From 88903c464321cdbc2d473c24cbf311f576cf05bc Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 15 May 2019 14:38:30 +0900 Subject: tracing/probe: Add ustring type for user-space string Add "ustring" type for fetching user-space string from kprobe event. User can specify ustring type at uprobe event, and it is same as "string" for uprobe. Note that probe-event provides this option but it doesn't choose the correct type automatically since we have not way to decide the address is in user-space or not on some arch (and on some other arch, you can fetch the string by "string" type). So user must carefully check the target code (e.g. if you see __user on the target variable) and use this new type. Link: http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2 Acked-by: Ingo Molnar Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 42 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 7d736248a070..439bf04d14ce 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -886,6 +886,15 @@ fetch_store_strlen(unsigned long addr) return (ret < 0) ? ret : len; } +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline int +fetch_store_strlen_user(unsigned long addr) +{ + const void __user *uaddr = (__force const void __user *)addr; + + return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE); +} + /* * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max * length and relative data location. @@ -894,19 +903,46 @@ static nokprobe_inline int fetch_store_string(unsigned long addr, void *dest, void *base) { int maxlen = get_loc_len(*(u32 *)dest); - u8 *dst = get_loc_data(dest, base); + void *__dest; long ret; if (unlikely(!maxlen)) return -ENOMEM; + + __dest = get_loc_data(dest, base); + /* * Try to get string again, since the string can be changed while * probing. */ - ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); + ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen); + if (ret >= 0) + *(u32 *)dest = make_data_loc(ret, __dest - base); + + return ret; +} +/* + * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf + * with max length and relative data location. + */ +static nokprobe_inline int +fetch_store_string_user(unsigned long addr, void *dest, void *base) +{ + const void __user *uaddr = (__force const void __user *)addr; + int maxlen = get_loc_len(*(u32 *)dest); + void *__dest; + long ret; + + if (unlikely(!maxlen)) + return -ENOMEM; + + __dest = get_loc_data(dest, base); + + ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen); if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, (void *)dst - base); + *(u32 *)dest = make_data_loc(ret, __dest - base); + return ret; } -- cgit v1.2.3 From e65f7ae7f4da56622ecf8f1eaed333b9a13f9435 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 15 May 2019 14:38:42 +0900 Subject: tracing/probe: Support user-space dereference Support user-space dereference syntax for probe event arguments to dereference the data-structure or array in user-space. The syntax is just adding 'u' before an offset value. +|-u() e.g. +u8(%ax), +u0(+0(%si)) For example, if you probe do_sched_setscheduler(pid, policy, param) and record param->sched_priority, you can add new probe as below; p do_sched_setscheduler priority=+u0($arg3) Note that kprobe event provides this and it doesn't change the dereference method automatically because we do not know whether the given address is in userspace or kernel on some archs. So as same as "ustring", this is an option for user, who has to carefully choose the dereference method. Link: http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2 Acked-by: Ingo Molnar Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 439bf04d14ce..ff14eb011c1c 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -952,6 +952,12 @@ probe_mem_read(void *dest, void *src, size_t size) return probe_kernel_read(dest, src, size); } +static nokprobe_inline int +probe_mem_read_user(void *dest, void *src, size_t size) +{ + return probe_user_read(dest, src, size); +} + /* Note that we don't verify it, since the code does not come from user space */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, -- cgit v1.2.3 From 539b75b2b9eece3fc6da5672d4b67440d5e454a9 