From ec6972ab724c23edb47394e1211c4d3dc635ea8f Mon Sep 17 00:00:00 2001

From: Valentin Lefebvre <valentin.lefebvre@suse.com>

Date: Mon, 13 Mar 2023 12:06:13 +0100

Subject: [PATCH] fix(dracut.sh): use dynamically uefi's sections offset

* Uefi section are creating by `objcopy` with hardcoded sections

offset. This commit allow to have the correct offset between

each part of the efi file, needed to create an UKI. Offsets

are simply calculated so no sections overlap, as recommended

in  https://wiki.archlinux.org/title/Unified_kernel_image#Manually

Moreover, efi stub file's header is parsed to apply the correct

offsets according the section alignment factor.

* Remove EFI_SECTION_VMA_INITRD, no need anymore as initrd

section offset dynamically calculated

Fixes dracutdevs#2275

Signed-off-by: Valentin Lefebvre <valentin.lefebvre@suse.com>

---

 dracut-functions.sh | 23 +++++++++++++++++++++++

 dracut.sh           | 45 +++++++++++++++++++++++++++++++++++----------

 2 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/dracut-functions.sh b/dracut-functions.sh

index 280e4e7..78547f3 100755

--- a/dracut-functions.sh

+++ b/dracut-functions.sh

@@ -1011,3 +1011,26 @@ get_dev_module() {

     fi

     echo "$dev_drivers"

 }

+

+# Check if file is in PE format

+pe_file_format() {

+    if [[ $# -eq 1 ]]; then

+        local magic

+        magic=$(objdump -p "$1" \

+            | awk '{if ($1 == "Magic"){print strtonum("0x"$2)}}')

+        magic=$(printf "0x%x" "$magic")

+        # 0x10b (PE32), 0x20b (PE32+)

+        [[ $magic == 0x20b || $magic == 0x10b ]] && return 0

+    fi

+    return 1

+}

+

+# Get the sectionAlignment data from the PE header

+pe_get_section_align() {

+    local align_hex

+    [[ $# -ne "1" ]] && return 1

+    [[ $(pe_file_format "$1") -eq 1 ]] && return 1

+    align_hex=$(objdump -p "$1" \

+        | awk '{if ($1 == "SectionAlignment"){print $2}}')

+    echo "$((16#$align_hex))"

+}

diff --git a/dracut.sh b/dracut.sh

index 031dd85..f42ef89 100755

--- a/dracut.sh

+++ b/dracut.sh

@@ -1447,7 +1447,6 @@ if [[ ! $print_cmdline ]]; then

             exit 1

         fi

         unset EFI_MACHINE_TYPE_NAME

-        EFI_SECTION_VMA_INITRD=0x3000000

         case "${DRACUT_ARCH:-$(uname -m)}" in

             x86_64)

                 EFI_MACHINE_TYPE_NAME=x64

@@ -1457,8 +1456,6 @@ if [[ ! $print_cmdline ]]; then

                 ;;

             aarch64)

                 EFI_MACHINE_TYPE_NAME=aa64

-                # aarch64 kernels are uncompressed and thus larger, so we need a bigger gap between vma sections

-                EFI_SECTION_VMA_INITRD=0x4000000

                 ;;

             *)

                 dfatal "Architecture '${DRACUT_ARCH:-$(uname -m)}' not supported to create a UEFI executable"

@@ -2617,29 +2614,57 @@ if [[ $uefi == yes ]]; then

         fi

     fi

+    offs=$(objdump -h "$uefi_stub" 2> /dev/null | awk 'NF==7 {size=strtonum("0x"$3);\

+                offset=strtonum("0x"$4)} END {print size + offset}')

+    if [[ $offs -eq 0 ]]; then

+        dfatal "Failed to get the size of $uefi_stub to create UEFI image file"

+        exit 1

+    fi

+    align=$(pe_get_section_align "$uefi_stub")

+    if [[ $? -eq 1 ]]; then

+        dfatal "Failed to get the sectionAlignment of the stub PE header to create the UEFI image file"

