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Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c75
1 files changed, 37 insertions, 38 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2a7c6fd934e9..9ff8a439d674 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2320,7 +2320,7 @@ struct saved_cmdlines_buffer {
unsigned *map_cmdline_to_pid;
unsigned cmdline_num;
int cmdline_idx;
- char *saved_cmdlines;
+ char saved_cmdlines[];
};
static struct saved_cmdlines_buffer *savedcmd;
@@ -2334,47 +2334,58 @@ static inline void set_cmdline(int idx, const char *cmdline)
strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
}
-static int allocate_cmdlines_buffer(unsigned int val,
- struct saved_cmdlines_buffer *s)
+static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
+{
+ int order = get_order(sizeof(*s) + s->cmdline_num * TASK_COMM_LEN);
+
+ kfree(s->map_cmdline_to_pid);
+ free_pages((unsigned long)s, order);
+}
+
+static struct saved_cmdlines_buffer *allocate_cmdlines_buffer(unsigned int val)
{
+ struct saved_cmdlines_buffer *s;
+ struct page *page;
+ int orig_size, size;
+ int order;
+
+ /* Figure out how much is needed to hold the given number of cmdlines */
+ orig_size = sizeof(*s) + val * TASK_COMM_LEN;
+ order = get_order(orig_size);
+ size = 1 << (order + PAGE_SHIFT);
+ page = alloc_pages(GFP_KERNEL, order);
+ if (!page)
+ return NULL;
+
+ s = page_address(page);
+ memset(s, 0, sizeof(*s));
+
+ /* Round up to actual allocation */
+ val = (size - sizeof(*s)) / TASK_COMM_LEN;
+ s->cmdline_num = val;
+
s->map_cmdline_to_pid = kmalloc_array(val,
sizeof(*s->map_cmdline_to_pid),
GFP_KERNEL);
- if (!s->map_cmdline_to_pid)
- return -ENOMEM;
-
- s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
- if (!s->saved_cmdlines) {
- kfree(s->map_cmdline_to_pid);
- return -ENOMEM;
+ if (!s->map_cmdline_to_pid) {
+ free_saved_cmdlines_buffer(s);
+ return NULL;
}
s->cmdline_idx = 0;
- s->cmdline_num = val;
memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP,
sizeof(s->map_pid_to_cmdline));
memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP,
val * sizeof(*s->map_cmdline_to_pid));
- return 0;
+ return s;
}
static int trace_create_savedcmd(void)
{
- int ret;
-
- savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);
- if (!savedcmd)
- return -ENOMEM;
-
- ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd);
- if (ret < 0) {
- kfree(savedcmd);
- savedcmd = NULL;
- return -ENOMEM;
- }
+ savedcmd = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT);
- return 0;
+ return savedcmd ? 0 : -ENOMEM;
}
int is_tracing_stopped(void)
@@ -6056,26 +6067,14 @@ tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
-static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
-{
- kfree(s->saved_cmdlines);
- kfree(s->map_cmdline_to_pid);
- kfree(s);
-}
-
static int tracing_resize_saved_cmdlines(unsigned int val)
{
struct saved_cmdlines_buffer *s, *savedcmd_temp;
- s = kmalloc(sizeof(*s), GFP_KERNEL);
+ s = allocate_cmdlines_buffer(val);
if (!s)
return -ENOMEM;
- if (allocate_cmdlines_buffer(val, s) < 0) {
- kfree(s);
- return -ENOMEM;
- }
-
preempt_disable();
arch_spin_lock(&trace_cmdline_lock);
savedcmd_temp = savedcmd;