On 7/4/25 08:07, Suren Baghdasaryan wrote: > Back in 2.6 era, last_addr used to be stored in seq_file->version > variable, which was unsigned long. As a result, sentinels to represent > gate vma and end of all vmas used unsigned values. In more recent > kernels we don't used seq_file->version anymore and therefore conversion > from loff_t into unsigned type is not needed. Similarly, sentinel values > don't need to be unsigned. Remove type conversion for set_file position > and change sentinel values to signed. > > Signed-off-by: Suren Baghdasaryan <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]> Some stuff in the code gave me a pause but it's out of scope here so just in case someone wants to do some extra churn... > --- > fs/proc/task_mmu.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 751479eb128f..b8bc06d05a72 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -135,7 +135,7 @@ static struct vm_area_struct *proc_get_vma(struct > proc_maps_private *priv, > if (vma) { > *ppos = vma->vm_start; > } else { > - *ppos = -2UL; > + *ppos = -2; > vma = get_gate_vma(priv->mm); > } > > @@ -145,11 +145,11 @@ static struct vm_area_struct *proc_get_vma(struct > proc_maps_private *priv, > static void *m_start(struct seq_file *m, loff_t *ppos) > { > struct proc_maps_private *priv = m->private; > - unsigned long last_addr = *ppos; > + loff_t last_addr = *ppos; > struct mm_struct *mm; > > /* See m_next(). Zero at the start or after lseek. */ > - if (last_addr == -1UL) > + if (last_addr == -1) > return NULL; > > priv->task = get_proc_task(priv->inode); > @@ -170,9 +170,9 @@ static void *m_start(struct seq_file *m, loff_t *ppos) > return ERR_PTR(-EINTR); > } > > - vma_iter_init(&priv->iter, mm, last_addr); > + vma_iter_init(&priv->iter, mm, (unsigned long)last_addr); I wonder if this should rather be done only after dealing with the -2 case below. It seems wrong to init the iterator with a bogus address. What if it acquires some sanity checks? > hold_task_mempolicy(priv); It seems suboptimal to do that mempolicy refcount dance for numa_maps sake even if we're reading a different /proc file... maybe priv could have a flag to determine? > - if (last_addr == -2UL) > + if (last_addr == -2) > return get_gate_vma(mm); I think only after the above it makes sense to init the iterator? > return proc_get_vma(priv, ppos); > @@ -180,8 +180,8 @@ static void *m_start(struct seq_file *m, loff_t *ppos) > > static void *m_next(struct seq_file *m, void *v, loff_t *ppos) > { > - if (*ppos == -2UL) { > - *ppos = -1UL; > + if (*ppos == -2) { > + *ppos = -1; > return NULL; > } > return proc_get_vma(m->private, ppos);
