From: "Steven Rostedt (Red Hat)" <rost...@goodmis.org> commit 9b77215382b42ef9c5b34293ad3a95332e5b71ef upsteam.
Add a seq_buf_can_fit() helper function that removes the possible mistakes of comparing the seq_buf length plus added data compared to the size of the buffer. Link: http://lkml.kernel.org/r/20141118164025.gl23...@pathway.suse.cz Reviewed-by: Petr Mladek <pmla...@suse.cz> [wanglong: backport to 3.10 stable] Signed-off-by: Wang Long <long.wangl...@huawei.com> Signed-off-by: Steven Rostedt <rost...@goodmis.org> --- kernel/trace/seq_buf.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/kernel/trace/seq_buf.c b/kernel/trace/seq_buf.c index ce17f65..6fc9d02 100644 --- a/kernel/trace/seq_buf.c +++ b/kernel/trace/seq_buf.c @@ -17,6 +17,19 @@ #include <linux/seq_buf.h> /** + * seq_buf_can_fit - can the new data fit in the current buffer? + * @s: the seq_buf descriptor + * @len: The length to see if it can fit in the current buffer + * + * Returns true if there's enough unused space in the seq_buf buffer + * to fit the amount of new data according to @len. + */ +static bool seq_buf_can_fit(struct seq_buf *s, size_t len) +{ + return s->len + len < s->size; +} + +/** * seq_buf_print_seq - move the contents of seq_buf into a seq_file * @m: the seq_file descriptor that is the destination * @s: the seq_buf descriptor that is the source. @@ -48,7 +61,7 @@ int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args) if (s->len < s->size) { len = vsnprintf(s->buffer + s->len, s->size - s->len, fmt, args); - if (s->len + len < s->size) { + if (seq_buf_can_fit(s, len)) { s->len += len; return 0; } @@ -137,7 +150,7 @@ int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary) if (s->len < s->size) { ret = bstr_printf(s->buffer + s->len, len, fmt, binary); - if (s->len + ret < s->size) { + if (seq_buf_can_fit(s, ret)) { s->len += ret; return 0; } @@ -161,7 +174,7 @@ int seq_buf_puts(struct seq_buf *s, const char *str) WARN_ON(s->size == 0); - if (s->len + len < s->size) { + if (seq_buf_can_fit(s, len)) { memcpy(s->buffer + s->len, str, len); s->len += len; return 0; @@ -183,7 +196,7 @@ int seq_buf_putc(struct seq_buf *s, unsigned char c) { WARN_ON(s->size == 0); - if (s->len + 1 < s->size) { + if (seq_buf_can_fit(s, 1)) { s->buffer[s->len++] = c; return 0; } @@ -207,7 +220,7 @@ int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len) { WARN_ON(s->size == 0); - if (s->len + len < s->size) { + if (seq_buf_can_fit(s, len)) { memcpy(s->buffer + s->len, mem, len); s->len += len; return 0; -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
