[PATCH v1] ftrace: Fix compile error when CONFIG_GENDWARFKSYMS is enabled

[Haiyue Wang]

When switching from CONFIG_GENKSYMS to CONFIG_GENDWARFKSYMS enabled, the
build is failed:

  AS      arch/x86/entry/entry.o
In file included from ./arch/x86/include/asm/asm-prototypes.h:2,
                 from <stdin>:3:
./arch/x86/include/asm/ftrace.h: In function ‘arch_ftrace_get_symaddr’:
./arch/x86/include/asm/ftrace.h:46:21: error: implicit declaration of function ‘get_kernel_nofault’ [-Werror=implicit-function-declaration]
   46 |                 if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE)))
      |                     ^~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors

File "asm-prototypes.h" is added to entry.S by 'scripts/Makefile.build',
adding the missed declaration header file can also fix the error:

 getasmexports =                                                        \
    { echo "\#include <linux/kernel.h>" ;                               \
      echo "\#include <linux/string.h>" ;                               \
+     echo "\#include <linux/uaccess.h>";                               \
      echo "\#include <asm/asm-prototypes.h>" ;                         \
      $(call getexportsymbols,EXPORT_SYMBOL(\1);) ; }

Fixes: 2bc56fdae1ba ("ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr")

Signed-off-by: Haiyue Wang <haiyuewa@xxxxxxx>
---
 arch/x86/include/asm/ftrace.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index f9cb4d07df58..063ce70837bb 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -34,6 +34,10 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
 	return addr;
 }
 
+#ifdef CONFIG_X86_KERNEL_IBT
+#include <linux/uaccess.h>
+#endif
+
 static inline unsigned long arch_ftrace_get_symaddr(unsigned long fentry_ip)
 {
 #ifdef CONFIG_X86_KERNEL_IBT
-- 
2.48.1