
--- a/contrib/maxlen.bash
+++ b/contrib/maxlen.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Find out the maximum supported filename length and print it.
 #
diff --git a/crossbuild.bash b/crossbuild.bash
index ff773ec..685674e 100755
--- a/crossbuild.bash
+++ b/crossbuild.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Build on all supported architectures & operating systems
 
@@ -31,3 +31,7 @@ time GOOS=darwin GOARCH=amd64 compile_tests
 
 # MacOS on Apple Silicon M1.
 GOOS=darwin GOARCH=arm64 build
+
+# FreeBSD
+GOOS=freebsd GOARCH=amd64 build
+
diff --git a/internal/fusefrontend/node_xattr_freebsd.go b/internal/fusefrontend/node_xattr_freebsd.go
new file mode 100644
index 0000000..9698283
--- /dev/null
+++ b/internal/fusefrontend/node_xattr_freebsd.go
@@ -0,0 +1,33 @@
+package fusefrontend
+
+import (
+	"golang.org/x/sys/unix"
+
+	"github.com/hanwen/go-fuse/v2/fuse"
+)
+
+const noSuchAttributeError = unix.ENOATTR
+
+func filterXattrSetFlags(flags int) int {
+	return flags
+}
+
+func (n *Node) getXAttr(cAttr string) (out []byte, errno unix.Errno) {
+	// TODO
+	return nil, unix.EOPNOTSUPP
+}
+
+func (n *Node) setXAttr(context *fuse.Context, cAttr string, cData []byte, flags uint32) (errno unix.Errno) {
+	// TODO
+	return unix.EOPNOTSUPP
+}
+
+func (n *Node) removeXAttr(cAttr string) (errno unix.Errno) {
+	// TODO
+	return unix.EOPNOTSUPP
+}
+
+func (n *Node) listXAttr() (out []string, errno unix.Errno) {
+	// TODO
+	return nil, unix.EOPNOTSUPP
+}
diff --git a/internal/fusefrontend_reverse/node_xattr_freebsd.go b/internal/fusefrontend_reverse/node_xattr_freebsd.go
new file mode 100644
index 0000000..949cf15
--- /dev/null
+++ b/internal/fusefrontend_reverse/node_xattr_freebsd.go
@@ -0,0 +1,17 @@
+package fusefrontend_reverse
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+const noSuchAttributeError = unix.ENOATTR
+
+func (n *Node) getXAttr(cAttr string) (out []byte, errno unix.Errno) {
+	// TODO
+	return nil, unix.EOPNOTSUPP
+}
+
+func (n *Node) listXAttr() (out []string, errno unix.Errno) {
+	// TODO
+	return nil, unix.EOPNOTSUPP
+}
diff --git a/internal/siv_aead/benchmark.bash b/internal/siv_aead/benchmark.bash
index 40b57b3..400c134 100755
--- a/internal/siv_aead/benchmark.bash
+++ b/internal/siv_aead/benchmark.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -eu
 
diff --git a/internal/speed/benchmark.bash b/internal/speed/benchmark.bash
index d2678a7..699ceb8 100755
--- a/internal/speed/benchmark.bash
+++ b/internal/speed/benchmark.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -eu
 
diff --git a/internal/stupidgcm/benchmark.bash b/internal/stupidgcm/benchmark.bash
index 8681495..8319659 100755
--- a/internal/stupidgcm/benchmark.bash
+++ b/internal/stupidgcm/benchmark.bash
@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 exec ../speed/benchmark.bash
diff --git a/internal/syscallcompat/asuser_freebsd.go b/internal/syscallcompat/asuser_freebsd.go
new file mode 100644
index 0000000..dfa8e18
--- /dev/null
+++ b/internal/syscallcompat/asuser_freebsd.go
@@ -0,0 +1,24 @@
+package syscallcompat
+
+import (
+	"golang.org/x/sys/unix"
+
+	"github.com/hanwen/go-fuse/v2/fuse"
+
+	"github.com/rfjakob/gocryptfs/v2/internal/tlog"
+)
+
+// asUser runs `f()` under the effective uid, gid, groups specified
+// in `context`.
+//
+// If `context` is nil, `f()` is executed directly without switching user id.
+//
+// FreeBSD does not support changing uid/gid per thread. If context is not nil,
+// an error is returned.
+func asUser(f func() (int, error), context *fuse.Context) (int, error) {
+	if context == nil {
+		return f()
+	}
+	tlog.Warn.Printf("asUser: error, only nil context is supported\n")
+	return 0, unix.EOPNOTSUPP
+}
diff --git a/internal/syscallcompat/emulate.go b/internal/syscallcompat/emulate.go
index 91b592b..435c579 100644
--- a/internal/syscallcompat/emulate.go
+++ b/internal/syscallcompat/emulate.go
@@ -1,3 +1,5 @@
+//go:build !freebsd
+
 package syscallcompat
 
