diff options
| -rw-r--r-- | arch/arm64/Kconfig | 4 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ftrace.h | 22 | ||||
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 6 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry-ftrace.S | 90 | ||||
| -rw-r--r-- | arch/arm64/kernel/ftrace.c | 46 | ||||
| -rw-r--r-- | arch/s390/kernel/mcount.S | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/ftrace_32.S | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/ftrace_64.S | 4 | ||||
| -rw-r--r-- | include/linux/ftrace.h | 61 | ||||
| -rw-r--r-- | kernel/bpf/trampoline.c | 12 | ||||
| -rw-r--r-- | kernel/trace/Kconfig | 2 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 438 | ||||
| -rw-r--r-- | kernel/trace/trace_selftest.c | 19 | ||||
| -rw-r--r-- | samples/Kconfig | 2 | ||||
| -rw-r--r-- | samples/ftrace/ftrace-direct-modify.c | 10 | ||||
| -rw-r--r-- | samples/ftrace/ftrace-direct-multi-modify.c | 9 | ||||
| -rw-r--r-- | samples/ftrace/ftrace-direct-multi.c | 5 | ||||
| -rw-r--r-- | samples/ftrace/ftrace-direct-too.c | 10 | ||||
| -rw-r--r-- | samples/ftrace/ftrace-direct.c | 10 |
19 files changed, 244 insertions, 516 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1023e896d46b..f3503d0cc1b8 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -185,6 +185,10 @@ config ARM64 select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ + if $(cc-option,-fpatchable-function-entry=2) + select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ + if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ !CC_OPTIMIZE_FOR_SIZE) diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 1c2672bbbf37..b87d70b693c6 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -70,10 +70,19 @@ struct ftrace_ops; #define arch_ftrace_get_regs(regs) NULL +/* + * Note: sizeof(struct ftrace_regs) must be a multiple of 16 to ensure correct + * stack alignment + */ struct ftrace_regs { /* x0 - x8 */ unsigned long regs[9]; + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + unsigned long direct_tramp; +#else unsigned long __unused; +#endif unsigned long fp; unsigned long lr; @@ -136,6 +145,19 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); 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 + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, + unsigned long addr) +{ + /* + * The ftrace trampoline will return to this address instead of the + * instrumented function. + */ + fregs->direct_tramp = addr; +} +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + #endif #define ftrace_return_address(n) return_address(n) diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index ae345b06e9f7..0996094b0d22 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -93,6 +93,9 @@ int main(void) DEFINE(FREGS_LR, offsetof(struct ftrace_regs, lr)); DEFINE(FREGS_SP, offsetof(struct ftrace_regs, sp)); DEFINE(FREGS_PC, offsetof(struct ftrace_regs, pc)); +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + DEFINE(FREGS_DIRECT_TRAMP, offsetof(struct ftrace_regs, direct_tramp)); +#endif DEFINE(FREGS_SIZE, sizeof(struct ftrace_regs)); BLANK(); #endif @@ -197,6 +200,9 @@ int main(void) #endif #ifdef CONFIG_FUNCTION_TRACER DEFINE(FTRACE_OPS_FUNC, offsetof(struct ftrace_ops, func)); +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + DEFINE(FTRACE_OPS_DIRECT_CALL, offsetof(struct ftrace_ops, direct_call)); +#endif #endif return 0; } diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index 350ed81324ac..1c38a60575aa 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -36,6 +36,31 @@ SYM_CODE_START(ftrace_caller) bti c +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS + /* + * The literal pointer to the ops is at an 8-byte aligned boundary + * which is either 12 or 16 bytes before the BL instruction in the call + * site. See ftrace_call_adjust() for details. + * + * Therefore here the LR points at `literal + 16` or `literal + 20`, + * and we can find the address of the literal in either case by + * aligning to an 8-byte boundary and subtracting 16. We do the + * alignment first as this allows us to fold the subtraction into the + * LDR. + */ + bic x11, x30, 0x7 + ldr x11, [x11, #-(4 * AARCH64_INSN_SIZE)] // op + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* + * If the op has a direct call, handle it immediately without + * saving/restoring registers. + */ + ldr x17, [x11, #FTRACE_OPS_DIRECT_CALL] // op->direct_call + cbnz x17, ftrace_caller_direct +#endif +#endif + /* Save original SP */ mov x10, sp @@ -49,6 +74,10 @@ SYM_CODE_START(ftrace_caller) stp x6, x7, [sp, #FREGS_X6] str x8, [sp, #FREGS_X8] +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + str xzr, [sp, #FREGS_DIRECT_TRAMP] +#endif + /* Save the callsite's FP, LR, SP */ str x29, [sp, #FREGS_FP] str x9, [sp, #FREGS_LR] @@ -71,20 +100,7 @@ SYM_CODE_START(ftrace_caller) mov x3, sp // regs #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS - /* - * The literal pointer to the ops is at