Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC, VMEMMAP and KERNEL_LINK_ADDR ranges), va bits and ram base for vmcore. Default pagetable levels and PAGE_OFFSET aren't same for different kernel version as below. For default pagetable levels, it sets sv57 on defaultly in latest kernel and do fallback to try to set sv48 on boot time if sv57 is not supported in current hardware.

For ram base, the default value is 0x80200000 for qemu riscv64 env, 0x200000 for riscv64 SoC platform(eg, SoC platform of RISC-V XuanTie 910 CPU).

* Linux Kernel 5.18 ~ * PGTABLE_LEVELS = 5 * PAGE_OFFSET = 0xff60000000000000 * Linux Kernel 5.17 ~ * PGTABLE_LEVELS = 4 * PAGE_OFFSET = 0xffffaf8000000000 * Linux Kernel 4.19 ~ * PGTABLE_LEVELS = 3 * PAGE_OFFSET = 0xffffffe000000000 Since these configurations change from time to time and version to version, it is preferable to export them via vmcoreinfo than to change the crash's code frequently, it can simplify the development of crash tool. Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com&gt; --- arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) create mode 100644 arch/riscv/kernel/crash_core.c diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index db6e4b1294ba..4cf303a779ab 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_KEXEC_CORE) += kexec_relocate.o crash_save_regs.o machine_kexec.o obj-$(CONFIG_KEXEC_FILE) += elf_kexec.o machine_kexec_file.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o +obj-$(CONFIG_CRASH_CORE) += crash_core.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c new file mode 100644 index 000000000000..8d7f5ff108da --- /dev/null +++ b/arch/riscv/kernel/crash_core.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/crash_core.h> +#include <linux/pagemap.h> + +void arch_crash_save_vmcoreinfo(void) +{ + VMCOREINFO_NUMBER(VA_BITS); + VMCOREINFO_NUMBER(phys_ram_base); + + vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=0x%lx\n", PAGE_OFFSET); + vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START); + vmcoreinfo_append_str("NUMBER(VMALLOC_END)=0x%lx\n", VMALLOC_END); + vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START); + vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END); +#ifdef CONFIG_64BIT + vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR); + vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END); +#endif + + if (IS_ENABLED(CONFIG_64BIT)) {

+#ifdef CONFIG_KASAN + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_START)=0x%lx\n", KASAN_SHADOW_START); + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_END)=0x%lx\n", KASAN_SHADOW_END); +#endif + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); + vmcoreinfo_append_str("NUMBER(ADDRESS_SPACE_END)=0x%lx\n", ADDRESS_SPACE_END); + } +} -- 2.17.1

On Fri, Oct 14, 2022 at 09:41:38PM +0800, Xianting Tian wrote: > Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC, > VMEMMAP and KERNEL_LINK_ADDR ranges), va bits and ram base for vmcore. > > Default pagetable levels and PAGE_OFFSET aren't same for different kernel > version as below. For default pagetable levels, it sets sv57 on defaultly > in latest kernel and do fallback to try to set sv48 on boot time if sv57 > is not supported in current hardware. nit: This would read better as "it sets sv57 by default and falls back to setting sv48 at boot time if sv57 is not supported by the hardware".

> For ram base, the default value is 0x80200000 for qemu riscv64 env, 0x200000 > for riscv64 SoC platform(eg, SoC platform of RISC-V XuanTie 910 CPU). The second part of this sentence I'm not really sure that that is true, I think you should reword it to something like "...for qemu riscv64 and, for example, is 0x200000 on the XuanTie 910 CPU." and avoid applying that number blanketly for other SoCs.

