diff options
Diffstat (limited to 'arch/riscv/kernel/ftrace.c')
| -rw-r--r-- | arch/riscv/kernel/ftrace.c | 82 |
1 files changed, 63 insertions, 19 deletions
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c index f5aa24d9e1c1..674dcdfae7a1 100644 --- a/arch/riscv/kernel/ftrace.c +++ b/arch/riscv/kernel/ftrace.c @@ -8,8 +8,9 @@ #include <linux/ftrace.h> #include <linux/uaccess.h> #include <linux/memory.h> +#include <linux/stop_machine.h> #include <asm/cacheflush.h> -#include <asm/patch.h> +#include <asm/text-patching.h> #ifdef CONFIG_DYNAMIC_FTRACE void ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex) @@ -35,7 +36,7 @@ static int ftrace_check_current_call(unsigned long hook_pos, unsigned int *expected) { unsigned int replaced[2]; - unsigned int nops[2] = {NOP4, NOP4}; + unsigned int nops[2] = {RISCV_INSN_NOP4, RISCV_INSN_NOP4}; /* we expect nops at the hook position */ if (!expected) @@ -67,7 +68,7 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, bool enable, bool ra) { unsigned int call[2]; - unsigned int nops[2] = {NOP4, NOP4}; + unsigned int nops[2] = {RISCV_INSN_NOP4, RISCV_INSN_NOP4}; if (ra) make_call_ra(hook_pos, target, call); @@ -75,8 +76,7 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, make_call_t0(hook_pos, target, call); /* Replace the auipc-jalr pair at once. Return -EPERM on write error. */ - if (patch_text_nosync - ((void *)hook_pos, enable ? call : nops, MCOUNT_INSN_SIZE)) + if (patch_insn_write((void *)hook_pos, enable ? call : nops, MCOUNT_INSN_SIZE)) return -EPERM; return 0; @@ -88,7 +88,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) make_call_t0(rec->ip, addr, call); - if (patch_text_nosync((void *)rec->ip, call, MCOUNT_INSN_SIZE)) + if (patch_insn_write((void *)rec->ip, call, MCOUNT_INSN_SIZE)) return -EPERM; return 0; @@ -97,9 +97,9 @@ 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[2] = {NOP4, NOP4}; + unsigned int nops[2] = {RISCV_INSN_NOP4, RISCV_INSN_NOP4}; - if (patch_text_nosync((void *)rec->ip, nops, MCOUNT_INSN_SIZE)) + if (patch_insn_write((void *)rec->ip, nops, MCOUNT_INSN_SIZE)) return -EPERM; return 0; @@ -127,16 +127,48 @@ int ftrace_update_ftrace_func(ftrace_func_t func) { int ret = __ftrace_modify_call((unsigned long)&ftrace_call, (unsigned long)func, true, true); - if (!ret) { - ret = __ftrace_modify_call((unsigned long)&ftrace_regs_call, - (unsigned long)func, true, true); - } return ret; } + +struct ftrace_modify_param { + int command; + atomic_t cpu_count; +}; + +static int __ftrace_modify_code(void *data) +{ + struct ftrace_modify_param *param = data; + + if (atomic_inc_return(¶m->cpu_count) == num_online_cpus()) { + ftrace_modify_all_code(param->command); + /* + * Make sure the patching store is effective *before* we + * increment the counter which releases all waiting CPUs + * by using the release variant of atomic increment. The + * release pairs with the call to local_flush_icache_all() + * on the waiting CPU. + */ + atomic_inc_return_release(¶m->cpu_count); + } else { + while (atomic_read(¶m->cpu_count) <= num_online_cpus()) + cpu_relax(); + + local_flush_icache_all(); + } + + return 0; +} + +void arch_ftrace_update_code(int command) +{ + struct ftrace_modify_param param = { command, ATOMIC_INIT(0) }; + + stop_machine(__ftrace_modify_code, ¶m, cpu_online_mask); +} #endif -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr) { @@ -178,16 +210,28 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, } #ifdef CONFIG_DYNAMIC_FTRACE -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS 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; + unsigned long return_hooker = (unsigned long)&return_to_handler; + unsigned long frame_pointer = arch_ftrace_regs(fregs)->s0; + unsigned long *parent = &arch_ftrace_regs(fregs)->ra; + unsigned long old; + + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; + + /* + * We don't suffer access faults, so no extra fault-recovery assembly + * is needed here. + */ + old = *parent; - prepare_ftrace_return(parent, ip, frame_pointer(regs)); + if (!function_graph_enter_regs(old, ip, frame_pointer, parent, fregs)) + *parent = return_hooker; } -#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#else /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */ extern void ftrace_graph_call(void); int ftrace_enable_ftrace_graph_caller(void) { @@ -200,6 +244,6 @@ int ftrace_disable_ftrace_graph_caller(void) 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_WITH_ARGS */ #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |