diff options
author | Palmer Dabbelt <palmer@rivosinc.com> | 2024-01-17 18:17:29 -0800 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-01-17 18:17:29 -0800 |
commit | 3074e8b175382b97545e4d9e26c98a5077b02cb1 (patch) | |
tree | e57038a1252cb344623d961374418745375b1bf4 /arch | |
parent | 448857ec53a47718b50cdb38b9380660b3f84b20 (diff) | |
parent | 629291dd8499e4dc7dff6e9ab8c13b1a841059e8 (diff) |
Merge patch series "riscv: ftrace: Miscellaneous ftrace improvements"
Björn Töpel <bjorn@kernel.org> says:
This series includes a three ftrace improvements for RISC-V:
1. Do not require to run recordmcount at build time (patch 1)
2. Simplification of the function graph functionality (patch 2)
3. Enable DYNAMIC_FTRACE_WITH_DIRECT_CALLS (patch 3 and 4)
The series has been tested on Qemu/rv64 virt/Debian sid with the
following test configs:
CONFIG_FTRACE_SELFTEST=y
CONFIG_FTRACE_STARTUP_TEST=y
CONFIG_SAMPLE_FTRACE_DIRECT=m
CONFIG_SAMPLE_FTRACE_DIRECT_MULTI=m
CONFIG_SAMPLE_FTRACE_OPS=m
All tests pass.
* b4-shazam-merge:
samples: ftrace: Add RISC-V support for SAMPLE_FTRACE_DIRECT[_MULTI]
riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
riscv: ftrace: Make function graph use ftrace directly
riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
Link: https://lore.kernel.org/r/20231130121531.1178502-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/riscv/Kconfig | 4 | ||||
-rw-r--r-- | arch/riscv/include/asm/ftrace.h | 18 | ||||
-rw-r--r-- | arch/riscv/kernel/ftrace.c | 30 | ||||
-rw-r--r-- | arch/riscv/kernel/mcount-dyn.S | 198 |
4 files changed, 195 insertions, 55 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 1070728c8321..d6f3fc393097 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -70,6 +70,7 @@ config RISCV select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND select EDAC_SUPPORT select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) + select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE select GENERIC_ARCH_TOPOLOGY select GENERIC_ATOMIC64 if !64BIT select GENERIC_CLOCKEVENTS_BROADCAST if SMP @@ -115,6 +116,7 @@ config RISCV select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS if MMU select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) + select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER @@ -142,6 +144,8 @@ config RISCV select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RETHOOK if !XIP_KERNEL select HAVE_RSEQ + select HAVE_SAMPLE_FTRACE_DIRECT + select HAVE_SAMPLE_FTRACE_DIRECT_MULTI select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index 2b2f5df7ef2c..329172122952 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -128,7 +128,23 @@ do { \ struct dyn_ftrace; int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); #define ftrace_init_nop ftrace_init_nop -#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +struct ftrace_ops; +struct ftrace_regs; +void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); +#define ftrace_graph_func ftrace_graph_func + +static inline void __arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr) +{ + regs->t1 = addr; +} +#define arch_ftrace_set_direct_caller(fregs, addr) \ + __arch_ftrace_set_direct_caller(&(fregs)->regs, addr) +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ + +#endif /* __ASSEMBLY__ */ #endif /* CONFIG_DYNAMIC_FTRACE */ diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c index 03a6434a8cdd..f5aa24d9e1c1 100644 --- a/arch/riscv/kernel/ftrace.c +++ b/arch/riscv/kernel/ftrace.c @@ -178,32 +178,28 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, } #ifdef CONFIG_DYNAMIC_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) +{ + struct pt_regs *regs = arch_ftrace_get_regs(fregs); + unsigned long *parent = (unsigned long *)®s->ra; + + prepare_ftrace_return(parent, ip, frame_pointer(regs)); +} +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ extern void ftrace_graph_call(void); -extern void ftrace_graph_regs_call(void); int ftrace_enable_ftrace_graph_caller(void) { - int ret; - - ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, - (unsigned long)&prepare_ftrace_return, true, true); - if (ret) - return ret; - - return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, + return __ftrace_modify_call((unsigned long)&ftrace_graph_call, (unsigned long)&prepare_ftrace_return, true, true); } int ftrace_disable_ftrace_graph_caller(void) { - int ret; - - ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, - (unsigned long)&prepare_ftrace_return, false, true); - if (ret) - return ret; - - return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, + return __ftrace_modify_call((unsigned long)&ftrace_graph_call, (unsigned long)&prepare_ftrace_return, false, true); } +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index 79dc81223238..b7561288e8da 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -57,31 +57,150 @@ .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) - save_from_x6_to_x31 + REG_S t0, PT_EPC(sp) + REG_S x1, PT_RA(sp) + + // save the ABI regs + + REG_S x10, PT_A0(sp) + REG_S x11, PT_A1(sp) + REG_S x12, PT_A2(sp) + REG_S x13, PT_A3(sp) + REG_S x14, PT_A4(sp) + 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) + REG_S x21, PT_S5(sp) + REG_S x22, PT_S6(sp) + REG_S x23, PT_S7(sp) + REG_S x24, PT_S8(sp) + REG_S x25, PT_S9(sp) + REG_S x26, PT_S10(sp) + REG_S x27, PT_S11(sp) + REG_S x28, PT_T3(sp) + 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 - REG_L x1, PT_RA(sp) - REG_L x2, PT_SP(sp) - REG_L x3, PT_GP(sp) - REG_L x4, PT_TP(sp) - /* Restore t0 with PT_EPC */ - REG_L x5, PT_EPC(sp) - restore_from_x6_to_x31 + .macro RESTORE_ABI_REGS, all=0 + REG_L t0, PT_EPC(sp) + REG_L x1, PT_RA(sp) + REG_L x10, PT_A0(sp) + REG_L x11, PT_A1(sp) + REG_L x12, PT_A2(sp) + REG_L x13, PT_A3(sp) + REG_L x14, PT_A4(sp) + 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 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) + REG_L x21, PT_S5(sp) + REG_L x22, PT_S6(sp) + REG_L x23, PT_S7(sp) + REG_L x24, PT_S8(sp) + REG_L x25, PT_S9(sp) + REG_L x26, PT_S10(sp) + REG_L x27, PT_S11(sp) + REG_L x28, PT_T3(sp) + REG_L x29, PT_T4(sp) + 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 + la a1, function_trace_op + REG_L a2, 0(a1) + mv a1, ra + mv a3, sp + .endm + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS SYM_FUNC_START(ftrace_caller) SAVE_ABI @@ -105,34 +224,39 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL) call ftrace_stub #endif RESTORE_ABI - jr t0 + jr t0 SYM_FUNC_END(ftrace_caller) -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ SYM_FUNC_START(ftrace_regs_caller) - SAVE_ALL - - addi a0, t0, -FENTRY_RA_OFFSET - la a1, function_trace_op - REG_L a2, 0(a1) - mv a1, ra - mv a3, sp + mv t1, zero + SAVE_ABI_REGS 1 + PREPARE_ARGS SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) call ftrace_stub -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - addi a0, sp, PT_RA - REG_L a1, PT_EPC(sp) - addi a1, a1, -FENTRY_RA_OFFSET -#ifdef HAVE_FUNCTION_GRAPH_FP_TEST - mv a2, s0 -#endif -SYM_INNER_LABEL(ftrace_graph_regs_call, SYM_L_GLOBAL) + RESTORE_ABI_REGS 1 + bnez t1, .Ldirect + jr t0 +.Ldirect: + jr t1 +SYM_FUNC_END(ftrace_regs_caller) + +SYM_FUNC_START(ftrace_caller) + SAVE_ABI_REGS 0 + PREPARE_ARGS + +SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) call ftrace_stub -#endif - RESTORE_ALL - jr t0 -SYM_FUNC_END(ftrace_regs_caller) + RESTORE_ABI_REGS 0 + jr t0 +SYM_FUNC_END(ftrace_caller) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +SYM_CODE_START(ftrace_stub_direct_tramp) + jr t0 +SYM_CODE_END(ftrace_stub_direct_tramp) +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |