Make platform-specific Feather-Trace depend on !CONFIG_DEBUG_RODATA

Feather-Trace rewrites instructions in the kernel's .text segment.
This segment may be write-protected if CONFIG_DEBUG_RODATA is selected.
In this case, fall back to the default flag-based Feather-Trace
implementation. In the future, we could either adopt the ftrace method
of rewriting .text addresses using non-.text mappings or we could
consider replacing Feather-Trace with ftrace altogether.

For now, this patch avoids unexpected runtime errors.

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/kernel/ft_event.c b/arch/x86/kernel/ft_event.c
index da9b3ccb7259..6552e2741ecf 100644
--- a/arch/x86/kernel/ft_event.c
+++ b/arch/x86/kernel/ft_event.c
@@ -6,6 +6,7 @@
  * exclusive access to the event table
  */
 
+#ifndef CONFIG_DEBUG_RODATA
 
 #define BYTE_JUMP      0xeb
 #define BYTE_JUMP_LEN  0x02
@@ -106,3 +107,5 @@ int ft_is_event_enabled(unsigned long id)
         }
         return 0;
 }
+
+#endif