Re: [PATCH v6 3/4] tracing: Use vmap_page_range() to map memmap ring buffer

[Steven Rostedt]

On Sun, 6 Apr 2025 10:39:27 -0700
Guenter Roeck <linux@xxxxxxxxxxxx> wrote:

> non-MMU builds (xtensa:nommu_kc705_defconfig):

Bah!

> 
> kernel/trace/trace.o:(.init.literal+0x250): undefined reference to `get_vm_area'

Does this fix it?

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b581e388a9d9..8ddf6b17215c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9806,6 +9806,7 @@ static int instance_mkdir(const char *name)
 	return ret;
 }
 
+#ifdef CONFIG_MMU
 static u64 map_pages(unsigned long start, unsigned long size)
 {
 	unsigned long vmap_start, vmap_end;
@@ -9828,6 +9829,12 @@ static u64 map_pages(unsigned long start, unsigned long size)
 
 	return (u64)vmap_start;
 }
+#else
+static inline u64 map_pages(unsigned long start, unsigned long size)
+{
+	return 0;
+}
+#endif
 
 /**
  * trace_array_get_by_name - Create/Lookup a trace array, given its name.


-- Steve