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 22 May 2019 17:27:52 +0900 Subject: tracing/kprobe: Cast user-space address correctly Cast user-space address correctly to pass to probe_user_read(). Reported-by: kbuild test robot Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index ff14eb011c1c..2c5357dddb92 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -955,7 +955,9 @@ probe_mem_read(void *dest, void *src, size_t size) static nokprobe_inline int probe_mem_read_user(void *dest, void *src, size_t size) { - return probe_user_read(dest, src, size); + const void __user *uaddr = (__force const void __user *)src; + + return probe_user_read(dest, uaddr, size); } /* Note that we don't verify it, since the code does not come from user space */ -- cgit v1.2.3 From 970988e19eb0a0dc24fe14bf91972019e48336e2 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 22 May 2019 17:32:35 +0900 Subject: tracing/kprobe: Add kprobe_event= boot parameter Add kprobe_event= boot parameter to define kprobe events at boot time. The definition syntax is similar to tracefs/kprobe_events interface, but use ',' and ';' instead of ' ' and '\n' respectively. e.g. kprobe_event=p,vfs_read,$arg1,$arg2 This puts a probe on vfs_read with argument1 and 2, and enable the new event. Link: http://lkml.kernel.org/r/155851395498.15728.830529496248543583.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 54 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 2c5357dddb92..004fffd24ec1 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -12,6 +12,8 @@ #include #include +#include /* for COMMAND_LINE_SIZE */ + #include "trace_dynevent.h" #include "trace_kprobe_selftest.h" #include "trace_probe.h" @@ -19,6 +21,17 @@ #define KPROBE_EVENT_SYSTEM "kprobes" #define KRETPROBE_MAXACTIVE_MAX 4096 +#define MAX_KPROBE_CMDLINE_SIZE 1024 + +/* Kprobe early definition from command line */ +static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; + +static int __init set_kprobe_boot_events(char *str) +{ + strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE); + return 0; +} +__setup("kprobe_event=", set_kprobe_boot_events); static int trace_kprobe_create(int argc, const char **argv); static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); @@ -1494,6 +1507,44 @@ void destroy_local_trace_kprobe(struct trace_event_call *event_call) } #endif /* CONFIG_PERF_EVENTS */ +static __init void enable_boot_kprobe_events(void) +{ + struct trace_array *tr = top_trace_array(); + struct trace_event_file *file; + struct trace_kprobe *tk; + struct dyn_event *pos; + + mutex_lock(&event_mutex); + for_each_trace_kprobe(tk, pos) { + list_for_each_entry(file, &tr->events, list) + if (file->event_call == &tk->tp.call) + trace_event_enable_disable(file, 1, 0); + } + mutex_unlock(&event_mutex); +} + +static __init void setup_boot_kprobe_events(void) +{ + char *p, *cmd = kprobe_boot_events_buf; + int ret; + + strreplace(kprobe_boot_events_buf, ',', ' '); + + while (cmd && *cmd != '\0') { + p = strchr(cmd, ';'); + if (p) + *p++ = '\0'; + + ret = trace_run_command(cmd, create_or_delete_trace_kprobe); + if (ret) + pr_warn("Failed to add event(%d): %s\n", ret, cmd); + + cmd = p; + } + + enable_boot_kprobe_events(); +} + /* Make a tracefs interface for controlling probe points */ static __init int init_kprobe_trace(void) { @@ -1525,6 +1576,9 @@ static __init int init_kprobe_trace(void) if (!entry) pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); + + setup_boot_kprobe_events(); + return 0; } fs_initcall(init_kprobe_trace); -- cgit v1.2.3 From b6399cc789341fc49a0603fb7d388a4e50aca212 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Thu, 23 May 2019 19:50:34 -0400 Subject: tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline When having kprobe trace event start up tests enabled and adding a kprobe_event on the kernel command line, it produced the following: trace_kprobe: Testing kprobe tracing: WARNING: CPU: 5 PID: 1 at kernel/trace/trace_kprobe.c:1724 kprobe_trace_self_tests_init+0x32d/0x36b Modules linked in: CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-test+ #249 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:kprobe_trace_self_tests_init+0x32d/0x36b