 import (
diff --git a/internal/syscallcompat/emulate_test.go b/internal/syscallcompat/emulate_test.go
index 16383f2..907ba3a 100644
--- a/internal/syscallcompat/emulate_test.go
+++ b/internal/syscallcompat/emulate_test.go
@@ -1,3 +1,5 @@
+//go:build !freebsd
+
 package syscallcompat
 
 import (
diff --git a/internal/syscallcompat/quirks_freebsd.go b/internal/syscallcompat/quirks_freebsd.go
new file mode 100644
index 0000000..c340cea
--- /dev/null
+++ b/internal/syscallcompat/quirks_freebsd.go
@@ -0,0 +1,22 @@
+package syscallcompat
+
+import (
+	"golang.org/x/sys/unix"
+
+	"github.com/rfjakob/gocryptfs/v2/internal/tlog"
+)
+
+// DetectQuirks decides if there are known quirks on the backing filesystem
+// that need to be workarounded.
+//
+// Tested by tests/root_test.TestBtrfsQuirks
+func DetectQuirks(cipherdir string) (q uint64) {
+	var st unix.Statfs_t
+	err := unix.Statfs(cipherdir, &st)
+	if err != nil {
+		tlog.Warn.Printf("DetectQuirks: Statfs on %q failed: %v", cipherdir, err)
+		return 0
+	}
+
+	return q
+}
diff --git a/internal/syscallcompat/sys_common.go b/internal/syscallcompat/sys_common.go
index 3cb9ffa..4f84d98 100644
--- a/internal/syscallcompat/sys_common.go
+++ b/internal/syscallcompat/sys_common.go
@@ -138,7 +138,7 @@ func getxattrSmartBuf(fn func(buf []byte) (int, error)) ([]byte, error) {
 	buf := make([]byte, GETXATTR_BUFSZ_SMALL)
 	sz, err := fn(buf)
 	// Non-existing xattr
-	if err == unix.ENODATA {
+	if err == ENODATA {
 		return nil, err
 	}
 	// Underlying fs does not support security.capabilities (example: tmpfs)
diff --git a/internal/syscallcompat/sys_darwin.go b/internal/syscallcompat/sys_darwin.go
index ef19f24..52d4e0f 100644
--- a/internal/syscallcompat/sys_darwin.go
+++ b/internal/syscallcompat/sys_darwin.go
@@ -24,6 +24,8 @@ const (
 	RENAME_NOREPLACE = unix.RENAME_EXCL
 	RENAME_EXCHANGE  = unix.RENAME_SWAP
 
