| Message ID | 20180316134633.10584-2-mpe@ellerman.id.au (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFC,1/2] ftrace: Allow arches to opt-out of static ftrace | expand |
On Sat, 17 Mar 2018 00:46:33 +1100 Michael Ellerman <mpe@ellerman.id.au> wrote: > We've had dynamic ftrace support for over 9 years since Steve first > wrote it, all the distros use dynamic, and static is basically > untested these days, so drop support for static ftrace. > > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> > --- > arch/powerpc/Kconfig | 1 + > arch/powerpc/include/asm/ftrace.h | 4 +--- > arch/powerpc/include/asm/module.h | 5 ----- > arch/powerpc/kernel/trace/ftrace.c | 2 -- > arch/powerpc/kernel/trace/ftrace_32.S | 20 ------------------ > arch/powerpc/kernel/trace/ftrace_64.S | 29 -------------------------- > arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 3 --- > arch/powerpc/kernel/trace/ftrace_64_pg.S | 2 -- > 8 files changed, 2 insertions(+), 64 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 73ce5dd07642..23a325df784a 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -189,6 +189,7 @@ config PPC > select HAVE_DEBUG_STACKOVERFLOW > select HAVE_DMA_API_DEBUG > select HAVE_DYNAMIC_FTRACE > + select HAVE_DYNAMIC_FTRACE_ONLY I still think adding: select DYNAMIC_FTRACE if FUNCTION_TRACER is the better approach. But I'm all for this patch. I've debated doing the same thing for x86, but the only reason I have not, was because it's the only way I test the !DYNAMIC_FTRACE code. I've broken the static function tracing several times and only find out during my test suite that still tests that case. But yeah, it would be nice to just nuke static function tracing for all archs. Perhaps after we finish removing unused archs, that may be the way to go forward. -- Steve > select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL > select HAVE_EBPF_JIT if PPC64 > select HAVE_EFFICIENT_UNALIGNED_ACCESS if !(CPU_LITTLE_ENDIAN && POWER7_CPU)
Steven Rostedt <rostedt@goodmis.org> writes: > On Sat, 17 Mar 2018 00:46:33 +1100 > Michael Ellerman <mpe@ellerman.id.au> wrote: > >> We've had dynamic ftrace support for over 9 years since Steve first >> wrote it, all the distros use dynamic, and static is basically >> untested these days, so drop support for static ftrace. >> >> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> >> --- >> arch/powerpc/Kconfig | 1 + >> arch/powerpc/include/asm/ftrace.h | 4 +--- >> arch/powerpc/include/asm/module.h | 5 ----- >> arch/powerpc/kernel/trace/ftrace.c | 2 -- >> arch/powerpc/kernel/trace/ftrace_32.S | 20 ------------------ >> arch/powerpc/kernel/trace/ftrace_64.S | 29 -------------------------- >> arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 3 --- >> arch/powerpc/kernel/trace/ftrace_64_pg.S | 2 -- >> 8 files changed, 2 insertions(+), 64 deletions(-) >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index 73ce5dd07642..23a325df784a 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -189,6 +189,7 @@ config PPC >> select HAVE_DEBUG_STACKOVERFLOW >> select HAVE_DMA_API_DEBUG >> select HAVE_DYNAMIC_FTRACE >> + select HAVE_DYNAMIC_FTRACE_ONLY > > I still think adding: > > select DYNAMIC_FTRACE if FUNCTION_TRACER > > is the better approach. OK. As I said in my other reply it's a bit fragile, but it does work. I'll do a version for powerpc using the above approach. > But I'm all for this patch. I've debated doing the same thing for x86, > but the only reason I have not, was because it's the only way I test > the !DYNAMIC_FTRACE code. I've broken the static function tracing > several times and only find out during my test suite that still tests > that case. But yeah, it would be nice to just nuke static function > tracing for all archs. Perhaps after we finish removing unused archs, > that may be the way to go forward. Yeah I did look and we still have some arches that support ftrace but not dynamic ftrace, but there's not many. cheers
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 73ce5dd07642..23a325df784a 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -189,6 +189,7 @@ config PPC select HAVE_DEBUG_STACKOVERFLOW select HAVE_DMA_API_DEBUG select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_ONLY select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL select HAVE_EBPF_JIT if PPC64 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 9abddde372ab..e6c34d740ee9 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -48,7 +48,6 @@ #else /* !