From 948927ee9e4f35f287e61a79c9f0e85ca2202c7d Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Tue, 12 Nov 2013 15:07:28 -0800 Subject: mm, mempolicy: make mpol_to_str robust and always succeed mpol_to_str() should not fail. Currently, it either fails because the string buffer is too small or because a string hasn't been defined for a mempolicy mode. If a new mempolicy mode is introduced and no string is defined for it, just warn and return "unknown". If the buffer is too small, just truncate the string and return, the same behavior as snprintf(). This also fixes a bug where there was no NULL-byte termination when doing *p++ = '=' and *p++ ':' and maxlen has been reached. Signed-off-by: David Rientjes Cc: KOSAKI Motohiro Cc: Chen Gang Cc: Rik van Riel Cc: Dave Jones Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 390bdab01c3c..9f1369fe0afb 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1387,8 +1387,8 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid) struct mm_struct *mm = vma->vm_mm; struct mm_walk walk = {}; struct mempolicy *pol; - int n; - char buffer[50]; + char buffer[64]; + int nid; if (!mm) return 0; @@ -1404,10 +1404,8 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid) walk.mm = mm; pol = get_vma_policy(task, vma, vma->vm_start); - n = mpol_to_str(buffer, sizeof(buffer), pol); + mpol_to_str(buffer, sizeof(buffer), pol); mpol_cond_put(pol); - if (n < 0) - return n; seq_printf(m, "%08lx %s", vma->vm_start, buffer); @@ -1460,9 +1458,9 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid) if (md->writeback) seq_printf(m, " writeback=%lu", md->writeback); - for_each_node_state(n, N_MEMORY) - if (md->node[n]) - seq_printf(m, " N%d=%lu", n, md->node[n]); + for_each_node_state(nid, N_MEMORY) + if (md->node[nid]) + seq_printf(m, " N%d=%lu", nid, md->node[nid]); out: seq_putc(m, '\n'); -- cgit v1.2.3