2021-02-04 03:13:08

by Jinyang He

[permalink] [raw]
Subject: [PATCH] MIPS: Use common way to parse elfcorehdr

"elfcorehdr" can be parsed at kernel/crash_dump.c

Signed-off-by: Jinyang He <[email protected]>
---
arch/mips/kernel/setup.c | 49 +++++++++++++++++++++---------------------------
1 file changed, 21 insertions(+), 28 deletions(-)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 7e1f8e2..4d2f915 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -29,6 +29,7 @@
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
#include <linux/dmi.h>
+#include <linux/crash_dump.h>

#include <asm/addrspace.h>
#include <asm/bootinfo.h>
@@ -404,34 +405,32 @@ static int __init early_parse_memmap(char *p)
}
early_param("memmap", early_parse_memmap);

-#ifdef CONFIG_PROC_VMCORE
-static unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
-static int __init early_parse_elfcorehdr(char *p)
+static void __init mips_reserve_vmcore(void)
{
+#ifdef CONFIG_PROC_VMCORE
phys_addr_t start, end;
u64 i;

- setup_elfcorehdr = memparse(p, &p);
-
- for_each_mem_range(i, &start, &end) {
- if (setup_elfcorehdr >= start && setup_elfcorehdr < end) {
- /*
- * Reserve from the elf core header to the end of
- * the memory segment, that should all be kdump
- * reserved memory.
- */
- setup_elfcorehdr_size = end - setup_elfcorehdr;
- break;
+ if (!elfcorehdr_size) {
+ for_each_mem_range(i, &start, &end) {
+ if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
+ /*
+ * Reserve from the elf core header to the end of
+ * the memory segment, that should all be kdump
+ * reserved memory.
+ */
+ elfcorehdr_size = end - elfcorehdr_addr;
+ break;
+ }
}
}
- /*
- * If we don't find it in the memory map, then we shouldn't
- * have to worry about it, as the new kernel won't use it.
- */
- return 0;
-}
-early_param("elfcorehdr", early_parse_elfcorehdr);
+
+ pr_info("Reserving %ldKB of memory at %ldKB for kdump\n",
+ (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10);
+
+ memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
#endif
+}

#ifdef CONFIG_KEXEC

@@ -653,13 +652,7 @@ static void __init arch_mem_init(char **cmdline_p)
*/
memblock_set_current_limit(PFN_PHYS(max_low_pfn));

-#ifdef CONFIG_PROC_VMCORE
- if (setup_elfcorehdr && setup_elfcorehdr_size) {
- printk(KERN_INFO "kdump reserved memory at %lx-%lx\n",
- setup_elfcorehdr, setup_elfcorehdr_size);
- memblock_reserve(setup_elfcorehdr, setup_elfcorehdr_size);
- }
-#endif
+ mips_reserve_vmcore();

mips_parse_crashkernel();
#ifdef CONFIG_KEXEC
--
2.1.0


2021-02-04 04:00:07

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Use common way to parse elfcorehdr

On 2/3/21 7:07 PM, Jinyang He wrote:
> "elfcorehdr" can be parsed at kernel/crash_dump.c
>
> Signed-off-by: Jinyang He <[email protected]>

Hm, looks like that would require CONFIG_CRASH_DUMP?


