diff options
Diffstat (limited to 'arch/riscv/kernel/ftrace.c')
| -rw-r--r-- | arch/riscv/kernel/ftrace.c | 104 |
1 files changed, 41 insertions, 63 deletions
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c index 2086f6585773..f5aa24d9e1c1 100644 --- a/arch/riscv/kernel/ftrace.c +++ b/arch/riscv/kernel/ftrace.c @@ -15,10 +15,19 @@ void ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex) { mutex_lock(&text_mutex); + + /* + * The code sequences we use for ftrace can't be patched while the + * kernel is running, so we need to use stop_machine() to modify them + * for now. This doesn't play nice with text_mutex, we use this flag + * to elide the check. + */ + riscv_patch_in_stop_machine = true; } void ftrace_arch_code_modify_post_process(void) __releases(&text_mutex) { + riscv_patch_in_stop_machine = false; mutex_unlock(&text_mutex); } @@ -55,12 +64,15 @@ static int ftrace_check_current_call(unsigned long hook_pos, } static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, - bool enable) + bool enable, bool ra) { unsigned int call[2]; unsigned int nops[2] = {NOP4, NOP4}; - make_call(hook_pos, target, call); + if (ra) + make_call_ra(hook_pos, target, call); + else + make_call_t0(hook_pos, target, call); /* Replace the auipc-jalr pair at once. Return -EPERM on write error. */ if (patch_text_nosync @@ -70,42 +82,13 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, return 0; } -/* - * Put 5 instructions with 16 bytes at the front of function within - * patchable function entry nops' area. - * - * 0: REG_S ra, -SZREG(sp) - * 1: auipc ra, 0x? - * 2: jalr -?(ra) - * 3: REG_L ra, -SZREG(sp) - * - * So the opcodes is: - * 0: 0xfe113c23 (sd)/0xfe112e23 (sw) - * 1: 0x???????? -> auipc - * 2: 0x???????? -> jalr - * 3: 0xff813083 (ld)/0xffc12083 (lw) - */ -#if __riscv_xlen == 64 -#define INSN0 0xfe113c23 -#define INSN3 0xff813083 -#elif __riscv_xlen == 32 -#define INSN0 0xfe112e23 -#define INSN3 0xffc12083 -#endif - -#define FUNC_ENTRY_SIZE 16 -#define FUNC_ENTRY_JMP 4 - int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { - unsigned int call[4] = {INSN0, 0, 0, INSN3}; - unsigned long target = addr; - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; + unsigned int call[2]; - call[1] = to_auipc_insn((unsigned int)(target - caller)); - call[2] = to_jalr_insn((unsigned int)(target - caller)); + make_call_t0(rec->ip, addr, call); - if (patch_text_nosync((void *)rec->ip, call, FUNC_ENTRY_SIZE)) + if (patch_text_nosync((void *)rec->ip, call, MCOUNT_INSN_SIZE)) return -EPERM; return 0; @@ -114,15 +97,14 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { - unsigned int nops[4] = {NOP4, NOP4, NOP4, NOP4}; + unsigned int nops[2] = {NOP4, NOP4}; - if (patch_text_nosync((void *)rec->ip, nops, FUNC_ENTRY_SIZE)) + if (patch_text_nosync((void *)rec->ip, nops, MCOUNT_INSN_SIZE)) return -EPERM; return 0; } - /* * This is called early on, and isn't wrapped by * ftrace_arch_code_modify_{prepare,post_process}() and therefor doesn't hold @@ -134,9 +116,9 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) { int out; - ftrace_arch_code_modify_prepare(); + mutex_lock(&text_mutex); out = ftrace_make_nop(mod, rec, MCOUNT_ADDR); - ftrace_arch_code_modify_post_process(); + mutex_unlock(&text_mutex); return out; } @@ -144,10 +126,10 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) int ftrace_update_ftrace_func(ftrace_func_t func) { int ret = __ftrace_modify_call((unsigned long)&ftrace_call, - (unsigned long)func, true); + (unsigned long)func, true, true); if (!ret) { ret = __ftrace_modify_call((unsigned long)&ftrace_regs_call, - (unsigned long)func, true); + (unsigned long)func, true, true); } return ret; @@ -159,16 +141,16 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr) { unsigned int call[2]; - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; + unsigned long caller = rec->ip; int ret; - make_call(caller, old_addr, call); + make_call_t0(caller, old_addr, call); ret = ftrace_check_current_call(caller, call); if (ret) return ret; - return __ftrace_modify_call(caller, addr, true); + return __ftrace_modify_call(caller, addr, true, false); } #endif @@ -196,32 +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); - if (ret) - return ret; - - return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, - (unsigned long)&prepare_ftrace_return, true); + 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); - if (ret) - return ret; - - return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, - (unsigned long)&prepare_ftrace_return, false); + 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 */ |