From: guoren@kernel.org To: anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de, rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com, bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com, andy.chiu@sifive.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Guo Ren <guoren@kernel.org> Subject: [PATCH V3 5/5] riscv: ftrace: Make ftrace_caller call ftrace_graph_func Date: Wed, 23 Nov 2022 10:39:50 -0500 [thread overview] Message-ID: <20221123153950.2911981-6-guoren@kernel.org> (raw) In-Reply-To: <20221123153950.2911981-1-guoren@kernel.org> From: Song Shuai <suagrfillet@gmail.com> In order to make the function graph use ftrace directly, ftrace_caller should be adjusted to save the necessary regs against the pt_regs layout so it can call ftrace_graph_func reasonably. SAVE_ALL now saves all the regs according to the pt_regs struct. Here supersedes SAVE_ALL by SAVE_ABI_REGS which has an extra option to allow saving only the necessary ABI-related regs for ftrace_caller. ftrace_caller and ftrace_regs_caller save their regs with the respective option of SAVE_ABI_REGS, then call the tracing function, especially graph_ops's ftrace_graph_func. So the ftrace_graph_[regs]_call labels aren't needed anymore if FTRACE_WITH_REGS is defined. As the previous patch described, the ftrace_caller remains with its ftrace_graph_call if FTRACE_WITH_REGS isn't defined, For convenience, the original argument setup for the tracing function in ftrace_[regs]_caller is separated as PREPARE_ARGS. Signed-off-by: Song Shuai <suagrfillet@gmail.com> Tested-by: Guo Ren <guoren@kernel.org> Signed-off-by: Guo Ren <guoren@kernel.org> --- arch/riscv/kernel/mcount-dyn.S | 142 ++++++++++++++++++++++++--------- 1 file changed, 104 insertions(+), 38 deletions(-) diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index 64bc79816f5e..466c6ef217b1 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -57,19 +57,52 @@ .endm #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - .macro SAVE_ALL + +/** +* SAVE_ABI_REGS - save regs against the pt_regs struct +* +* @all: tell if saving all the regs +* +* If all is set, all the regs will be saved, otherwise only ABI +* related regs (a0-a7,epc,ra and optional s0) will be saved. +* +* After the stack is established, +* +* 0(sp) stores the PC of the traced function which can be accessed +* by &(fregs)->regs->epc in tracing function. Note that the real +* function entry address should be computed with -FENTRY_RA_OFFSET. +* +* 8(sp) stores the function return address (i.e. parent IP) that +* can be accessed by &(fregs)->regs->ra in tracing function. +* +* The other regs are saved at the respective localtion and accessed +* by the respective pt_regs member. +* +* Here is the layout of stack for your reference. +* +* PT_SIZE_ON_STACK -> +++++++++ +* + ..... + +* + t3-t6 + +* + s2-s11+ +* + a0-a7 + --++++-> ftrace_caller saved +* + s1 + + +* + s0 + --+ +* + t0-t2 + + +* + tp + + +* + gp + + +* + sp + + +* + ra + --+ // parent IP +* sp -> + epc + --+ // PC +* +++++++++ +**/ + .macro SAVE_ABI_REGS, all=0 addi sp, sp, -PT_SIZE_ON_STACK REG_S t0, PT_EPC(sp) REG_S x1, PT_RA(sp) - REG_S x2, PT_SP(sp) - REG_S x3, PT_GP(sp) - REG_S x4, PT_TP(sp) - REG_S x5, PT_T0(sp) - REG_S x6, PT_T1(sp) - REG_S x7, PT_T2(sp) - REG_S x8, PT_S0(sp) - REG_S x9, PT_S1(sp) + + // always save the ABI regs + REG_S x10, PT_A0(sp) REG_S x11, PT_A1(sp) REG_S x12, PT_A2(sp) @@ -78,6 +111,18 @@ REG_S x15, PT_A5(sp) REG_S x16, PT_A6(sp) REG_S x17, PT_A7(sp) + + // save the leftover regs + + .if \all == 1 + REG_S x2, PT_SP(sp) + REG_S x3, PT_GP(sp) + REG_S x4, PT_TP(sp) + REG_S x5, PT_T0(sp) + REG_S x6, PT_T1(sp) + REG_S x7, PT_T2(sp) + REG_S x8, PT_S0(sp) + REG_S x9, PT_S1(sp) REG_S x18, PT_S2(sp) REG_S x19, PT_S3(sp) REG_S x20, PT_S4(sp) @@ -92,19 +137,19 @@ REG_S x29, PT_T4(sp) REG_S x30, PT_T5(sp) REG_S x31, PT_T6(sp) + + // save s0 if FP_TEST defined + + .else +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + REG_S x8, PT_S0(sp) +#endif + .endif .endm - .macro RESTORE_ALL + .macro RESTORE_ABI_REGS, all=0 REG_L t0, PT_EPC(sp) REG_L x1, PT_RA(sp) - REG_L x2, PT_SP(sp) - REG_L x3, PT_GP(sp) - REG_L x4, PT_TP(sp) - REG_L x5, PT_T0(sp) - REG_L x6, PT_T1(sp) - REG_L x7, PT_T2(sp) - REG_L x8, PT_S0(sp) - REG_L x9, PT_S1(sp) REG_L x10, PT_A0(sp) REG_L x11, PT_A1(sp) REG_L x12, PT_A2(sp) @@ -113,6 +158,16 @@ REG_L x15, PT_A5(sp) REG_L x16, PT_A6(sp) REG_L x17, PT_A7(sp) + + .if \all == 1 + REG_L x2, PT_SP(sp) + REG_L x3, PT_GP(sp) + REG_L x4, PT_TP(sp) + REG_L x5, PT_T0(sp) + REG_L x6, PT_T1(sp) + REG_L x7, PT_T2(sp) + REG_L x8, PT_S0(sp) + REG_L x9, PT_S1(sp) REG_L x18, PT_S2(sp) REG_L x19, PT_S3(sp) REG_L x20, PT_S4(sp) @@ -128,10 +183,25 @@ REG_L x30, PT_T5(sp) REG_L x31, PT_T6(sp) + .else +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + REG_L x8, PT_S0(sp) +#endif + .endif addi sp, sp, PT_SIZE_ON_STACK .endm + + .macro PREPARE_ARGS + addi a0, t0, -FENTRY_RA_OFFSET // ip + la a1, function_trace_op + REG_L a2, 0(a1) // op + REG_L a1, PT_RA(sp) // parent_ip + mv a3, sp // fregs + .endm + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS ENTRY(ftrace_caller) SAVE_ABI @@ -160,33 +230,29 @@ ftrace_graph_call: jr t0 ENDPROC(ftrace_caller) -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ ENTRY(ftrace_regs_caller) - SAVE_ALL - - addi a0, t0, -FENTRY_RA_OFFSET - la a1, function_trace_op - REG_L a2, 0(a1) - REG_L a1, PT_RA(sp) - mv a3, sp + SAVE_ABI_REGS 1 + PREPARE_ARGS ftrace_regs_call: .global ftrace_regs_call call ftrace_stub -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - addi a0, sp, PT_RA - REG_L a1, PT_T0(sp) - addi a1, a1, -FENTRY_RA_OFFSET -#ifdef HAVE_FUNCTION_GRAPH_FP_TEST - mv a2, s0 -#endif -ftrace_graph_regs_call: - .global ftrace_graph_regs_call - call ftrace_stub -#endif - RESTORE_ALL + RESTORE_ABI_REGS 1 jr t0 ENDPROC(ftrace_regs_caller) + +ENTRY(ftrace_caller) + SAVE_ABI_REGS 0 + PREPARE_ARGS + +ftrace_call: + .global ftrace_call + call ftrace_stub + + RESTORE_ABI_REGS 0 + jr t0 +ENDPROC(ftrace_caller) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ -- 2.36.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
WARNING: multiple messages have this Message-ID (diff)
