diff options
Diffstat (limited to 'arch/powerpc/kernel/trace')
-rw-r--r-- | arch/powerpc/kernel/trace/Makefile | 11 | ||||
-rw-r--r-- | arch/powerpc/kernel/trace/ftrace.c | 310 | ||||
-rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64_pg.c | 85 | ||||
-rw-r--r-- | arch/powerpc/kernel/trace/ftrace_entry.S | 244 |
4 files changed, 506 insertions, 144 deletions
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile index 125f4ca588b9..d6c3885453bd 100644 --- a/arch/powerpc/kernel/trace/Makefile +++ b/arch/powerpc/kernel/trace/Makefile @@ -9,12 +9,15 @@ CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_ftrace_64_pg.o = $(CC_FLAGS_FTRACE) endif -obj32-$(CONFIG_FUNCTION_TRACER) += ftrace.o ftrace_entry.o -ifdef CONFIG_MPROFILE_KERNEL -obj64-$(CONFIG_FUNCTION_TRACER) += ftrace.o ftrace_entry.o +ifdef CONFIG_FUNCTION_TRACER +obj32-y += ftrace.o ftrace_entry.o +ifeq ($(CONFIG_MPROFILE_KERNEL)$(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY),) +obj64-y += ftrace_64_pg.o ftrace_64_pg_entry.o else -obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_pg.o ftrace_64_pg_entry.o +obj64-y += ftrace.o ftrace_entry.o +endif endif + obj-$(CONFIG_TRACING) += trace_clock.o obj-$(CONFIG_PPC64) += $(obj64-y) diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index d8d6b4fd9a14..6dca92d5a6e8 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -23,7 +23,7 @@ #include <linux/list.h> #include <asm/cacheflush.h> -#include <asm/code-patching.h> +#include <asm/text-patching.h> #include <asm/ftrace.h> #include <asm/syscall.h> #include <asm/inst.h> @@ -37,8 +37,12 @@ unsigned long ftrace_call_adjust(unsigned long addr) if (addr >= (unsigned long)__exittext_begin && addr < (unsigned long)__exittext_end) return 0; - if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) + if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY) && + !IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) { addr += MCOUNT_INSN_SIZE; + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS)) + addr += MCOUNT_INSN_SIZE; + } return addr; } @@ -82,7 +86,7 @@ static inline int ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_ { int ret = ftrace_validate_inst(ip, old); - if (!ret) + if (!ret && !ppc_inst_equal(old, new)) ret = patch_instruction((u32 *)ip, new); return ret; @@ -106,28 +110,66 @@ static unsigned long find_ftrace_tramp(unsigned long ip) return 0; } +#ifdef CONFIG_MODULES +static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr) +{ + struct module *mod = NULL; + + scoped_guard(rcu) + mod = __module_text_address(ip); + if (!mod) + pr_err("No module loaded at addr=%lx\n", ip); + + return (addr == (unsigned long)ftrace_caller ? mod->arch.tramp : mod->arch.tramp_regs); +} +#else +static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr) +{ + return 0; +} +#endif + +static unsigned long ftrace_get_ool_stub(struct dyn_ftrace *rec) +{ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + return rec->arch.ool_stub; +#else + BUILD_BUG(); +#endif +} + static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, ppc_inst_t *call_inst) { - unsigned long ip = rec->ip; + unsigned long ip; unsigned long stub; - if (is_offset_in_branch_range(addr - ip)) { + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */ + else + ip = rec->ip; + + if (!is_offset_in_branch_range(addr - ip) && addr != FTRACE_ADDR && + addr != FTRACE_REGS_ADDR) { + /* This can only happen with ftrace direct */ + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS)) { + pr_err("0x%lx (0x%lx): Unexpected target address 