Make riscv64 / ppc64le / loongarch64 sysroots PIE-ready

README.md

@@ -62,5 +62,14 @@ FreeBSD:
 
 - Run ./refresh-freebsd-sysroot.sh
 
+PIE-readiness on Linux targets:
+
+- Run `./refresh-linux-sysroot.sh <arch>` (or `./refresh-linux-sysroot.sh all`)
+  where `<arch>` is `riscv64`, `ppc64le`, or `loongarch64`. This adds the
+  minimal set of files missing from each sysroot so ClickHouse can be
+  linked as a Position-Independent Executable (`-pie`): a `librt.so` link
+  for riscv64, and `Scrt1.o` for ppc64le / loongarch64. See the header
+  comment of the script for details.
+
 TODO:
 - simplify directory structure even more.

linux-riscv64/lib/riscv64-linux-gnu/librt.so

@@ -0,0 +1 @@
+librt.so.1

refresh-freebsd-sysroot.sh

@@ -9,9 +9,9 @@ if [[ -z "$URL" ]]; then
 Usage: ./refresh-freebsd-sysroot.sh <URL>
 
 URL examples:
-  https://download.freebsd.org/releases/arm64/13.4-RELEASE/base.txz
-  https://download.freebsd.org/releases/amd64/13.4-RELEASE/base.txz
-  https://download.freebsd.org/releases/powerpc64/13.4-RELEASE/base.txz
+  https://download.freebsd.org/releases/amd64/13.5-RELEASE/base.txz
+  https://download.freebsd.org/releases/arm64/13.5-RELEASE/base.txz
+  https://download.freebsd.org/releases/powerpc/powerpc64le/13.5-RELEASE/base.txz
 
 The sysroot directory is automatically determined from the URL architecture.
 EOF
@@ -44,6 +44,7 @@ mkdir -p "$SYSROOT/usr/include" "$SYSROOT/lib"
 cp -va "$NEW_SYSROOT/usr/include/." "$SYSROOT/usr/include/"
 
 for p in crt1.o crtbegin.o crtend.o crti.o crtn.o \
+         Scrt1.o crtbeginS.o crtendS.o \
          libc.a libm.a librt.a; do
   cp -va "$NEW_SYSROOT/usr/lib/$p" "$SYSROOT/lib/"
 done

