Commit Graph

5 Commits

Author SHA1 Message Date
Kairui Song
c76820bddd early-kdump: Use consistent symbol link for kernel and initramfs
There is no need to follow user's configuration when installtion the
kernel and initramfs for early kdump, just use a fixed a symbol link is
enough, this help avoid a check_boot_dir call.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2020-08-27 11:23:45 +08:00
Lianbo Jiang
073646998f Revert "kdump-lib: switch to the kexec_file_load() syscall on x86_64 by default"
This reverts commit 6a20bd5447.

Let's restore the logic of secureboot status check, and remove the
option 'KDUMP_FILE_LOAD=on|off'. We will use the option KEXEC_ARGS="-s"
to enable the kexec file load later, which can avoid failures when
the secureboot is enabled.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2020-07-01 17:07:46 +08:00
Lianbo Jiang
6a20bd5447 kdump-lib: switch to the kexec_file_load() syscall on x86_64 by default
UEFI Secure boot is a signature verification mechanism, designed to
prevent malicious code being loaded and executed at the early boot
stage. This makes sure that code executed is trusted by firmware.

Previously, with kexec_file_load() interface, kernel prevents unsigned
kernel image from being loaded if secure boot is enabled. So kdump will
detect whether secure boot is enabled firstly, then decide which interface
is chosen to execute, kexec_load() or kexec_file_load(). Otherwise unsigned
kernel loading will fail if secure boot enabled, and kexec_file_load() is
entered.

Now, the implementation of kexec_file_load() is adjusted in below commit.
With this change, if CONFIG_KEXEC_SIG_FORCE is not set, unsigned kernel
still has a chance to be allowed to load under some conditions.

commit 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG
and KEXEC_SIG_FORCE")

And in the current Fedora, the CONFIG_KEXEC_SIG_FORCE is not set, only the
CONFIG_KEXEC_SIG and CONFIG_BZIMAGE_VERIFY_SIG are set on x86_64 by default.
It's time to spread kexec_file_load() onto all systems of x86_64, including
Secure-boot platforms and legacy platforms. Please refer to the following
form.

.----------------------------------------------------------------------.
| .                    |     signed kernel     |    unsigned kernel    |
|    .      types      |-----------------------|-----------------------|
|       .              |Secure boot|  Legacy   |Secure boot|  Legacy   |
|          .           |-----------|-----------|-----------|-----------|
| options     .        | prev| now | prev| now |     |     | prev| now |
|                .     |(file|(file|(only|(file| prev| now |(only|(file|
|                    . |load)|load)|load)|load)|     |     |load)|load)|
|----------------------|-----|-----|-----|-----|-----|-----|-----|-----|
|KEXEC_SIG=y           |     |     |     |     |     |     |     |     |
|SIG_FORCE is not set  |succ |succ |succ |succ |  X  |  X  |succ |succ |
|BZIMAGE_VERIFY_SIG=y  |     |     |     |     |     |     |     |     |
|----------------------|-----|-----|-----|-----|-----|-----|-----|-----|
|KEXEC_SIG=y           |     |     |     |     |     |     |     |     |
|SIG_FORCE is not set  |     |     |     |     |     |     |     |     |
|BZIMAGE_VERIFY_SIG is |fail |fail |succ |fail |  X  |  X  |succ |fail |
|not set               |     |     |     |     |     |     |     |     |
|----------------------|-----|-----|-----|-----|-----|-----|-----|-----|
|KEXEC_SIG=y           |     |     |     |     |     |     |     |     |
|SIG_FORCE=y           |succ |succ |succ |fail |  X  |  X  |succ |fail |
|BZIMAGE_VERIFY_SIG=y  |     |     |     |     |     |     |     |     |
|----------------------|-----|-----|-----|-----|-----|-----|-----|-----|
|KEXEC_SIG=y           |     |     |     |     |     |     |     |     |
|SIG_FORCE=y           |     |     |     |     |     |     |     |     |
|BZIMAGE_VERIFY_SIG is |fail |fail |succ |fail |  X  |  X  |succ |fail |
|not set               |     |     |     |     |     |     |     |     |
|----------------------|-----|-----|-----|-----|-----|-----|-----|-----|
|KEXEC_SIG is not set  |     |     |     |     |     |     |     |     |
|SIG_FORCE is not set  |     |     |     |     |     |     |     |     |
|BZIMAGE_VERIFY_SIG is |fail |fail |succ |succ |  X  |  X  |succ |succ |
|not set               |     |     |     |     |     |     |     |     |
 ----------------------------------------------------------------------
Note:
[1] The 'X' indicates that the 1st kernel(unsigned) can not boot when the
    Secure boot is enabled.

Hence, in this patch, if on x86_64, let's use the kexec_file_load() only.
See if anything wrong happened in this case, in Fedora firstly for the
time being.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Acked-by: Kairui Song <kasong@redhat.com>
2020-02-06 21:57:14 +08:00
Kairui Song
8a476dabf0 earlykdump: generate symlink with stable name to kernel image and iniramfs
There is currently a problem with earlykdump image building, when a user
is upgrading kernel, dracut will generate new initramfs for the new
kernel, and earlykdump will install currently running version of kernel
into the initramfs, and remain the version based kernel image naming
untouched. But after a reboot the new kernel is running, and it
will try to load the image corresponding to the new kernel version by
file naming.

This patch fixes the problem by creating a symlink with unified stable
naming to the installed kernel image and initramfs, and use the symlink
instand so it will always work despite the kernel version number change.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2019-01-10 18:11:49 +08:00
Lianbo Jiang
1704064885 Add early kdump support in initramfs.
Kdump service starts too late, so early crashes will have no chance
to get kdump kernel booting, this will cause crash information to be
lost. It is necessary to add a dracut module in order to load crash
kernel and initramfs as early as possible. You can provide "rd.early
kdump" in grub commandline to enable, then the early kdump will load
those files like the normal kdump, which is disabled by default.

For the normal kdump service, it can check whether the early kdump
has loaded the crash kernel and initramfs. It has no conflict with
the early kdump.

If you rebuild the new initramfs for early kdump, the new initramfs
size will become large, because it will put the vmlinuz and kdump
initramfs into the new initramfs.

In addition, early kdump doesn't support fadump.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Reviewed-by: Kazuhito Hagio <khagio@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2018-05-29 10:19:19 +08:00