Code: b7 e8 4f 8d a2 fe 85 c0 74 10 0f 0b 48 c7 c7 c8 1b 0d b7 ff c3 e8 19 af 99 fe 48 c7 c7 40 93 27 b7 e8 7f 1a a5 fe 85 c0 74 10 <0f> 0b 48 c7 c7 f8 1b 0d b7 ff c3 e8 f9 ae 9 a0 fe 85 RSP: 0018:ffffb36e40653e08 EFLAGS: 00010286 RAX: 00000000fffffff0 RBX: 0000000000000000 RCX: ffffb36e40653d5c RDX: 0000000000000000 RSI: ffffffffb72776e0 RDI: 0000000000000246 RBP: ffff98414fe58ff8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffff98415d8aa940 R12: 0000000000000000 R13: ffffffffb737c1b0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff98415ea80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f959ce741b8 CR3: 000000011a210002 CR4: 00000000001606e0 Call Trace: ? init_kprobe_trace+0x19e/0x19e ? do_early_param+0x8e/0x8e do_one_initcall+0x6f/0x2b4 ? do_early_param+0x8e/0x8e kernel_init_freeable+0x21d/0x2c6 ? rest_init+0x146/0x146 kernel_init+0xa/0x10a ret_from_fork+0x3a/0x50 ---[ end trace 488430c083a4c956 ]--- As with the trace events, if a trace event is set on the kernel command line, the trace events start up tests are suspended. The kprobe start up tests should do the same when a kprobe is enabled on the kernel command line. Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 004fffd24ec1..7958da2fd922 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -25,6 +25,7 @@ /* Kprobe early definition from command line */ static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; +static bool kprobe_boot_events_enabled __initdata; static int __init set_kprobe_boot_events(char *str) { @@ -1538,6 +1539,8 @@ static __init void setup_boot_kprobe_events(void) ret = trace_run_command(cmd, create_or_delete_trace_kprobe); if (ret) pr_warn("Failed to add event(%d): %s\n", ret, cmd); + else + kprobe_boot_events_enabled = true; cmd = p; } @@ -1611,6 +1614,11 @@ static __init int kprobe_trace_self_tests_init(void) if (tracing_is_disabled()) return -ENODEV; + if (kprobe_boot_events_enabled) { + pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n"); + return 0; + } + target = kprobe_trace_selftest_target; pr_info("Testing kprobe tracing: "); -- cgit v1.2.3 From f730e0f2da4d0035775ab3c85757fee37bb9cbbe Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:16:46 +0900 Subject: tracing/kprobe: Set print format right after parsed command Set event call's print format right after parsed command for simplifying (un)register_kprobe_event(). Link: http://lkml.kernel.org/r/155931580625.28323.5158822928646225903.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 7958da2fd922..01fc49f08b70 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -272,6 +272,7 @@ static void free_trace_kprobe(struct trace_kprobe *tk) kfree(tk->tp.call.class->system); kfree(tk->tp.call.name); + kfree(tk->tp.call.print_fmt); kfree(tk->symbol); free_percpu(tk->nhit); kfree(tk); @@ -730,6 +731,10 @@ static int trace_kprobe_create(int argc, const char *argv[]) goto error; /* This can be -ENOMEM */ } + ret = traceprobe_set_print_fmt(&tk->tp, is_return); + if (ret < 0) + goto error; + ret = register_trace_kprobe(tk); if (ret) { trace_probe_log_set_index(1); @@ -1416,18 +1421,14 @@ static int register_kprobe_event(struct trace_kprobe *tk) init_trace_event_call(tk, call); - if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) - return -ENOMEM; ret = register_trace_event(&call->event); - if (!ret) { - kfree(call->print_fmt); + if (!ret) return -ENODEV; - } + ret = trace_add_event_call(call); if (ret) { pr_info("Failed to register kprobe event: %s\n", trace_event_name(call)); - kfree(call->print_fmt); unregister_trace_event(&call->event); } return ret; @@ -1435,13 +1436,8 @@ static int register_kprobe_event(struct trace_kprobe *tk) static int unregister_kprobe_event(struct trace_kprobe *tk) { - int ret; - /* tp->event is unregistered in trace_remove_event_call() */ - ret = trace_remove_event_call(&tk->tp.call); - if (!ret) - kfree(tk->tp.call.print_fmt); - return ret; + return trace_remove_event_call(&tk->tp.call); } #ifdef CONFIG_PERF_EVENTS @@ -1479,10 +1475,8 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, } ret = __register_trace_kprobe(tk); - if (ret < 0) { - kfree(tk->tp.call.print_fmt); + if (ret < 0) goto error; - } return &tk->tp.call; error: @@ -1503,7 +1497,6 @@ void destroy_local_trace_kprobe(struct trace_event_call *event_call) __unregister_trace_kprobe(tk); - kfree(tk->tp.call.print_fmt); free_trace_kprobe(tk); } #endif /* CONFIG_PERF_EVENTS */ -- cgit v1.2.3 From 455b289973f7df350ea179c7eb8bfed0c766ec40 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:17:06 +0900 Subject: tracing/probe: Add trace_probe init and free functions Add common trace_probe init and cleanup function in trace_probe.c, and use it from trace_kprobe.c and trace_uprobe.c Link: http://lkml.kernel.org/r/155931582664.28323.5934870189034740822.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 49 ++++++++++++--------------------------------- 1 file changed, 13 insertions(+), 36 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 01fc49f08b70..c43c2d419ded 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -197,6 +197,16 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); +static void free_trace_kprobe(struct trace_kprobe *tk) +{ + if (tk) { + trace_probe_cleanup(&tk->tp); + kfree(tk->symbol); + free_percpu(tk->nhit); + kfree(tk); + } +} + /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -235,49 +245,17 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group, tk->rp.maxactive = maxactive; - if (!event || !group) { - ret = -EINVAL; - goto error; - } - - tk->tp.call.class = &tk->tp.class; - tk->tp.call.name = kstrdup(event, GFP_KERNEL); - if (!tk->tp.call.name) - goto error; - - tk->tp.class.system = kstrdup(group, GFP_KERNEL); - if (!tk->tp.class.system) + ret = trace_probe_init(&tk->tp, event, group); + if (ret < 0) goto error; dyn_event_init(&tk->devent, &trace_kprobe_ops); - INIT_LIST_HEAD(&tk->tp.files); return tk; error: - kfree(tk->tp.call.name); - kfree(tk->symbol); - free_percpu(tk->nhit); - kfree(tk); + free_trace_kprobe(tk); return ERR_PTR(ret); } -static void free_trace_kprobe(struct trace_kprobe *tk) -{ - int i; - - if (!tk) - return; - - for (i = 0; i < tk->tp.nr_args; i++) - traceprobe_free_probe_arg(&tk->tp.args[i]); - - kfree(tk->tp.call.class->system); - kfree(tk->tp.call.name); - kfree(tk->tp.call.print_fmt); - kfree(tk->symbol); - free_percpu(tk->nhit); - kfree(tk); -} - static struct trace_kprobe *find_trace_kprobe(const char *event, const char *group) { @@ -1400,7 +1378,6 @@ static struct trace_event_functions kprobe_funcs = { static inline void init_trace_event_call(struct trace_kprobe *tk, struct trace_event_call *call) { - INIT_LIST_HEAD(&call->class->fields); if (trace_kprobe_is_return(tk)) { call->event.funcs = &kretprobe_funcs; call->class->define_fields = kretprobe_event_define_fields; -- cgit v1.2.3 From 46e5376d404d14cb321f5d4e446fe3fb6d8a93ab Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:17:16 +0900 Subject: tracing/probe: Add trace_event_call register API for trace_probe Since trace_event_call is a field of trace_probe, these operations should be done in trace_probe.c. trace_kprobe and trace_uprobe use new functions to register/unregister trace_event_call. Link: http://lkml.kernel.org/r/155931583643.28323.14828411185591538876.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index c43c2d419ded..7f802ee27266 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1393,28 +1393,14 @@ static inline void init_trace_event_call(struct trace_kprobe *tk, static int register_kprobe_event(struct trace_kprobe *tk) { - struct trace_event_call *call = &tk->tp.call; - int ret = 0; - - init_trace_event_call(tk, call); - - ret = register_trace_event(&call->event); - if (!ret) - return -ENODEV; + init_trace_event_call(tk, &tk->tp.call); - ret = trace_add_event_call(call); - if (ret) { - pr_info("Failed to register kprobe event: %s\n", - trace_event_name(call)); - unregister_trace_event(&call->event); - } - return ret; + return trace_probe_register_event_call(&tk->tp); } static int unregister_kprobe_event(struct trace_kprobe *tk) { - /* tp->event is unregistered in trace_remove_event_call() */ - return trace_remove_event_call(&tk->tp.call); + return trace_probe_unregister_event_call(&tk->tp); } #ifdef CONFIG_PERF_EVENTS -- cgit v1.2.3 From