1. There is no reason to reset ->tail_vma in m_start(), if we return IS_ERR_OR_NULL() it won't be used.
2. m_start() also clears priv->task to ensure that m_stop() won't use the stale pointer if we fail before get_task_struct(). But this is ugly and confusing, move this initialization in m_stop(). Signed-off-by: Oleg Nesterov <[email protected]> --- fs/proc/task_mmu.c | 9 +++------ 1 files changed, 3 insertions(+), 6 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index c4c8825..5f7fb45 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -145,17 +145,12 @@ static void *m_start(struct seq_file *m, loff_t *pos) struct vm_area_struct *vma, *tail_vma = NULL; loff_t l = *pos; - /* Clear the per syscall fields in priv */ - priv->task = NULL; - priv->tail_vma = NULL; - /* * We remember last_addr rather than next_addr to hit with * vmacache most of the time. We have zero last_addr at * the beginning and also after lseek. We will have -1 last_addr * after the end of the vmas. */ - if (last_addr == -1UL) return NULL; @@ -227,8 +222,10 @@ static void m_stop(struct seq_file *m, void *v) if (!IS_ERR_OR_NULL(v)) vma_stop(priv); - if (priv->task) + if (priv->task) { put_task_struct(priv->task); + priv->task = NULL; + } } static int proc_maps_open(struct inode *inode, struct file *file, -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
