[PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE
Naveen N. Rao
naveen.n.rao at linux.vnet.ibm.com
Mon Apr 18 17:00:09 AEST 2022
Christophe Leroy wrote:
> 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
> ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c
>
> Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
> ---
> 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\", at 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.
> 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
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