Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec

2023-06-14 Thread Eric DeVolder




On 6/14/23 10:24, Alexander Gordeev wrote:

On Mon, Jun 12, 2023 at 01:27:53PM -0400, Eric DeVolder wrote:
...

+config KEXEC_FILE
+   bool "Enable kexec file based system call"
+   depends on ARCH_HAS_KEXEC_FILE
+   select KEXEC_CORE
+   help
+ This is new version of kexec system call. This system call is
+ file based and takes file descriptors as system call argument
+ for kernel and initramfs as opposed to list of segments as
+ accepted by previous system call.


Which "previous"? I guess, "by kexec system call" would sound clear.

Thanks!


OK, will make that change!
eric


Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec

2023-06-14 Thread Alexander Gordeev
On Mon, Jun 12, 2023 at 01:27:53PM -0400, Eric DeVolder wrote:
...
> +config KEXEC_FILE
> + bool "Enable kexec file based system call"
> + depends on ARCH_HAS_KEXEC_FILE
> + select KEXEC_CORE
> + help
> +   This is new version of kexec system call. This system call is
> +   file based and takes file descriptors as system call argument
> +   for kernel and initramfs as opposed to list of segments as
> +   accepted by previous system call.

Which "previous"? I guess, "by kexec system call" would sound clear.

Thanks!


Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec

2023-06-14 Thread Eric DeVolder




On 6/13/23 20:19, Leizhen (ThunderTown) wrote:



On 2023/6/13 1:27, Eric DeVolder wrote:

The config options for kexec and crash features are consolidated
into new file kernel/Kconfig.kexec. Under the "General Setup" submenu
is a new submenu "Kexec and crash handling" where all the kexec and
crash options that were once in the arch-dependent submenu "Processor
type and features" are now consolidated.

The following options are impacted:

  - KEXEC
  - KEXEC_FILE
  - KEXEC_SIG
  - KEXEC_SIG_FORCE
  - KEXEC_BZIMAGE_VERIFY_SIG
  - KEXEC_JUMP
  - CRASH_DUMP

The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP.

Architectures specify support of certain KEXEC and CRASH features with
similarly named new ARCH_HAS_ config options.

Architectures can utilize the new ARCH_SUPPORTS_ config
options to specify additional components when  is enabled.

To summarize, the ARCH_HAS_ permits the  to be
enabled, and the ARCH_SUPPORTS_ handles side effects (ie.
select statements).

Signed-off-by: Eric DeVolder 
---
  arch/Kconfig |  13 --
  init/Kconfig |   2 +
  kernel/Kconfig.kexec | 103 +++
  3 files changed, 105 insertions(+), 13 deletions(-)
  create mode 100644 kernel/Kconfig.kexec

diff --git a/arch/Kconfig b/arch/Kconfig
index 205fd23e0cad..a37730679730 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -11,19 +11,6 @@ source "arch/$(SRCARCH)/Kconfig"
  
  menu "General architecture-dependent options"
  
-config CRASH_CORE

-   bool
-
-config KEXEC_CORE
-   select CRASH_CORE
-   bool
-
-config KEXEC_ELF
-   bool
-
-config HAVE_IMA_KEXEC
-   bool
-
  config ARCH_HAS_SUBPAGE_FAULTS
bool
help
diff --git a/init/Kconfig b/init/Kconfig
index 32c24950c4ce..4424447e23a5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1917,6 +1917,8 @@ config BINDGEN_VERSION_TEXT
  config TRACEPOINTS
bool
  
+source "kernel/Kconfig.kexec"

+
  endmenu   # General setup
  
  source "arch/Kconfig"

diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
new file mode 100644
index ..660048099865
--- /dev/null
+++ b/kernel/Kconfig.kexec
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "Kexec and crash features"
+
+config CRASH_CORE
+   bool
+
+config KEXEC_CORE
+   select CRASH_CORE
+   bool
+
+config KEXEC_ELF
+   bool
+
+config HAVE_IMA_KEXEC
+   bool
+
+config KEXEC
+   bool "Enable kexec system call"
+   default ARCH_DEFAULT_KEXEC
+   depends on ARCH_HAS_KEXEC
+   select KEXEC_CORE
+   help
+ kexec is a system call that implements the ability to shutdown your
+ current kernel, and to start another kernel.  It is like a reboot
+ but it is independent of the system firmware.   And like a reboot
+ you can start any kernel with it, not just Linux.