b5f935ee133911b3ed2d4429dd86d2bd5385519d Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:17:26 +0900 Subject: tracing/probe: Add trace_event_file access APIs for trace_probe Add trace_event_file access APIs for trace_probe data structure. This simplifies enabling/disabling operations in uprobe and kprobe events so that those don't touch deep inside the trace_probe. This also removing a redundant synchronization when the kprobe event is used from perf, since the perf itself uses tracepoint_synchronize_unregister() after disabling (ftrace- defined) event, thus we don't have to synchronize in that path. Also we don't need to identify local trace_kprobe too anymore. Link: http://lkml.kernel.org/r/155931584587.28323.372301976283354629.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 85 ++++++++++++++++----------------------------- 1 file changed, 29 insertions(+), 56 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 7f802ee27266..87a52094378c 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -290,34 +290,27 @@ static inline int __enable_trace_kprobe(struct trace_kprobe *tk) static int enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) { - struct event_file_link *link; + bool enabled = trace_probe_is_enabled(&tk->tp); int ret = 0; if (file) { - link = kmalloc(sizeof(*link), GFP_KERNEL); - if (!link) { - ret = -ENOMEM; - goto out; - } - - link->file = file; - list_add_tail_rcu(&link->list, &tk->tp.files); + ret = trace_probe_add_file(&tk->tp, file); + if (ret) + return ret; + } else + tk->tp.flags |= TP_FLAG_PROFILE; - tk->tp.flags |= TP_FLAG_TRACE; - ret = __enable_trace_kprobe(tk); - if (ret) { - list_del_rcu(&link->list); - kfree(link); - tk->tp.flags &= ~TP_FLAG_TRACE; - } + if (enabled) + return 0; - } else { - tk->tp.flags |= TP_FLAG_PROFILE; - ret = __enable_trace_kprobe(tk); - if (ret) + ret = __enable_trace_kprobe(tk); + if (ret) { + if (file) + trace_probe_remove_file(&tk->tp, file); + else tk->tp.flags &= ~TP_FLAG_PROFILE; } - out: + return ret; } @@ -328,54 +321,34 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) static int disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) { - struct event_file_link *link = NULL; - int wait = 0; + struct trace_probe *tp = &tk->tp; int ret = 0; if (file) { - link = find_event_file_link(&tk->tp, file); - if (!link) { - ret = -EINVAL; - goto out; - } - - list_del_rcu(&link->list); - wait = 1; - if (!list_empty(&tk->tp.files)) + if (!trace_probe_get_file_link(tp, file)) + return -ENOENT; + if (!trace_probe_has_single_file(tp)) goto out; - - tk->tp.flags &= ~TP_FLAG_TRACE; + tp->flags &= ~TP_FLAG_TRACE; } else - tk->tp.flags &= ~TP_FLAG_PROFILE; + tp->flags &= ~TP_FLAG_PROFILE; - if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { + if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) { if (trace_kprobe_is_return(tk)) disable_kretprobe(&tk->rp); else disable_kprobe(&tk->rp.kp); - wait = 1; } - /* - * if tk is not added to any list, it must be a local trace_kprobe - * created with perf_event_open. We don't need to wait for these - * trace_kprobes - */ - if (list_empty(&tk->devent.list)) - wait = 0; out: - if (wait) { + if (file) /* - * Synchronize with kprobe_trace_func/kretprobe_trace_func - * to ensure disabled (all running handlers are finished). - * This is not only for kfree(), but also the caller, - * trace_remove_event_call() supposes it for releasing - * event_call related objects, which will be accessed in - * the kprobe_trace_func/kretprobe_trace_func. + * Synchronization is done in below function. For perf event, + * file == NULL and perf_trace_event_unreg() calls + * tracepoint_synchronize_unregister() to ensure synchronize + * event. We don't need to care about it. */ - synchronize_rcu(); - kfree(link); /* Ignored if link == NULL */ - } + trace_probe_remove_file(tp, file); return ret; } @@ -1044,7 +1017,7 @@ kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) { struct event_file_link *link; - list_for_each_entry_rcu(link, &tk->tp.files, list) + trace_probe_for_each_link_rcu(link, &tk->tp) __kprobe_trace_func(tk, regs, link->file); } NOKPROBE_SYMBOL(kprobe_trace_func); @@ -1094,7 +1067,7 @@ kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, { struct event_file_link *link; - list_for_each_entry_rcu(link, &tk->tp.files, list) + trace_probe_for_each_link_rcu(link, &tk->tp) __kretprobe_trace_func(tk, ri, regs, link->file); } NOKPROBE_SYMBOL(kretprobe_trace_func); -- cgit v1.2.3 From 747774d6b018ca02493fd3f321624dfce749da61 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:17:37 +0900 Subject: tracing/probe: Add trace flag access APIs for trace_probe Add trace_probe_test/set/clear_flag() functions for accessing trace_probe.flag field. This flags field should not be accessed directly. Link: http://lkml.kernel.org/r/155931585683.28323.314290023236905988.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 87a52094378c..c3ab84cb25c8 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -298,7 +298,7 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) if (ret) return ret; } else - tk->tp.flags |= TP_FLAG_PROFILE; + trace_probe_set_flag(&tk->tp, TP_FLAG_PROFILE); if (enabled) return 0; @@ -308,7 +308,7 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) if (file) trace_probe_remove_file(&tk->tp, file); else - tk->tp.flags &= ~TP_FLAG_PROFILE; + trace_probe_clear_flag(&tk->tp, TP_FLAG_PROFILE); } return ret; @@ -329,9 +329,9 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) return -ENOENT; if (!trace_probe_has_single_file(tp)) goto out; - tp->flags &= ~TP_FLAG_TRACE; + trace_probe_clear_flag(tp, TP_FLAG_TRACE); } else - tp->flags &= ~TP_FLAG_PROFILE; + trace_probe_clear_flag(tp, TP_FLAG_PROFILE); if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) { if (trace_kprobe_is_return(tk)) @@ -408,7 +408,7 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) ret = register_kprobe(&tk->rp.kp); if (ret == 0) - tk->tp.flags |= TP_FLAG_REGISTERED; + trace_probe_set_flag(&tk->tp, TP_FLAG_REGISTERED); return ret; } @@ -420,7 +420,7 @@ static void __unregister_trace_kprobe(struct trace_kprobe *tk) unregister_kretprobe(&tk->rp); else unregister_kprobe(&tk->rp.kp); - tk->tp.flags &= ~TP_FLAG_REGISTERED; + trace_probe_clear_flag(&tk->tp, TP_FLAG_REGISTERED); /* Cleanup kprobe for reuse */ if (tk->rp.kp.symbol_name) tk->rp.kp.addr = NULL; @@ -1313,10 +1313,10 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) raw_cpu_inc(*tk->nhit); - if (tk->tp.flags & TP_FLAG_TRACE) + if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) kprobe_trace_func(tk, regs); #ifdef CONFIG_PERF_EVENTS - if (tk->tp.flags & TP_FLAG_PROFILE) + if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) ret = kprobe_perf_func(tk, regs); #endif return ret; @@ -1330,10 +1330,10 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) raw_cpu_inc(*tk->nhit); - if (tk->tp.flags & TP_FLAG_TRACE) + if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) kretprobe_trace_func(tk, ri, regs); #ifdef CONFIG_PERF_EVENTS - if (tk->tp.flags & TP_FLAG_PROFILE) + if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) kretprobe_perf_func(tk, ri, regs); #endif return 0; /* We don't tweek kernel, so just return 0 */ -- cgit v1.2.3 From b55ce203a8f327b623688c8fb551ac3f9781edea Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:17:47 +0900 Subject: tracing/probe: Add probe event name and group name accesses APIs Add trace_probe_name() and trace_probe_group_name() functions for accessing probe name and group name of trace_probe. Link: http://lkml.kernel.org/r/155931586717.28323.8738615064952254761.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index c3ab84cb25c8..3cf8cee4f276 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -142,8 +142,8 @@ static bool trace_kprobe_match(const char *system, const char *event, { struct trace_kprobe *tk = to_trace_kprobe(ev); - return strcmp(trace_event_name(&tk->tp.call), event) == 0 && - (!system || strcmp(tk->tp.call.class->system, system) == 0); + return strcmp(trace_probe_name(&tk->tp), event) == 0 && + (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0); } static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) @@ -263,8 +263,8 @@ static struct trace_kprobe *find_trace_kprobe(const char *event, struct trace_kprobe *tk; for_each_trace_kprobe(tk, pos) - if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && - strcmp(tk->tp.call.class->system, group) == 