From: guoren@kernel.org To: anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de, rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com, bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com, andy.chiu@sifive.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Guo Ren <guoren@kernel.org> Subject: [PATCH V3 5/5] riscv: ftrace: Make ftrace_caller call ftrace_graph_func Date: Wed, 23 Nov 2022 10:39:50 -0500 [thread overview] Message-ID: <20221123153950.2911981-6-guoren@kernel.org> (raw) In-Reply-To: <20221123153950.2911981-1-guoren@kernel.org> From: Song Shuai <suagrfillet@gmail.com> In order to make the function graph use ftrace directly, ftrace_caller should be adjusted to save the necessary regs against the pt_regs layout so it can call ftrace_graph_func reasonably. SAVE_ALL now saves all the regs according to the pt_regs struct. Here supersedes SAVE_ALL by SAVE_ABI_REGS which has an extra option to allow saving only the necessary ABI-related regs for ftrace_caller. ftrace_caller and ftrace_regs_caller save their regs with the respective option of SAVE_ABI_REGS, then call the tracing function, especially graph_ops's ftrace_graph_func. So the ftrace_graph_[regs]_call labels aren't needed anymore if FTRACE_WITH_REGS is defined. As the previous patch described, the ftrace_caller remains with its ftrace_graph_call if FTRACE_WITH_REGS isn't defined, For convenience, the original argument setup for the tracing function in ftrace_[regs]_caller is separated as PREPARE_ARGS. Signed-off-by: Song Shuai <suagrfillet@gmail.com> Tested-by: Guo Ren <guoren@kernel.org> Signed-off-by: Guo Ren <guoren@kernel.org> --- arch/riscv/kernel/mcount-dyn.S | 142 ++++++++++++++++++++++++--------- 1 file changed, 104 insertions(+), 38 deletions(-) diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index 64bc79816f5e..466c6ef217b1 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -57,19 +57,52 @@ .endm #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - .macro SAVE_ALL + +/** +* SAVE_ABI_REGS - save regs against the pt_regs struct +* +* @all: tell if saving all the regs +* +* If all is set, all the regs will be saved, otherwise only ABI +* related regs (a0-a7,epc,ra and optional s0) will be saved. +* +* After the stack is established, +* +* 0(sp) stores the PC of the traced function which can be accessed +* by &(fregs)->regs->epc in tracing function. Note that the real +* function entry address should be computed with -FENTRY_RA_OFFSET. +* +* 8(sp) stores the function return address (i.e. parent IP) that +* can be accessed by &(fregs)->regs->ra in tracing function. +* +* The other regs are saved at the respective localtion and accessed +* by the respective pt_regs member. +* +* Here is the layout of stack for your reference. +* +* PT_SIZE_ON_STACK -> +++++++++ +* + ..... + +* + t3-t6 + +* + s2-s11+ +* + a0-a7 + --++++-> ftrace_caller saved +* + s1 + + +* + s0 + --+ +* + t0-t2 + + +* + tp + + +* + gp + + +* + sp + + +* + ra + --+ // parent IP +* sp -> + epc + --+ // PC +* +++++++++ +**/ + .macro SAVE_ABI_REGS, all=0 addi sp, sp, -PT_SIZE_ON_STACK REG_S t0, PT_EPC(sp) REG_S x1, PT_RA(sp) - REG_S x2, PT_SP(sp) - REG_S x3, PT_GP(sp) - REG_S x4, PT_TP(sp) - REG_S x5, PT_T0(sp) - REG_S x6, PT_T1(sp) - REG_S x7, PT_T2(sp) - REG_S x8, PT_S0(sp) - REG_S x9, PT_S1(sp) + + // always save the ABI regs + REG_S x10, PT_A0(sp) REG_S x11, PT_A1(sp) REG_S x12, PT_A2(sp) @@ -78,6 +111,18 @@ REG_S x15, PT_A5(sp) REG_S x16, PT_A6(sp) REG_S x17, PT_A7(sp) + + // save the leftover regs + + .if \all == 1 + REG_S x2, PT_SP(sp) + REG_S x3, PT_GP(sp) + REG_S x4, PT_TP(sp) + REG_S x5, PT_T0(sp) + REG_S x6, PT_T1(sp) + REG_S x7, PT_T2(sp) + REG_S x8, PT_S0(sp) + REG_S x9, PT_S1(sp) REG_S x18, PT_S2(sp) REG_S x19, PT_S3(sp) REG_S x20, PT_S4(sp) @@ -92,19 +137,19 @@ REG_S x29, PT_T4(sp) REG_S x30, PT_T5(sp) REG_S