From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF921C388F7 for ; Thu, 29 Oct 2020 00:22:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 674D7207DE for ; Thu, 29 Oct 2020 00:22:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388733AbgJ2AW6 (ORCPT ); Wed, 28 Oct 2020 20:22:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:48356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388031AbgJ2AW4 (ORCPT ); Wed, 28 Oct 2020 20:22:56 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 755AA206BE; Thu, 29 Oct 2020 00:22:54 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1kXviP-005fgy-03; Wed, 28 Oct 2020 20:22:53 -0400 Message-ID: <20201029002252.818328302@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 28 Oct 2020 20:08:17 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Alexei Starovoitov , Jiri Olsa , Josh Poimboeuf , Jiri Kosina Subject: [RFC][PATCH 1/3 v3] ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs References: <20201029000816.272878754@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (VMware)" In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled. Signed-off-by: Steven Rostedt (VMware) --- arch/x86/kernel/kprobes/ftrace.c | 3 ++- include/linux/ftrace.h | 16 ++++++++++++++-- include/linux/kprobes.h | 2 +- kernel/livepatch/patch.c | 3 ++- kernel/trace/ftrace.c | 27 +++++++++++++++------------ kernel/trace/trace_event_perf.c | 2 +- kernel/trace/trace_functions.c | 9 ++++----- kernel/trace/trace_irqsoff.c | 2 +- kernel/trace/trace_sched_wakeup.c | 2 +- kernel/trace/trace_selftest.c | 20 +++++++++++--------- kernel/trace/trace_stack.c | 2 +- 11 files changed, 53 insertions(+), 35 deletions(-) diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c index a40a6cdfcca3..a01849ffe013 100644 --- a/arch/x86/kernel/kprobes/ftrace.c +++ b/arch/x86/kernel/kprobes/ftrace.c @@ -14,8 +14,9 @@ /* Ftrace callback handler for kprobes -- called under preepmt disabed */ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops, struct pt_regs *regs) + struct ftrace_ops *ops, struct ftrace_regs *fregs) { + struct pt_regs *regs = ftrace_get_regs(fregs); struct kprobe *p; struct kprobe_ctlblk *kcb; int bit; diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 8dde9c17aaa5..24e1fa52337d 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -90,8 +90,20 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, struct ftrace_ops; +struct ftrace_regs { + struct pt_regs regs; +}; + +static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) +{ + if (!fregs) + return NULL; + + return &fregs->regs; +} + typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs); + struct ftrace_ops *op, struct ftrace_regs *fregs); ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); @@ -259,7 +271,7 @@ int register_ftrace_function(struct ftrace_ops *ops); int unregister_ftrace_function(struct ftrace_ops *ops); extern void ftrace_stub(unsigned long a0, unsigned long a1, - struct ftrace_ops *op, struct pt_regs *regs); + struct ftrace_ops *op, struct ftrace_regs *fregs); #else /* !CONFIG_FUNCTION_TRACER */ /* diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 8aab327b5539..5ac1d9b1d58c 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -325,7 +325,7 @@ static inline void wait_for_kprobe_optimizer(void) { } #endif /* CONFIG_OPTPROBES */ #ifdef CONFIG_KPROBES_ON_FTRACE extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops, struct pt_regs *regs); + struct ftrace_ops *ops, struct ftrace_regs *fregs); extern int arch_prepare_kprobe_ftrace(struct kprobe *p); #endif diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index 6c0164d24bbd..9af0a7c8a255 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -40,8 +40,9 @@ struct klp_ops *klp_find_ops(void *old_func) static void notrace klp_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *fops, - struct pt_regs *regs) + struct ftrace_regs *fregs) { + struct pt_regs *regs = ftrace_get_regs(fregs); struct klp_ops *ops; struct klp_func *func; int patch_state; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2dcae8251104..7ef9048b3d1e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -121,7 +121,7 @@ struct ftrace_ops global_ops; #if ARCH_SUPPORTS_FTRACE_OPS static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs); + struct ftrace_ops *op, struct ftrace_regs *fregs); #else /* See comment below, where ftrace_ops_list_func is defined */ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); @@ -140,7 +140,7 @@ static inline void ftrace_ops_init(struct ftrace_ops *ops) } static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_array *tr = op->private; int pid; @@ -154,7 +154,7 @@ static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, return; } - op->saved_func(ip, parent_ip, op, regs); + op->saved_func(ip, parent_ip, op, fregs); } static void ftrace_sync_ipi(void *data) @@ -754,7 +754,7 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) static void function_profile_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops, struct pt_regs *regs) + struct ftrace_ops *ops, struct ftrace_regs *fregs) { struct ftrace_profile_stat *stat; struct ftrace_profile *rec; @@ -2143,6 +2143,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) else rec->flags &= ~FTRACE_FL_TRAMP_EN; } + if (flag & FTRACE_FL_DIRECT) { /* * If there's only one user (direct_ops helper) @@ -2368,8 +2369,9 @@ unsigned long ftrace_find_rec_direct(unsigned long ip) } static void call_direct_funcs(unsigned long ip, unsigned long pip, - struct ftrace_ops *ops, struct pt_regs *regs) + struct ftrace_ops *ops, struct ftrace_regs *fregs) { + struct pt_regs *regs = ftrace_get_regs(fregs); unsigned long addr; addr = ftrace_find_rec_direct(ip); @@ -4293,7 +4295,7 @@ static int __init ftrace_mod_cmd_init(void) core_initcall(ftrace_mod_cmd_init); static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { struct ftrace_probe_ops *probe_ops; struct ftrace_func_probe *probe; @@ -6913,8 +6915,9 @@ void ftrace_reset_array_ops(struct trace_array *tr) static nokprobe_inline void __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ignored, struct pt_regs *regs) + struct ftrace_ops *ignored, struct ftrace_regs *fregs) { + struct pt_regs *regs = ftrace_get_regs(fregs); struct ftrace_ops *op; int bit; @@ -6947,7 +6950,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, pr_warn("op=%p %pS\n", op, op); goto out; } - op->func(ip, parent_ip, op, regs); + op->func(ip, parent_ip, op, fregs); } } while_for_each_ftrace_op(op); out: @@ -6970,9 +6973,9 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, */ #if ARCH_SUPPORTS_FTRACE_OPS static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { - __ftrace_ops_list_func(ip, parent_ip, NULL, regs); + __ftrace_ops_list_func(ip, parent_ip, NULL, fregs); } NOKPROBE_SYMBOL(ftrace_ops_list_func); #else @@ -6989,7 +6992,7 @@ NOKPROBE_SYMBOL(ftrace_ops_no_ops); * this function will be called by the mcount trampoline. */ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { int bit; @@ -7002,7 +7005,7 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, preempt_disable_notrace(); - op->func(ip, parent_ip, op, regs); + op->func(ip, parent_ip, op, fregs); preempt_enable_notrace(); trace_clear_recursion(bit); diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index a2b9fddb8148..86b7cdff1403 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -432,7 +432,7 @@ NOKPROBE_SYMBOL(perf_trace_buf_update); #ifdef CONFIG_FUNCTION_TRACER static void perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops, struct pt_regs *pt_regs) + struct ftrace_ops *ops, struct ftrace_regs *fregs) { struct ftrace_entry *entry; struct perf_event *event; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 89c414ce1388..9f88de3f1d47 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -23,10 +23,10 @@ static void tracing_start_function_trace(struct trace_array *tr); static void tracing_stop_function_trace(struct trace_array *tr); static void function_trace_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs); + struct ftrace_ops *op, struct ftrace_regs *fregs); static void function_stack_trace_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs); + struct ftrace_ops *op, struct ftrace_regs *fregs); static struct tracer_flags func_flags; /* Our option */ @@ -89,7 +89,6 @@ void ftrace_destroy_function_files(struct trace_array *tr) static int function_trace_init(struct trace_array *tr) { ftrace_func_t func; - /* * Instance trace_arrays get their ops allocated * at instance creation. Unless it failed @@ -129,7 +128,7 @@ static void function_trace_start(struct trace_array *tr) static void function_trace_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_array *tr = op->private; struct trace_array_cpu *data; @@ -178,7 +177,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip, static void function_stack_trace_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_array *tr = op->private; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 10bbb0f381d5..d06aab4dcbb8 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -138,7 +138,7 @@ static int func_prolog_dec(struct trace_array *tr, */ static void irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_array *tr = irqsoff_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 97b10bb31a1f..c0181066dbe9 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -212,7 +212,7 @@ static void wakeup_print_header(struct seq_file *s) */ static void wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_array *tr = wakeup_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 50dd913d23e7..23f07370f40e 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -107,7 +107,7 @@ static int trace_selftest_test_probe1_cnt; static void trace_selftest_test_probe1_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { trace_selftest_test_probe1_cnt++; } @@ -116,7 +116,7 @@ static int trace_selftest_test_probe2_cnt; static void trace_selftest_test_probe2_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { trace_selftest_test_probe2_cnt++; } @@ -125,7 +125,7 @@ static int trace_selftest_test_probe3_cnt; static void trace_selftest_test_probe3_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { trace_selftest_test_probe3_cnt++; } @@ -134,7 +134,7 @@ static int trace_selftest_test_global_cnt; static void trace_selftest_test_global_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { trace_selftest_test_global_cnt++; } @@ -143,7 +143,7 @@ static int trace_selftest_test_dyn_cnt; static void trace_selftest_test_dyn_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { trace_selftest_test_dyn_cnt++; } @@ -414,7 +414,7 @@ static int trace_selftest_recursion_cnt; static void trace_selftest_test_recursion_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { /* * This function is registered without the recursion safe flag. @@ -429,7 +429,7 @@ static void trace_selftest_test_recursion_func(unsigned long ip, static void trace_selftest_test_recursion_safe_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { /* * We said we would provide our own recursion. By calling @@ -543,9 +543,11 @@ static enum { static void trace_selftest_test_regs_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, - struct pt_regs *pt_regs) + struct ftrace_regs *fregs) { - if (pt_regs) + struct pt_regs *regs = ftrace_get_regs(fregs); + + if (regs) trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND; else trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND; diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 969db526a563..63c285042051 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -290,7 +290,7 @@ static void check_stack(unsigned long ip, unsigned long *stack) static void stack_trace_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { unsigned long stack; -- 2.28.0