refresh-linux-sysroot.sh

@@ -0,0 +1,263 @@
+#!/usr/bin/env bash
+#
+# Add the bits to each Linux cross-sysroot that are needed to link
+# ClickHouse as a Position-Independent Executable (PIE).
+#
+# Design philosophy: do the smallest possible change per target. For each
+# arch we only add what is missing:
+#
+#   * riscv64
+#       - The sysroot already ships `librt.so.1` (glibc 2.32) and a
+#         non-PIC `librt.a`. There is no `librt.so` symlink, so `-lrt`
+#         falls back to the static archive and the linker emits
+#         R_RISCV_HI20/LO12 errors against a PIE output.
+#       - Fix: add a `librt.so -> librt.so.1` symlink. (usr/lib is a
+#         symlink to ../lib in this sysroot, so we only touch one path.)
+#         That makes `-lrt` resolve to the shared library, which contains
+#         all the POSIX-timer symbols we need.
+#       - No new files are downloaded. No archives are replaced. The
+#         runtime glibc floor for the resulting binary is unchanged.
+#
+#   * ppc64le
+#       - The sysroot has no PIE entry object. Linking with `-pie` fails
+#         with "cannot open Scrt1.o".
+#       - Fix: copy `Scrt1.o` from Debian trixie's libc6-dev-ppc64el-cross
+#         package into both lib64 paths the sysroot uses. `Scrt1.o` only
+#         references `__libc_start_main` (present since glibc 2.0), so it
+#         is safe to drop into an older sysroot.
+#
+#   * loongarch64
+#       - Same story as ppc64le: no `Scrt1.o`.
+#       - Fix: copy `Scrt1.o` from Debian trixie's libc6-dev-loong64-cross
+#         package into `usr/lib/loongarch64-linux-gnu/`.
+#
+#   * x86_64-musl
+#       - ClickHouse's musl build is statically linked (`-static -lc`). Under
+#         `-pie`, that combination is incoherent: clang's driver picks
+#         `crtbeginT.o` (the non-PIC "typical" static-exe CRT) and `lld`
+#         then rejects its absolute `R_X86_64_32` relocations against
+#         `__TMC_END__` etc. Switching to `-static-pie` makes the driver
+#         pick the PIC variants (`rcrt1.o`, `crtbeginS.o`, `crtendS.o`),
+#         but those files are not in this sysroot.
+#       - Fix: copy `rcrt1.o` (musl's relocatable CRT entry), `crtbeginS.o`
+#         and `crtendS.o` from Alpine's musl-dev / libgcc / gcc packages
+#         into `lib/`. musl's existing `libc.a` / `crt1.o` / `crti.o` /
+#         `crtn.o` are already PIC-clean, so no other changes are needed.
+#         The corresponding build-system change is to switch the musl
+#         build from `-static` to `-static-pie` in
+#         `cmake/linux/default_libs.cmake` in the main repo.
+#
+# This script is intentionally not a "full sysroot refresh". Upgrading
+# the glibc/musl version compiled against is a separate, larger change.
+#
+# Usage:
+#   ./refresh-linux-sysroot.sh <arch>      # refresh one arch
+#   ./refresh-linux-sysroot.sh all         # refresh all four
+#
+# Supported <arch>: riscv64, ppc64le, loongarch64, x86_64-musl
+#
+# Requires: docker (for all arches except riscv64).
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+STAGE_ROOT=""
+cleanup() {
+  if [[ -n "$STAGE_ROOT" && -d "$STAGE_ROOT" ]]; then
+    rm -rf "$STAGE_ROOT"
+  fi
+}
+trap cleanup EXIT
+
+# Extract libc6-dev-<arch>-cross from Debian trixie into a staging dir.
+# We run the container as root (apt-get needs it) and chown the output tree
+# back to the invoking user so the host can clean it up without sudo.
+#
+# Result is placed in the global variable EXTRACTED_DIR. We avoid command
+# substitution here because `FOO=$(func)` runs `func` in a subshell, so any
+# modifications to globals (including STAGE_ROOT) and any EXIT traps are
+# lost as soon as the subshell finishes.
+EXTRACTED_DIR=""
+extract_cross_dev() {
+  local deb_arch="$1"
+  if [[ -z "$STAGE_ROOT" ]]; then
+    STAGE_ROOT="$(mktemp -d)"
+  fi
+  local dest="$STAGE_ROOT/$deb_arch"
+  if [[ -d "$dest/usr" ]]; then
+    EXTRACTED_DIR="$dest"
+    return 0
+  fi
+  mkdir -p "$dest"
+  local uid gid
+  uid="$(id -u)"
+  gid="$(id -g)"
+  docker run --rm -v "$dest":/out debian:trixie-slim bash -c "
+    set -e
+    apt-get update -qq >/dev/null
+    mkdir -p /tmp/debs && cd /tmp/debs
+    apt-get download libc6-dev-${deb_arch}-cross >/dev/null
+    for d in *.deb; do dpkg-deb -x \"\$d\" /out; done
+    chown -R ${uid}:${gid} /out
+  " >/dev/null
+  EXTRACTED_DIR="$dest"
+}
+
+refresh_riscv64() {
+  local sysroot="$SCRIPT_DIR/linux-riscv64"
+  local dir="$sysroot/lib/riscv64-linux-gnu"
+  echo ">> riscv64: $sysroot"
+  if [[ ! -d "$dir" ]]; then
+    echo "Error: missing target dir $dir" >&2
+    return 1
+  fi
+  # Note: usr/lib is a symlink to ../lib in this sysroot so this also
+  # makes the file visible under usr/lib/riscv64-linux-gnu/librt.so.
+  if [[ -L "$dir/librt.so" ]]; then
+    echo "   $dir/librt.so already a symlink, leaving it"
+  else
+    ln -sfv librt.so.1 "$dir/librt.so"
+  fi
+}
+
+refresh_ppc64le() {
+  local sysroot="$SCRIPT_DIR/linux-powerpc64le"
+  local triplet="powerpc64le-linux-gnu"
+  echo ">> ppc64le: $sysroot"
+
+  extract_cross_dev ppc64el
+  local src="$EXTRACTED_DIR/usr/${triplet}/lib/Scrt1.o"
+  if [[ ! -e "$src" ]]; then
+    echo "Error: Scrt1.o not found in libc6-dev-ppc64el-cross at $src" >&2
+    return 1
+  fi
+
+  for rel in ${triplet}/libc/lib64 ${triplet}/libc/usr/lib64; do
+    local dir="$sysroot/$rel"
+    if [[ ! -d "$dir" ]]; then
+      echo "   Skipping missing dir: $dir" >&2
+      continue
+    fi
+    cp --preserve=mode,timestamps -v "$src" "$dir/Scrt1.o"
+  done
+}
+
+refresh_loongarch64() {
+  local sysroot="$SCRIPT_DIR/linux-loongarch64"
+  local triplet="loongarch64-linux-gnu"
+  echo ">> loongarch64: $sysroot"
+
+  # Debian calls this arch "loong64", but the GNU triplet is
+  # "loongarch64-linux-gnu" and that is what the sysroot uses.
+  extract_cross_dev loong64
+  local src="$EXTRACTED_DIR/usr/${triplet}/lib/Scrt1.o"
+  if [[ ! -e "$src" ]]; then
+    echo "Error: Scrt1.o not found in libc6-dev-loong64-cross at $src" >&2
+    return 1
+  fi
+
+  local dir="$sysroot/usr/lib/${triplet}"
+  if [[ ! -d "$dir" ]]; then
+    echo "Error: missing target dir $dir" >&2
+    return 1
+  fi
+  cp --preserve=mode,timestamps -v "$src" "$dir/Scrt1.o"
+}
+
+# Pull the PIC CRT startup objects for x86_64-linux-musl out of Alpine's
+# `musl-dev` + `libgcc` packages. Unlike the Debian-based arches above we
+# can't use `apt-get download` here because Debian does not ship a
+# musl-dev-x86-64-cross package; Alpine is the canonical source.
+extract_alpine_musl() {
+  if [[ -z "$STAGE_ROOT" ]]; then
+    STAGE_ROOT="$(mktemp -d)"
+  fi
+  local dest="$STAGE_ROOT/alpine-musl"
+  if [[ -d "$dest/usr" ]]; then
+    EXTRACTED_DIR="$dest"
+    return 0
+  fi
+  mkdir -p "$dest"
+  local uid gid
+  uid="$(id -u)"
+  gid="$(id -g)"
+  # musl-dev ships rcrt1.o / crt1.o / crti.o / crtn.o / libc.a.
+  # The PIC crtstuff (crtbeginS.o, crtendS.o) lives in the `gcc` package,
+  # not `libgcc` — libgcc only has the shared runtime.
+  docker run --rm -v "$dest":/out alpine:latest sh -c "
+    set -e
+    cd /out
+    apk fetch --no-cache --quiet musl-dev gcc 2>/dev/null
+    for f in *.apk; do tar -xzf \"\$f\" 2>/dev/null || true; done
+    chown -R ${uid}:${gid} /out
+  " >/dev/null
+  EXTRACTED_DIR="$dest"
+}
+
+refresh_x86_64_musl() {
+  local sysroot="$SCRIPT_DIR/linux-x86_64-musl"
+  echo ">> x86_64-musl: $sysroot"
+
+  extract_alpine_musl
+  local dir="$sysroot/lib"
+  if [[ ! -d "$dir" ]]; then
+    echo "Error: missing target dir $dir" >&2
+    return 1
+  fi
+
+  # musl's relocatable CRT entry object (driver picks this for -static-pie).
+  local rcrt1="$EXTRACTED_DIR/usr/lib/rcrt1.o"
+  if [[ ! -e "$rcrt1" ]]; then
+    echo "Error: rcrt1.o not found in Alpine musl-dev at $rcrt1" >&2
+    return 1
+  fi
+  cp --preserve=mode,timestamps -v "$rcrt1" "$dir/rcrt1.o"
+
+  # PIC variants of libgcc's crtstuff. They live under a versioned
+  # gcc-toolchain directory inside the libgcc package; glob for the first
+  # one we find so we don't hard-code the gcc version.
+  local gcclib
+  gcclib=$(ls -d "$EXTRACTED_DIR"/usr/lib/gcc/x86_64-alpine-linux-musl/*/ 2>/dev/null | head -1 || true)
+  if [[ -z "$gcclib" ]]; then
+    echo "Error: no libgcc tree under $EXTRACTED_DIR/usr/lib/gcc/" >&2
+    return 1
+  fi
+  for f in crtbeginS.o crtendS.o; do
+    if [[ ! -e "$gcclib/$f" ]]; then
+      echo "Error: $f not found under $gcclib" >&2
+      return 1
+    fi
+    cp --preserve=mode,timestamps -v "$gcclib/$f" "$dir/$f"
+  done
+}
+
+ARCH="${1:-}"
+if [[ -z "$ARCH" ]]; then
+  cat <<EOF
+Usage: $0 <arch>
+
+Supported <arch>: riscv64, ppc64le, loongarch64, x86_64-musl, all
+EOF
+  exit 1
+fi
+
+case "$ARCH" in
+  riscv64)     refresh_riscv64 ;;
+  ppc64le)     refresh_ppc64le ;;
+  loongarch64) refresh_loongarch64 ;;
+  x86_64-musl) refresh_x86_64_musl ;;
+  all)
+    refresh_riscv64
+    refresh_ppc64le
+    refresh_loongarch64
+    refresh_x86_64_musl
+    ;;
+  *)
+    echo "Error: unsupported arch '$ARCH'." >&2
+    exit 1
+    ;;
+esac
+
+echo
+echo "Done. Review with: git -C ${SCRIPT_DIR} status"