Using SysCare

This chapter describes how to use SysCare on openEuler.


openEuler 22.03 LTS SP1 has been installed.

Using SysCare CLI Tools

You can use syscare build to create patches and use syscare patch to manage patches, including installing, activating, deactivating, and uninstalling patches.

Creating Patches

syscare-build is used to create patches, for example:

syscare-build --name redis_cve_2021_32675 \
        --source redis-6.2.5-1.src.rpm \
        --debuginfo redis-debuginfo-6.2.5-1.x86_64.rpm \
        --target-elfname redis-server \
        --summary CVE-2021-32675 \

Managing Patches

The format of a patch name is TARGET_PACKAGE_NAME/PATCH_NAME. If PATCH_NAME is unique, TARGET_PACKAGE_NAME/ can be omitted.

  1. Installing a patch:

    syscare apply PATCH_NAME
  2. Activating a patch:

    syscare active PATCH_NAME
  3. Deactivating a patch:

    syscare deactive PATCH_NAME
  4. Uninstalling/removing a patch:

    syscare remove PATCH_NAME
  5. Querying the status of a patch:

    syscare status PATCH_NAME
  6. Querying all SysCare patches:

    syscare list

Patch Making Module

Installing from Source

The syscare/build directory stores the source code of the SysCare patch making module.

cd syscare/build

cargo build

SysCare Patch Making Tool

syscare-build is a CLI tool that creates kernel- and user-mode live patches from RPM packages. Patches are encapsulated into RPM packages.

Command Parameters

usage: syscare-build [OPTIONS] --patch-name <PATCH_NAME> --source <SOURCE> --debuginfo <DEBUGINFO> <PATCHES>...

  <PATCHES>...  Patch file(s)

  -n, --patch-name <PATCH_NAME>                Patch name
      --patch-arch <PATCH_ARCH>                Patch architecture [default: x86_64]
      --patch-version <PATCH_VERSION>          Patch version [default: 1]
      --patch-description <PATCH_DESCRIPTION>  Patch description [default: (none)]
      --target-name <TARGET_NAME>              Patch target name
  -t, --target-elfname <TARGET_ELFNAME>        Patch target executable name
      --target-arch <TARGET_ARCH>              parch target architecture
      --target-epoch <TARGET_EPOCH>            Patch target epoch
      --target-version <TARGET_VERSION>        Patch target version
      --target-release <TARGET_RELEASE>        Patch target release
      --target-license <TARGET_LICENSE>        Patch target license
  -s, --source <SOURCE>                        Source package
  -d, --debuginfo <DEBUGINFO>                  Debuginfo package
      --workdir <WORKDIR>                      Working directory [default: .]
  -o, --output <OUTPUT>                        Generated patch output directory [default: .]
      --kjobs <N>                              Kernel make jobs [default: 32]
      --skip-compiler-check                    Skip compiler version check (not recommended)
      --skip-cleanup                           Skip post-build cleanup
  -v, --verbose                                Provide more detailed info
  -h, --help                                   Print help information
  -V, --version                                Print version information

Mandatory parameters:

--patch-namePatch name
--sourceSource package of the target software
--debuginfoDebugging information package of the target software
--target-elfnameName of the executable file of the target software, which can be omitted for kernel patches
--PATCHESPatch list

An example command is as follows:

syscare-build \
    --patch-name CVE-2021-32675 \
    --source redis-6.2.5-1.src.rpm \
    --debuginfo redis-debuginfo-6.2.5-1.x86_64.rpm \
    --target-elfname redis-server \
    --output output \

Patch Output

  • A patch package that contains the binary file of SysCare and meta information. This package is used to install the live patch.
  • A patch source package that contains the target software source code and the new patch. This package is used to create live patches for new versions.

Naming rules:


Patch Information

The patch meta information contains the following fields:

namePatch name
typePatch type
archPatch architecture
targetTarget software name
elf_nameName of the executable file of the target software
licenseTarget software license
versionPatch version
releasePatch release
descriptionPatch description
builderVersion of the patch making tool


Collecting patch info
name:        CVE-2021-32675
type:        UserPatch
target:      redis-6.2.5-1
elf_name:    redis-server
license:     BSD and MIT
version:     1
release:     31fc7544
description: None

patch list:
0001-Prevent-unauthenticated-client-from-easily-consuming.patch 31fc7544

Patch Making Process

  1. Prepare the source package (source RPM) and debugging information package (debuginfo RPM) of the target software.


    yumdownloader kernel --source
    yumdownloader kernel --debuginfo
  2. Ensure that the related software build dependencies are installed.


    dnf install make gcc bison flex openssl-devel dwarves python3-devel elfutils-libelf-devel
  3. Run the syscare-build command.


    syscare-build \
            --patch-name kernel_version \
            --source kernel-5.10.0- \
            --debuginfo kernel-debuginfo-5.10.0- \
            --output output \

    During patch making, a temporary folder whose name starts with syscare-build is created in the directory specified by --workdir (the current directory by default) to store temporary files and build logs.


    dev@openeuler-dev:[~]$ ls -l syscare-build.111602/
    total 100
    -rw-r--r--. 1 dev dev 92303 Nov 12 00:00 build.log
    drwxr-xr-x. 6 dev dev 4096 Nov 12 00:00 package
    drwxr-xr-x. 4 dev dev 4096 Nov 12 00:00 patch

    Build logs (build.log) are generated in the temporary folder.

    dev@openeuler-dev:[~]$ cat syscare-build.111602/build.log | less

    If the patch is created successfully, the temporary folder will be deleted after patch making.

  4. Check the build result.


    dev@openeuler-dev:[~]$ ls -l
    total 189680
    -rw-r--r--. 1 dev dev 194218767 Nov 12 00:00 kernel-5.10.0-
    -rw-r--r--. 1 dev dev     10937 Nov 12 00:00 patch-kernel-5.10.0-

    In the output:

    patch-kernel-5.10.0- is the patch package.

    kernel-5.10.0- is the patch source package.

  5. Install the patch.

    rpm -ivh patch-xxx.rpm

    After the patch is installed, files in the patch are stored in the /usr/lib/syscare/patches/target_software_package_name/patch_name directory

  6. Uninstall the patch.

    rpm -e patch-xxx.rpm

    The patch package can be uninstalled only when the patch is in the not-apply state.

Error Handling

If an error occurs, see the build logs:

Error output example:

Building patch, this may take a while
ERROR: Process '/usr/libexec/syscare/upatch-build' exited unsuccessfully, exit_code=255

Bug Catching

Buggy Content

Bug Description

Submit As Issue

It's a little complicated....

I'd like to ask someone.


Just a small problem.

I can fix it online!

Bug Type
Specifications and Common Mistakes

● Misspellings or punctuation mistakes;

● Incorrect links, empty cells, or wrong formats;

● Chinese characters in English context;

● Minor inconsistencies between the UI and descriptions;

● Low writing fluency that does not affect understanding;

● Incorrect version numbers, including software package names and version numbers on the UI.


● Incorrect or missing key steps;

● Missing prerequisites or precautions;

● Ambiguous figures, tables, or texts;

● Unclear logic, such as missing classifications, items, and steps.


● Technical principles, function descriptions, or specifications inconsistent with those of the software;

● Incorrect schematic or architecture diagrams;

● Incorrect commands or command parameters;

● Incorrect code;

● Commands inconsistent with the functions;

● Wrong screenshots.

Risk Warnings

● Lack of risk warnings for operations that may damage the system or important data.

Content Compliance

● Contents that may violate applicable laws and regulations or geo-cultural context-sensitive words and expressions;

● Copyright infringement.

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