an 8-byte aligned boundary - * which is either 12 or 16 bytes before the BL instruction in the call - * site. See ftrace_call_adjust() for details. - * - * Therefore here the LR points at `literal + 16` or `literal + 20`, - * and we can find the address of the literal in either case by - * aligning to an 8-byte boundary and subtracting 16. We do the - * alignment first as this allows us to fold the subtraction into the - * LDR. - */ - bic x2, x30, 0x7 - ldr x2, [x2, #-16] // op - + mov x2, x11 // op ldr x4, [x2, #FTRACE_OPS_FUNC] // op->func blr x4 // op->func(ip, parent_ip, op, regs) @@ -107,8 +123,15 @@ SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) ldp x6, x7, [sp, #FREGS_X6] ldr x8, [sp, #FREGS_X8] - /* Restore the callsite's FP, LR, PC */ + /* Restore the callsite's FP */ ldr x29, [sp, #FREGS_FP] + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + ldr x17, [sp, #FREGS_DIRECT_TRAMP] + cbnz x17, ftrace_caller_direct_late +#endif + + /* Restore the callsite's LR and PC */ ldr x30, [sp, #FREGS_LR] ldr x9, [sp, #FREGS_PC] @@ -116,8 +139,45 @@ SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) add sp, sp, #FREGS_SIZE + 32 ret x9 + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +SYM_INNER_LABEL(ftrace_caller_direct_late, SYM_L_LOCAL) + /* + * Head to a direct trampoline in x17 after having run other tracers. + * The ftrace_regs are live, and x0-x8 and FP have been restored. The + * LR, PC, and SP have not been restored. + */ + + /* + * Restore the callsite's LR and PC matching the trampoline calling + * convention. + */ + ldr x9, [sp, #FREGS_LR] + ldr x30, [sp, #FREGS_PC] + + /* Restore the callsite's SP */ + add sp, sp, #FREGS_SIZE + 32 + +SYM_INNER_LABEL(ftrace_caller_direct, SYM_L_LOCAL) + /* + * Head to a direct trampoline in x17. + * + * We use `BR X17` as this can safely land on a `BTI C` or `PACIASP` in + * the trampoline, and will not unbalance any return stack. + */ + br x17 +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ SYM_CODE_END(ftrace_caller) +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +SYM_CODE_START(ftrace_stub_direct_tramp) + bti c + mov x10, x30 + mov x30, x9 + ret x10 +SYM_CODE_END(ftrace_stub_direct_tramp) +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + #else /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */ /* diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 5545fe1a9012..432626c866a8 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -195,15 +195,22 @@ int ftrace_update_ftrace_func(ftrace_func_t func) return ftrace_modify_code(pc, 0, new, false); } -static struct plt_entry *get_ftrace_plt(struct module *mod, unsigned long addr) +static struct plt_entry *get_ftrace_plt(struct module *mod) { #ifdef CONFIG_ARM64_MODULE_PLTS struct plt_entry *plt = mod->arch.ftrace_trampolines; - if (addr == FTRACE_ADDR) - return &plt[FTRACE_PLT_IDX]; -#endif + return &plt[FTRACE_PLT_IDX]; +#else return NULL; +#endif +} + +static bool reachable_by_bl(unsigned long addr, unsigned long pc) +{ + long offset = (long)addr - (long)pc; + + return offset >= -SZ_128M && offset < SZ_128M; } /* @@ -220,14 +227,21 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace *rec, unsigned long *addr) { unsigned long pc = rec->ip; - long offset = (long)*addr - (long)pc; struct plt_entry *plt; /* + * If a custom trampoline is unreachable, rely on the ftrace_caller + * trampoline which knows how to indirectly reach that trampoline + * through ops->direct_call. + */ + if (*addr != FTRACE_ADDR && !reachable_by_bl(*addr, pc)) + *addr = FTRACE_ADDR; + + /* * When the target is within range of the 'BL' instruction, use 'addr' * as-is and branch to that directly. */ - if (offset >= -SZ_128M && offset < SZ_128M) + if (reachable_by_bl(*addr, pc)) return true; /* @@ -256,7 +270,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace *rec, if (WARN_ON(!mod)) return false; - plt = get_ftrace_plt(mod, *addr); + plt = get_ftrace_plt(mod); if (!plt) { pr_err("ftrace: no module PLT for %ps\n", (void *)*addr); return false; @@ -330,12 +344,24 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr) { - if (WARN_ON_ONCE(old_addr != (unsigned long)ftrace_caller)) + unsigned long pc = rec->ip; + u32 old, new; + int ret; + + ret = ftrace_rec_set_ops(rec, arm64_rec_get_ops(rec)); + if (ret) + return ret; + + if (!ftrace_find_callable_addr(rec, NULL, &old_addr)) return -EINVAL; - if (WARN_ON_ONCE(addr != (unsigned long)ftrace_caller)) + if (!ftrace_find_callable_addr(rec, NULL, &addr)) return -EINVAL; - return ftrace_rec_update_ops(rec); + old = aarch64_insn_gen_branch_imm(pc, old_addr, + AARCH64_INSN_BRANCH_LINK); + new = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK); + + return ftrace_modify_code(pc, old, new, true); } #endif diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S index 43ff91073d2a..6c10da43b538 100644 --- a/arch/s390/kernel/mcount.S +++ b/arch/s390/kernel/mcount.S @@ -32,6 +32,11 @@ ENTRY(ftrace_stub) BR_EX %r14 ENDPROC(ftrace_stub) +SYM_CODE_START(ftrace_stub_direct_tramp) + lgr %r1, %r0 + BR_EX %r1 +SYM_CODE_END(ftrace_stub_direct_tramp) + .macro ftrace_regs_entry, allregs=0 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S index a0ed0e4a2c0c..0d9a14528176 100644 --- a/arch/x86/kernel/ftrace_32.S +++ b/arch/x86/kernel/ftrace_32.S @@ -163,6 +163,11 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) jmp .Lftrace_ret SYM_CODE_END(ftrace_regs_caller) +SYM_FUNC_START(ftrace_stub_direct_tramp) + CALL_DEPTH_ACCOUNT + RET +SYM_FUNC_END(ftrace_stub_direct_tramp) + #ifdef CONFIG_FUNCTION_GRAPH_TRACER SYM_CODE_START(ftrace_graph_caller) pushl %eax diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index fb4f1e01b64a..970d8445fdc4 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -309,6 +309,10 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) SYM_FUNC_END(ftrace_regs_caller) STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller) +SYM_FUNC_START(ftrace_stub_direct_tramp) + CALL_DEPTH_ACCOUNT + RET +SYM_FUNC_END(ftrace_stub_direct_tramp) #else /* ! CONFIG_DYNAMIC_FTRACE */ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 366c730beaa3..931f3d904529 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -241,6 +241,12 @@ enum { FTRACE_OPS_FL_DIRECT = BIT(17), }; +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS +#define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS +#else +#define FTRACE_OPS_FL_SAVE_ARGS 0 +#endif + /* * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes * to a ftrace_ops. Note, the requests may fail. @@ -321,6 +327,9 @@ struct ftrace_ops { unsigned long trampoline_size; struct list_head list; ftrace_ops_func_t ops_func; +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + unsigned long direct_call; +#endif #endif }; @@ -397,64 +406,36 @@ struct ftrace_func_entry { #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS extern int ftrace_direct_func_count; -int register_ftrace_direct(unsigned long ip, unsigned long addr); -int unregister_ftrace_direct(unsigned long ip, unsigned long addr); -int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr); -struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr); -int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, - struct dyn_ftrace *rec, - unsigned long old_addr, - unsigned long new_addr); unsigned long ftrace_find_rec_direct(unsigned long ip); -int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); -int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); -int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); -int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr); +int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); +int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, + bool free_filters); +int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); +int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr); + +void ftrace_stub_direct_tramp(void); #else struct ftrace_ops; # define ftrace_direct_func_count 0 -static inline int register_ftrace_direct(unsigned long ip, unsigned long addr) -{ - return -ENOTSUPP; -} -static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr) -{ - return -ENOTSUPP; -} -static inline int modify_ftrace_direct(unsigned long ip, - unsigned long old_addr, unsigned long new_addr) -{ - return -ENOTSUPP; -} -static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) -{ - return NULL; -} -static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, - struct dyn_ftrace *rec, - unsigned long old_addr, - unsigned long new_addr) -{ - return -ENODEV; -} static inline unsigned long ftrace_find_rec_direct(unsigned long ip) { return 0; } -static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +static inline int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) { return -ENODEV; } -static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +static inline int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, + bool free_filters) { return -ENODEV; } -static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +static inline int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) { return -ENODEV; } -static inline int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr) +static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) { return -ENODEV; } diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index d0ed7d6f5eec..a14d0af534b3 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -45,8 +45,8 @@ static int bpf_tramp_ftrace_ops_func(struct ftrace_ops *ops, enum ftrace_ops_cmd lockdep_assert_held_once(&tr->mutex); /* Instead of updating the trampoline here, we propagate - * -EAGAIN to register_ftrace_direct_multi(). Then we can - * retry register_ftrace_direct_multi() after updating the + * -EAGAIN to register_ftrace_direct(). Then we can + * retry register_ftrace_direct() after updating the * trampoline. */ if ((tr->flags & BPF_TRAMP_F_CALL_ORIG) && @@ -198,7 +198,7 @@ static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr) int ret; if (tr->func.ftrace_managed) - ret = unregister_ftrace_direct_multi(tr->fops, (long)old_addr); + ret = unregister_ftrace_direct(tr->fops, (long)old_addr, false); else ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, NULL); @@ -215,9 +215,9 @@ static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_ad if (tr->func.ftrace_managed) { if (lock_direct_mutex) - ret = modify_ftrace_direct_multi(tr->fops, (long)new_addr); + ret = modify_ftrace_direct(tr->fops, (long)new_addr); else - ret = modify_ftrace_direct_multi_nolock(tr->fops, (long)new_addr); + ret = modify_ftrace_direct_nolock(tr->fops, (long)new_addr); } else { ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, new_addr); } @@ -243,7 +243,7 @@ static int register_fentry(struct bpf_trampoline *tr, void *new_addr) if (tr->func.ftrace_managed) { ftrace_set_filter_ip(tr->fops, (unsigned long)ip, 0, 1); - ret = register_ftrace_direct_multi(tr->fops, (long)new_addr); + ret = register_ftrace_direct(tr->fops, (long)new_addr); } else { ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, NULL, new_addr); } diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a856d4a34c67..5b1e7fa41ca8 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -257,7 +257,7 @@ config DYNAMIC_FTRACE_WITH_REGS config DYNAMIC_FTRACE_WITH_DIRECT_CALLS def_bool y - depends on DYNAMIC_FTRACE_WITH_REGS + depends on DYNAMIC_FTRACE_WITH_REGS || DYNAMIC_FTRACE_WITH_ARGS depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS config DYNAMIC_FTRACE_WITH_CALL_OPS diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0feea145bb29..3b46dba3f69b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2583,28 +2583,13 @@ ftrace_add_rec_direct(unsigned long ip, unsigned long addr, static void call_direct_funcs(unsigned long ip, unsigned long pip, struct ftrace_ops *ops, struct ftrace_regs *fregs) { - unsigned long addr; + unsigned long addr = READ_ONCE(ops->direct_call); - addr = ftrace_find_rec_direct(ip); if (!addr) return; arch_ftrace_set_direct_caller(fregs, addr); } - -static struct ftrace_ops direct_ops = { - .func = call_direct_funcs, - .flags = FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS - | FTRACE_OPS_FL_PERMANENT, - /* - * By declaring the main trampoline as this trampoline - * it will never have one allocated for it. Allocated - * trampolines should not call direct functions. - * The direct_ops should only be called by the builtin - * ftrace_regs_caller trampoline. - */ - .trampoline = FTRACE_REGS_ADDR, -}; #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ /** @@ -5301,388 +5286,9 @@ struct ftrace_direct_func { static LIST_HEAD(ftrace_direct_funcs); -/** - * ftrace_find_direct_func - test an address if it is a registered direct caller - * @addr: The address of a registered direct caller - * - * This searches to see if a ftrace direct caller has been registered - * at a specific address, and if so, it returns a descriptor for it. - * - * This can be used by architecture code to see if an address is - * a direct caller (trampoline) attached to a fentry/mcount location. - * This is useful for the function_graph tracer, as it may need to - * do adjustments if it traced a location that also has a direct - * trampoline attached to it. - */ -struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) -{ - struct ftrace_direct_func *entry; - bool found = false; - - /* May be called by fgraph trampoline (protected by rcu tasks) */ - list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) { - if (entry->addr == addr) { - found = true; - break; - } - } - if (found) - return entry; - - return NULL; -} - -static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr) -{ - struct ftrace_direct_func *direct; - - direct = kmalloc(sizeof(*direct), GFP_KERNEL); - if (!direct) - return NULL; - direct->addr = addr; - direct->count = 0; - list_add_rcu(&direct->next, &ftrace_direct_funcs); - ftrace_direct_func_count++; - return direct; -} - static int register_ftrace_function_nolock(struct ftrace_ops *ops); -/** - * register_ftrace_direct - Call a custom trampoline directly - * @ip: The address of the nop at the beginning of a function - * @addr: The address of the trampoline to call at @ip - * - * This is used to connect a direct call from the nop location (@ip) - * at the start of ftrace traced functions. The location that it calls - * (@addr) must be able to handle a direct call, and save the parameters - * of the function being traced, and restore them (or inject new ones - * if needed), before returning. - * - * Returns: - * 0 on success - * -EBUSY - Another direct function is already attached (there can be only one) - * -ENODEV - @ip does not point to a ftrace nop location (or not supported) - * -ENOMEM - There was an allocation failure. - */ -int register_ftrace_direct(unsigned long ip, unsigned long addr) -{ - struct ftrace_direct_func *direct; - struct ftrace_func_entry *entry; - struct ftrace_hash *free_hash = NULL; - struct dyn_ftrace *rec; - int ret = -ENODEV; - - mutex_lock(&direct_mutex); - - ip = ftrace_location(ip); - if (!ip) - goto out_unlock; - - /* See if there's a direct function at @ip already */ - ret = -EBUSY; - if (ftrace_find_rec_direct(ip)) - goto out_unlock; - - ret = -ENODEV; - rec = lookup_rec(ip, ip); - if (!rec) - goto out_unlock; - - /* - * Check if the rec says it has a direct call but we didn't - * find one earlier? - */ - if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) - goto out_unlock; - - /* Make sure the ip points to the exact record */ - if (ip != rec->ip) { - ip = rec->ip; - /* Need to check this ip for a direct. */ - if (ftrace_find_rec_direct(ip)) - goto out_unlock; - } - - ret = -ENOMEM; - direct = ftrace_find_direct_func(addr); - if (!direct) { - direct = ftrace_alloc_direct_func(addr); - if (!direct) - goto out_unlock; - } - - entry = ftrace_add_rec_direct(ip, addr, &free_hash); - if (!entry) - goto out_unlock; - - ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); - - if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { - ret = register_ftrace_function_nolock(&direct_ops); - if (ret) - ftrace_set_filter_ip(&direct_ops, ip, 1, 0); - } - - if (ret) { - remove_hash_entry(direct_functions, entry); - kfree(entry); - if (!direct->count) { - list_del_rcu(&direct->next); - synchronize_rcu_tasks(); - kfree(direct); - if (free_hash) - free_ftrace_hash(free_hash); - free_hash = NULL; - ftrace_direct_func_count--; - } - } else { - direct->count++; - } - out_unlock: - mutex_unlock(&direct_mutex); - - if (free_hash) { - synchronize_rcu_tasks(); - free_ftrace_hash(free_hash); - } - - return ret; -} -EXPORT_SYMBOL_GPL(register_ftrace_direct); - -static struct ftrace_func_entry *find_direct_entry(unsigned long *ip, - struct dyn_ftrace **recp) -{ - struct ftrace_func_entry *entry; - struct dyn_ftrace *rec; - - rec = lookup_rec(*ip, *ip); - if (!rec) - return NULL; - - entry = __ftrace_lookup_ip(direct_functions, rec->ip); - if (!entry) { - WARN_ON(rec->flags & FTRACE_FL_DIRECT); - return NULL; - } - - WARN_ON(!(rec->flags & FTRACE_FL_DIRECT)); - - /* Passed in ip just needs to be on the call site */ - *ip = rec->ip; - - if (recp) - *recp = rec; - - return entry; -} - -int unregister_ftrace_direct(unsigned long ip, unsigned long addr) -{ - struct ftrace_direct_func *direct; - struct ftrace_func_entry *entry; - struct ftrace_hash *hash; - int ret = -ENODEV; - - mutex_lock(&direct_mutex); - - ip = ftrace_location(ip); - if (!ip) - goto out_unlock; - - entry = find_direct_entry(&ip, NULL); - if (!entry) - goto out_unlock; - - hash = direct_ops.func_hash->filter_hash; - if (hash->count == 1) - unregister_ftrace_function(&direct_ops); - - ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0); - - WARN_ON(ret); - - remove_hash_entry(direct_functions, entry); - - direct = ftrace_find_direct_func(addr); - if (!WARN_ON(!direct)) { - /* This is the good path (see the ! before WARN) */ - direct->count--; - WARN_ON(direct->count < 0); - if (!direct->count) { - list_del_rcu(&direct->next); - synchronize_rcu_tasks(); - kfree(direct); - kfree(entry); - ftrace_direct_func_count--; - } - } - out_unlock: - mutex_unlock(&direct_mutex); - - return ret; -} -EXPORT_SYMBOL_GPL(unregister_ftrace_direct); - -static struct ftrace_ops stub_ops = { - .func = ftrace_stub, -}; - -/** - * ftrace_modify_direct_caller - modify ftrace nop directly - * @entry: The ftrace hash entry of the direct helper for @rec - * @rec: The record representing the function site to patch - * @old_addr: The location that the site at @rec->ip currently calls - * @new_addr: The location that the site at @rec->ip should call - * - * An architecture may overwrite this function to optimize the - * changing of the direct callback on an ftrace nop location. - * This is called with the ftrace_lock mutex held, and no other - * ftrace callbacks are on the associated record (@rec). Thus, - * it is safe to modify the ftrace record, where it should be - * currently calling @old_addr directly, to call @new_addr. - * - * This is called with direct_mutex locked. - * - * Safety checks should be made to make sure that the code at - * @rec->ip is currently calling @old_addr. And this must - * also update entry->direct to @new_addr. - */ -int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, - struct dyn_ftrace *rec, - unsigned long old_addr, - unsigned long new_addr) -{ - unsigned long ip = rec->ip; - int ret; - - lockdep_assert_held(&direct_mutex); - - /* - * The ftrace_lock was used to determine if the record - * had more than one registered user to it. If it did, - * we needed to prevent that from changing to do the quick - * switch. But if it did not (only a direct caller was attached) - * then this function is called. But this function can deal - * with attached callers to the rec that we care about, and - * since this function uses standard