+        exit 1

+    fi

+    offs=$((offs + "$align" - offs % "$align"))

+    [[ -s $dracutsysrootdir/usr/lib/os-release ]] && uefi_osrelease="$dracutsysrootdir/usr/lib/os-release"

+    [[ -s $dracutsysrootdir/etc/os-release ]] && uefi_osrelease="$dracutsysrootdir/etc/os-release"

+    [[ -s $uefi_osrelease ]] \

+        && uefi_osrelease_offs=${offs} \

+        && offs=$((offs + $(stat -Lc%s "$uefi_osrelease"))) \

+        && offs=$((offs + "$align" - offs % "$align"))

+

     if [[ $kernel_cmdline ]] || [[ $hostonly_cmdline == yes && -e "${uefi_outdir}/cmdline.txt" ]]; then

         echo -ne "\x00" >> "$uefi_outdir/cmdline.txt"

         dinfo "Using UEFI kernel cmdline:"

         dinfo "$(tr -d '\000' < "$uefi_outdir/cmdline.txt")"

         uefi_cmdline="${uefi_outdir}/cmdline.txt"

+        uefi_cmdline_offs=${offs}

+        offs=$((offs + $(stat -Lc%s "$uefi_cmdline")))

+        offs=$((offs + "$align" - offs % "$align"))

     else

         unset uefi_cmdline

     fi

-    [[ -s $dracutsysrootdir/usr/lib/os-release ]] && uefi_osrelease="$dracutsysrootdir/usr/lib/os-release"

-    [[ -s $dracutsysrootdir/etc/os-release ]] && uefi_osrelease="$dracutsysrootdir/etc/os-release"

     if [[ -s ${dracutsysrootdir}${uefi_splash_image} ]]; then

         uefi_splash_image="${dracutsysrootdir}${uefi_splash_image}"

+        uefi_splash_offs=${offs}

+        offs=$((offs + $(stat -Lc%s "$uefi_splash_image")))

+        offs=$((offs + "$align" - offs % "$align"))

     else

         unset uefi_splash_image

     fi

+    uefi_linux_offs="${offs}"

+    offs=$((offs + $(stat -Lc%s "$kernel_image")))

+    offs=$((offs + "$align" - offs % "$align"))

+    uefi_initrd_offs="${offs}"

+

     if objcopy \

-        ${uefi_osrelease:+--add-section .osrel="$uefi_osrelease" --change-section-vma .osrel=0x20000} \

-        ${uefi_cmdline:+--add-section .cmdline="$uefi_cmdline" --change-section-vma .cmdline=0x30000} \

-        ${uefi_splash_image:+--add-section .splash="$uefi_splash_image" --change-section-vma .splash=0x40000} \

-        --add-section .linux="$kernel_image" --change-section-vma .linux=0x2000000 \

-        --add-section .initrd="${DRACUT_TMPDIR}/initramfs.img" --change-section-vma .initrd="${EFI_SECTION_VMA_INITRD}" \

+        ${uefi_osrelease:+--add-section .osrel="$uefi_osrelease" --change-section-vma .osrel=$(printf 0x%x "$uefi_osrelease_offs")} \

+        ${uefi_cmdline:+--add-section .cmdline="$uefi_cmdline" --change-section-vma .cmdline=$(printf 0x%x "$uefi_cmdline_offs")} \

+        ${uefi_splash_image:+--add-section .splash="$uefi_splash_image" --change-section-vma .splash=$(printf 0x%x "$uefi_splash_offs")} \

+        --add-section .linux="$kernel_image" --change-section-vma .linux="$(printf 0x%x "$uefi_linux_offs")" \

+        --add-section .initrd="${DRACUT_TMPDIR}/initramfs.img" --change-section-vma .initrd="$(printf 0x%x "$uefi_initrd_offs")" \

         "$uefi_stub" "${uefi_outdir}/linux.efi"; then

         if [[ -n ${uefi_secureboot_key} && -n ${uefi_secureboot_cert} ]]; then

             if sbsign \

-- 

2.39.2