Le 18/04/2022 à 09:00, Naveen N. Rao a écrit :

Christophe Leroy wrote:

quoted

Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
static"), CONFIG_DYNAMIC_FTRACE is always selected when
CONFIG_FUNCTION_TRACER is selected.

To avoid confusion and have the reader wonder what's happen when
CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE.

As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER,
ftrace.o doesn't need to appear for both symbols in Makefile.

Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected

and since it implies CONFIG_DYNAMIC_FTRACE, CONFIG_DYNAMIC_FTRACE is not 
needed in ftrace.c

Ok, added to the commit message

quoted

ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c

Signed-off-by: Christophe Leroy <redacted>
---
 arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
 arch/powerpc/include/asm/module.h            | 4 ++--
 arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
 arch/powerpc/kernel/module_32.c              | 4 ++--
 arch/powerpc/kernel/module_64.c              | 6 +++---
 arch/powerpc/kernel/trace/Makefile           | 4 +---
 arch/powerpc/kernel/trace/ftrace.c           | 4 ----
 8 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h 

b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 772e00dc4ef1..992aed626eb4 100644

--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h

@@ -124,7 +124,7 @@ static inline bool pte_user(pte_t pte)

  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
defined(CONFIG_BDI_SWITCH) ||\
-    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h 

b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 875730d5af40..cf01b609572f 100644

--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h

@@ -169,7 +169,7 @@

  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
defined(CONFIG_BDI_SWITCH) || \
-    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX

diff --git a/arch/powerpc/include/asm/module.h 

b/arch/powerpc/include/asm/module.h
index 857d9ff24295..e6f5963fd96e 100644

--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h

@@ -39,7 +39,7 @@ struct mod_arch_specific {

     unsigned int init_plt_section;
 #endif /* powerpc64 */

-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
     unsigned long tramp;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
     unsigned long tramp_regs;

@@ -68,7 +68,7 @@ struct mod_arch_specific {

 #    endif    /* MODULE */
 #endif

-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 #    ifdef MODULE
     asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
 #    endif    /* MODULE */

diff --git a/arch/powerpc/include/asm/nohash/pgtable.h 

b/arch/powerpc/include/asm/nohash/pgtable.h
index ac75f4ab0dba..2e8cf217a191 100644

--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h

@@ -23,7 +23,7 @@

  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || 
defined(CONFIG_BDI_SWITCH) ||\
-    defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
+    defined(CONFIG_KPROBES) || defined(CONFIG_FUNCTION_TRACER)
 #define PAGE_KERNEL_TEXT    PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT    PAGE_KERNEL_ROX

diff --git a/arch/powerpc/kernel/module_32.c 

b/arch/powerpc/kernel/module_32.c
index a0432ef46967..2aa368ce21c9 100644

--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c

@@ -39,7 +39,7 @@ static unsigned int count_relocs(const Elf32_Rela 

*rela, unsigned int num)
             r_addend = rela[i].r_addend;
         }

-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
     _count_relocs++;    /* add one for ftrace_caller */
 #endif
     return _count_relocs;

@@ -288,7 +288,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,

     return 0;
 }

-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 int module_trampoline_target(struct module *mod, unsigned long addr,
                  unsigned long *target)
 {

diff --git a/arch/powerpc/kernel/module_64.c 

b/arch/powerpc/kernel/module_64.c
index 794720530442..b13a72665eee 100644

--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c

@@ -207,7 +207,7 @@ static unsigned long get_stubs_size(const 

Elf64_Ehdr *hdr,
         }
     }

-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
     /* make the trampoline to the ftrace_caller */
     relocs++;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS

@@ -372,7 +372,7 @@ static bool is_mprofile_ftrace_call(const char *name)

 {
     if (!strcmp("_mcount", name))
         return true;
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
     if (!strcmp("ftrace_caller", name))
         return true;
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS

@@ -740,7 +740,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,

     return 0;
 }

-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 int module_trampoline_target(struct module *mod, unsigned long addr,
                  unsigned long *target)
 {

The below two changes to trace/Makefile and trace/ftrace.c make sense, 
but I'm not sure the above changes are necessary.

For generic code (outside arch/powerpc/kernel/trace), I think it is good 
to retain the actual dependency which is DYNAMIC_FTRACE. In my view, 
gating some of the above code on FUNCTION_TRACER is also confusing. The 
primary implication of always selecting DYNAMIC_FTRACE is within the 
powerpc trace code, and it is good to keep it that way.

Ok I keep only the changes to trace directory for now.

quoted

diff --git a/arch/powerpc/kernel/trace/Makefile 

b/arch/powerpc/kernel/trace/Makefile
index fc32ec30b297..af8527538fe4 100644

--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile

@@ -14,9 +14,7 @@ obj64-$(CONFIG_FUNCTION_TRACER)        += 

ftrace_mprofile.o
 else
 obj64-$(CONFIG_FUNCTION_TRACER)        += ftrace_64_pg.o
 endif
-obj-$(CONFIG_FUNCTION_TRACER)        += ftrace_low.o
-obj-$(CONFIG_DYNAMIC_FTRACE)        += ftrace.o
-obj-$(CONFIG_FUNCTION_GRAPH_TRACER)    += ftrace.o
+obj-$(CONFIG_FUNCTION_TRACER)        += ftrace_low.o ftrace.o
 obj-$(CONFIG_TRACING)            += trace_clock.o

 obj-$(CONFIG_PPC64)            += $(obj64-y)

diff --git a/arch/powerpc/kernel/trace/ftrace.c 

b/arch/powerpc/kernel/trace/ftrace.c
index 2c7e42e439bb..188f59f4ee4a 100644

--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c

@@ -28,9 +28,6 @@

 #include <asm/syscall.h>
 #include <asm/inst.h>

-
-#ifdef CONFIG_DYNAMIC_FTRACE
-
 /*
  * We generally only have a single long_branch tramp and at most 2 or 
3 plt
  * tramps generated. But, we don't use the plt tramps currently. We 
also allot

@@ -783,7 +780,6 @@ int __init ftrace_dyn_arch_init(void)

     return 0;
 }
 #endif
-#endif /* CONFIG_DYNAMIC_FTRACE */

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER

-- 
2.35.1

- Naveen