The __mm_flags_set_word() function is slightly ambiguous - we use 'set' to refer to setting individual bits (such as in mm_flags_set()) but here we use it to refer to overwriting the value altogether. Rename it to __mm_flags_overwrite_word() to eliniate this ambiguity. We additionally simplify the functions, eliminating unnecessary bitmap_xxx() operations (the compiler would have optimised these out but it's worth being as clear as we can be here). Signed-off-by: Lorenzo Stoakes --- include/linux/mm_types.h | 14 +++++--------- kernel/fork.c | 4 ++-- 2 files changed, 7 insertions(+), 11 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 5021047485a9..b47bd829ec9d 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1289,15 +1289,13 @@ struct mm_struct { unsigned long cpu_bitmap[]; }; -/* Set the first system word of mm flags, non-atomically. */ -static inline void __mm_flags_set_word(struct mm_struct *mm, unsigned long value) +/* Copy value to the first system word of mm flags, non-atomically. */ +static inline void __mm_flags_overwrite_word(struct mm_struct *mm, unsigned long value) { - unsigned long *bitmap = ACCESS_PRIVATE(&mm->flags, __mm_flags); - - bitmap_copy(bitmap, &value, BITS_PER_LONG); + *ACCESS_PRIVATE(&mm->flags, __mm_flags) = value; } -/* Obtain a read-only view of the bitmap. */ +/* Obtain a read-only view of the mm flags bitmap. */ static inline const unsigned long *__mm_flags_get_bitmap(const struct mm_struct *mm) { return (const unsigned long *)ACCESS_PRIVATE(&mm->flags, __mm_flags); @@ -1306,9 +1304,7 @@ static inline const unsigned long *__mm_flags_get_bitmap(const struct mm_struct /* Read the first system word of mm flags, non-atomically. */ static inline unsigned long __mm_flags_get_word(const struct mm_struct *mm) { - const unsigned long *bitmap = __mm_flags_get_bitmap(mm); - - return bitmap_read(bitmap, 0, BITS_PER_LONG); + return *__mm_flags_get_bitmap(mm); } /* diff --git a/kernel/fork.c b/kernel/fork.c index dd0bb5fe4305..5e3309a2332c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1061,10 +1061,10 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, if (current->mm) { unsigned long flags = __mm_flags_get_word(current->mm); - __mm_flags_set_word(mm, mmf_init_legacy_flags(flags)); + __mm_flags_overwrite_word(mm, mmf_init_legacy_flags(flags)); mm->def_flags = current->mm->def_flags & VM_INIT_DEF_MASK; } else { - __mm_flags_set_word(mm, default_dump_filter); + __mm_flags_overwrite_word(mm, default_dump_filter); mm->def_flags = 0; } -- 2.51.0