diff options
| -rw-r--r-- | include/linux/trace_seq.h | 20 | ||||
| -rw-r--r-- | kernel/trace/seq_buf.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 21 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 9 | ||||
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 5 | ||||
| -rw-r--r-- | kernel/trace/trace_seq.c | 2 |
6 files changed, 42 insertions, 17 deletions
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index 85d37106be3d..cfaf5a1d4bad 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -24,6 +24,24 @@ trace_seq_init(struct trace_seq *s) } /** + * trace_seq_used - amount of actual data written to buffer + * @s: trace sequence descriptor + * + * Returns the amount of data written to the buffer. + * + * IMPORTANT! + * + * Use this instead of @s->seq.len if you need to pass the amount + * of data from the buffer to another buffer (userspace, or what not). + * The @s->seq.len on overflow is bigger than the buffer size and + * using it can cause access to undefined memory. + */ +static inline int trace_seq_used(struct trace_seq *s) +{ + return seq_buf_used(&s->seq); +} + +/** * trace_seq_buffer_ptr - return pointer to next location in buffer * @s: trace sequence descriptor * @@ -35,7 +53,7 @@ trace_seq_init(struct trace_seq *s) static inline unsigned char * trace_seq_buffer_ptr(struct trace_seq *s) { - return s->buffer + s->seq.len; + return s->buffer + seq_buf_used(&s->seq); } /** diff --git a/kernel/trace/seq_buf.c b/kernel/trace/seq_buf.c index 9ec5305d9da7..ce17f65268ed 100644 --- a/kernel/trace/seq_buf.c +++ b/kernel/trace/seq_buf.c @@ -328,7 +328,7 @@ int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt) if (s->len <= s->readpos) return -EBUSY; - len = s->len - s->readpos; + len = seq_buf_used(s) - s->readpos; if (cnt > len) cnt = len; ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0aa75be843a0..9023446b2c2b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -944,10 +944,10 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) { int len; - if (s->seq.len <= s->seq.readpos) + if (trace_seq_used(s) <= s->seq.readpos) return -EBUSY; - len = s->seq.len - s->seq.readpos; + len = trace_seq_used(s) - s->seq.readpos; if (cnt > len) cnt = len; memcpy(buf, s->buffer + s->seq.readpos, cnt); @@ -4514,18 +4514,18 @@ waitagain: trace_access_lock(iter->cpu_file); while (trace_find_next_entry_inc(iter) != NULL) { enum print_line_t ret; - int len = iter->seq.seq.len; + int save_len = iter->seq.seq.len; ret = print_trace_line(iter); if (ret == TRACE_TYPE_PARTIAL_LINE) { /* don't print partial lines */ - iter->seq.seq.len = len; + iter->seq.seq.len = save_len; break; } if (ret != TRACE_TYPE_NO_CONSUME) trace_consume(iter); - if (iter->seq.seq.len >= cnt) + if (trace_seq_used(&iter->seq) >= cnt) break; /* @@ -4541,7 +4541,7 @@ waitagain: /* Now copy what we have to the user */ sret = trace_seq_to_user(&iter->seq, ubuf, cnt); - if (iter->seq.seq.readpos >= iter->seq.seq.len) + if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq)) trace_seq_init(&iter->seq); /* @@ -4598,7 +4598,7 @@ tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) break; } - count = iter->seq.seq.len - save_len; + count = trace_seq_used(&iter->seq) - save_len; if (rem < count) { rem = 0; iter->seq.seq.len = save_len; @@ -4682,13 +4682,13 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, /* Copy the data into the page, so we can start over. */ ret = trace_seq_to_buffer(&iter->seq, page_address(spd.pages[i]), - iter->seq.seq.len); + trace_seq_used(&iter->seq)); if (ret < 0) { __free_page(spd.pages[i]); break; } spd.partial[i].offset = 0; - spd.partial[i].len = iter->seq.seq.len; + spd.partial[i].len = trace_seq_used(&iter->seq); trace_seq_init(&iter->seq); } @@ -5689,7 +5689,8 @@ tracing_stats_read(struct file *filp, char __user *ubuf, cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu); trace_seq_printf(s, "read events: %ld\n", cnt); - count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->seq.len); + count = simple_read_from_buffer(ubuf, count, ppos, + s->buffer, trace_seq_used(s)); kfree(s); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 4d0067dd7f88..935cbea78532 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1044,7 +1044,8 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, mutex_unlock(&event_mutex); if (file) - r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->seq.len); + r = simple_read_from_buffer(ubuf, cnt, ppos, + s->buffer, trace_seq_used(s)); kfree(s); @@ -1210,7 +1211,8 @@ subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, trace_seq_init(s); print_subsystem_event_filter(system, s); - r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->seq.len); + r = simple_read_from_buffer(ubuf, cnt, ppos, + s->buffer, trace_seq_used(s)); kfree(s); @@ -1265,7 +1267,8 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) trace_seq_init(s); func(s); - r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->seq.len); + r = simple_read_from_buffer(ubuf, cnt, ppos, + s->buffer, trace_seq_used(s)); kfree(s); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 6d1342ae7a44..ec35468349a7 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -1153,6 +1153,9 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent, return ret; } + if (trace_seq_has_overflowed(s)) + goto out; + /* Strip ending newline */ if (s->buffer[s->seq.len - 1] == '\n') { s->buffer[s->seq.len - 1] = '\0'; @@ -1160,7 +1163,7 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent, } trace_seq_puts(s, " */\n"); - + out: return trace_handle_return(s); } diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c index 74cacc930c24..f8b45d8792f9 100644 --- a/kernel/trace/trace_seq.c +++ b/kernel/trace/trace_seq.c @@ -30,7 +30,7 @@ #define TRACE_SEQ_BUF_LEFT(s) seq_buf_buffer_left(&(s)->seq) /* How much buffer is written? */ -#define TRACE_SEQ_BUF_USED(s) min((s)->seq.len, (unsigned int)(PAGE_SIZE - 1)) +#define TRACE_SEQ_BUF_USED(s) seq_buf_used(&(s)->seq) /* * trace_seq should work with being initialized with 0s. |