x31, PT_T6(sp) + + // save s0 if FP_TEST defined + + .else +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + REG_S x8, PT_S0(sp) +#endif + .endif .endm - .macro RESTORE_ALL + .macro RESTORE_ABI_REGS, all=0 REG_L t0, PT_EPC(sp) REG_L x1, PT_RA(sp) - REG_L x2, PT_SP(sp) - REG_L x3, PT_GP(sp) - REG_L x4, PT_TP(sp) - REG_L x5, PT_T0(sp) - REG_L x6, PT_T1(sp) - REG_L x7, PT_T2(sp) - REG_L x8, PT_S0(sp) - REG_L x9, PT_S1(sp) REG_L x10, PT_A0(sp) REG_L x11, PT_A1(sp) REG_L x12, PT_A2(sp) @@ -113,6 +158,16 @@ REG_L x15, PT_A5(sp) REG_L x16, PT_A6(sp) REG_L x17, PT_A7(sp) + + .if \all == 1 + REG_L x2, PT_SP(sp) + REG_L x3, PT_GP(sp) + REG_L x4, PT_TP(sp) + REG_L x5, PT_T0(sp) + REG_L x6, PT_T1(sp) + REG_L x7, PT_T2(sp) + REG_L x8, PT_S0(sp) + REG_L x9, PT_S1(sp) REG_L x18, PT_S2(sp) REG_L x19, PT_S3(sp) REG_L x20, PT_S4(sp) @@ -128,10 +183,25 @@ REG_L x30, PT_T5(sp) REG_L x31, PT_T6(sp) + .else +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + REG_L x8, PT_S0(sp) +#endif + .endif addi sp, sp, PT_SIZE_ON_STACK .endm + + .macro PREPARE_ARGS + addi a0, t0, -FENTRY_RA_OFFSET // ip + la a1, function_trace_op + REG_L a2, 0(a1) // op + REG_L a1, PT_RA(sp) // parent_ip + mv a3, sp // fregs + .endm + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS ENTRY(ftrace_caller) SAVE_ABI @@ -160,33 +230,29 @@ ftrace_graph_call: jr t0 ENDPROC(ftrace_caller) -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ ENTRY(ftrace_regs_caller) - SAVE_ALL - - addi a0, t0, -FENTRY_RA_OFFSET - la a1, function_trace_op - REG_L a2, 0(a1) - REG_L a1, PT_RA(sp) - mv a3, sp + SAVE_ABI_REGS 1 + PREPARE_ARGS ftrace_regs_call: .global ftrace_regs_call call ftrace_stub -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - addi a0, sp, PT_RA - REG_L a1, PT_T0(sp) - addi a1, a1, -FENTRY_RA_OFFSET -#ifdef HAVE_FUNCTION_GRAPH_FP_TEST - mv a2, s0 -#endif -ftrace_graph_regs_call: - .global ftrace_graph_regs_call - call ftrace_stub -#endif - RESTORE_ALL + RESTORE_ABI_REGS 1 jr t0 ENDPROC(ftrace_regs_caller) + +ENTRY(ftrace_caller) + SAVE_ABI_REGS 0 + PREPARE_ARGS + +ftrace_call: + .global ftrace_call + call ftrace_stub + + RESTORE_ABI_REGS 0 + jr t0 +ENDPROC(ftrace_caller) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ -- 2.36.1
next prev parent reply other threads:[~2022-11-23 15:40 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-11-23 15:39 [PATCH V3 0/5] riscv: ftrace: Fixup ftrace detour code & Optimization guoren 2022-11-23 15:39 ` guoren 2022-11-23 15:39 ` [PATCH V3 1/5] riscv: ftrace: Fixup panic by disabling preemption guoren 2022-11-23 15:39 ` guoren 2022-11-23 20:07 ` Conor Dooley 2022-11-23 20:07 ` Conor Dooley 2022-11-24 2:10 ` Guo Ren 2022-11-24 2:10 ` Guo Ren 2022-11-23 15:39 ` [PATCH V3 2/5] riscv: ftrace: Remove wasted nops for !RISCV_ISA_C guoren 2022-11-23 15:39 ` guoren 2022-11-23 15:39 ` [PATCH V3 3/5] riscv: ftrace: Reduce the detour code size to half guoren 2022-11-23 15:39 ` guoren 2022-11-23 20:00 ` Conor Dooley 2022-11-23 20:00 ` Conor Dooley 2022-11-24 2:11 ` Guo Ren 2022-11-24 2:11 ` Guo Ren 2022-11-23 15:39 ` [PATCH V3 4/5] riscv: ftrace: Add ftrace_graph_func guoren 2022-11-23 15:39 ` guoren 2022-11-23 15:39 ` guoren [this message] 2022-11-23 15:39 ` [PATCH V3 5/5] riscv: ftrace: Make ftrace_caller call ftrace_graph_func guoren
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