0x%lx\n", + ip, rec->ip, addr); + return -EINVAL; + } + addr = FTRACE_ADDR; + } + + if (is_offset_in_branch_range(addr - ip)) /* Within range */ stub = addr; -#ifdef CONFIG_MODULES - } else if (rec->arch.mod) { - /* Module code would be going to one of the module stubs */ - stub = (addr == (unsigned long)ftrace_caller ? rec->arch.mod->arch.tramp : - rec->arch.mod->arch.tramp_regs); -#endif - } else if (core_kernel_text(ip)) { + else if (core_kernel_text(ip)) /* We would be branching to one of our ftrace stubs */ stub = find_ftrace_tramp(ip); - if (!stub) { - pr_err("0x%lx: No ftrace stubs reachable\n", ip); - return -EINVAL; - } - } else { + else + stub = ftrace_lookup_module_stub(ip, addr); + + if (!stub) { + pr_err("0x%lx (0x%lx): No ftrace stubs reachable\n", ip, rec->ip); return -EINVAL; } @@ -135,6 +177,145 @@ static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, ppc_ return 0; } +static int ftrace_init_ool_stub(struct module *mod, struct dyn_ftrace *rec) +{ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + static int ool_stub_text_index, ool_stub_text_end_index, ool_stub_inittext_index; + int ret = 0, ool_stub_count, *ool_stub_index; + ppc_inst_t inst; + /* + * See ftrace_entry.S if changing the below instruction sequence, as we rely on + * decoding the last branch instruction here to recover the correct function ip. + */ + struct ftrace_ool_stub *ool_stub, ool_stub_template = { + .insn = { + PPC_RAW_MFLR(_R0), + PPC_RAW_NOP(), /* bl ftrace_caller */ + PPC_RAW_MTLR(_R0), + PPC_RAW_NOP() /* b rec->ip + 4 */ + } + }; + + WARN_ON(rec->arch.ool_stub); + + if (is_kernel_inittext(rec->ip)) { + ool_stub = ftrace_ool_stub_inittext; + ool_stub_index = &ool_stub_inittext_index; + ool_stub_count = ftrace_ool_stub_inittext_count; + } else if (is_kernel_text(rec->ip)) { + /* + * ftrace records are sorted, so we first use up the stub area within .text + * (ftrace_ool_stub_text) before using the area at the end of .text + * (ftrace_ool_stub_text_end), unless the stub is out of range of the record. + */ + if (ool_stub_text_index >= ftrace_ool_stub_text_count || + !is_offset_in_branch_range((long)rec->ip - + (long)&ftrace_ool_stub_text[ool_stub_text_index])) { + ool_stub = ftrace_ool_stub_text_end; + ool_stub_index = &ool_stub_text_end_index; + ool_stub_count = ftrace_ool_stub_text_end_count; + } else { + ool_stub = ftrace_ool_stub_text; + ool_stub_index = &ool_stub_text_index; + ool_stub_count = ftrace_ool_stub_text_count; + } +#ifdef CONFIG_MODULES + } else if (mod) { + ool_stub = mod->arch.ool_stubs; + ool_stub_index = &mod->arch.ool_stub_index; + ool_stub_count = mod->arch.ool_stub_count; +#endif + } else { + return -EINVAL; + } + + ool_stub += (*ool_stub_index)++; + + if (WARN_ON(*ool_stub_index > ool_stub_count)) + return -EINVAL; + + if (!is_offset_in_branch_range((long)rec->ip - (long)&ool_stub->insn[0]) || + !is_offset_in_branch_range((long)(rec->ip + MCOUNT_INSN_SIZE) - + (long)&ool_stub->insn[3])) { + pr_err("%s: ftrace ool stub out of range (%p -> %p).\n", + __func__, (void *)rec->ip, (void *)&ool_stub->insn[0]); + return -EINVAL; + } + + rec->arch.ool_stub = (unsigned long)&ool_stub->insn[0]; + + /* bl ftrace_caller */ + if (!mod) + ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &inst); +#ifdef CONFIG_MODULES + else + /* + * We can't use ftrace_get_call_inst() since that uses + * __module_text_address(rec->ip) to look up the module. + * But, since the module is not fully formed at this stage, + * the lookup fails. We know the target though, so generate + * the branch inst directly. + */ + inst = ftrace_create_branch_inst(ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE, + mod->arch.tramp, 1); +#endif + ool_stub_template.insn[1] = ppc_inst_val(inst); + + /* b rec->ip + 4 */ + if (!ret && create_branch(&inst, &ool_stub->insn[3], rec->ip + MCOUNT_INSN_SIZE, 0)) + return -EINVAL; + ool_stub_template.insn[3] = ppc_inst_val(inst); + + if (!ret) + ret = patch_instructions((u32 *)ool_stub, (u32 *)&ool_stub_template, + sizeof(ool_stub_template), false); + + return ret; +#else /* !CONFIG_PPC_FTRACE_OUT_OF_LINE */ + BUILD_BUG(); +#endif +} + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS +static const struct ftrace_ops *powerpc_rec_get_ops(struct dyn_ftrace *rec) +{ + const struct ftrace_ops *ops = NULL; + + if (rec->flags & FTRACE_FL_CALL_OPS_EN) { + ops = ftrace_find_unique_ops(rec); + WARN_ON_ONCE(!ops); + } + + if (!ops) + ops = &ftrace_list_ops; + + return ops; +} + +static int ftrace_rec_set_ops(struct dyn_ftrace *rec, const struct ftrace_ops *ops) +{ + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + return patch_ulong((void *)(ftrace_get_ool_stub(rec) - sizeof(unsigned long)), + (unsigned long)ops); + else + return patch_ulong((void *)(rec->ip - MCOUNT_INSN_SIZE - sizeof(unsigned long)), + (unsigned long)ops); +} + +static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec) +{ + return ftrace_rec_set_ops(rec, &ftrace_nop_ops); +} + +static int ftrace_rec_update_ops(struct dyn_ftrace *rec) +{ + return ftrace_rec_set_ops(rec, powerpc_rec_get_ops(rec)); +} +#else +static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec) { return 0; } +static int ftrace_rec_update_ops(struct dyn_ftrace *rec) { return 0; } +#endif + #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr) { @@ -147,18 +328,33 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { ppc_inst_t old, new; - int ret; + unsigned long ip = rec->ip; + int ret = 0; /* This can only ever be called during module load */ - if (WARN_ON(!IS_ENABLED(CONFIG_MODULES) || core_kernel_text(rec->ip))) + if (WARN_ON(!IS_ENABLED(CONFIG_MODULES) || core_kernel_text(ip))) return -EINVAL; old = ppc_inst(PPC_RAW_NOP()); - ret = ftrace_get_call_inst(rec, addr, &new); + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) { + ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */ + ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &old); + } + + ret |= ftrace_get_call_inst(rec, addr, &new); + + if (!ret) + ret = ftrace_modify_code(ip, old, new); + + ret = ftrace_rec_update_ops(rec); if (ret) return ret; - return ftrace_modify_code(rec->ip, old, new); + if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + ret = ftrace_modify_code(rec->ip, ppc_inst(PPC_RAW_NOP()), + ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) - (long)rec->ip))); + + return ret; } int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) @@ -191,6 +387,13 @@ void ftrace_replace_code(int enable) new_addr = ftrace_get_addr_new(rec); update = ftrace_update_record(rec, enable); + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) && update != FTRACE_UPDATE_IGNORE) { + ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; + ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &nop_inst); + if (ret) + goto out; + } + switch (update) { case FTRACE_UPDATE_IGNORE: default: @@ -198,16 +401,19 @@ void ftrace_replace_code(int enable) case FTRACE_UPDATE_MODIFY_CALL: ret = ftrace_get_call_inst(rec, new_addr, &new_call_inst); ret |= ftrace_get_call_inst(rec, addr, &call_inst); + ret |= ftrace_rec_update_ops(rec); old = call_inst; new = new_call_inst; break; case