When using trace_printk for cpumask I've got wrong results,
some bitmaps were completely different from what I expected.
Currently you get wrong results when using trace_printk
on local cpumask, like:
void test(void)
{
struct cpumask mask;
...
trace_printk("mask '%*pbl'\n", cpumask_pr_args(&mask));
}
The reason is that trace_printk stores the data into binary
buffer (pointer for cpumask), which is read after via read
handler of trace/trace_pipe files. At that time pointer for
local cpumask is no longer valid and you get wrong data.
Fixing this by storing complete cpumask into tracing buffer.
Cc: Steven Rostedt <rost...@goodmis.org>
Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
lib/vsprintf.c | 41 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 36 insertions(+), 5 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 0967771d8f7f..f21d68e1b5fc 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -388,7 +388,8 @@ enum format_type {
struct printf_spec {
unsigned int type:8; /* format_type enum */
signed int field_width:24; /* width of output field */
- unsigned int flags:8; /* flags to number() */
+ unsigned int flags:7; /* flags to number() */
+ unsigned int cpumask:1; /* pointer to cpumask flag */
unsigned int base:8; /* number base, 8, 10 or 16 only */
signed int precision:16; /* # of digits/chars */
} __packed;
@@ -1864,6 +1865,7 @@ qualifier:
case 'p':
spec->type = FORMAT_TYPE_PTR;
+ spec->cpumask = fmt[1] == 'b';
return ++fmt - start;
case '%':
@@ -2338,7 +2340,23 @@ do {
\
}
case FORMAT_TYPE_PTR:
- save_arg(void *);
+ if (spec.cpumask) {
+ /*
+ * Store entire cpumask directly to buffer
+ * instead of storing just a pointer.
+ */
+ struct cpumask *mask = va_arg(args, void *);
+
+ str = PTR_ALIGN(str, sizeof(u32));
+
+ if (str + sizeof(*mask) <= end)
+ cpumask_copy((struct cpumask *) str,
mask);
+
+ str += sizeof(*mask);
+ } else {
+ save_arg(void *);
+ }
+
/* skip all alphanumeric pointer suffixes */
while (isalnum(*fmt))
fmt++;
@@ -2490,12 +2508,25 @@ int bstr_printf(char *buf, size_t size, const char
*fmt, const u32 *bin_buf)
break;
}
- case FORMAT_TYPE_PTR:
- str = pointer(fmt, str, end, get_arg(void *), spec);
+ case FORMAT_TYPE_PTR: {
+ void *ptr;
+
+ if (spec.cpumask) {
+ /*
+ * Load cpumask directly from buffer.
+ */
+ args = PTR_ALIGN(args, sizeof(u32));
+ ptr = (void *) args;
+ args += sizeof(struct cpumask);
+ } else {
+ ptr = get_arg(void *);
+ }
+
+ str = pointer(fmt, str, end, ptr, spec);
while (isalnum(*fmt))
fmt++;
break;
-
+ }
case FORMAT_TYPE_PERCENT_CHAR:
if (str < end)
*str = '%';
--
2.4.11
