2022-10-26 14:50:39

by Xianting Tian

[permalink] [raw]
Subject: [PATCH V5 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support

Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC,
VMEMMAP ranges and KERNEL_LINK_ADDR), va bits and ram base for vmcore.

Default pagetable levels and PAGE_OFFSET aren't same for different kernel
version as below. For pagetable levels, 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 and,
for example, is 0x200000 on the 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 <[email protected]>
---
arch/riscv/kernel/Makefile | 1 +
arch/riscv/kernel/crash_core.c | 21 +++++++++++++++++++++
2 files changed, 22 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..b351a3c01355
--- /dev/null
+++ b/arch/riscv/kernel/crash_core.c
@@ -0,0 +1,21 @@
+// 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
+ vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR);
+}
--
2.17.1



2022-11-17 04:31:58

by Deepak Gupta

[permalink] [raw]
Subject: Re: [PATCH V5 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support

On Wed, Oct 26, 2022 at 10:42:07PM +0800, Xianting Tian wrote:
>Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC,
>VMEMMAP ranges and KERNEL_LINK_ADDR), va bits and ram base for vmcore.
>
>Default pagetable levels and PAGE_OFFSET aren't same for different kernel
>version as below. For pagetable levels, 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 and,
>for example, is 0x200000 on the 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 <[email protected]>
>---
> arch/riscv/kernel/Makefile | 1 +
> arch/riscv/kernel/crash_core.c | 21 +++++++++++++++++++++
> 2 files changed, 22 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..b351a3c01355
>--- /dev/null
>+++ b/arch/riscv/kernel/crash_core.c
>@@ -0,0 +1,21 @@
>+// 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
>+ vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR);
>+}
>--
>2.17.1
>

I had been looking around to play around with crash-utility.
Applied v5 patches, triggered a crash and have been able to use crash tool with commands
like vtop/bt.

Tested-by: Deepak Gupta <[email protected]>

Thanks
debug


2022-11-17 15:52:43

by Guo Ren

[permalink] [raw]
Subject: Re: [PATCH V5 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support

Tested-by: Guo Ren <[email protected]>

On Wed, Oct 26, 2022 at 10:42 PM Xianting Tian
<[email protected]> wrote:
>
> Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC,
> VMEMMAP ranges and KERNEL_LINK_ADDR), va bits and ram base for vmcore.
>
> Default pagetable levels and PAGE_OFFSET aren't same for different kernel
> version as below. For pagetable levels, 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 and,
> for example, is 0x200000 on the 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 <[email protected]>
> ---
> arch/riscv/kernel/Makefile | 1 +
> arch/riscv/kernel/crash_core.c | 21 +++++++++++++++++++++
> 2 files changed, 22 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..b351a3c01355
> --- /dev/null
> +++ b/arch/riscv/kernel/crash_core.c
> @@ -0,0 +1,21 @@
> +// 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
> + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR);
> +}
> --
> 2.17.1
>


--
Best Regards
Guo Ren