> * Linux Kernel 5.18 ~ > * PGTABLE_LEVELS = 5 > * PAGE_OFFSET = 0xff60000000000000 > * Linux Kernel 5.17 ~ > * PGTABLE_LEVELS = 4 > * PAGE_OFFSET = 0xffffaf8000000000 > * Linux Kernel 4.19 ~ > * PGTABLE_LEVELS = 3 > * PAGE_OFFSET = 0xffffffe000000000 > > Since these configurations change from time to time and version to version, > it is preferable to export them via vmcoreinfo than to change the crash's > code frequently, it can simplify the development of crash tool. > > Signed-off-by: Xianting Tian&lt;xianting.tian(a)linux.alibaba.com&gt; > --- > arch/riscv/kernel/Makefile | 1 + > arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+) > create mode 100644 arch/riscv/kernel/crash_core.c > > diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile > index db6e4b1294ba..4cf303a779ab 100644 > --- a/arch/riscv/kernel/Makefile > +++ b/arch/riscv/kernel/Makefile > @@ -81,6 +81,7 @@ obj-$(CONFIG_KGDB) += kgdb.o > obj-$(CONFIG_KEXEC_CORE) += kexec_relocate.o crash_save_regs.o machine_kexec.o > obj-$(CONFIG_KEXEC_FILE) += elf_kexec.o machine_kexec_file.o > obj-$(CONFIG_CRASH_DUMP) += crash_dump.o > +obj-$(CONFIG_CRASH_CORE) += crash_core.o > > obj-$(CONFIG_JUMP_LABEL) += jump_label.o > > diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c > new file mode 100644 > index 000000000000..8d7f5ff108da > --- /dev/null > +++ b/arch/riscv/kernel/crash_core.c > @@ -0,0 +1,29 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +#include <linux/crash_core.h> > +#include <linux/pagemap.h> > + > +void arch_crash_save_vmcoreinfo(void) > +{ > + VMCOREINFO_NUMBER(VA_BITS); > + VMCOREINFO_NUMBER(phys_ram_base); > + > + vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=0x%lx\n", PAGE_OFFSET); > + vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START); > + vmcoreinfo_append_str("NUMBER(VMALLOC_END)=0x%lx\n", VMALLOC_END); > + vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START); > + vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END); > +#ifdef CONFIG_64BIT > + vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR); > + vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END); > +#endif > + > + if (IS_ENABLED(CONFIG_64BIT)) { You've already got a #ifdef CONFIG_64BIT above, is there a reason why you'd use the IS_ENABLED here rather than merge this with the above section? I'm a big fan of IS_ENABLED but I'm not sure what it adds here, maybe you can show me the light :)

Thanks, Conor. > +#ifdef CONFIG_KASAN > + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_START)=0x%lx\n", KASAN_SHADOW_START); > + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_END)=0x%lx\n", KASAN_SHADOW_END); > +#endif > + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); > + vmcoreinfo_append_str("NUMBER(ADDRESS_SPACE_END)=0x%lx\n", ADDRESS_SPACE_END); > + } > +} > -- > 2.17.1 > >

On 18/10/2022 03:28, Xianting Tian wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > 在 2022/10/18 上午3:54, Conor Dooley 写道: > >> On Fri, Oct 14, 2022 at 09:41:38PM +0800, Xianting Tian wrote: >>> * Linux Kernel 5.18 ~ >>> * PGTABLE_LEVELS = 5 >>> * PAGE_OFFSET = 0xff60000000000000 >>> * Linux Kernel 5.17 ~ >>> * PGTABLE_LEVELS = 4 >>> * PAGE_OFFSET = 0xffffaf8000000000 >>> * Linux Kernel 4.19 ~ >>> * PGTABLE_LEVELS = 3 >>> * PAGE_OFFSET = 0xffffffe000000000 >>> >>> Since these configurations change from time to time and version to version, >>> it is preferable to export them via vmcoreinfo than to change the crash's >>> code frequently, it can simplify the development of crash tool. >>> >>> Signed-off-by: Xianting Tian&lt;xianting.tian(a)linux.alibaba.com&gt; >>> --- >>> arch/riscv/kernel/Makefile | 1 + >>> arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++++++++++++++ >>> 2 files changed, 30 insertions(+) >>> create mode 100644 arch/riscv/kernel/crash_core.c >>> >>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile >>> index db6e4b1294ba..4cf303a779ab 100644 >>> --- a/arch/riscv/kernel/Makefile >>> +++ b/arch/riscv/kernel/Makefile >>> @@ -81,6 +81,7 @@ obj-$(CONFIG_KGDB) += kgdb.o >>> obj-$(CONFIG_KEXEC_CORE) += kexec_relocate.o crash_save_regs.o machine_kexec.o >>> obj-$(CONFIG_KEXEC_FILE) += elf_kexec.o machine_kexec_file.o >>> obj-$(CONFIG_CRASH_DUMP) += crash_dump.o >>> +obj-$(CONFIG_CRASH_CORE) += crash_core.o >>> >>> obj-$(CONFIG_JUMP_LABEL) += jump_label.o >>> >>> diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c >>> new file mode 100644 >>> index 000000000000..8d7f5ff108da >>> --- /dev/null >>> +++ b/arch/riscv/kernel/crash_core.c >>> @@ -0,0 +1,29 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> + >>> +#include <linux/crash_core.h> >>> +#include <linux/pagemap.h> >>> + >>> +void arch_crash_save_vmcoreinfo(void) >>> +{ >>> + VMCOREINFO_NUMBER(VA_BITS); >>> + VMCOREINFO_NUMBER(phys_ram_base); >>> + >>> + vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=0x%lx\n", PAGE_OFFSET); >>> + vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START); >>> + vmcoreinfo_append_str("NUMBER(VMALLOC_END)=0x%lx\n", VMALLOC_END); >>> + vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START); >>> + vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END); >>> +#ifdef CONFIG_64BIT >>> + vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR); >>> + vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END); >>> +#endif >>> + >>> + if (IS_ENABLED(CONFIG_64BIT)) { >> You've already got a #ifdef CONFIG_64BIT above, is there a reason why >> you'd use the IS_ENABLED here rather than merge this with the above >> section? I'm a big fan of IS_ENABLED but I'm not sure what it adds here, >> maybe you can show me the light :) > The IS_ENABLED() check prevents the line from getting executed, but > unlike an #ifdef it relies on it to be parsable. Hey Xianting, Firstly, neither this nor the other version of this message made it to the mailing list - and since I usually use lei to get my mails that is a bit of a problem :(