__ASSEMBLY__ */ extern void _mcount(void); -#ifdef CONFIG_DYNAMIC_FTRACE # define FTRACE_ADDR ((unsigned long)ftrace_caller) # define FTRACE_REGS_ADDR FTRACE_ADDR static inline unsigned long ftrace_call_adjust(unsigned long addr) @@ -60,13 +59,12 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) struct dyn_arch_ftrace { struct module *mod; }; -#endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* __ASSEMBLY__ */ #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS #define ARCH_SUPPORTS_FTRACE_OPS 1 #endif -#endif +#endif /* CONFIG_FUNCTION_TRACER */ #if defined(CONFIG_FTRACE_SYSCALLS) && !defined(__ASSEMBLY__) #ifdef PPC64_ELF_ABI_v1 diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h index 7e28442827f1..e09c96d0db69 100644 --- a/arch/powerpc/include/asm/module.h +++ b/arch/powerpc/include/asm/module.h @@ -90,11 +90,6 @@ int module_trampoline_target(struct module *mod, unsigned long trampoline, #ifdef CONFIG_DYNAMIC_FTRACE int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs); -#else -static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs) -{ - return 0; -} #endif #endif /* __KERNEL__ */ diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 4741fe112f05..c6d196d85260 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -538,7 +538,6 @@ int __init ftrace_dyn_arch_init(void) #ifdef CONFIG_FUNCTION_GRAPH_TRACER -#ifdef CONFIG_DYNAMIC_FTRACE extern void ftrace_graph_call(void); extern void ftrace_graph_stub(void); @@ -567,7 +566,6 @@ int ftrace_disable_ftrace_graph_caller(void) return ftrace_modify_code(ip, old, new); } -#endif /* CONFIG_DYNAMIC_FTRACE */ /* * Hook the return address and push it in the stack of return addrs diff --git a/arch/powerpc/kernel/trace/ftrace_32.S b/arch/powerpc/kernel/trace/ftrace_32.S index afef2c076282..2c29098f630f 100644 --- a/arch/powerpc/kernel/trace/ftrace_32.S +++ b/arch/powerpc/kernel/trace/ftrace_32.S @@ -14,7 +14,6 @@ #include <asm/ftrace.h> #include <asm/export.h> -#ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL(mcount) _GLOBAL(_mcount) /* @@ -47,26 +46,7 @@ _GLOBAL(ftrace_graph_stub) MCOUNT_RESTORE_FRAME /* old link register ends up in ctr reg */ bctr -#else -_GLOBAL(mcount) -_GLOBAL(_mcount) - - MCOUNT_SAVE_FRAME - subi r3, r3, MCOUNT_INSN_SIZE - LOAD_REG_ADDR(r5, ftrace_trace_function) - lwz r5,0(r5) - - mtctr r5 - bctrl - nop - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - b ftrace_graph_caller -#endif - MCOUNT_RESTORE_FRAME - bctr -#endif EXPORT_SYMBOL(_mcount) _GLOBAL(ftrace_stub) diff --git a/arch/powerpc/kernel/trace/ftrace_64.S b/arch/powerpc/kernel/trace/ftrace_64.S index e5ccea19821e..e25f77c10a72 100644 --- a/arch/powerpc/kernel/trace/ftrace_64.S +++ b/arch/powerpc/kernel/trace/ftrace_64.S @@ -14,7 +14,6 @@ #include <asm/ppc-opcode.h> #include <asm/export.h> -#ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL(mcount) _GLOBAL(_mcount) EXPORT_SYMBOL(_mcount) @@ -23,34 +22,6 @@ EXPORT_SYMBOL(_mcount) mtlr r0 bctr -#else /* CONFIG_DYNAMIC_FTRACE */ -_GLOBAL_TOC(_mcount) -EXPORT_SYMBOL(_mcount) - /* Taken from output of objdump from lib64/glibc */ - mflr r3 - ld r11, 0(r1) - stdu r1, -112(r1) - std r3, 128(r1) - ld r4, 16(r11) - - subi r3, r3, MCOUNT_INSN_SIZE - LOAD_REG_ADDR(r5,ftrace_trace_function) - ld r5,0(r5) - ld r5,0(r5) - mtctr r5 - bctrl - nop - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - b ftrace_graph_caller -#endif - ld r0, 128(r1) - mtlr r0 - addi r1, r1, 112 -_GLOBAL(ftrace_stub) - blr -#endif /* CONFIG_DYNAMIC_FTRACE */ - #ifdef CONFIG_FUNCTION_GRAPH_TRACER _GLOBAL(return_to_handler) /* need to save return values */ diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S index 3f3e81852422..625f9b758da7 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S +++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S @@ -17,7 +17,6 @@ #include <asm/bug.h> #include <asm/ptrace.h> -#ifdef CONFIG_DYNAMIC_FTRACE /* * * ftrace_caller() is the function that replaces _mcount() when ftrace is @@ -236,8 +235,6 @@ livepatch_handler: blr #endif /* CONFIG_LIVEPATCH */ -#endif /* CONFIG_DYNAMIC_FTRACE */ - #ifdef CONFIG_FUNCTION_GRAPH_TRACER _GLOBAL(ftrace_graph_caller) stdu r1, -112(r1) diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.S b/arch/powerpc/kernel/trace/ftrace_64_pg.S index f095358da96e..f18762827e51 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_pg.S +++ b/arch/powerpc/kernel/trace/ftrace_64_pg.S @@ -14,7 +14,6 @@ #include <asm/ppc-opcode.h> #include <asm/export.h> -#ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL_TOC(ftrace_caller) /* Taken from output of objdump from lib64/glibc */ mflr r3 @@ -39,7 +38,6 @@ _GLOBAL(ftrace_graph_stub) _GLOBAL(ftrace_stub) blr -#endif /* CONFIG_DYNAMIC_FTRACE */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER _GLOBAL(ftrace_graph_caller)
We've had dynamic ftrace support for over 9 years since Steve first wrote it, all the distros use dynamic, and static is basically untested these days, so drop support for static ftrace. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/ftrace.h | 4 +--- arch/powerpc/include/asm/module.h | 5 ----- arch/powerpc/kernel/trace/ftrace.c | 2 -- arch/powerpc/kernel/trace/ftrace_32.S | 20 ------------------ arch/powerpc/kernel/trace/ftrace_64.S | 29 -------------------------- arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 3 --- arch/powerpc/kernel/trace/ftrace_64_pg.S | 2 -- 8 files changed, 2 insertions(+), 64 deletions(-)