How to run IronPdf on Linux ARM?

IronPdf’s PDF rendering engine relies on Chromium Embedded Framework (CEF), which currently presents a limitation on Linux ARM/ARM64 platforms related to Thread Local Storage (TLS).

Issue Description

When attempting to run IronPdf on Linux ARM, the following error is encountered:

cannot allocate memory in static TLS block

This error occurs when the Linux dynamic linker cannot allocate enough TLS memory to load libcef.so. It is a known issue in CEF, particularly with newer versions that require more TLS slots than the system provides by default.

See official reference: CEF Forum – Static TLS block error on ARM

Current Status & Workaround

IronPdf can work on Linux ARM64, but with a manual workaround:

Required Step

You must set the LD_PRELOAD environment variable to preload libcef.so before your application starts.

Example (non-Docker):

export LD_PRELOAD=/path/to/libcef.so

Using Docker?

In a Docker environment, you can configure this directly in the Dockerfile:

ENV LD_PRELOAD=/app/runtimes/linux-arm64/native/libcef.so

Here is a sample Dockerfile that worked in testing:

# Base image for runtime (ARM64)
FROM mcr.microsoft.com/dotnet/runtime:8.0 AS base
USER root
WORKDIR /app
RUN apt update \
    && apt install -y sudo libxkbcommon-x11-0 libc6 libc6-dev libgtk2.0-0 libnss3 libatk-bridge2.0-0 libx11-xcb1 libxcb-dri3-0 libdrm-common libgbm1 libasound2 libxrender1 libfontconfig1 libxshmfence1 libgdiplus libva-dev
# Base image for build (ARM64)
FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
WORKDIR /src
COPY . .
RUN dotnet publish -c Release -o /app/publish
# Final image with IronPdf and system dependencies
FROM base AS final
WORKDIR /app
ENV LD_PRELOAD=/app/runtimes/linux-arm64/native/libcef.so
COPY --from=build /app/publish .
ENTRYPOINT ["dotnet", "IronPdfLinuxArm.dll"]