From patchwork series 394255

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=394255

Author: Fox Snowpatch

arch/powerpc/include/asm/ftrace.h

@@ -20,14 +20,7 @@
 #ifndef __ASSEMBLY__
 extern void _mcount(void);
 
-static inline unsigned long ftrace_call_adjust(unsigned long addr)
-{
-	if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY))
-		addr += MCOUNT_INSN_SIZE;
-
-	return addr;
-}
-
+unsigned long ftrace_call_adjust(unsigned long addr);
 unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
 				    unsigned long sp);
 

arch/powerpc/include/asm/sections.h

@@ -14,6 +14,7 @@ typedef struct func_desc func_desc_t;
 
 extern char __head_end[];
 extern char __srwx_boundary[];
+extern char _sexittext[], _eexittext[];
 
 /* Patch sites */
 extern s32 patch__call_flush_branch_caches1;

arch/powerpc/kernel/trace/ftrace.c

@@ -27,10 +27,22 @@
 #include <asm/ftrace.h>
 #include <asm/syscall.h>
 #include <asm/inst.h>
+#include <asm/sections.h>
 
 #define	NUM_FTRACE_TRAMPS	2
 static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
 
+unsigned long ftrace_call_adjust(unsigned long addr)
+{
+	if (addr >= (unsigned long)_sexittext && addr < (unsigned long)_eexittext)
+		return 0;
+
+	if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY))
+		addr += MCOUNT_INSN_SIZE;
+
+	return addr;
+}
+
 static ppc_inst_t ftrace_create_branch_inst(unsigned long ip, unsigned long addr, int link)
 {
 	ppc_inst_t op;

arch/powerpc/kernel/vmlinux.lds.S

@@ -281,7 +281,9 @@ SECTIONS
 	 * to deal with references from __bug_table
 	 */
 	.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
+		_sexittext = .;
 		EXIT_TEXT
+		_eexittext = .;
 	}
 
 	. = ALIGN(PAGE_SIZE);