Commit 14e56fb2 authored by Mike Rapoport (IBM)'s avatar Mike Rapoport (IBM) Committed by Luis Chamberlain
Browse files

x86/ftrace: enable dynamic ftrace without CONFIG_MODULES 



Dynamic ftrace must allocate memory for code and this was impossible
without CONFIG_MODULES.

With execmem separated from the modules code, execmem_text_alloc() is
available regardless of CONFIG_MODULES.

Remove dependency of dynamic ftrace on CONFIG_MODULES and make
CONFIG_DYNAMIC_FTRACE select CONFIG_EXECMEM in Kconfig.

Signed-off-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent 0cc2dc49

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ config X86_64 
	select SWIOTLB

	select ARCH_HAS_ELFCORE_COMPAT

	select ZONE_DMA32

	select EXECMEM if DYNAMIC_FTRACE



config FORCE_DYNAMIC_FTRACE

	def_bool y

arch/x86/kernel/ftrace.c

+0 −10
Original line number Diff line number Diff line
@@ -261,8 +261,6 @@ void arch_ftrace_update_code(int command) 
/* Currently only x86_64 supports dynamic trampolines */

#ifdef CONFIG_X86_64



#ifdef CONFIG_MODULES

/* Module allocation simplifies allocating memory for code */

static inline void *alloc_tramp(unsigned long size)

{

	return execmem_alloc(EXECMEM_FTRACE, size);
@@ -271,14 +269,6 @@ static inline void tramp_free(void *tramp) 
{

	execmem_free(tramp);

}

#else

/* Trampolines can only be created if modules are supported */

static inline void *alloc_tramp(unsigned long size)

{

	return NULL;

}

static inline void tramp_free(void *tramp) { }

#endif



/* Defined as markers to the end of the ftrace default trampolines */

extern void ftrace_regs_caller_end(void);