> ---
> arch/mips/kernel/setup.c | 49 +++++++++++++++++++++---------------------------
> 1 file changed, 21 insertions(+), 28 deletions(-)
>
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 7e1f8e2..4d2f915 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -29,6 +29,7 @@
> #include <linux/of_fdt.h>
> #include <linux/of_reserved_mem.h>
> #include <linux/dmi.h>
> +#include <linux/crash_dump.h>
>
> #include <asm/addrspace.h>
> #include <asm/bootinfo.h>
> @@ -404,34 +405,32 @@ static int __init early_parse_memmap(char *p)
> }
> early_param("memmap", early_parse_memmap);
>
> -#ifdef CONFIG_PROC_VMCORE
> -static unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
> -static int __init early_parse_elfcorehdr(char *p)
> +static void __init mips_reserve_vmcore(void)
> {
> +#ifdef CONFIG_PROC_VMCORE
> phys_addr_t start, end;
> u64 i;
>
> - setup_elfcorehdr = memparse(p, &p);
> -
> - for_each_mem_range(i, &start, &end) {
> - if (setup_elfcorehdr >= start && setup_elfcorehdr < end) {
> - /*
> - * Reserve from the elf core header to the end of
> - * the memory segment, that should all be kdump
> - * reserved memory.
> - */
> - setup_elfcorehdr_size = end - setup_elfcorehdr;
> - break;
> + if (!elfcorehdr_size) {
> + for_each_mem_range(i, &start, &end) {
> + if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
> + /*
> + * Reserve from the elf core header to the end of
> + * the memory segment, that should all be kdump
> + * reserved memory.
> + */
> + elfcorehdr_size = end - elfcorehdr_addr;
> + break;
> + }
> }
> }
> - /*
> - * If we don't find it in the memory map, then we shouldn't
> - * have to worry about it, as the new kernel won't use it.
> - */
> - return 0;
> -}
> -early_param("elfcorehdr", early_parse_elfcorehdr);
> +
> + pr_info("Reserving %ldKB of memory at %ldKB for kdump\n",
> + (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10);
> +
> + memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
> #endif
> +}
>
> #ifdef CONFIG_KEXEC
>
> @@ -653,13 +652,7 @@ static void __init arch_mem_init(char **cmdline_p)
> */
> memblock_set_current_limit(PFN_PHYS(max_low_pfn));
>
> -#ifdef CONFIG_PROC_VMCORE
> - if (setup_elfcorehdr && setup_elfcorehdr_size) {
> - printk(KERN_INFO "kdump reserved memory at %lx-%lx\n",
> - setup_elfcorehdr, setup_elfcorehdr_size);
> - memblock_reserve(setup_elfcorehdr, setup_elfcorehdr_size);
> - }
> -#endif
> + mips_reserve_vmcore();
>
> mips_parse_crashkernel();
> #ifdef CONFIG_KEXEC
>


--
~Randy

2021-02-04 04:01:12

by Jinyang He

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Use common way to parse elfcorehdr

On 02/04/2021 11:28 AM, Randy Dunlap wrote:

> On 2/3/21 7:07 PM, Jinyang He wrote:
>> "elfcorehdr" can be parsed at kernel/crash_dump.c
>>
>> Signed-off-by: Jinyang He <[email protected]>
> Hm, looks like that would require CONFIG_CRASH_DUMP?
Hi,

I don't think so. We expect to generate a /proc/vmcore when we reserved
memory for elfcorehdr. So put it under CONFIG_PROC_VMCORE. If only rely
on CONFIG_CRASH_DUMP and CONFIG_PROC_VMCORE is not enabled, we will
reserve these memory while cannot use these later. And the reason why
kernel/crash_dump.c being under CONFIG_CRASH_DUMP is that it provide
is_kdump_kernel() for others.

