Re: [PATCH v1 1/2] mm/ksm: support fork/exec for prctl

From: Stefan Roesch
Date: Wed Sep 20 2023 - 12:29:28 EST



David Hildenbrand <david@xxxxxxxxxx> writes:

> On 19.09.23 22:51, Stefan Roesch wrote:
>> A process can enable KSM with the prctl system call. When the process is
>> forked the KSM flag is inherited by the child process. However if the
>> process is executing an exec system call directly after the fork, the
>> KSM setting is cleared. This patch addresses this problem.
>> Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
>> Reported-by: Carl Klemm <carl@xxxxxxxx>
>> ---
>> include/linux/sched/coredump.h | 7 +++++--
>> 1 file changed, 5 insertions(+), 2 deletions(-)
>> diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
>> index 0ee96ea7a0e9..205aa9917394 100644
>> --- a/include/linux/sched/coredump.h
>> +++ b/include/linux/sched/coredump.h
>> @@ -87,8 +87,11 @@ static inline int get_dumpable(struct mm_struct *mm)
>> #define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP)
>> +#define MMF_VM_MERGE_ANY 29
>> +#define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY)
>> +
>> #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
>> - MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK)
>> + MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\
>> + MMF_VM_MERGE_ANY_MASK)
>> -#define MMF_VM_MERGE_ANY 29
>> #endif /* _LINUX_SCHED_COREDUMP_H */
>
> Fixes: tag?
>

Added fixes tag

> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>