"kernel.  It is like", "firmware.   And like"

A few more spaces, I don't know the original author's intention, perhaps can be 
removed.


I'll remove the extra spaces.


+
+ The name comes from the similarity to the exec system call.
+
+ It is an ongoing process to be certain the hardware in a machine
+ is properly shutdown, so do not be surprised if this code does not
+ initially work for you.  As of this writing the exact hardware
+ interface is strongly in flux, so no good recommendation can be
+ made.
+
+config KEXEC_FILE
+   bool "Enable kexec file based system call"
+   depends on ARCH_HAS_KEXEC_FILE
+   select KEXEC_CORE
+   help
+ This is new version of kexec system call. This system call is
+ file based and takes file descriptors as system call argument
+ for kernel and initramfs as opposed to list of segments as
+ accepted by previous system call.
+
+config KEXEC_SIG
+   bool "Verify kernel signature during kexec_file_load() syscall"
+   depends on KEXEC_FILE && MODULE_SIG_FORMAT


I see that there is no "depends on MODULE_SIG_FORMAT" on x86 and arm64.

Good catch, I'll remove MODULE_SIG_FORMAT and place it on just s390 (which is the only arch that had 
it this way).



+   help
+


This blank line can be deleted.


I will remove it.

Thank you, Zhen!
eric


+ This option makes the kexec_file_load() syscall check for a valid
+ signature of the kernel image.  The image can still be loaded without
+ a valid signature unless you also enable KEXEC_SIG_FORCE, though if
+ there's a signature that we can check, then it must be valid.
+
+ In addition to this option, you need to enable signature
+ verification for the corresponding kernel image type being
+ loaded in order for this to work.
+
+config KEXEC_SIG_FORCE
+   bool "Require a valid signature in kexec_file_load() syscall"
+   depends on KEXEC_SIG
+   help
+ This option makes kernel signature verification mandatory for
+ the 

Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec

2023-06-13 Thread Leizhen (ThunderTown)



On 2023/6/13 1:27, Eric DeVolder wrote:
> The config options for kexec and crash features are consolidated
> into new file kernel/Kconfig.kexec. Under the "General Setup" submenu
> is a new submenu "Kexec and crash handling" where all the kexec and
> crash options that were once in the arch-dependent submenu "Processor
> type and features" are now consolidated.
> 
> The following options are impacted:
> 
>  - KEXEC
>  - KEXEC_FILE
>  - KEXEC_SIG
>  - KEXEC_SIG_FORCE
>  - KEXEC_BZIMAGE_VERIFY_SIG
>  - KEXEC_JUMP
>  - CRASH_DUMP
> 
> The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP.
> 
> Architectures specify support of certain KEXEC and CRASH features with
> similarly named new ARCH_HAS_ config options.
> 
> Architectures can utilize the new ARCH_SUPPORTS_ config
> options to specify additional components when  is enabled.
> 
> To summarize, the ARCH_HAS_ permits the  to be
> enabled, and the ARCH_SUPPORTS_ handles side effects (ie.
> select statements).
> 
> Signed-off-by: Eric DeVolder 
> ---
>  arch/Kconfig |  13 --
>  init/Kconfig |   2 +
>  kernel/Kconfig.kexec | 103 +++
>  3 files changed, 105 insertions(+), 13 deletions(-)
>  create mode 100644 kernel/Kconfig.kexec
> 
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 205fd23e0cad..a37730679730 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -11,19 +11,6 @@ source "arch/$(SRCARCH)/Kconfig"
>  
>  menu "General architecture-dependent options"
>  
> -config CRASH_CORE
> - bool
> -
> -config KEXEC_CORE
> - select CRASH_CORE
> - bool
> -
> -config KEXEC_ELF
> - bool
> -
> -config HAVE_IMA_KEXEC
> - bool
> -
>  config ARCH_HAS_SUBPAGE_FAULTS
>   bool
>   help
> diff --git a/init/Kconfig b/init/Kconfig
> index 32c24950c4ce..4424447e23a5 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1917,6 +1917,8 @@ config BINDGEN_VERSION_TEXT
>  config TRACEPOINTS
>   bool
>  
> +source "kernel/Kconfig.kexec"
> +
>  endmenu  # General setup
>  
>  source "arch/Kconfig"
> diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
> new file mode 100644
> index ..660048099865
> --- /dev/null
> +++ b/kernel/Kconfig.kexec
> @@ -0,0 +1,103 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +menu "Kexec and crash features"
> +
> +config CRASH_CORE
> + bool
> +
> +config KEXEC_CORE
> + select CRASH_CORE
> + bool
> +
> +config KEXEC_ELF
> + bool
> +
> +config HAVE_IMA_KEXEC
> + bool
> +
> +config KEXEC
> + bool "Enable kexec system call"
> + default ARCH_DEFAULT_KEXEC
> + depends on ARCH_HAS_KEXEC
> + select KEXEC_CORE
> + help
> +   kexec is a system call that implements the ability to shutdown your
> +   current kernel, and to start another kernel.  It is like a reboot
> +   but it is independent of the system firmware.   And like a reboot
> +   you can start any kernel with it, not just Linux.

