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Diffstat (limited to 'kernel/trace/trace_output.c')
-rw-r--r--kernel/trace/trace_output.c75
1 files changed, 61 insertions, 14 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index b6c12c6a1bcd..8e46b3323cdc 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -23,13 +23,21 @@ static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
static int next_event_type = __TRACE_LAST_TYPE + 1;
-void trace_print_seq(struct seq_file *m, struct trace_seq *s)
+int trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
+ int ret;
+
+ ret = seq_write(m, s->buffer, len);
- seq_write(m, s->buffer, len);
+ /*
+ * Only reset this buffer if we successfully wrote to the
+ * seq_file buffer.
+ */
+ if (!ret)
+ trace_seq_init(s);
- trace_seq_init(s);
+ return ret;
}
enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
@@ -85,7 +93,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
va_list ap;
int ret;
- if (!len)
+ if (s->full || !len)
return 0;
va_start(ap, fmt);
@@ -93,8 +101,10 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
va_end(ap);
/* If we can't write it all, don't bother writing anything */
- if (ret >= len)
+ if (ret >= len) {
+ s->full = 1;
return 0;
+ }
s->len += ret;
@@ -119,14 +129,16 @@ trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
int len = (PAGE_SIZE - 1) - s->len;
int ret;
- if (!len)
+ if (s->full || !len)
return 0;
ret = vsnprintf(s->buffer + s->len, len, fmt, args);
/* If we can't write it all, don't bother writing anything */
- if (ret >= len)
+ if (ret >= len) {
+ s->full = 1;
return 0;
+ }
s->len += ret;
@@ -139,14 +151,16 @@ int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
int len = (PAGE_SIZE - 1) - s->len;
int ret;
- if (!len)
+ if (s->full || !len)
return 0;
ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
/* If we can't write it all, don't bother writing anything */
- if (ret >= len)
+ if (ret >= len) {
+ s->full = 1;
return 0;
+ }
s->len += ret;
@@ -167,8 +181,13 @@ int trace_seq_puts(struct trace_seq *s, const char *str)
{
int len = strlen(str);
- if (len > ((PAGE_SIZE - 1) - s->len))
+ if (s->full)
+ return 0;
+
+ if (len > ((PAGE_SIZE - 1) - s->len)) {
+ s->full = 1;
return 0;
+ }
memcpy(s->buffer + s->len, str, len);
s->len += len;
@@ -178,9 +197,14 @@ int trace_seq_puts(struct trace_seq *s, const char *str)
int trace_seq_putc(struct trace_seq *s, unsigned char c)
{
- if (s->len >= (PAGE_SIZE - 1))
+ if (s->full)
return 0;
+ if (s->len >= (PAGE_SIZE - 1)) {
+ s->full = 1;
+ return 0;
+ }
+
s->buffer[s->len++] = c;
return 1;
@@ -188,9 +212,14 @@ int trace_seq_putc(struct trace_seq *s, unsigned char c)
int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
{
- if (len > ((PAGE_SIZE - 1) - s->len))
+ if (s->full)
return 0;
+ if (len > ((PAGE_SIZE - 1) - s->len)) {
+ s->full = 1;
+ return 0;
+ }
+
memcpy(s->buffer + s->len, mem, len);
s->len += len;
@@ -203,6 +232,9 @@ int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
const unsigned char *data = mem;
int i, j;
+ if (s->full)
+ return 0;
+
#ifdef __BIG_ENDIAN
for (i = 0, j = 0; i < len; i++) {
#else
@@ -220,8 +252,13 @@ void *trace_seq_reserve(struct trace_seq *s, size_t len)
{
void *ret;
- if (len > ((PAGE_SIZE - 1) - s->len))
+ if (s->full)
+ return 0;
+
+ if (len > ((PAGE_SIZE - 1) - s->len)) {
+ s->full = 1;
return NULL;
+ }
ret = s->buffer + s->len;
s->len += len;
@@ -233,8 +270,14 @@ int trace_seq_path(struct trace_seq *s, struct path *path)
{
unsigned char *p;
- if (s->len >= (PAGE_SIZE - 1))
+ if (s->full)
+ return 0;
+
+ if (s->len >= (PAGE_SIZE - 1)) {
+ s->full = 1;
return 0;
+ }
+
p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
if (!IS_ERR(p)) {
p = mangle_path(s->buffer + s->len, p, "\n");
@@ -247,6 +290,7 @@ int trace_seq_path(struct trace_seq *s, struct path *path)
return 1;
}
+ s->full = 1;
return 0;
}
@@ -373,6 +417,9 @@ int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
unsigned long vmstart = 0;
int ret = 1;
+ if (s->full)
+ return 0;
+
if (mm) {
const struct vm_area_struct *vma;