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-rw-r--r--fs/proc/task_mmu.c14
-rw-r--r--include/linux/mempolicy.h5
-rw-r--r--mm/mempolicy.c52
3 files changed, 24 insertions, 47 deletions
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');
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index ea4d2495c646..9fe426b30a41 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -169,7 +169,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
extern int mpol_parse_str(char *str, struct mempolicy **mpol);
#endif
-extern int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
+extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
/* Check if a vma is migratable */
static inline int vma_migratable(struct vm_area_struct *vma)
@@ -307,9 +307,8 @@ static inline int mpol_parse_str(char *str, struct mempolicy **mpol)
}
#endif
-static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
+static inline void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
{
- return 0;
}
static inline int mpol_misplaced(struct page *page, struct vm_area_struct *vma,
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 71cb253368cb..260b8213a873 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2914,62 +2914,45 @@ out:
* @maxlen: length of @buffer
* @pol: pointer to mempolicy to be formatted
*
- * Convert a mempolicy into a string.
- * Returns the number of characters in buffer (if positive)
- * or an error (negative)
+ * Convert @pol into a string. If @buffer is too short, truncate the string.
+ * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
+ * longest flag, "relative", and to display at least a few node ids.
*/
-int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
+void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
{
char *p = buffer;
- int l;
- nodemask_t nodes;
- unsigned short mode;
- unsigned short flags = pol ? pol->flags : 0;
-
- /*
- * Sanity check: room for longest mode, flag and some nodes
- */
- VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
+ nodemask_t nodes = NODE_MASK_NONE;
+ unsigned short mode = MPOL_DEFAULT;
+ unsigned short flags = 0;
- if (!pol || pol == &default_policy)
- mode = MPOL_DEFAULT;
- else
+ if (pol && pol != &default_policy) {
mode = pol->mode;
+ flags = pol->flags;
+ }
switch (mode) {
case MPOL_DEFAULT:
- nodes_clear(nodes);
break;
-
case MPOL_PREFERRED:
- nodes_clear(nodes);
if (flags & MPOL_F_LOCAL)
mode = MPOL_LOCAL;
else
node_set(pol->v.preferred_node, nodes);
break;
-
case MPOL_BIND:
- /* Fall through */
case MPOL_INTERLEAVE:
nodes = pol->v.nodes;
break;
-
default:
- return -EINVAL;
+ WARN_ON_ONCE(1);
+ snprintf(p, maxlen, "unknown");
+ return;
}
- l = strlen(policy_modes[mode]);
- if (buffer + maxlen < p + l + 1)
- return -ENOSPC;
-
- strcpy(p, policy_modes[mode]);
- p += l;
+ p += snprintf(p, maxlen, policy_modes[mode]);
if (flags & MPOL_MODE_FLAGS) {
- if (buffer + maxlen < p + 2)
- return -ENOSPC;
- *p++ = '=';
+ p += snprintf(p, buffer + maxlen - p, "=");
/*
* Currently, the only defined flags are mutually exclusive
@@ -2981,10 +2964,7 @@ int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
}
if (!nodes_empty(nodes)) {
- if (buffer + maxlen < p + 2)
- return -ENOSPC;
- *p++ = ':';
+ p += snprintf(p, buffer + maxlen - p, ":");
p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
}
- return p - buffer;
}