Re: [PATCH v3 5/9] crash_core: move crashk_*res definition into crash_core.c

From: Leizhen (ThunderTown)
Date: Mon Sep 18 2023 - 09:00:38 EST




On 2023/9/14 11:31, Baoquan He wrote:
> Both crashk_res and crashk_low_res are used to mark the reserved
> crashkernel regions in iomem_resource tree. And later the generic
> crashkernel resrvation will be added into crash_core.c. So move
> crashk_res and crashk_low_res definition into crash_core.c to avoid
> compiling error if CONFIG_CRASH_CORE=on while CONFIG_KEXEC_CORE is
> unset.
>
> Meanwhile include <asm/crash_core.h> in <linux/crash_core.h> if generic
> reservation is needed. In that case, <asm/crash_core.h> need be added
> by ARCH. In asm/crash_core.h, ARCH can provide its own macro definitions
> to override macros in <linux/crash_core.h> if needed. Wrap the including
> into CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION ifdeffery scope to
> avoid compiling error in other ARCH-es which don't take the generic
> reservation way yet.

Reviewed-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

>
> Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> ---
> include/linux/crash_core.h | 8 ++++++++
> include/linux/kexec.h | 4 ----
> kernel/crash_core.c | 16 ++++++++++++++++
> kernel/kexec_core.c | 17 -----------------
> 4 files changed, 24 insertions(+), 21 deletions(-)
>
> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
> index 4dbd6565e0ff..3c735a7e33fb 100644
> --- a/include/linux/crash_core.h
> +++ b/include/linux/crash_core.h
> @@ -5,6 +5,14 @@
> #include <linux/linkage.h>
> #include <linux/elfcore.h>
> #include <linux/elf.h>
> +#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
> +#include <asm/crash_core.h>
> +#endif
> +
> +/* Location of a reserved region to hold the crash kernel.
> + */
> +extern struct resource crashk_res;
> +extern struct resource crashk_low_res;
>
> #define CRASH_CORE_NOTE_NAME "CORE"
> #define CRASH_CORE_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 32c78078552c..8227455192b7 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -22,10 +22,6 @@
> #include <uapi/linux/kexec.h>
> #include <linux/verification.h>
>
> -/* Location of a reserved region to hold the crash kernel.
> - */
> -extern struct resource crashk_res;
> -extern struct resource crashk_low_res;
> extern note_buf_t __percpu *crash_notes;
>
> #ifdef CONFIG_KEXEC_CORE
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index ca66b5f41dc7..ad7dc03f3993 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -35,6 +35,22 @@ u32 *vmcoreinfo_note;
> /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
> static unsigned char *vmcoreinfo_data_safecopy;
>
> +/* Location of the reserved area for the crash kernel */
> +struct resource crashk_res = {
> + .name = "Crash kernel",
> + .start = 0,
> + .end = 0,
> + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> + .desc = IORES_DESC_CRASH_KERNEL
> +};
> +struct resource crashk_low_res = {
> + .name = "Crash kernel",
> + .start = 0,
> + .end = 0,
> + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> + .desc = IORES_DESC_CRASH_KERNEL
> +};
> +
> /*
> * parsing the "crashkernel" commandline
> *
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index 9dc728982d79..be5642a4ec49 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -52,23 +52,6 @@ atomic_t __kexec_lock = ATOMIC_INIT(0);
> /* Flag to indicate we are going to kexec a new kernel */
> bool kexec_in_progress = false;
>
> -
> -/* Location of the reserved area for the crash kernel */
> -struct resource crashk_res = {
> - .name = "Crash kernel",
> - .start = 0,
> - .end = 0,
> - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> - .desc = IORES_DESC_CRASH_KERNEL
> -};
> -struct resource crashk_low_res = {
> - .name = "Crash kernel",
> - .start = 0,
> - .end = 0,
> - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> - .desc = IORES_DESC_CRASH_KERNEL
> -};
> -
> int kexec_should_crash(struct task_struct *p)
> {
> /*
>

--
Regards,
Zhen Lei