ftrace calls that take - * the ftrace_lock mutex, we need to release it. - */ - mutex_unlock(&ftrace_lock); - - /* - * By setting a stub function at the same address, we force - * the code to call the iterator and the direct_ops helper. - * This means that @ip does not call the direct call, and - * we can simply modify it. - */ - ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0); - if (ret) - goto out_lock; - - ret = register_ftrace_function_nolock(&stub_ops); - if (ret) { - ftrace_set_filter_ip(&stub_ops, ip, 1, 0); - goto out_lock; - } - - entry->direct = new_addr; - - /* - * By removing the stub, we put back the direct call, calling - * the @new_addr. - */ - unregister_ftrace_function(&stub_ops); - ftrace_set_filter_ip(&stub_ops, ip, 1, 0); - - out_lock: - mutex_lock(&ftrace_lock); - - return ret; -} - -/** - * modify_ftrace_direct - Modify an existing direct call to call something else - * @ip: The instruction pointer to modify - * @old_addr: The address that the current @ip calls directly - * @new_addr: The address that the @ip should call - * - * This modifies a ftrace direct caller at an instruction pointer without - * having to disable it first. The direct call will switch over to the - * @new_addr without missing anything. - * - * Returns: zero on success. Non zero on error, which includes: - * -ENODEV : the @ip given has no direct caller attached - * -EINVAL : the @old_addr does not match the current direct caller - */ -int modify_ftrace_direct(unsigned long ip, - unsigned long old_addr, unsigned long new_addr) -{ - struct ftrace_direct_func *direct, *new_direct = NULL; - struct ftrace_func_entry *entry; - struct dyn_ftrace *rec; - int ret = -ENODEV; - - mutex_lock(&direct_mutex); - - mutex_lock(&ftrace_lock); - - ip = ftrace_location(ip); - if (!ip) - goto out_unlock; - - entry = find_direct_entry(&ip, &rec); - if (!entry) - goto out_unlock; - - ret = -EINVAL; - if (entry->direct != old_addr) - goto out_unlock; - - direct = ftrace_find_direct_func(old_addr); - if (WARN_ON(!direct)) - goto out_unlock; - if (direct->count > 1) { - ret = -ENOMEM; - new_direct = ftrace_alloc_direct_func(new_addr); - if (!new_direct) - goto out_unlock; - direct->count--; - new_direct->count++; - } else { - direct->addr = new_addr; - } - - /* - * If there's no other ftrace callback on the rec->ip location, - * then it can be changed directly by the architecture. - * If there is another caller, then we just need to change the - * direct caller helper to point to @new_addr. - */ - if (ftrace_rec_count(rec) == 1) { - ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr); - } else { - entry->direct = new_addr; - ret = 0; - } - - if (unlikely(ret && new_direct)) { - direct->count++; - list_del_rcu(&new_direct->next); - synchronize_rcu_tasks(); - kfree(new_direct); - ftrace_direct_func_count--; - } - - out_unlock: - mutex_unlock(&ftrace_lock); - mutex_unlock(&direct_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(modify_ftrace_direct); - -#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS) +#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS) static int check_direct_multi(struct ftrace_ops *ops) { @@ -5711,7 +5317,7 @@ static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long } /** - * register_ftrace_direct_multi - Call a custom trampoline directly + * register_ftrace_direct - Call a custom trampoline directly * for multiple functions registered in @ops * @ops: The address of the struct ftrace_ops object * @addr: The address of the trampoline to call at @ops functions @@ -5732,7 +5338,7 @@ static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long * -ENODEV - @ip does not point to a ftrace nop location (or not supported) * -ENOMEM - There was an allocation failure. */ -int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) { struct ftrace_hash *hash, *free_hash = NULL; struct ftrace_func_entry *entry, *new; @@ -5774,6 +5380,7 @@ int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) ops->func = call_direct_funcs; ops->flags = MULTI_FLAGS; ops->trampoline = FTRACE_REGS_ADDR; + ops->direct_call = addr; err = register_ftrace_function_nolock(ops); @@ -5790,11 +5397,11 @@ int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) } return err; } -EXPORT_SYMBOL_GPL(register_ftrace_direct_multi); +EXPORT_SYMBOL_GPL(register_ftrace_direct); /** - * unregister_ftrace_direct_multi - Remove calls to custom trampoline - * previously registered by register_ftrace_direct_multi for @ops object. + * unregister_ftrace_direct - Remove calls to custom trampoline + * previously registered by register_ftrace_direct for @ops object. * @ops: The address of the struct ftrace_ops object * * This is used to remove a direct calls to @addr from the nop locations @@ -5805,7 +5412,8 @@ EXPORT_SYMBOL_GPL(register_ftrace_direct_multi); * 0 on success * -EINVAL - The @ops object was not properly registered. */ -int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, + bool