+	ENODATA = unix.ENODATA
+
 	// Only exists on Linux. Define here to fix build failure, even though
 	// we will never see this flag.
 	RENAME_WHITEOUT = 1 << 30
diff --git a/internal/syscallcompat/sys_freebsd.go b/internal/syscallcompat/sys_freebsd.go
new file mode 100644
index 0000000..d88b1cf
--- /dev/null
+++ b/internal/syscallcompat/sys_freebsd.go
@@ -0,0 +1,160 @@
+// Package syscallcompat wraps FreeBSD-specific syscalls
+package syscallcompat
+
+import (
+	"time"
+
+	"golang.org/x/sys/unix"
+
+	"github.com/hanwen/go-fuse/v2/fuse"
+
+	"github.com/rfjakob/gocryptfs/v2/internal/tlog"
+)
+
+const (
+	O_DIRECT = unix.O_DIRECT
+
+	// O_PATH is supported on FreeBSD, but is missing from the sys/unix package
+	// FreeBSD-15.0 /usr/src/sys/sys/fcntl.h:135
+	O_PATH = 0x00400000
+
+	// Only defined on Linux, but we can emulate the functionality on FreeBSD
+	// in Renameat2() below
+	RENAME_NOREPLACE = 0x1
+	RENAME_EXCHANGE  = 0x2
+	RENAME_WHITEOUT  = 0x4
+
+	// ENODATA is only defined on Linux, but FreeBSD provides ENOATTR
+	ENODATA = unix.ENOATTR
+
+	// On FreeBSD, we only have O_NOFOLLOW.
+	OpenatFlagNofollowSymlink = unix.O_NOFOLLOW
+
+	// For the utimensat syscall on FreeBSD
+	AT_EMPTY_PATH = 0x4000
+)
+
+// EnospcPrealloc is supposed to preallocate ciphertext space without
+// changing the file size. This guarantees that we don't run out of
+// space while writing a ciphertext block (that would corrupt the block).
+//
+// The fallocate syscall isn't supported on FreeBSD with the same semantics
+// as Linux, in particular the _FALLOC_FL_KEEP_SIZE mode isn't supported.
+func EnospcPrealloc(fd int, off int64, len int64) (err error) {
+	return nil
+}
+
+// Fallocate wraps the posix_fallocate() syscall.
+// Fallocate returns an error if mode is not 0
+func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
+	if mode != 0 {
+		tlog.Warn.Printf("Fallocate: unsupported mode\n")
+		return unix.EOPNOTSUPP
+	}
+	_, _, err = unix.Syscall(unix.SYS_POSIX_FALLOCATE, uintptr(fd), uintptr(off), uintptr(len))
+	return err
+}
+
+// Mknodat wraps the Mknodat syscall.
+func Mknodat(dirfd int, path string, mode uint32, dev int) (err error) {
+	return unix.Mknodat(dirfd, path, mode, uint64(dev))
+}
+
+// Dup3 wraps the Dup3 syscall. We want to use Dup3 rather than Dup2 because Dup2
+// is not implemented on arm64.
+func Dup3(oldfd int, newfd int, flags int) (err error) {
+	return unix.Dup3(oldfd, newfd, flags)
+}
+
+// FchmodatNofollow is like Fchmodat but never follows symlinks.
+func FchmodatNofollow(dirfd int, path string, mode uint32) (err error) {
+	return unix.Fchmodat(dirfd, path, mode, unix.AT_SYMLINK_NOFOLLOW)
+}
+
+// LsetxattrUser runs the Lsetxattr syscall in the context of a different user.
+// This is useful when setting ACLs, as the result depends on the user running
+// the operation (see fuse-xfstests generic/375).
+//
+// If `context` is nil, this function behaves like ordinary Lsetxattr.
+func LsetxattrUser(path string, attr string, data []byte, flags int, context *fuse.Context) (err error) {
+	f := func() (int, error) {
+		err := unix.Lsetxattr(path, attr, data, flags)
+		return -1, err
+	}
+	_, err = asUser(f, context)
+	return err
+}
+
+func timesToTimespec(a *time.Time, m *time.Time) []unix.Timespec {
+	ts := make([]unix.Timespec, 2)
+	if a == nil {
+		ts[0] = unix.Timespec{Nsec: unix.UTIME_OMIT}
+	} else {
+		ts[0], _ = unix.TimeToTimespec(*a)
+	}
+	if m == nil {
+		ts[1] = unix.Timespec{Nsec: unix.UTIME_OMIT}
+	} else {
+		ts[1], _ = unix.TimeToTimespec(*m)
+	}
+	return ts
+}
+
+// FutimesNano syscall.
+func FutimesNano(fd int, a *time.Time, m *time.Time) (err error) {
+	ts := timesToTimespec(a, m)
+	return unix.UtimesNanoAt(unix.AT_FDCWD, "", ts, AT_EMPTY_PATH)
+}
+
+// UtimesNanoAtNofollow is like UtimesNanoAt but never follows symlinks.
+// Retries on EINTR.
+func UtimesNanoAtNofollow(dirfd int, path string, a *time.Time, m *time.Time) (err error) {
+	ts := timesToTimespec(a, m)
+	err = retryEINTR(func() error {
+		return unix.UtimesNanoAt(dirfd, path, ts, unix.AT_SYMLINK_NOFOLLOW)
+	})
+	return err
+}
+
+// Getdents syscall with "." and ".." filtered out.
+func Getdents(fd int) ([]fuse.DirEntry, error) {
+	entries, _, err := emulateGetdents(fd)
+	return entries, err
+}
+
+// GetdentsSpecial calls the Getdents syscall,
+// with normal entries and "." / ".." split into two slices.
+func GetdentsSpecial(fd int) (entries []fuse.DirEntry, entriesSpecial []fuse.DirEntry, err error) {
+	return emulateGetdents(fd)
+}
+
+// Renameat2 does not exist on FreeBSD, so we have to wrap it here.
+// Retries on EINTR.
+// The RENAME_EXCHANGE and RENAME_WHITEOUT flags are not supported.
+func Renameat2(olddirfd int, oldpath string, newdirfd int, newpath string, flags uint) (err error) {
+	if flags&(RENAME_NOREPLACE|RENAME_EXCHANGE) == RENAME_NOREPLACE|RENAME_EXCHANGE {
+		return unix.EINVAL
+	}
+	if flags&(RENAME_NOREPLACE|RENAME_EXCHANGE) == RENAME_NOREPLACE|RENAME_EXCHANGE {
+		return unix.EINVAL
+	}
+
+	if flags&RENAME_NOREPLACE != 0 {
+		var st unix.Stat_t
+		err = unix.Fstatat(newdirfd, newpath, &st, 0)
+		if err == nil {
+			// Assume newpath is an existing file if we can stat() it.
+			// On Linux, RENAME_NOREPLACE fails with EEXIST if newpath
+			// already exists.
+			return unix.EEXIST
+		}
+	}
+	if flags&RENAME_EXCHANGE != 0 {
+		return unix.EINVAL
+	}
+	if flags&RENAME_WHITEOUT != 0 {
+		return unix.EINVAL
+	}
+
+	return unix.Renameat(olddirfd, oldpath, newdirfd, newpath)
+}
diff --git a/internal/syscallcompat/sys_linux.go b/internal/syscallcompat/sys_linux.go
index 71478af..a850ba1 100644
--- a/internal/syscallcompat/sys_linux.go
+++ b/internal/syscallcompat/sys_linux.go
@@ -32,6 +32,9 @@ const (
 	// On Darwin we use O_SYMLINK which allows opening a symlink itself.
 	// On Linux, we only have O_NOFOLLOW.
 	OpenatFlagNofollowSymlink = unix.O_NOFOLLOW
+
+	// Only defined on Linux
+	ENODATA = unix.ENODATA
 )
 
 var preallocWarn sync.Once
diff --git a/internal/syscallcompat/unix2syscall_darwin.go b/internal/syscallcompat/unix2syscall.go
index 5767a27..fa2e8c4 100644
--- a/internal/syscallcompat/unix2syscall_darwin.go
+++ b/internal/syscallcompat/unix2syscall.go
@@ -1,3 +1,5 @@
+//go:build darwin || freebsd
+
 package syscallcompat
 
 import (
diff --git a/package-release-tarballs.bash b/package-release-tarballs.bash
index 881bce0..3581008 100755
--- a/package-release-tarballs.bash
+++ b/package-release-tarballs.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -eu
 
diff --git a/profiling/ls.bash b/profiling/ls.bash
index 35f5a39..334d8be 100755
--- a/profiling/ls.bash
+++ b/profiling/ls.bash
@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
+
+set -eu
 
 cd "$(dirname "$0")"
 
diff --git a/profiling/streaming-read.bash b/profiling/streaming-read.bash
index 86ef942..138148c 100755
--- a/profiling/streaming-read.bash
+++ b/profiling/streaming-read.bash
@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
+
+set -eu
 
 cd "$(dirname "$0")"
 
diff --git a/profiling/streaming-write.bash b/profiling/streaming-write.bash
index 6f3af56..3c29ee6 100755
--- a/profiling/streaming-write.bash
+++ b/profiling/streaming-write.bash
@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
+
+set -eu
 
 cd "$(dirname "$0")"
 
diff --git a/profiling/tar-extract.bash b/profiling/tar-extract.bash
index f176368..e98100a 100755
--- a/profiling/tar-extract.bash
+++ b/profiling/tar-extract.bash
@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
+
+set -eu
 
 cd "$(dirname "$0")"
 
diff --git a/profiling/write-trace.bash b/profiling/write-trace.bash
index 31af492..8b7cec9 100755
--- a/profiling/write-trace.bash
+++ b/profiling/write-trace.bash
@@ -1,8 +1,10 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
 #
 # Write an execution trace of writing 100MB of data
 # to a new gocryptfs mount on /tmp
 
+set -eu
+
 cd "$(dirname "$0")"
 