FTRACE_UPDATE_MAKE_NOP: ret = ftrace_get_call_inst(rec, addr, &call_inst); + ret |= ftrace_rec_set_nop_ops(rec); old = call_inst; new = nop_inst; break; case FTRACE_UPDATE_MAKE_CALL: ret = ftrace_get_call_inst(rec, new_addr, &call_inst); + ret |= ftrace_rec_update_ops(rec); old = nop_inst; new = call_inst; break; @@ -215,6 +421,24 @@ void ftrace_replace_code(int enable) if (!ret) ret = ftrace_modify_code(ip, old, new); + + if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) && + (update == FTRACE_UPDATE_MAKE_NOP || update == FTRACE_UPDATE_MAKE_CALL)) { + /* Update the actual ftrace location */ + call_inst = ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) - + (long)rec->ip)); + nop_inst = ppc_inst(PPC_RAW_NOP()); + ip = rec->ip; + + if (update == FTRACE_UPDATE_MAKE_NOP) + ret = ftrace_modify_code(ip, call_inst, nop_inst); + else + ret = ftrace_modify_code(ip, nop_inst, call_inst); + + if (ret) + goto out; + } + if (ret) goto out; } @@ -234,20 +458,27 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) /* Verify instructions surrounding the ftrace location */ if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) { /* Expect nops */ - ret = ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_NOP())); + if (!IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + ret = ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_NOP())); if (!ret) ret = ftrace_validate_inst(ip, ppc_inst(PPC_RAW_NOP())); } else if (IS_ENABLED(CONFIG_PPC32)) { /* Expected sequence: 'mflr r0', 'stw r0,4(r1)', 'bl _mcount' */ ret = ftrace_validate_inst(ip - 8, ppc_inst(PPC_RAW_MFLR(_R0))); - if (!ret) - ret = ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_STW(_R0, _R1, 4))); + if (ret) + return ret; + ret = ftrace_modify_code(ip - 4, ppc_inst(PPC_RAW_STW(_R0, _R1, 4)), + ppc_inst(PPC_RAW_NOP())); } else if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) { /* Expected sequence: 'mflr r0', ['std r0,16(r1)'], 'bl _mcount' */ ret = ftrace_read_inst(ip - 4, &old); if (!ret && !ppc_inst_equal(old, ppc_inst(PPC_RAW_MFLR(_R0)))) { + /* Gcc v5.x emit the additional 'std' instruction, gcc v6.x don't */ ret = ftrace_validate_inst(ip - 8, ppc_inst(PPC_RAW_MFLR(_R0))); - ret |= ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_STD(_R0, _R1, 16))); + if (ret) + return ret; + ret = ftrace_modify_code(ip - 4, ppc_inst(PPC_RAW_STD(_R0, _R1, 16)), + ppc_inst(PPC_RAW_NOP())); } } else { return -EINVAL; @@ -256,13 +487,9 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) if (ret) return ret; - if (!core_kernel_text(ip)) { - if (!mod) { - pr_err("0x%lx: No module provided for non-kernel address\n", ip); - return -EFAULT; - } - rec->arch.mod = mod; - } + /* Set up out-of-line stub */ + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + return ftrace_init_ool_stub(mod, rec); /* Nop-out the ftrace location */ new = ppc_inst(PPC_RAW_NOP()); @@ -302,6 +529,13 @@ int ftrace_update_ftrace_func(ftrace_func_t func) ppc_inst_t old, new; int ret; + /* + * When using CALL_OPS, the function to call is associated with the + * call site, and we don't have a global function pointer to update. + */ + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS)) + return 0; + old = ppc_inst_read((u32 *)&ftrace_call); new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1); ret = ftrace_modify_code(ip, old, new); @@ -421,8 +655,7 @@ int __init ftrace_dyn_arch_init(void) void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) { - unsigned long sp = fregs->regs.gpr[1]; - int bit; + unsigned long sp = arch_ftrace_regs(fregs)->regs.gpr[1]; if (unlikely(ftrace_graph_is_dead())) goto out; @@ -430,15 +663,10 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; - bit = ftrace_test_recursion_trylock(ip, parent_ip); - if (bit < 0) - goto out; - - if (!function_graph_enter(parent_ip, ip, 0, (unsigned long *)sp)) + if (!function_graph_enter_regs(parent_ip, ip, 0, (unsigned long *)sp, fregs)) parent_ip = ppc_function_entry(return_to_handler); - ftrace_test_recursion_unlock(bit); out: - fregs->regs.link = parent_ip; + arch_ftrace_regs(fregs)->regs.link = parent_ip; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.c b/arch/powerpc/kernel/trace/ftrace_64_pg.c index 12fab1803bcf..5c6e545d1708 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_pg.c +++ b/arch/powerpc/kernel/trace/ftrace_64_pg.c @@ -23,7 +23,7 @@ #include <linux/list.h> #include <asm/cacheflush.h> -#include <asm/code-patching.h> +#include <asm/text-patching.h> #include <asm/ftrace.h> #include <asm/syscall.h> #include <asm/inst.h> @@ -116,6 +116,18 @@ static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op) } #ifdef CONFIG_MODULES +static struct module *ftrace_lookup_module(struct dyn_ftrace *rec) +{ + struct module *mod; + + scoped_guard(rcu) + mod = __module_text_address(rec->ip); + if (!mod) + pr_err("No module loaded at addr=%lx\n", rec->ip); + + return mod; +} + static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) @@ -124,6 +136,12 @@ __ftrace_make_nop(struct module *mod, unsigned long ip = rec->ip; ppc_inst_t op, pop; + if (!mod) { + mod = ftrace_lookup_module(rec); + if (!mod) + return -EINVAL; + } + /* read where this goes */ if (copy_inst_from_kernel_nofault(&op, (void *)ip)) { pr_err("Fetching opcode failed.\n"); @@ -366,27 +384,6 @@ int ftrace_make_nop(struct module *mod, return -EINVAL; } - /* - * Out of range jumps are called from modules. - * We should either already have a pointer to the module - * or it has been passed in. - */ - if (!rec->arch.mod) { - if (!mod) { - pr_err("No module loaded addr=%lx\n", addr); - return -EFAULT; - } - rec->arch.mod = mod; - } else if (mod) { - if (mod != rec->arch.mod) { - pr_err("Record mod %p not equal to passed in mod %p\n", - rec->arch.mod, mod); - return -EINVAL; - } - /* nothing to do if mod == rec->arch.mod */ - } else - mod = rec->arch.mod; - return __ftrace_make_nop(mod, rec, addr); } @@ -411,7 +408,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) ppc_inst_t op[2]; void *ip = (void *)rec->ip; unsigned long entry, ptr, tramp; - struct module *mod = rec->arch.mod; + struct module *mod = ftrace_lookup_module(rec); + + if (!mod) + return -EINVAL; /* read where this goes */ if (copy_inst_from_kernel_nofault(op, ip)) @@ -533,16 +533,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) return -EINVAL; } - /* - * Out of range jumps are called from modules. - * Being that we are converting from nop, it had better - * already have a module defined. - */ - if (!rec->arch.mod) { - pr_err("No module loaded\n"); - return -EINVAL; - } - return __ftrace_make_call(rec, addr); } @@ -555,7 +545,10 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, ppc_inst_t op; unsigned long ip = rec->ip; unsigned long entry, ptr, tramp; - struct module *mod = rec->arch.mod; + struct module *mod = ftrace_lookup_module(rec); + + if (!mod) + return -EINVAL; /* If we never set up ftrace trampolines, then bail */ if (!mod->arch.tramp || !mod->arch.tramp_regs) { @@ -668,14 +661,6 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, return -EINVAL; } - /* - * Out of range jumps are called from modules. - */ - if (!rec->arch.mod) { - pr_err("No module loaded\n"); - return -EINVAL; - } - return __ftrace_modify_call(rec, old_addr, addr); } #endif @@ -800,10 +785,10 @@ int ftrace_disable_ftrace_graph_caller(void) * in current thread info. Return the address we want to divert to. */ static unsigned long -__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp) +__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp, + struct ftrace_regs *fregs) { unsigned long return_hooker; - int bit; if (unlikely(ftrace_graph_is_dead())) goto out; @@ -811,16 +796,11 @@ __prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; - bit = ftrace_test_recursion_trylock(ip, parent); - if (bit < 0) - goto out; - return_hooker = ppc_function_entry(return_to_handler); - if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp)) + if (!function_graph_enter_regs(parent, ip, 0, (unsigned long *)sp, fregs)) parent = return_hooker; - ftrace_test_recursion_unlock(bit); out: return parent; } @@ -829,13 +809,14 @@ out: void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) { - fregs->regs.link = __prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]); + arch_ftrace_regs(fregs)->regs.link = __prepare_ftrace_return(parent_ip, ip, + arch_ftrace_regs(fregs)->regs.gpr[1], fregs); } #else unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp) { - return __prepare_ftrace_return(parent, ip, sp); + return __prepare_ftrace_return(parent, ip, sp, NULL); } #endif #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/powerpc/kernel/trace/ftrace_entry.S b/arch/powerpc/kernel/trace/ftrace_entry.S index 76dbe9fd2c0f..2c1b24100eca 100644 --- a/arch/powerpc/kernel/trace/ftrace_entry.S +++ b/arch/powerpc/kernel/trace/ftrace_entry.S @@ -39,13 +39,37 @@ /* Create our stack frame + pt_regs */ PPC_STLU r1,-SWITCH_FRAME_SIZE(r1) + .if \allregs == 1 + SAVE_GPRS(11, 12, r1) + .endif + + /* Get the _mcount() call site out of LR */ + mflr r11 + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Load the ftrace_op */ + PPC_LL r12, -(MCOUNT_INSN_SIZE*2 + SZL)(r11) + + /* Load direct_call from the ftrace_op */ + PPC_LL r12, FTRACE_OPS_DIRECT_CALL(r12) + PPC_LCMPI r12, 0 + .if \allregs == 1 + bne .Lftrace_direct_call_regs + .else + bne .Lftrace_direct_call + .endif +#endif + + /* Save the previous LR in pt_regs->link */ + PPC_STL r0, _LINK(r1) + /* Also save it in A's stack frame */ + PPC_STL r0, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE+LRSAVE(r1) + /* Save all gprs to pt_regs */ SAVE_GPR(0, r1) SAVE_GPRS(3, 10, r1) #ifdef CONFIG_PPC64 - /* Save the original return address in A's stack frame */ - std r0, LRSAVE+SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE(r1) /* Ok to continue? */ lbz r3, PACA_FTRACE_ENABLED(r13) cmpdi r3, 0 @@ -54,9 +78,9 @@ .if \allregs == 1 SAVE_GPR(2, r1) - SAVE_GPRS(11, 31, r1) + SAVE_GPRS(13, 31, r1) .else -#ifdef CONFIG_LIVEPATCH_64 +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) SAVE_GPR(14, r1) #endif .endif @@ -67,80 +91,143 @@ .if \allregs == 1 /* Load special regs for save below */ + mfcr r7 mfmsr r8 mfctr r9 mfxer r10 - mfcr r11 .else /* Clear MSR to flag as ftrace_caller versus frace_regs_caller */ li r8, 0 .endif - /* Get the _mcount() call site out of LR */ - mflr r7 - /* Save it as pt_regs->nip */ - PPC_STL r7, _NIP(r1) - /* Also save it in B's stackframe header for proper unwind */ - PPC_STL r7, LRSAVE+SWITCH_FRAME_SIZE(r1) - /* Save the read LR in pt_regs->link */ - PPC_STL r0, _LINK(r1) - #ifdef CONFIG_PPC64 /* Save callee's TOC in the ABI compliant location */ std r2, STK_GOT(r1) LOAD_PACA_TOC() /* get