free_filters) { struct ftrace_hash *hash = ops->func_hash->filter_hash; int err; @@ -5823,12 +5431,15 @@ int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) /* cleanup for possible another register call */ ops->func = NULL; ops->trampoline = 0; + + if (free_filters) + ftrace_free_filter(ops); return err; } -EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi); +EXPORT_SYMBOL_GPL(unregister_ftrace_direct); static int -__modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +__modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) { struct ftrace_hash *hash; struct ftrace_func_entry *entry, *iter; @@ -5844,6 +5455,7 @@ __modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) /* Enable the tmp_ops to have the same functions as the direct ops */ ftrace_ops_init(&tmp_ops); tmp_ops.func_hash = ops->func_hash; + tmp_ops.direct_call = addr; err = register_ftrace_function_nolock(&tmp_ops); if (err) @@ -5865,6 +5477,8 @@ __modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) entry->direct = addr; } } + /* Prevent store tearing if a trampoline concurrently accesses the value */ + WRITE_ONCE(ops->direct_call, addr); mutex_unlock(&ftrace_lock); @@ -5875,7 +5489,7 @@ __modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) } /** - * modify_ftrace_direct_multi_nolock - Modify an existing direct 'multi' call + * modify_ftrace_direct_nolock - Modify an existing direct 'multi' call * to call something else * @ops: The address of the struct ftrace_ops object * @addr: The address of the new trampoline to call at @ops functions @@ -5892,19 +5506,19 @@ __modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) * Returns: zero on success. Non zero on error, which includes: * -EINVAL - The @ops object was not properly registered. */ -int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr) +int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) { if (check_direct_multi(ops)) return -EINVAL; if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) return -EINVAL; - return __modify_ftrace_direct_multi(ops, addr); + return __modify_ftrace_direct(ops, addr); } -EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi_nolock); +EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock); /** - * modify_ftrace_direct_multi - Modify an existing direct 'multi' call + * modify_ftrace_direct - Modify an existing direct 'multi' call * to call something else * @ops: The address of the struct ftrace_ops object * @addr: The address of the new trampoline to call at @ops functions @@ -5918,7 +5532,7 @@ EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi_nolock); * Returns: zero on success. Non zero on error, which includes: * -EINVAL - The @ops object was not properly registered. */ -int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) { int err; @@ -5928,11 +5542,11 @@ int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) return -EINVAL; mutex_lock(&direct_mutex); - err = __modify_ftrace_direct_multi(ops, addr); + err = __modify_ftrace_direct(ops, addr); mutex_unlock(&direct_mutex); return err; } -EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi); +EXPORT_SYMBOL_GPL(modify_ftrace_direct); #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ /** diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index ff0536cea968..a931d9aaea26 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -785,14 +785,7 @@ static struct fgraph_ops fgraph_ops __initdata = { }; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS -#ifndef CALL_DEPTH_ACCOUNT -#define CALL_DEPTH_ACCOUNT "" -#endif - -noinline __noclone static void trace_direct_tramp(void) -{ - asm(CALL_DEPTH_ACCOUNT); -} +static struct ftrace_ops direct; #endif /* @@ -870,8 +863,9 @@ trace_selftest_startup_function_graph(struct tracer *trace, * Register direct function together with graph tracer * and make sure we get graph trace. */ - ret = register_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME, - (unsigned long) trace_direct_tramp); + ftrace_set_filter_ip(&direct, (unsigned long)DYN_FTRACE_TEST_NAME, 0, 0); + ret = register_ftrace_direct(&direct, + (unsigned long)ftrace_stub_direct_tramp); if (ret) goto out; @@ -891,8 +885,9 @@ trace_selftest_startup_function_graph(struct tracer *trace, unregister_ftrace_graph(&fgraph_ops); - ret = unregister_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME, - (unsigned long) trace_direct_tramp); + ret = unregister_ftrace_direct(&direct, + (unsigned long)ftrace_stub_direct_tramp, + true); if (ret) goto out; diff --git a/samples/Kconfig b/samples/Kconfig index 30ef8bd48ba3..fd24daa99f34 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -38,7 +38,7 @@ config SAMPLE_FTRACE_DIRECT that hooks to wake_up_process and prints the parameters. config SAMPLE_FTRACE_DIRECT_MULTI - tristate "Build register_ftrace_direct_multi() example" + tristate "Build register_ftrace_direct() on multiple ips example" depends on DYNAMIC_FTRACE_WITH_DIRECT_CALLS && m