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Commit f2942487 authored by Carsten Emde's avatar Carsten Emde Committed by Steven Rostedt
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tracing: Remove comparing of NULL to va_list in trace_array_vprintk() 



Olof Johansson stated the following:

  Comparing a va_list with NULL is bogus. It's supposed to be treated like
  an opaque type and only be manipulated with va_* accessors.

Olof noticed that this code broke the ARM builds:

    kernel/trace/trace.c: In function 'trace_array_vprintk':
    kernel/trace/trace.c:1364: error: invalid operands to binary == (have 'va_list' and 'void *')
    kernel/trace/trace.c: In function 'tracing_mark_write':
    kernel/trace/trace.c:3349: error: incompatible type for argument 3 of 'trace_vprintk'

This patch partly reverts c13d2f7c and
re-installs the original mark_printk() mechanism.

Reported-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarCarsten Emde <C.Emde@osadl.org>
LKML-Reference: <4B1BAB74.104@osadl.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent be1eca39

kernel/trace/trace.c

+12 −6
Original line number Diff line number Diff line
@@ -1361,10 +1361,6 @@ int trace_array_vprintk(struct trace_array *tr, 
	pause_graph_tracing();

	raw_local_irq_save(irq_flags);

	__raw_spin_lock(&trace_buf_lock);

	if (args == NULL) {

		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);

		len = strlen(trace_buf);

	} else

	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);



	size = sizeof(*entry) + len + 1;
@@ -3353,6 +3349,16 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, 
	return cnt;

}



static int mark_printk(const char *fmt, ...)

{

	int ret;

	va_list args;

	va_start(args, fmt);

	ret = trace_vprintk(0, fmt, args);

	va_end(args);

	return ret;

}



static ssize_t

tracing_mark_write(struct file *filp, const char __user *ubuf,

					size_t cnt, loff_t *fpos)
@@ -3379,7 +3385,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, 
	} else

		buf[cnt] = '\0';



	cnt = trace_vprintk(0, buf, NULL);

	cnt = mark_printk("%s", buf);

	kfree(buf);

	*fpos += cnt;