kernel TOC in r2 */ +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS + /* r11 points to the instruction following the call to ftrace */ + PPC_LL r5, -(MCOUNT_INSN_SIZE*2 + SZL)(r11) + PPC_LL r12, FTRACE_OPS_FUNC(r5) + mtctr r12 +#else /* !CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS */ +#ifdef CONFIG_PPC64 LOAD_REG_ADDR(r3, function_trace_op) ld r5,0(r3) #else lis r3,function_trace_op@ha lwz r5,function_trace_op@l(r3) #endif - -#ifdef CONFIG_LIVEPATCH_64 - mr r14, r7 /* remember old NIP */ #endif - /* Calculate ip from nip-4 into r3 for call below */ - subi r3, r7, MCOUNT_INSN_SIZE - - /* Put the original return address in r4 as parent_ip */ - mr r4, r0 - /* Save special regs */ PPC_STL r8, _MSR(r1) .if \allregs == 1 + PPC_STL r7, _CCR(r1) PPC_STL r9, _CTR(r1) PPC_STL r10, _XER(r1) - PPC_STL r11, _CCR(r1) .endif +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Clear orig_gpr3 to later detect ftrace_direct call */ + li r7, 0 + PPC_STL r7, ORIG_GPR3(r1) +#endif + +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + /* Save our real return address in nvr for return */ + .if \allregs == 0 + SAVE_GPR(15, r1) + .endif + mr r15, r11 + /* + * We want the ftrace location in the function, but our lr (in r11) + * points at the 'mtlr r0' instruction in the out of line stub. To + * recover the ftrace location, we read the branch instruction in the + * stub, and adjust our lr by the branch offset. + * + * See ftrace_init_ool_stub() for the profile sequence. + */ + lwz r8, MCOUNT_INSN_SIZE(r11) + slwi r8, r8, 6 + srawi r8, r8, 6 + add r3, r11, r8 + /* + * Override our nip to point past the branch in the original function. + * This allows reliable stack trace and the ftrace stack tracer to work as-is. + */ + addi r11, r3, MCOUNT_INSN_SIZE +#else + /* Calculate ip from nip-4 into r3 for call below */ + subi r3, r11, MCOUNT_INSN_SIZE +#endif + + /* Save NIP as pt_regs->nip */ + PPC_STL r11, _NIP(r1) + /* Also save it in B's stackframe header for proper unwind */ + PPC_STL r11, LRSAVE+SWITCH_FRAME_SIZE(r1) +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) + mr r14, r11 /* remember old NIP */ +#endif + + /* Put the original return address in r4 as parent_ip */ + mr r4, r0 + /* Load &pt_regs in r6 for call below */ addi r6, r1, STACK_INT_FRAME_REGS .endm .macro ftrace_regs_exit allregs - /* Load ctr with the possibly modified NIP */ - PPC_LL r3, _NIP(r1) +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Check orig_gpr3 to detect ftrace_direct call */ + PPC_LL r3, ORIG_GPR3(r1) + PPC_LCMPI cr1, r3, 0 mtctr r3 +#endif + /* Restore possibly modified LR */ + PPC_LL r0, _LINK(r1) + +#ifndef CONFIG_PPC_FTRACE_OUT_OF_LINE + /* Load ctr with the possibly modified NIP */ + PPC_LL r3, _NIP(r1) #ifdef CONFIG_LIVEPATCH_64 cmpd r14, r3 /* has NIP been altered? */ #endif +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + beq cr1,2f + mtlr r3 + b 3f +#endif +2: mtctr r3 + mtlr r0 +3: + +#else /* !CONFIG_PPC_FTRACE_OUT_OF_LINE */ + /* Load LR with the possibly modified NIP */ + PPC_LL r3, _NIP(r1) + cmpd r14, r3 /* has NIP been altered? */ + bne- 1f + + mr r3, r15 + .if \allregs == 0 + REST_GPR(15, r1) + .endif +1: mtlr r3 +#endif + /* Restore gprs */ .if \allregs == 1 REST_GPRS(2, 31, r1) .else REST_GPRS(3, 10, r1) -#ifdef CONFIG_LIVEPATCH_64 +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) REST_GPR(14, r1) #endif .endif - /* Restore possibly modified LR */ - PPC_LL r0, _LINK(r1) - mtlr r0 - #ifdef CONFIG_PPC64 /* Restore callee's TOC */ ld r2, STK_GOT(r1) @@ -153,23 +240,46 @@ /* Based on the cmpd above, if the NIP was altered handle livepatch */ bne- livepatch_handler #endif - bctr /* jump after _mcount site */ + + /* jump after _mcount site */ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + bnectr cr1 +#endif + /* + * Return with blr to keep the link stack balanced. The function profiling sequence + * uses 'mtlr r0' to restore LR. + */ + blr +#else + bctr +#endif .endm -_GLOBAL(ftrace_regs_caller) - ftrace_regs_entry 1 - /* ftrace_call(r3, r4, r5, r6) */ +.macro ftrace_regs_func allregs +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS + bctrl +#else + .if \allregs == 1 .globl ftrace_regs_call ftrace_regs_call: + .else +.globl ftrace_call +ftrace_call: + .endif + /* ftrace_call(r3, r4, r5, r6) */ bl ftrace_stub +#endif +.endm + +_GLOBAL(ftrace_regs_caller) + ftrace_regs_entry 1 + ftrace_regs_func 1 ftrace_regs_exit 1 _GLOBAL(ftrace_caller) ftrace_regs_entry 0 - /* ftrace_call(r3, r4, r5, r6) */ -.globl ftrace_call -ftrace_call: - bl ftrace_stub + ftrace_regs_func 0 ftrace_regs_exit 0 _GLOBAL(ftrace_stub) @@ -177,6 +287,11 @@ _GLOBAL(ftrace_stub) #ifdef CONFIG_PPC64 ftrace_no_trace: +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + REST_GPR(3, r1) + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + blr +#else mflr r3 mtctr r3 REST_GPR(3, r1) @@ -184,6 +299,22 @@ ftrace_no_trace: mtlr r0 bctr #endif +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +.Lftrace_direct_call_regs: + mtctr r12 + REST_GPRS(11, 12, r1) + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + bctr +.Lftrace_direct_call: + mtctr r12 + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + bctr +SYM_FUNC_START(ftrace_stub_direct_tramp) + blr +SYM_FUNC_END(ftrace_stub_direct_tramp) +#endif #ifdef CONFIG_LIVEPATCH_64 /* @@ -194,11 +325,17 @@ ftrace_no_trace: * We get here when a function A, calls another function B, but B has * been live patched with a new function C. * - * On entry: - * - we have no stack frame and can not allocate one + * On entry, we have no stack frame and can not allocate one. + * + * With PPC_FTRACE_OUT_OF_LINE=n, on entry: * - LR points back to the original caller (in A) * - CTR holds the new NIP in C * - r0, r11 & r12 are free + * + * With PPC_FTRACE_OUT_OF_LINE=y, on entry: + * - r0 points back to the original caller (in A) + * - LR holds the new NIP in C + * - r11 & r12 are free */ livepatch_handler: ld r12, PACA_THREAD_INFO(r13) @@ -208,18 +345,23 @@ livepatch_handler: addi r11, r11, 24 std r11, TI_livepatch_sp(r12) - /* Save toc & real LR on livepatch stack */ - std r2, -24(r11) - mflr r12 - std r12, -16(r11) - /* Store stack end marker */ lis r12, STACK_END_MAGIC@h ori r12, r12, STACK_END_MAGIC@l std r12, -8(r11) - /* Put ctr in r12 for global entry and branch there */ + /* Save toc & real LR on livepatch stack */ + std r2, -24(r11) +#ifndef CONFIG_PPC_FTRACE_OUT_OF_LINE + mflr r12 + std r12, -16(r11) mfctr r12 +#else + std r0, -16(r11) + mflr r12 + /* Put ctr in r12 for global entry and branch there */ + mtctr r12 +#endif bctrl /* @@ -308,6 +450,14 @@ _GLOBAL(return_to_handler) blr #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE +SYM_DATA(ftrace_ool_stub_text_count, .long CONFIG_PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE) + +SYM_START(ftrace_ool_stub_text, SYM_L_GLOBAL, .balign SZL) + .space CONFIG_PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE * FTRACE_OOL_STUB_SIZE +SYM_CODE_END(ftrace_ool_stub_text) +#endif + .pushsection ".tramp.ftrace.text","aw",@progbits; .globl ftrace_tramp_text ftrace_tramp_text: |