Yeah, I know that that is what IS_ENABLED() does, it's just in this situation it does not look very intentional & more like disjoint bits of copy-paste. It's fine though, leave it as it is.

Thanks, Conor. > I wrote this arch_crash_save_vmcoreinfo() func with reference to this: static void __init print_vm_layout(void) // arch/riscv/mm/init.c > { > pr_notice("Virtual kernel memory layout:\n"); > print_ml("fixmap", (unsigned long)FIXADDR_START, > (unsigned long)FIXADDR_TOP); > print_ml("pci io", (unsigned long)PCI_IO_START, > (unsigned long)PCI_IO_END); > print_ml("vmemmap", (unsigned long)VMEMMAP_START, > (unsigned long)VMEMMAP_END); > print_ml("vmalloc", (unsigned long)VMALLOC_START, > (unsigned long)VMALLOC_END); > #ifdef CONFIG_64BIT > print_ml("modules", (unsigned long)MODULES_VADDR, > (unsigned long)MODULES_END); > #endif > print_ml("lowmem", (unsigned long)PAGE_OFFSET, > (unsigned long)high_memory); > if (IS_ENABLED(CONFIG_64BIT)) { > #ifdef CONFIG_KASAN > print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END); > #endif > > print_ml("kernel", (unsigned long)KERNEL_LINK_ADDR, > (unsigned long)ADDRESS_SPACE_END); > } > } > >> Thanks, >> Conor. >> >> >>> +#ifdef CONFIG_KASAN >>> + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_START)=0x%lx\n", KASAN_SHADOW_START); >>> + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_END)=0x%lx\n", KASAN_SHADOW_END); >>> +#endif >>> + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); >>> + vmcoreinfo_append_str("NUMBER(ADDRESS_SPACE_END)=0x%lx\n", ADDRESS_SPACE_END); >>> + } >>> +} >>> -- >>> 2.17.1 >>> >>>

The following interrelated definitions and ranges are needed by the kdump crash tool, they are exported by "arch/riscv/kernel/crash_core.c": VA_BITS, PAGE_OFFSET, phys_ram_base, MODULES_VADDR ~ MODULES_END, VMALLOC_START ~ VMALLOC_END, VMEMMAP_START ~ VMEMMAP_END, KASAN_SHADOW_START ~ KASAN_SHADOW_END, KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END Document these RISCV64 exports above. Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com&gt; --- .../admin-guide/kdump/vmcoreinfo.rst | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 6726f439958c..8e2e164cf3db 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -595,3 +595,33 @@ X2TLB ----- Indicates whether the crashed kernel enabled SH extended mode. + +RISCV64 +======= + +VA_BITS +------- + +The maximum number of bits for virtual addresses. Used to compute the +virtual memory ranges. + +PAGE_OFFSET +----------- + +Indicates the virtual kernel start address of direct-mapped RAM region.

+ +phys_ram_base +------------- + +Indicates the start physical RAM address. + +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END|KASAN_SHADOW_START|KASAN_SHADOW_END|KERNEL_LINK_ADDR|ADDRESS_SPACE_END +---------------------------------------------------------------------------------------------------------------------------------------------------- + +Used to get the correct ranges: + + * MODULES_VADDR ~ MODULES_END : Kernel module space. + * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space. + * VMEMMAP_START ~ VMEMMAP_END : vmemmap region, used for struct page array.

+ * KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space. + * KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space. -- 2.17.1

