Messages in this thread | | | Subject | Re: [PATCH v6 5/9] LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support | From | Qing Zhang <> | Date | Tue, 15 Nov 2022 17:22:49 +0800 |
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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.
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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