Re: [PATCH v5] crash: Fix crash memory reserve exceed system memory bug

Jinjie Ruan
2024-07-29T03:24:26Z

On 2024/7/23 13:17, Baoquan He wrote:
> On 07/23/24 at 10:07am, Jinjie Ruan wrote:
>> On x86_32 Qemu machine with 1GB memory, the cmdline "crashkernel=4G" is ok
>> as below:
>> crashkernel reserved: 0x0000000020000000 - 0x0000000120000000 (4096 MB)
>>
>> It's similar on other architectures, such as ARM32 and RISCV32.
>>
>> The cause is that the crash_size is parsed and printed with "unsigned long
>> long" data type which is 8 bytes but allocated used with "phys_addr_t"
>> which is 4 bytes in memblock_phys_alloc_range().
>>
>> Fix it by checking if crash_size is greater than system RAM size and
>> return error if so.
>>
>> After this patch, there is no above confusing reserve success info.
>>
>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>> Suggested-by: Baoquan He <bhe@redhat.com>
>> Suggested-by: Mike Rapoport <rppt@kernel.org>
>
>
> My Suggested-by can be taken off because I suggested to check the parsed
> value after parse_crashkernel(), Mike's suggestion is better.

Hi, Can the suggested-by be removed when this version is merged, or a
new version needs to be sent?

>
> For this version,
>
> Acked-by: Baoquan He <bhe@redhat.com>
>
>> ---
>> v5:
>> - Fix it in common parse_crashkernel() instead of per-arch.
>> - Add suggested-by.
>>
>> v4:
>> - Update the warn info to align with parse_crashkernel_mem().
>> - Rebased on the "ARM: Use generic interface to simplify crashkernel
>> reservation" patch.
>> - Also fix for riscv32.
>> - Update the commit message.
>>
>> v3:
>> - Handle the check in reserve_crashkernel() Baoquan suggested.
>> - Split x86_32 and arm32.
>> - Add Suggested-by.
>> - Drop the wrong fix tag.
>>
>> v2:
>> - Also fix for x86_32.
>> - Update the fix method.
>> - Peel off the other two patches.
>> - Update the commit message.
>> ---
>> kernel/crash_reserve.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c
>> index ad5b3f2c5487..5387269114f6 100644
>> --- a/kernel/crash_reserve.c
>> +++ b/kernel/crash_reserve.c
>> @@ -335,6 +335,9 @@ int __init parse_crashkernel(char *cmdline,
>> if (!*crash_size)
>> ret = -EINVAL;
>>
>> + if (*crash_size >= system_ram)
>> + ret = -EINVAL;
>> +
>> return ret;
>> }
>>
>> --
>> 2.34.1
>>
>
>