 T=$(mktemp -d)
diff --git a/test-without-openssl.bash b/test-without-openssl.bash
index e596753..d2cd7e4 100755
--- a/test-without-openssl.bash
+++ b/test-without-openssl.bash
@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
+
+set -eu
 
 cd "$(dirname "$0")"
 
diff --git a/test.bash b/test.bash
index d5da874..12e6b7f 100755
--- a/test.bash
+++ b/test.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # test.bash runs the gocryptfs test suite against $TMPDIR,
 # or, if unset, /var/tmp.
diff --git a/tests/canonical-benchmarks.bash b/tests/canonical-benchmarks.bash
index 4c1a357..963fd6a 100755
--- a/tests/canonical-benchmarks.bash
+++ b/tests/canonical-benchmarks.bash
@@ -1,4 +1,4 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
 #
 # Run the set of "canonical" benchmarks that are shown on
 # https://nuetzlich.net/gocryptfs/comparison/
@@ -6,6 +6,7 @@
 #
 # This is called by the top-level script "benchmark.bash".
 
+set -eu
 
 MYNAME=$(basename "$0")
 
diff --git a/tests/dl-linux-tarball.bash b/tests/dl-linux-tarball.bash
index 03c0e7d..3c325db 100755
--- a/tests/dl-linux-tarball.bash
+++ b/tests/dl-linux-tarball.bash
@@ -1,8 +1,10 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
 #
 # This script checks the size of /tmp/linux-3.0.tar.gz and downloads
 # a fresh copy if the size is incorrect or the file is missing.
 
+set -eu
+
 URL=https://cdn.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.gz
 TGZ=/tmp/linux-3.0.tar.gz
 
diff --git a/tests/fuse-unmount.bash b/tests/fuse-unmount.bash
index b36f28c..02c6e4c 100755
--- a/tests/fuse-unmount.bash
+++ b/tests/fuse-unmount.bash
@@ -1,10 +1,13 @@
-#!/bin/bash -eu
+#!/usr/bin/env bash
 #
 # Compatibility wrapper around "fusermount" on Linux and "umount" on
 # Mac OS X and friends.
 #
 # This script can be sourced or executed directly.
 #
+
+set -eu
+
 fuse-unmount() {
 	local MYNAME=$(basename "$BASH_SOURCE")
 	if [[ $# -eq 0 ]] ; then
diff --git a/tests/matrix/atime_darwin.go b/tests/matrix/atime_darwin+freebsd.go
index 5f89c69..43db0d5 100644
--- a/tests/matrix/atime_darwin.go
+++ b/tests/matrix/atime_darwin+freebsd.go
@@ -1,3 +1,5 @@
+//go:build darwin || freebsd
+
 package matrix
 
 import (
diff --git a/tests/reverse/linux-tarball-test.bash b/tests/reverse/linux-tarball-test.bash
index 4054c29..27afa23 100755
--- a/tests/reverse/linux-tarball-test.bash
+++ b/tests/reverse/linux-tarball-test.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -eu
 
diff --git a/tests/sshfs-benchmark.bash b/tests/sshfs-benchmark.bash
index 4695f8d..2421f20 100755
--- a/tests/sshfs-benchmark.bash
+++ b/tests/sshfs-benchmark.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -eu
 
diff --git a/tests/stress_tests/extractloop.bash b/tests/stress_tests/extractloop.bash
index 1f78a5e..714d2d7 100755
--- a/tests/stress_tests/extractloop.bash
+++ b/tests/stress_tests/extractloop.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Mount a gocryptfs filesystem somewhere on /tmp, then run two parallel
 # infinite loops inside that do the following:
diff --git a/tests/stress_tests/fsstress-gocryptfs.bash b/tests/stress_tests/fsstress-gocryptfs.bash
index e6c3281..7e3f160 100755
--- a/tests/stress_tests/fsstress-gocryptfs.bash
+++ b/tests/stress_tests/fsstress-gocryptfs.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Mount a gocryptfs filesystem in /var/tmp and run fsstress against it
 # in an infinite loop, only exiting on errors.
diff --git a/tests/stress_tests/pingpong.bash b/tests/stress_tests/pingpong.bash
index d0d21b3..4fd5ff2 100755
--- a/tests/stress_tests/pingpong.bash
+++ b/tests/stress_tests/pingpong.bash
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Mounts two gocryptfs filesystems, "ping" and "pong" and moves the
 # linux-3.0 kernel tree back and forth between them, checking integrity