devtool: added strip command

Added `devtool strip` command. This command can strip binaries out of
DWARF debug sections. The command can be parameterized by
`--target-libc (musl|gnu)`, which sets the libc used by a specific
toolchain (e.g. x86_64-uknown-linux-${libc_flavor}).

Signed-off-by: Iulian Barbu <[email protected]>

Author: Iulian Barbu

CHANGELOG.md

@@ -25,6 +25,7 @@
   snapshot.
 - Added a new API call, `PUT /snapshot/load`, for loading a snapshot.
 - Added metrics for the vsock device.
+- Added devtool strip command to strip release binaries out of DWARF sections.
 
 ### Fixed
 

tools/devtool

@@ -385,6 +385,15 @@ cmd_help() {
     echo "        -l, --libc musl|gnu   Choose the libc flavor against which Firecracker will"
     echo "                              be linked. Default is musl."
     echo ""
+    echo "    strip [--target_libc musl|gnu]"
+    echo "        Strip from debug symbols the Firecracker binaries."
+    echo ""
+    echo "        --target_libc musl|gnu   Choose the target libc flavor which determines the"
+    echo "                                 toolchain used to build Firecracker release binaries."
+    echo "                                 Stripping will occur only for the Firecracker release"
+    echo "                                 binaries corresponding to the inferred toolchain. Default"
+    echo "                                 is musl."
+    echo ""
     echo "    fmt"
     echo "        Auto-format all Rust source files, to match the Firecracker requirements."
     echo "        This should be used as the last step in every commit, to ensure that the"
@@ -500,6 +509,54 @@ cmd_build() {
     return $ret
 }
 
+cmd_strip() {
+    profile="release"
+    libc="musl"
+    target="$(uname -m)-unknown-linux-${libc}"
+
+    # Parse any command line args.
+    while [ $# -gt 0 ]; do
+        case "$1" in
+            "-h"|"--help")  { cmd_help; exit 1;     } ;;
+            "--target-libc")
+                shift
+                [[ "$1" =~ ^(musl|gnu)$ ]] || \
+                    die "Invalid libc: $1. Valid options are \"musl\" and \"gnu\"."
+                libc="$1"
+                target="$(uname -m)-unknown-linux-${libc}"
+                ;;
+            *)
+                die "Unknown argument: $1. Please use --help for help."
+            ;;
+        esac
+        shift
+    done
+
+    # Check prerequisites
+    ensure_devctr
+    ensure_build_dir
+
+    say "Starting stripping the debug symbols for $profile binaries built against $target target."
+    strip_flags="--strip-debug"
+    say "Strip flags: $strip_flags."
+
+    run_devctr \
+      --user "$(id -u):$(id -g)" \
+      -- \
+      strip $strip_flags\
+        "$CTR_CARGO_TARGET_DIR/$target/$profile/firecracker" \
+        "$CTR_CARGO_TARGET_DIR/$target/$profile/jailer"
+    ret=$?
+
+    [ $ret -eq 0 ] && {
+        cargo_bin_dir="$CARGO_TARGET_DIR/$target/$profile"
+        say "Stripping was successful."
+        say "Stripped binaries placed under $cargo_bin_dir."
+    }
+
+    return $?
+}
+
 # `$0 test` - run integration tests
 # Please see `$0 help` for more information.
 #