From 89a3927a775c0a7212e2e3c4e2d42cd48895bee0 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Tue, 18 Feb 2020 20:27:39 +0800 Subject: csky: Implement ftrace with regs This patch implements FTRACE_WITH_REGS for csky, 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/or modified. Signed-off-by: Guo Ren --- arch/csky/Kconfig | 1 + arch/csky/abiv2/inc/abi/entry.h | 60 +++++++++++++++++++++++++++++++++++++++++ arch/csky/abiv2/mcount.S | 48 +++++++++++++++++++++++++++++++++ arch/csky/include/asm/ftrace.h | 2 ++ arch/csky/kernel/asm-offsets.c | 1 + arch/csky/kernel/ftrace.c | 11 ++++++++ 6 files changed, 123 insertions(+) (limited to 'arch/csky') diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 0e9b14367fa8..6cf169a15794 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -38,6 +38,7 @@ config CSKY select HAVE_ARCH_AUDITSYSCALL select HAVE_COPY_THREAD_TLS select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FTRACE_MCOUNT_RECORD diff --git a/arch/csky/abiv2/inc/abi/entry.h b/arch/csky/abiv2/inc/abi/entry.h index 94a7a58765df..6a404393d0f4 100644 --- a/arch/csky/abiv2/inc/abi/entry.h +++ b/arch/csky/abiv2/inc/abi/entry.h @@ -100,6 +100,66 @@ rte .endm +.macro SAVE_REGS_FTRACE + subi sp, 152 + stw tls, (sp, 0) + stw lr, (sp, 4) + + mfcr lr, psr + stw lr, (sp, 12) + + addi lr, sp, 152 + stw lr, (sp, 16) + + stw a0, (sp, 20) + stw a0, (sp, 24) + stw a1, (sp, 28) + stw a2, (sp, 32) + stw a3, (sp, 36) + + addi sp, 40 + stm r4-r13, (sp) + + addi sp, 40 + stm r16-r30, (sp) +#ifdef CONFIG_CPU_HAS_HILO + mfhi lr + stw lr, (sp, 60) + mflo lr + stw lr, (sp, 64) + mfcr lr, cr14 + stw lr, (sp, 68) +#endif + subi sp, 80 +.endm + +.macro RESTORE_REGS_FTRACE + ldw tls, (sp, 0) + ldw a0, (sp, 16) + mtcr a0, ss0 + +#ifdef CONFIG_CPU_HAS_HILO + ldw a0, (sp, 140) + mthi a0 + ldw a0, (sp, 144) + mtlo a0 + ldw a0, (sp, 148) + mtcr a0, cr14 +#endif + + ldw a0, (sp, 24) + ldw a1, (sp, 28) + ldw a2, (sp, 32) + ldw a3, (sp, 36) + + addi sp, 40 + ldm r4-r13, (sp) + addi sp, 40 + ldm r16-r30, (sp) + addi sp, 72 + mfcr sp, ss0 +.endm + .macro SAVE_SWITCH_STACK subi sp, 64 stm r4-r11, (sp) diff --git a/arch/csky/abiv2/mcount.S b/arch/csky/abiv2/mcount.S index 326402e65f9e..9331c7ed5958 100644 --- a/arch/csky/abiv2/mcount.S +++ b/arch/csky/abiv2/mcount.S @@ -3,6 +3,8 @@ #include #include +#include +#include /* * csky-gcc with -pg will put the following asm after prologue: @@ -44,6 +46,22 @@ jmp t1 .endm +.macro mcount_enter_regs + subi sp, 8 + stw lr, (sp, 0) + stw r8, (sp, 4) + SAVE_REGS_FTRACE +.endm + +.macro mcount_exit_regs + RESTORE_REGS_FTRACE + ldw t1, (sp, 0) + ldw r8, (sp, 4) + ldw lr, (sp, 8) + addi sp, 12 + jmp t1 +.endm + .macro save_return_regs subi sp, 16 stw a0, (sp, 0) @@ -122,6 +140,8 @@ ENTRY(ftrace_caller) ldw a0, (sp, 16) subi a0, 4 ldw a1, (sp, 24) + lrw a2, function_trace_op + ldw a2, (a2, 0) nop GLOBAL(ftrace_call) @@ -157,3 +177,31 @@ ENTRY(return_to_handler) jmp lr END(return_to_handler) #endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +ENTRY(ftrace_regs_caller) + mcount_enter_regs + + lrw t1, PT_FRAME_SIZE + add t1, sp + + ldw a0, (t1, 0) + subi a0, 4 + ldw a1, (t1, 8) + lrw a2, function_trace_op + ldw a2, (a2, 0) + mov a3, sp + + nop +GLOBAL(ftrace_regs_call) + nop32_stub + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + nop +GLOBAL(ftrace_graph_regs_call) + nop32_stub +#endif + + mcount_exit_regs +ENDPROC(ftrace_regs_caller) +#endif /* CONFIG_DYNAMIC_FTRACE */ diff --git a/arch/csky/include/asm/ftrace.h b/arch/csky/include/asm/ftrace.h index ba35d93ecda2..fae72b0b1374 100644 --- a/arch/csky/include/asm/ftrace.h +++ b/arch/csky/include/asm/ftrace.h @@ -10,6 +10,8 @@ #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR +#define ARCH_SUPPORTS_FTRACE_OPS 1 + #define MCOUNT_ADDR ((unsigned long)_mcount) #ifndef __ASSEMBLY__ diff --git a/arch/csky/kernel/asm-offsets.c b/arch/csky/kernel/asm-offsets.c index 9b48b1b1a61b..f8be348df9e4 100644 --- a/arch/csky/kernel/asm-offsets.c +++ b/arch/csky/kernel/asm-offsets.c @@ -72,6 +72,7 @@ int main(void) DEFINE(PT_RLO, offsetof(struct pt_regs, rlo)); #endif DEFINE(PT_USP, offsetof(struct pt_regs, usp)); + DEFINE(PT_FRAME_SIZE, sizeof(struct pt_regs)); /* offsets into the irq_cpustat_t struct */ DEFINE(CPUSTAT_SOFTIRQ_PENDING, offsetof(irq_cpustat_t, diff --git a/arch/csky/kernel/ftrace.c b/arch/csky/kernel/ftrace.c index 44f4880179b7..b4502cd2eabe 100644 --- a/arch/csky/kernel/ftrace.c +++ b/arch/csky/kernel/ftrace.c @@ -126,6 +126,9 @@ int ftrace_update_ftrace_func(ftrace_func_t func) { int ret = ftrace_modify_code((unsigned long)&ftrace_call, (unsigned long)func, true, true); + if (!ret) + ret = ftrace_modify_code((unsigned long)&ftrace_regs_call, + (unsigned long)func, true, true); return ret; } @@ -135,6 +138,14 @@ int __init ftrace_dyn_arch_init(void) } #endif /* CONFIG_DYNAMIC_FTRACE */ +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, + unsigned long addr) +{ + return ftrace_modify_code(rec->ip, addr, true, true); +} +#endif + #ifdef CONFIG_FUNCTION_GRAPH_TRACER void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, unsigned long frame_pointer) -- cgit v1.2.3