In case debugtrace is writing to memory and the last entry is repeated
don't fill up the trace buffer, but modify the count prefix to "x-y "
style instead.
Signed-off-by: Juergen Gross <jgr...@suse.com>
---
xen/drivers/char/console.c | 42 +++++++++++++++++++++++++++++++-----------
1 file changed, 31 insertions(+), 11 deletions(-)
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 41ec13ce52..f41b689847 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -1225,13 +1225,26 @@ void debugtrace_dump(void)
watchdog_enable();
}
+static void debugtrace_add_to_buf(char *buf)
+{
+ char *p;
+
+ for ( p = buf; *p != '\0'; p++ )
+ {
+ debugtrace_buf[debugtrace_prd++] = *p;
+ /* Always leave a nul byte at the end of the buffer. */
+ if ( debugtrace_prd == (debugtrace_bytes - 1) )
+ debugtrace_prd = 0;
+ }
+}
+
void debugtrace_printk(const char *fmt, ...)
{
- static char buf[1024];
- static u32 count;
+ static char buf[1024], last_buf[1024];
+ static unsigned int count, last_count, last_prd;
+ char cntbuf[24];
va_list args;
- char *p;
unsigned long flags;
if ( debugtrace_bytes == 0 )
@@ -1243,25 +1256,32 @@ void debugtrace_printk(const char *fmt, ...)
ASSERT(debugtrace_buf[debugtrace_bytes - 1] == 0);
- snprintf(buf, sizeof(buf), "%u ", ++count);
-
va_start(args, fmt);
- (void)vsnprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), fmt, args);
+ vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
if ( debugtrace_send_to_console )
{
+ snprintf(cntbuf, sizeof(cntbuf), "%u ", ++count);
+ serial_puts(sercon_handle, cntbuf);
serial_puts(sercon_handle, buf);
}
else
{
- for ( p = buf; *p != '\0'; p++ )
+ if ( strcmp(buf, last_buf) )
+ {
+ last_prd = debugtrace_prd;
+ last_count = ++count;
+ safe_strcpy(last_buf, buf);
+ snprintf(cntbuf, sizeof(cntbuf), "%u ", count);
+ }
+ else
{
- debugtrace_buf[debugtrace_prd++] = *p;
- /* Always leave a nul byte at the end of the buffer. */
- if ( debugtrace_prd == (debugtrace_bytes - 1) )
- debugtrace_prd = 0;
+ debugtrace_prd = last_prd;
+ snprintf(cntbuf, sizeof(cntbuf), "%u-%u ", last_count, ++count);
}
+ debugtrace_add_to_buf(cntbuf);
+ debugtrace_add_to_buf(buf);
}
spin_unlock_irqrestore(&debugtrace_lock, flags);
--
2.16.4
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