在 2022/10/18 上午3:40, Conor Dooley 写道: > On Fri, Oct 14, 2022 at 09:41:39PM +0800, Xianting Tian wrote: > > The following interrelated definitions and ranges are needed by the kdump > > crash tool, they are exported by "arch/riscv/kernel/crash_core.c": > > VA_BITS, > > PAGE_OFFSET, > > phys_ram_base, > > MODULES_VADDR ~ MODULES_END, > > VMALLOC_START ~ VMALLOC_END, > > VMEMMAP_START ~ VMEMMAP_END, > > KASAN_SHADOW_START ~ KASAN_SHADOW_END, > > KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END > > > > Document these RISCV64 exports above. > > > > Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com&gt; > > --- > > .../admin-guide/kdump/vmcoreinfo.rst | 30 +++++++++++++++++++ > > 1 file changed, 30 insertions(+) > > > > diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst > > index 6726f439958c..8e2e164cf3db 100644 > > --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst > > +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst > > @@ -595,3 +595,33 @@ X2TLB > > ----- > > Indicates whether the crashed kernel enabled SH extended mode. > > + > > +RISCV64 > > +======= > > + > > +VA_BITS > > +------- > > + > > +The maximum number of bits for virtual addresses. Used to compute the > > +virtual memory ranges. > > + > > +PAGE_OFFSET > > +----------- > > + > > +Indicates the virtual kernel start address of direct-mapped RAM region. > Apologies for not seeing this sooner, but should there not be a "the" > prior to "direct-mapped"? will fix in v3 > > > + > > +phys_ram_base > > +------------- > > + > > +Indicates the start physical RAM address. > > + > > +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END|KASAN_SHADOW_START|KASAN_SHADOW_END|KERNEL_LINK_ADDR|ADDRESS_SPACE_END > > +---------------------------------------------------------------------------------------------------------------------------------------------------- > > + > > +Used to get the correct ranges: > > + > > + * MODULES_VADDR ~ MODULES_END : Kernel module space. > > + * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space. > > + * VMEMMAP_START ~ VMEMMAP_END : vmemmap region, used for struct page array. > Since I'm in pedant mode, it does look a little odd that you're using > region for vmemmap but space for the others but idc that much. Sorry, I didn't get your point :( it contains vmemmap area with reference wth arch/arm64/kernel/crash_core.c.

> > Thanks, > Conor. > > > + * KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space. > > + * KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space. > > -- > > 2.17.1 > > > > _______________________________________________ linux-riscv mailing list linux-riscv(a)lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv

On Fri, Oct 14, 2022 at 09:41:39PM +0800, Xianting Tian wrote: > The following interrelated definitions and ranges are needed by the kdump > crash tool, they are exported by "arch/riscv/kernel/crash_core.c": Better say "..., which are exported by ..."

> diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst > index 6726f439958c..8e2e164cf3db 100644 > --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst > +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst > @@ -595,3 +595,33 @@ X2TLB > ----- > > Indicates whether the crashed kernel enabled SH extended mode. > + > +RISCV64 > +======= > + > +VA_BITS > +------- > + > +The maximum number of bits for virtual addresses. Used to compute the > +virtual memory ranges. > + > +PAGE_OFFSET > +----------- > + > +Indicates the virtual kernel start address of direct-mapped RAM region. > + > +phys_ram_base > +------------- > + > +Indicates the start physical RAM address. > + > +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END|KASAN_SHADOW_START|KASAN_SHADOW_END|KERNEL_LINK_ADDR|ADDRESS_SPACE_END > +---------------------------------------------------------------------------------------------------------------------------------------------------- > + > +Used to get the correct ranges: > + > + * MODULES_VADDR ~ MODULES_END : Kernel module space. > + * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space. > + * VMEMMAP_START ~ VMEMMAP_END : vmemmap region, used for struct page array. > + * KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space. > + * KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space. The documentation LGTM, thanks. When the patch subject is fixed, Reviewed-by: Bagas Sanjaya <bagasdotme(a)gmail.com&gt;

在 2022/10/18 上午11:19, Bagas Sanjaya 写道: > On Fri, Oct 14, 2022 at 09:41:39PM +0800, Xianting Tian wrote: >> The following interrelated definitions and ranges are needed by the kdump >> crash tool, they are exported by "arch/riscv/kernel/crash_core.c": > Better say "..., which are exported by ..." > >> diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst >> index 6726f439958c..8e2e164cf3db 100644 >> --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst >> +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst >> @@ -595,3 +595,33 @@ X2TLB >>   ----- >>     Indicates whether the crashed kernel enabled SH extended mode. >> + >> +RISCV64 >> +======= >> + >> +VA_BITS >> +------- >> + >> +The maximum number of bits for virtual addresses. Used to compute the >> +virtual memory ranges. >> + >> +PAGE_OFFSET >> +----------- >> + >> +Indicates the virtual kernel start address of direct-mapped RAM region. >> + >> +phys_ram_base >> +------------- >> + >> +Indicates the start physical RAM address. >> + >> +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END|KASAN_SHADOW_START|KASAN_SHADOW_END|KERNEL_LINK_ADDR|ADDRESS_SPACE_END >> +---------------------------------------------------------------------------------------------------------------------------------------------------- >> + >> +Used to get the correct ranges: >> + >> +  * MODULES_VADDR ~ MODULES_END : Kernel module space. >> +  * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space. >> +  * VMEMMAP_START ~ VMEMMAP_END : vmemmap region, used for struct page array. >> +  * KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space. >> +  * KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space. > The documentation LGTM, thanks. > > When the patch subject is fixed, Could you tell me what patch subject should be changed to ? thanks