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

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1d027ce94ab12b08d4162b88a03243fafe7c6b61..2a851d31f1200ac8cd151f549e3f4f29dd16728a 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -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)

diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index b3f6184f77eaade525b07b1b415d1a981f573a9f..45c3d6f11daac001cbfd0e486f2692d962c1dfa6 100644 (file)
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h
@@ -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

diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 37af961eb74cc815d14551f41197fc3d3455fdba..6f10de6af6e3499d9c62092dbd33cfd2678c634a 100644 (file)
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -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