Thanks,
Jinyang

>
>> ---
>> arch/mips/kernel/setup.c | 49 +++++++++++++++++++++---------------------------
>> 1 file changed, 21 insertions(+), 28 deletions(-)
>>
>> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
>> index 7e1f8e2..4d2f915 100644
>> --- a/arch/mips/kernel/setup.c
>> +++ b/arch/mips/kernel/setup.c
>> @@ -29,6 +29,7 @@
>> #include <linux/of_fdt.h>
>> #include <linux/of_reserved_mem.h>
>> #include <linux/dmi.h>
>> +#include <linux/crash_dump.h>
>>
>> #include <asm/addrspace.h>
>> #include <asm/bootinfo.h>
>> @@ -404,34 +405,32 @@ static int __init early_parse_memmap(char *p)
>> }
>> early_param("memmap", early_parse_memmap);
>>
>> -#ifdef CONFIG_PROC_VMCORE
>> -static unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
>> -static int __init early_parse_elfcorehdr(char *p)
>> +static void __init mips_reserve_vmcore(void)
>> {
>> +#ifdef CONFIG_PROC_VMCORE
>> phys_addr_t start, end;
>> u64 i;
>>
>> - setup_elfcorehdr = memparse(p, &p);
>> -
>> - for_each_mem_range(i, &start, &end) {
>> - if (setup_elfcorehdr >= start && setup_elfcorehdr < end) {
>> - /*
>> - * Reserve from the elf core header to the end of
>> - * the memory segment, that should all be kdump
>> - * reserved memory.
>> - */
>> - setup_elfcorehdr_size = end - setup_elfcorehdr;
>> - break;
>> + if (!elfcorehdr_size) {
>> + for_each_mem_range(i, &start, &end) {
>> + if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
>> + /*
>> + * Reserve from the elf core header to the end of
>> + * the memory segment, that should all be kdump
>> + * reserved memory.
>> + */
>> + elfcorehdr_size = end - elfcorehdr_addr;
>> + break;
>> + }
>> }
>> }
>> - /*
>> - * If we don't find it in the memory map, then we shouldn't
>> - * have to worry about it, as the new kernel won't use it.
>> - */
>> - return 0;
>> -}
>> -early_param("elfcorehdr", early_parse_elfcorehdr);
>> +
>> + pr_info("Reserving %ldKB of memory at %ldKB for kdump\n",
>> + (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10);
>> +
>> + memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
>> #endif
>> +}
>>
>> #ifdef CONFIG_KEXEC
>>
>> @@ -653,13 +652,7 @@ static void __init arch_mem_init(char **cmdline_p)
>> */
>> memblock_set_current_limit(PFN_PHYS(max_low_pfn));
>>
>> -#ifdef CONFIG_PROC_VMCORE
>> - if (setup_elfcorehdr && setup_elfcorehdr_size) {
>> - printk(KERN_INFO "kdump reserved memory at %lx-%lx\n",
>> - setup_elfcorehdr, setup_elfcorehdr_size);
>> - memblock_reserve(setup_elfcorehdr, setup_elfcorehdr_size);
>> - }
>> -#endif
>> + mips_reserve_vmcore();
>>
>> mips_parse_crashkernel();
>> #ifdef CONFIG_KEXEC
>>
>

2021-02-04 04:11:20

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Use common way to parse elfcorehdr

On 2/3/21 7:57 PM, Jinyang He wrote:
> On 02/04/2021 11:28 AM, Randy Dunlap wrote:
>
>> On 2/3/21 7:07 PM, Jinyang He wrote:
>>> "elfcorehdr" can be parsed at kernel/crash_dump.c
>>>
>>> Signed-off-by: Jinyang He <[email protected]>
>> Hm, looks like that would require CONFIG_CRASH_DUMP?
> Hi,
>
> I don't think so. We expect to generate a /proc/vmcore when we reserved
> memory for elfcorehdr. So put it under CONFIG_PROC_VMCORE. If only rely
> on CONFIG_CRASH_DUMP and CONFIG_PROC_VMCORE is not enabled, we will
> reserve these memory while cannot use these later. And the reason why
> kernel/crash_dump.c being under CONFIG_CRASH_DUMP is that it provide
> is_kdump_kernel() for others.
>
> Thanks,
> Jinyang

Hi,

I'm referring to kernel/Makefile:

obj-$(CONFIG_CRASH_DUMP) += crash_dump.o

so that's not an issue here? Please explain.