depends on HAVE_SAMPLE_FTRACE_DIRECT_MULTI help diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c index d93abbcb1f4c..25fba66f61c0 100644 --- a/samples/ftrace/ftrace-direct-modify.c +++ b/samples/ftrace/ftrace-direct-modify.c @@ -96,6 +96,8 @@ asm ( #endif /* CONFIG_S390 */ +static struct ftrace_ops direct; + static unsigned long my_tramp = (unsigned long)my_tramp1; static unsigned long tramps[2] = { (unsigned long)my_tramp1, @@ -114,7 +116,7 @@ static int simple_thread(void *arg) if (ret) continue; t ^= 1; - ret = modify_ftrace_direct(my_ip, my_tramp, tramps[t]); + ret = modify_ftrace_direct(&direct, tramps[t]); if (!ret) my_tramp = tramps[t]; WARN_ON_ONCE(ret); @@ -129,7 +131,9 @@ static int __init ftrace_direct_init(void) { int ret; - ret = register_ftrace_direct(my_ip, my_tramp); + ftrace_set_filter_ip(&direct, (unsigned long) my_ip, 0, 0); + ret = register_ftrace_direct(&direct, my_tramp); + if (!ret) simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn"); return ret; @@ -138,7 +142,7 @@ static int __init ftrace_direct_init(void) static void __exit ftrace_direct_exit(void) { kthread_stop(simple_tsk); - unregister_ftrace_direct(my_ip, my_tramp); + unregister_ftrace_direct(&direct, my_tramp, true); } module_init(ftrace_direct_init); diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c index b58c594efb51..f72623899602 100644 --- a/samples/ftrace/ftrace-direct-multi-modify.c +++ b/samples/ftrace/ftrace-direct-multi-modify.c @@ -123,7 +123,7 @@ static int simple_thread(void *arg) if (ret) continue; t ^= 1; - ret = modify_ftrace_direct_multi(&direct, tramps[t]); + ret = modify_ftrace_direct(&direct, tramps[t]); if (!ret) my_tramp = tramps[t]; WARN_ON_ONCE(ret); @@ -141,7 +141,7 @@ static int __init ftrace_direct_multi_init(void) ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0); ftrace_set_filter_ip(&direct, (unsigned long) schedule, 0, 0); - ret = register_ftrace_direct_multi(&direct, my_tramp); + ret = register_ftrace_direct(&direct, my_tramp); if (!ret) simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn"); @@ -151,13 +151,12 @@ static int __init ftrace_direct_multi_init(void) static void __exit ftrace_direct_multi_exit(void) { kthread_stop(simple_tsk); - unregister_ftrace_direct_multi(&direct, my_tramp); - ftrace_free_filter(&direct); + unregister_ftrace_direct(&direct, my_tramp, true); } module_init(ftrace_direct_multi_init); module_exit(ftrace_direct_multi_exit); MODULE_AUTHOR("Jiri Olsa"); -MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct_multi()"); +MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct()"); MODULE_LICENSE("GPL"); diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c index c27cf130c319..1547c2c6be02 100644 --- a/samples/ftrace/ftrace-direct-multi.c +++ b/samples/ftrace/ftrace-direct-multi.c @@ -73,13 +73,12 @@ static int __init ftrace_direct_multi_init(void) ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0); ftrace_set_filter_ip(&direct, (unsigned long) schedule, 0, 0); - return register_ftrace_direct_multi(&direct, (unsigned long) my_tramp); + return register_ftrace_direct(&direct, (unsigned long) my_tramp); } static void __exit ftrace_direct_multi_exit(void) { - unregister_ftrace_direct_multi(&direct, (unsigned long) my_tramp); - ftrace_free_filter(&direct); + unregister_ftrace_direct(&direct, (unsigned long) my_tramp, true); } module_init(ftrace_direct_multi_init); diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c index 8139dce2a31c..f28e7b99840f 100644 --- a/samples/ftrace/ftrace-direct-too.c +++ b/samples/ftrace/ftrace-direct-too.c @@ -70,16 +70,18 @@ asm ( #endif /* CONFIG_S390 */ +static struct ftrace_ops direct; + static int __init ftrace_direct_init(void) { - return register_ftrace_direct((unsigned long)handle_mm_fault, - (unsigned long)my_tramp); + ftrace_set_filter_ip(&direct, (unsigned long) handle_mm_fault, 0, 0); + + return register_ftrace_direct(&direct, (unsigned long) my_tramp); } static void __exit ftrace_direct_exit(void) { - unregister_ftrace_direct((unsigned long)handle_mm_fault, - (unsigned long)my_tramp); + unregister_ftrace_direct(&direct, (unsigned long)my_tramp, true); } module_init(ftrace_direct_init); diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c index 1d3d307ca33d..d81a9473b585 100644 --- a/samples/ftrace/ftrace-direct.c +++ b/samples/ftrace/ftrace-direct.c @@ -63,16 +63,18 @@ asm ( #endif /* CONFIG_S390 */ +static struct ftrace_ops direct; + static int __init ftrace_direct_init(void) { - return register_ftrace_direct((unsigned long)wake_up_process, - (unsigned long)my_tramp); + ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0); + + return register_ftrace_direct(&direct, (unsigned long) my_tramp); } static void __exit ftrace_direct_exit(void) { - unregister_ftrace_direct((unsigned long)wake_up_process, - (unsigned long)my_tramp); + unregister_ftrace_direct(&direct, (unsigned long)my_tramp, true); } module_init(ftrace_direct_init); |