"kernel.  It is like", "firmware.   And like"

A few more spaces, I don't know the original author's intention, perhaps can be 
removed.

> +
> +   The name comes from the similarity to the exec system call.
> +
> +   It is an ongoing process to be certain the hardware in a machine
> +   is properly shutdown, so do not be surprised if this code does not
> +   initially work for you.  As of this writing the exact hardware
> +   interface is strongly in flux, so no good recommendation can be
> +   made.
> +
> +config KEXEC_FILE
> + bool "Enable kexec file based system call"
> + depends on ARCH_HAS_KEXEC_FILE
> + select KEXEC_CORE
> + help
> +   This is new version of kexec system call. This system call is
> +   file based and takes file descriptors as system call argument
> +   for kernel and initramfs as opposed to list of segments as
> +   accepted by previous system call.
> +
> +config KEXEC_SIG
> + bool "Verify kernel signature during kexec_file_load() syscall"
> + depends on KEXEC_FILE && MODULE_SIG_FORMAT

I see that there is no "depends on MODULE_SIG_FORMAT" on x86 and arm64.

> + help
> +

This blank line can be deleted.

> +   This option makes the kexec_file_load() syscall check for a valid
> +   signature of the kernel image.  The image can still be loaded without
> +   a valid signature unless you also enable KEXEC_SIG_FORCE, though if
> +   there's a signature that we can check, then it must be valid.
> +
> +   In addition to this option, you need to enable signature
> +   verification for the corresponding kernel image type being
> +   loaded in order for this to work.
> +
> +config KEXEC_SIG_FORCE
> + bool "Require a valid signature in kexec_file_load() syscall"
> + depends on KEXEC_SIG
> + help
> +   This option makes kernel signature verification mandatory for
> +   the kexec_file_load() syscall.
> +
> +config KEXEC_BZIMAGE_VERIFY_SIG
> + bool "Enable 

[PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec

2023-06-12 Thread Eric DeVolder
The config options for kexec and crash features are consolidated
into new file kernel/Kconfig.kexec. Under the "General Setup" submenu
is a new submenu "Kexec and crash handling" where all the kexec and
crash options that were once in the arch-dependent submenu "Processor
type and features" are now consolidated.

The following options are impacted:

 - KEXEC
 - KEXEC_FILE
 - KEXEC_SIG
 - KEXEC_SIG_FORCE
 - KEXEC_BZIMAGE_VERIFY_SIG
 - KEXEC_JUMP
 - CRASH_DUMP

The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP.

Architectures specify support of certain KEXEC and CRASH features with
similarly named new ARCH_HAS_ config options.

Architectures can utilize the new ARCH_SUPPORTS_ config
options to specify additional components when  is enabled.

To summarize, the ARCH_HAS_ permits the  to be
enabled, and the ARCH_SUPPORTS_ handles side effects (ie.
select statements).

