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 surenb@google.com
Reviewed-by: Vlastimil Babka vbabka@suse.cz
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;
vma = get_gate_vma(priv->mm); }*ppos = -2;
@@ -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) {
return NULL; } return proc_get_vma(m->private, ppos);*ppos = -1;