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Merge branch 'printk-rework' into for-linus

This commit is contained in:
Petr Mladek 2021-01-21 16:06:21 +01:00
parent a91bd6223e f0e386ee0c
commit 535b6a122c
2 changed files with 30 additions and 12 deletions
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40
kernel/printk/printk.c
View File

@ -1291,11 +1291,16 @@ static size_t info_print_prefix(const struct printk_info *info, bool syslog,
* done:
*
* - Add prefix for each line.
* - Drop truncated lines that no longer fit into the buffer.
* - Add the trailing newline that has been removed in vprintk_store().
* - Drop truncated lines that do not longer fit into the buffer.
* - Add a string terminator.
*
* Since the produced string is always terminated, the maximum possible
* return value is @r->text_buf_size - 1;
*
* Return: The length of the updated/prepared text, including the added
* prefixes and the newline. The dropped line(s) are not counted.
* prefixes and the newline. The terminator is not counted. The dropped
* line(s) are not counted.
*/
static size_t record_print_text(struct printk_record *r, bool syslog,
bool time)
@ -1338,26 +1343,31 @@ static size_t record_print_text(struct printk_record *r, bool syslog,
/*
* Truncate the text if there is not enough space to add the
* prefix and a trailing newline.
* prefix and a trailing newline and a terminator.
*/
if (len + prefix_len + text_len + 1 > buf_size) {
if (len + prefix_len + text_len + 1 + 1 > buf_size) {
/* Drop even the current line if no space. */
if (len + prefix_len + line_len + 1 > buf_size)
if (len + prefix_len + line_len + 1 + 1 > buf_size)
break;
text_len = buf_size - len - prefix_len - 1;
text_len = buf_size - len - prefix_len - 1 - 1;
truncated = true;
}
memmove(text + prefix_len, text, text_len);
memcpy(text, prefix, prefix_len);
/*
* Increment the prepared length to include the text and
* prefix that were just moved+copied. Also increment for the
* newline at the end of this line. If this is the last line,
* there is no newline, but it will be added immediately below.
*/
len += prefix_len + line_len + 1;
if (text_len == line_len) {
/*
* Add the trailing newline removed in
* vprintk_store().
* This is the last line. Add the trailing newline
* removed in vprintk_store().
*/
text[prefix_len + line_len] = '\n';
break;
@ -1382,6 +1392,14 @@ static size_t record_print_text(struct printk_record *r, bool syslog,
text_len -= line_len + 1;
}
/*
* If a buffer was provided, it will be terminated. Space for the
* string terminator is guaranteed to be available. The terminator is
* not counted in the return value.
*/
if (buf_size > 0)
text[len] = 0;
return len;
}
@ -3427,7 +3445,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
while (prb_read_valid_info(prb, seq, &info, &line_count)) {
if (r.info->seq >= dumper->next_seq)
break;
l += get_record_print_text_size(&info, line_count, true, time);
l += get_record_print_text_size(&info, line_count, syslog, time);
seq = r.info->seq + 1;
}
@ -3437,7 +3455,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
&info, &line_count)) {
if (r.info->seq >= dumper->next_seq)
break;
l -= get_record_print_text_size(&info, line_count, true, time);
l -= get_record_print_text_size(&info, line_count, syslog, time);
seq = r.info->seq + 1;
}

2
kernel/printk/printk_ringbuffer.c
View File

@ -1718,7 +1718,7 @@ static bool copy_data(struct prb_data_ring *data_ring,
/* Caller interested in the line count? */
if (line_count)
*line_count = count_lines(data, data_size);
*line_count = count_lines(data, len);
/* Caller interested in the data content? */
if (!buf || !buf_size)