Messages in this thread | | | From | Huacai Chen <> | Date | Tue, 15 Nov 2022 17:24:31 +0800 | Subject | Re: [PATCH v6 5/9] LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support |
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On Tue, Nov 15, 2022 at 5:22 PM Qing Zhang <zhangqing@loongson.cn> wrote: > > Hi, Huacai > > On 2022/11/15 下午4:41, Huacai Chen wrote: > > Hi, Qing, > > > > Patch5 and Patch6 are small and related, maybe they can be combined > > with a name "LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_{ARGS,REGS} > > support" > I think they should be independent due to different use scenarios. From the commit message it seems DYNAMIC_FTRACE_WITH_ARGS depend on DYNAMIC_FTRACE_WITH_REGS.
Huacai > > Thanks, > -Qing > > > > Huacai > > > > On Tue, Nov 15, 2022 at 10:55 AM Qing Zhang <zhangqing@loongson.cn> wrote: > >> > >> This patch implements DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows > >> a traced function's arguments (and some other registers) to be captured > >> into a struct pt_regs, allowing these to be inspected and modified. > >> > >> Co-developed-by: Jinyang He <hejinyang@loongson.cn> > >> Signed-off-by: Jinyang He <hejinyang@loongson.cn> > >> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> > >> --- > >> arch/loongarch/Kconfig | 1 + > >> arch/loongarch/include/asm/ftrace.h | 3 +++ > >> arch/loongarch/kernel/ftrace_dyn.c | 17 ++++++++++++++ > >> arch/loongarch/kernel/mcount-dyn.S | 36 +++++++++++++++++++++++++++-- > >> 4 files changed, 55 insertions(+), 2 deletions(-) > >> > >> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig > >> index 615ce62422b8..12e3e91a68ae 100644 > >> --- a/arch/loongarch/Kconfig > >> +++ b/arch/loongarch/Kconfig > >> @@ -90,6 +90,7 @@ config LOONGARCH > >> select HAVE_DEBUG_STACKOVERFLOW > >> select HAVE_DMA_CONTIGUOUS > >> select HAVE_DYNAMIC_FTRACE > >> + select HAVE_DYNAMIC_FTRACE_WITH_REGS > >> select HAVE_EBPF_JIT > >> select HAVE_EXIT_THREAD > >> select HAVE_FAST_GUP > >> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h > >> index 76ca58767f4d..a3f974a7a5ce 100644 > >> --- a/arch/loongarch/include/asm/ftrace.h > >> +++ b/arch/loongarch/include/asm/ftrace.h > >> @@ -28,6 +28,9 @@ struct dyn_ftrace; > >> int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); > >> #define ftrace_init_nop ftrace_init_nop > >> > >> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > >> +#define ARCH_SUPPORTS_FTRACE_OPS 1 > >> +#endif > >> #endif /* CONFIG_DYNAMIC_FTRACE */ > >> #endif /* __ASSEMBLY__ */ > >> #endif /* CONFIG_FUNCTION_TRACER */ > >> diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c > >> index 3fe791b6783e..ec3d951be50c 100644 > >> --- a/arch/loongarch/kernel/ftrace_dyn.c > >> +++ b/arch/loongarch/kernel/ftrace_dyn.c > >> @@ -99,6 +99,23 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, > >> return ftrace_modify_code(pc, old, new, true); > >> } > >> > >> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > >> +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, > >> + unsigned long addr) > >> +{ > >> + unsigned long pc; > >> + long offset; > >> + u32 old, new; > >> + > >> + pc = rec->ip + LOONGARCH_INSN_SIZE; > >> + > >> + old = larch_insn_gen_bl(pc, old_addr); > >> + new = larch_insn_gen_bl(pc, addr); > >> + > >> + return ftrace_modify_code(pc, old, new, true); > >> +} > >> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > >> + > >> void arch_ftrace_update_code(int command) > >> { > >> command |= FTRACE_MAY_SLEEP; > >> diff --git a/arch/loongarch/kernel/mcount-dyn.S b/arch/loongarch/kernel/mcount-dyn.S > >> index 0c12cc108e6f..02835186b463 100644 > >> --- a/arch/loongarch/kernel/mcount-dyn.S > >> +++ b/arch/loongarch/kernel/mcount-dyn.S > >> @@ -27,7 +27,7 @@ > >> * follows the LoongArch psABI well. > >> */ > >> > >> - .macro ftrace_regs_entry > >> + .macro ftrace_regs_entry allregs=0 > >> PTR_ADDI sp, sp, -PT_SIZE > >> /* Save trace function ra at PT_ERA */ > >> PTR_S ra, sp, PT_ERA > >> @@ -43,16 +43,48 @@ > >> PTR_S a7, sp, PT_R11 > >> PTR_S fp, sp, PT_R22 > >> > >> + .if \allregs > >> + PTR_S t0, sp, PT_R12 > >> + PTR_S t1, sp, PT_R13 > >> + PTR_S t2, sp, PT_R14 > >> + PTR_S t3, sp, PT_R15 > >> + PTR_S t4, sp, PT_R16 > >> + PTR_S t5, sp, PT_R17 > >> + PTR_S t6, sp, PT_R18 > >> + PTR_S t7, sp, PT_R19 > >> + PTR_S t8, sp, PT_R20 > >> + PTR_S s0, sp, PT_R23 > >> + PTR_S s1, sp, PT_R24 > >> + PTR_S s2, sp, PT_R25 > >> + PTR_S s3, sp, PT_R26 > >> + PTR_S s4, sp, PT_R27 > >> + PTR_S s5, sp, PT_R28 > >> + PTR_S s6, sp, PT_R29 > >> + PTR_S s7, sp, PT_R30 > >> + PTR_S s8, sp, PT_R31 > >> + PTR_S tp, sp, PT_R2 > >> + /* Clear it for later use as a flag sometimes. */ > >> + PTR_S zero, sp, PT_R0 > >> + PTR_S $r21, sp, PT_R21 > >> + .endif > >> + > >> PTR_ADDI t8, sp, PT_SIZE > >> PTR_S t8, sp, PT_R3 > >> > >> .endm > >> > >> SYM_CODE_START(ftrace_caller) > >> - ftrace_regs_entry > >> + ftrace_regs_entry allregs=0 > >> b ftrace_common > >> SYM_CODE_END(ftrace_caller) > >> > >> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > >> +SYM_CODE_START(ftrace_regs_caller) > >> + ftrace_regs_entry allregs=1 > >> + b ftrace_common > >> +SYM_CODE_END(ftrace_regs_caller) > >> +#endif > >> + > >> SYM_CODE_START(ftrace_common) > >> PTR_ADDI a0, ra, -8 /* arg0: ip */ > >> move a1, t0 /* arg1: parent_ip */ > >> -- > >> 2.36.0 > >> > >> > >
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