diff options
| -rw-r--r-- | include/linux/seq_buf.h | 6 | ||||
| -rw-r--r-- | kernel/trace/seq_buf.c | 9 |
2 files changed, 9 insertions, 6 deletions
diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h index 93718e570d4c..0800a24b4348 100644 --- a/include/linux/seq_buf.h +++ b/include/linux/seq_buf.h @@ -43,13 +43,13 @@ seq_buf_init(struct seq_buf *s, unsigned char *buf, unsigned int size) static inline bool seq_buf_has_overflowed(struct seq_buf *s) { - return s->len == s->size; + return s->len > s->size; } static inline void seq_buf_set_overflow(struct seq_buf *s) { - s->len = s->size; + s->len = s->size + 1; } /* @@ -61,7 +61,7 @@ seq_buf_buffer_left(struct seq_buf *s) if (seq_buf_has_overflowed(s)) return 0; - return (s->size - 1) - s->len; + return s->size - s->len; } /* How much buffer was written? */ diff --git a/kernel/trace/seq_buf.c b/kernel/trace/seq_buf.c index 6fc9d021cbef..c53f1d5088e8 100644 --- a/kernel/trace/seq_buf.c +++ b/kernel/trace/seq_buf.c @@ -26,7 +26,7 @@ */ static bool seq_buf_can_fit(struct seq_buf *s, size_t len) { - return s->len + len < s->size; + return s->len + len <= s->size; } /** @@ -110,8 +110,11 @@ int seq_buf_bitmask(struct seq_buf *s, const unsigned long *maskp, WARN_ON(s->size == 0); /* - * The last byte of the buffer is used to determine if we - * overflowed or not. + * Note, because bitmap_scnprintf() only returns the number of bytes + * written and not the number that would be written, we use the last + * byte of the buffer to let us know if we overflowed. There's a small + * chance that the bitmap could have fit exactly inside the buffer, but + * it's not that critical if that does happen. */ if (len > 1) { ret = bitmap_scnprintf(s->buffer + s->len, len, maskp, nmaskbits); |