Signed-off-by: Eric DeVolder 
---
 arch/Kconfig |  13 --
 init/Kconfig |   2 +
 kernel/Kconfig.kexec | 103 +++
 3 files changed, 105 insertions(+), 13 deletions(-)
 create mode 100644 kernel/Kconfig.kexec

diff --git a/arch/Kconfig b/arch/Kconfig
index 205fd23e0cad..a37730679730 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -11,19 +11,6 @@ source "arch/$(SRCARCH)/Kconfig"
 
 menu "General architecture-dependent options"
 
-config CRASH_CORE
-   bool
-
-config KEXEC_CORE
-   select CRASH_CORE
-   bool
-
-config KEXEC_ELF
-   bool
-
-config HAVE_IMA_KEXEC
-   bool
-
 config ARCH_HAS_SUBPAGE_FAULTS
bool
help
diff --git a/init/Kconfig b/init/Kconfig
index 32c24950c4ce..4424447e23a5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1917,6 +1917,8 @@ config BINDGEN_VERSION_TEXT
 config TRACEPOINTS
bool
 
+source "kernel/Kconfig.kexec"
+
 endmenu# General setup
 
 source "arch/Kconfig"
diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
new file mode 100644
index ..660048099865
--- /dev/null
+++ b/kernel/Kconfig.kexec
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "Kexec and crash features"
+
+config CRASH_CORE
+   bool
+
+config KEXEC_CORE
+   select CRASH_CORE
+   bool
+
+config KEXEC_ELF
+   bool
+
+config HAVE_IMA_KEXEC
+   bool
+
+config KEXEC
+   bool "Enable kexec system call"
+   default ARCH_DEFAULT_KEXEC
+   depends on ARCH_HAS_KEXEC
+   select KEXEC_CORE
+   help
+ kexec is a system call that implements the ability to shutdown your
+ current kernel, and to start another kernel.  It is like a reboot
+ but it is independent of the system firmware.   And like a reboot
+ you can start any kernel with it, not just Linux.
+
+ The name comes from the similarity to the exec system call.
+
+ It is an ongoing process to be certain the hardware in a machine
+ is properly shutdown, so do not be surprised if this code does not
+ initially work for you.  As of this writing the exact hardware
+ interface is strongly in flux, so no good recommendation can be
+ made.
+
+config KEXEC_FILE
+   bool "Enable kexec file based system call"
+   depends on ARCH_HAS_KEXEC_FILE
+   select KEXEC_CORE
+   help
+ This is new version of kexec system call. This system call is
+ file based and takes file descriptors as system call argument
+ for kernel and initramfs as opposed to list of segments as
+ accepted by previous system call.
+
+config KEXEC_SIG
+   bool "Verify kernel signature during kexec_file_load() syscall"
+   depends on KEXEC_FILE && MODULE_SIG_FORMAT
+   help
+
+ This option makes the kexec_file_load() syscall check for a valid
+ signature of the kernel image.  The image can still be loaded without
+ a valid signature unless you also enable KEXEC_SIG_FORCE, though if
+ there's a signature that we can check, then it must be valid.
+
+ In addition to this option, you need to enable signature
+ verification for the corresponding kernel image type being
+ loaded in order for this to work.
+
+config KEXEC_SIG_FORCE
+   bool "Require a valid signature in kexec_file_load() syscall"
+   depends on KEXEC_SIG
+   help
+ This option makes kernel signature verification mandatory for
+ the kexec_file_load() syscall.
+
+config KEXEC_BZIMAGE_VERIFY_SIG
+   bool "Enable bzImage signature verification support"
+   depends on KEXEC_SIG
+   depends on SIGNED_PE_FILE_VERIFICATION
+   select SYSTEM_TRUSTED_KEYRING
+   help
+ Enable bzImage signature verification support.
+
+config KEXEC_JUMP
+   bool "kexec jump"
+   depends on KEXEC && HIBERNATION
+   depends on ARCH_HAS_KEXEC_JUMP
+   help
+ Jump between original kernel and kexeced kernel and invoke
+ code in physical address mode via KEXEC
+