Commit 40b035ef authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS 



Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS. It accelerates the call
of livepatching.

Also note that powerpc being the last one to convert to
CONFIG_DYNAMIC_FTRACE_WITH_ARGS, it will now be possible to remove
klp_arch_set_pc() on all architectures.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5831f711a778fcd6eb51eb5898f1faae4378b35b.1640017960.git.christophe.leroy@csgroup.eu
parent c75388a8

arch/powerpc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -201,6 +201,7 @@ config PPC 
	select HAVE_DEBUG_KMEMLEAK

	select HAVE_DEBUG_STACKOVERFLOW

	select HAVE_DYNAMIC_FTRACE

	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if MPROFILE_KERNEL || PPC32

	select HAVE_DYNAMIC_FTRACE_WITH_REGS	if MPROFILE_KERNEL || PPC32

	select HAVE_EBPF_JIT

	select HAVE_EFFICIENT_UNALIGNED_ACCESS	if !(CPU_LITTLE_ENDIAN && POWER7_CPU)

arch/powerpc/include/asm/ftrace.h

+17 −0
Original line number Diff line number Diff line
@@ -22,6 +22,23 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) 
struct dyn_arch_ftrace {

	struct module *mod;

};



#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS

struct ftrace_regs {

	struct pt_regs regs;

};



static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)

{

	return &fregs->regs;

}



static __always_inline void ftrace_instruction_pointer_set(struct ftrace_regs *fregs,

							   unsigned long ip)

{

	regs_set_return_ip(&fregs->regs, ip);

}

#endif

#endif /* __ASSEMBLY__ */



#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS

arch/powerpc/include/asm/livepatch.h

+1 −3
Original line number Diff line number Diff line
@@ -14,9 +14,7 @@ 
#ifdef CONFIG_LIVEPATCH

static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)

{

	struct pt_regs *regs = ftrace_get_regs(fregs);



	regs_set_return_ip(regs, ip);

	ftrace_instruction_pointer_set(fregs, ip);

}



#define klp_get_ftrace_location klp_get_ftrace_location