diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-10-29 15:26:09 -0400 |
|---|---|---|
| committer | Daniel Thompson <daniel.thompson@linaro.org> | 2017-02-24 15:59:43 +0000 |
| commit | 8c40ca3484188ddc7161beda3ba915533b73663b (patch) | |
| tree | 2b17906139e9274acd2e8d2aa1ff0f530e9bf40b | |
| parent | ff497141807fccde53e91be1b961791d4e12306f (diff) | |
UPSTREAM: tracing: Have seq_buf use full buffer
Currently seq_buf is full when all but one byte of the buffer is
filled. Change it so that the seq_buf is full when all of the
buffer is filled.
Some of the functions would fill the buffer completely and report
everything was fine. This was inconsistent with the max of size - 1.
Changing this to be max of size makes all functions consistent.
Link: http://lkml.kernel.org/r/20141104160222.502133196@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.811957882@goodmis.org
Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Patchset: trace-seq/seq-buf/x86/printk: Print all stacks from NMI safely
(cherry picked from commit 8cd709ae7658a7fd7f6630699e3229188c2591e4)
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| -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); |