>>> ---
>>>   arch/mips/kernel/setup.c | 49 +++++++++++++++++++++---------------------------
>>>   1 file changed, 21 insertions(+), 28 deletions(-)
>>>
>>> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
>>> index 7e1f8e2..4d2f915 100644
>>> --- a/arch/mips/kernel/setup.c
>>> +++ b/arch/mips/kernel/setup.c
>>> @@ -29,6 +29,7 @@
>>>   #include <linux/of_fdt.h>
>>>   #include <linux/of_reserved_mem.h>
>>>   #include <linux/dmi.h>
>>> +#include <linux/crash_dump.h>
>>>     #include <asm/addrspace.h>
>>>   #include <asm/bootinfo.h>
>>> @@ -404,34 +405,32 @@ static int __init early_parse_memmap(char *p)
>>>   }
>>>   early_param("memmap", early_parse_memmap);
>>>   -#ifdef CONFIG_PROC_VMCORE
>>> -static unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
>>> -static int __init early_parse_elfcorehdr(char *p)
>>> +static void __init mips_reserve_vmcore(void)
>>>   {
>>> +#ifdef CONFIG_PROC_VMCORE
>>>       phys_addr_t start, end;
>>>       u64 i;
>>>   -    setup_elfcorehdr = memparse(p, &p);
>>> -
>>> -    for_each_mem_range(i, &start, &end) {
>>> -        if (setup_elfcorehdr >= start && setup_elfcorehdr < end) {
>>> -            /*
>>> -             * Reserve from the elf core header to the end of
>>> -             * the memory segment, that should all be kdump
>>> -             * reserved memory.
>>> -             */
>>> -            setup_elfcorehdr_size = end - setup_elfcorehdr;
>>> -            break;
>>> +    if (!elfcorehdr_size) {
>>> +        for_each_mem_range(i, &start, &end) {
>>> +            if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
>>> +                /*
>>> +                 * Reserve from the elf core header to the end of
>>> +                 * the memory segment, that should all be kdump
>>> +                 * reserved memory.
>>> +                 */
>>> +                elfcorehdr_size = end - elfcorehdr_addr;
>>> +                break;
>>> +            }
>>>           }
>>>       }
>>> -    /*
>>> -     * If we don't find it in the memory map, then we shouldn't
>>> -     * have to worry about it, as the new kernel won't use it.
>>> -     */
>>> -    return 0;
>>> -}
>>> -early_param("elfcorehdr", early_parse_elfcorehdr);
>>> +
>>> +    pr_info("Reserving %ldKB of memory at %ldKB for kdump\n",
>>> +        (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10);
>>> +
>>> +    memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
>>>   #endif
>>> +}
>>>     #ifdef CONFIG_KEXEC
>>>   @@ -653,13 +652,7 @@ static void __init arch_mem_init(char **cmdline_p)
>>>        */
>>>       memblock_set_current_limit(PFN_PHYS(max_low_pfn));
>>>   -#ifdef CONFIG_PROC_VMCORE
>>> -    if (setup_elfcorehdr && setup_elfcorehdr_size) {
>>> -        printk(KERN_INFO "kdump reserved memory at %lx-%lx\n",
>>> -               setup_elfcorehdr, setup_elfcorehdr_size);
>>> -        memblock_reserve(setup_elfcorehdr, setup_elfcorehdr_size);
>>> -    }
>>> -#endif
>>> +    mips_reserve_vmcore();
>>>         mips_parse_crashkernel();
>>>   #ifdef CONFIG_KEXEC
>>>
>>
>


--
~Randy

2021-02-04 04:36:53

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Use common way to parse elfcorehdr

On 2/3/21 8:19 PM, Jinyang He wrote:
> On 02/04/2021 12:01 PM, Randy Dunlap wrote:
>
>> On 2/3/21 7:57 PM, Jinyang He wrote:
>>> On 02/04/2021 11:28 AM, Randy Dunlap wrote:
>>>
>>>> On 2/3/21 7:07 PM, Jinyang He wrote:
>>>>> "elfcorehdr" can be parsed at kernel/crash_dump.c
>>>>>
>>>>> Signed-off-by: Jinyang He <[email protected]>
>>>> Hm, looks like that would require CONFIG_CRASH_DUMP?
>>> Hi,
>>>
>>> I don't think so. We expect to generate a /proc/vmcore when we reserved
>>> memory for elfcorehdr. So put it under CONFIG_PROC_VMCORE. If only rely
>>> on CONFIG_CRASH_DUMP and CONFIG_PROC_VMCORE is not enabled, we will
>>> reserve these memory while cannot use these later. And the reason why
>>> kernel/crash_dump.c being under CONFIG_CRASH_DUMP is that it provide
>>> is_kdump_kernel() for others.
>>>
>>> Thanks,
>>> Jinyang
>> Hi,
>>
>> I'm referring to kernel/Makefile:
>>
>> obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
>>
>> so that's not an issue here?  Please explain.
> Hi,
>
> CONFIG_PROC_VMCORE depends on CONFIG_PROC_FS && CONFIG_CRASH_DUMP.
> So...

Got it. Thank you.

--
~Randy