0) + if (strcmp(trace_probe_name(&tk->tp), event) == 0 && + strcmp(trace_probe_group_name(&tk->tp), group) == 0) return tk; return NULL; } @@ -453,8 +453,8 @@ static int register_trace_kprobe(struct trace_kprobe *tk) mutex_lock(&event_mutex); /* Delete old (same name) event if exist */ - old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), - tk->tp.call.class->system); + old_tk = find_trace_kprobe(trace_probe_name(&tk->tp), + trace_probe_group_name(&tk->tp)); if (old_tk) { ret = unregister_trace_kprobe(old_tk); if (ret < 0) @@ -507,7 +507,7 @@ static int trace_kprobe_module_callback(struct notifier_block *nb, ret = __register_trace_kprobe(tk); if (ret) pr_warn("Failed to re-register probe %s on %s: %d\n", - trace_event_name(&tk->tp.call), + trace_probe_name(&tk->tp), mod->name, ret); } } @@ -737,8 +737,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) int i; seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); - seq_printf(m, ":%s/%s", tk->tp.call.class->system, - trace_event_name(&tk->tp.call)); + seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), + trace_probe_name(&tk->tp)); if (!tk->symbol) seq_printf(m, " 0x%p", tk->rp.kp.addr); @@ -812,7 +812,7 @@ static int probes_profile_seq_show(struct seq_file *m, void *v) tk = to_trace_kprobe(ev); seq_printf(m, " %-44s %15lu %15lu\n", - trace_event_name(&tk->tp.call), + trace_probe_name(&tk->tp), trace_kprobe_nhit(tk), tk->rp.kp.nmissed); @@ -1084,7 +1084,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags, field = (struct kprobe_trace_entry_head *)iter->ent; tp = container_of(event, struct trace_probe, call.event); - trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); + trace_seq_printf(s, "%s: (", trace_probe_name(tp)); if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) goto out; @@ -1111,7 +1111,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags, field = (struct kretprobe_trace_entry_head *)iter->ent; tp = container_of(event, struct trace_probe, call.event); - trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); + trace_seq_printf(s, "%s: (", trace_probe_name(tp)); if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) goto out; -- cgit v1.2.3 From e3dc9f898ef9c6a1a96378517573ee2d04d0abcc Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:17:57 +0900 Subject: tracing/probe: Add trace_event_call accesses APIs Add trace_event_call access APIs for trace_probe. Instead of accessing trace_probe.call directly, use those accesses by trace_probe_event_call() method. This hides the relationship of trace_event_call and trace_probe from trace_kprobe and trace_uprobe. Link: http://lkml.kernel.org/r/155931587711.28323.8335129014686133120.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 3cf8cee4f276..62362ad1ad98 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -985,7 +985,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, struct ring_buffer *buffer; int size, dsize, pc; unsigned long irq_flags; - struct trace_event_call *call = &tk->tp.call; + struct trace_event_call *call = trace_probe_event_call(&tk->tp); WARN_ON(call != trace_file->event_call); @@ -1033,7 +1033,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct ring_buffer *buffer; int size, pc, dsize; unsigned long irq_flags; - struct trace_event_call *call = &tk->tp.call; + struct trace_event_call *call = trace_probe_event_call(&tk->tp); WARN_ON(call != trace_file->event_call); @@ -1163,7 +1163,7 @@ static int kretprobe_event_define_fields(struct trace_event_call *event_call) static int kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) { - struct trace_event_call *call = &tk->tp.call; + struct trace_event_call *call = trace_probe_event_call(&tk->tp); struct kprobe_trace_entry_head *entry; struct hlist_head *head; int size, __size, dsize; @@ -1213,7 +1213,7 @@ static void kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct pt_regs *regs) { - struct trace_event_call *call = &tk->tp.call; + struct trace_event_call *call = trace_probe_event_call(&tk->tp); struct kretprobe_trace_entry_head *entry; struct hlist_head *head; int size, __size, dsize; @@ -1348,9 +1348,10 @@ static struct trace_event_functions kprobe_funcs = { .trace = print_kprobe_event }; -static inline void init_trace_event_call(struct trace_kprobe *tk, - struct trace_event_call *call) +static inline void init_trace_event_call(struct trace_kprobe *tk) { + struct trace_event_call *call = trace_probe_event_call(&tk->tp); + if (trace_kprobe_is_return(tk)) { call->event.funcs = &kretprobe_funcs; call->class->define_fields = kretprobe_event_define_fields; @@ -1366,7 +1367,7 @@ static inline void init_trace_event_call(struct trace_kprobe *tk, static int register_kprobe_event(struct trace_kprobe *tk) { - init_trace_event_call(tk, &tk->tp.call); + init_trace_event_call(tk); return trace_probe_register_event_call(&tk->tp); } @@ -1403,7 +1404,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, return ERR_CAST(tk); } - init_trace_event_call(tk, &tk->tp.call); + init_trace_event_call(tk); if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { ret = -ENOMEM; @@ -1414,7 +1415,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, if (ret < 0) goto error; - return &tk->tp.call; + return trace_probe_event_call(&tk->tp); error: free_trace_kprobe(tk); return ERR_PTR(ret); @@ -1447,7 +1448,7 @@ static __init void enable_boot_kprobe_events(void) mutex_lock(&event_mutex); for_each_trace_kprobe(tk, pos) { list_for_each_entry(file, &tr->events, list) - if (file->event_call == &tk->tp.call) + if (file->event_call == trace_probe_event_call(&tk->tp)) trace_event_enable_disable(file, 1, 0); } mutex_unlock(&event_mutex); @@ -1523,7 +1524,7 @@ find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) struct trace_event_file *file; list_for_each_entry(file, &tr->events, list) - if (file->event_call == &tk->tp.call) + if (file->event_call == trace_probe_event_call(&tk->tp)) return file; return NULL; -- cgit v1.2.3 From 715fa2fd4c6c3e9165659ac26a582b8a2e607b93 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 1 Jun 2019 00:18:07 +0900 Subject: tracing/kprobe: Check registered state using kprobe Change registered check only by trace_kprobe and remove TP_FLAG_REGISTERED from trace_probe, since this feature is only used for trace_kprobe. Link: http://lkml.kernel.org/r/155931588704.28323.4952266828256245833.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 62362ad1ad98..9d483ad9bb6c 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -157,6 +157,12 @@ static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) return nhit; } +static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk) +{ + return !(list_empty(&tk->rp.kp.list) && + hlist_unhashed(&tk->rp.kp.hlist)); +} + /* Return 0 if it fails to find the symbol address */ static nokprobe_inline unsigned long trace_kprobe_address(struct trace_kprobe *tk) @@ -244,6 +250,8 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group, tk->rp.kp.pre_handler = kprobe_dispatcher; tk->rp.maxactive = maxactive; + INIT_HLIST_NODE(&tk->rp.kp.hlist); + INIT_LIST_HEAD(&tk->rp.kp.list); ret = trace_probe_init(&tk->tp, event, group); if (ret < 0) @@ -273,7 +281,7 @@ static inline int __enable_trace_kprobe(struct trace_kprobe *tk) { int ret = 0; - if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { + if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) { if (trace_kprobe_is_return(tk)) ret = enable_kretprobe(&tk->rp); else @@ -333,7 +341,7 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) } else trace_probe_clear_flag(tp, TP_FLAG_PROFILE); - if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) { + if (!trace_probe_is_enabled(tp) && trace_kprobe_is_registered(tk)) { if (trace_kprobe_is_return(tk)) disable_kretprobe(&tk->rp); else @@ -381,7 +389,7 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) { int i, ret; - if (trace_probe_is_registered(&tk->tp)) + if (trace_kprobe_is_registered(tk)) return -EINVAL; if (within_notrace_func(tk)) { @@ -407,21 +415,20 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) else ret = register_kprobe(&tk->rp.kp); - if (ret == 0) - trace_probe_set_flag(&tk->tp, TP_FLAG_REGISTERED); return ret; } /* Internal unregister function - just handle k*probes and flags */ static void __unregister_trace_kprobe(struct trace_kprobe *tk) { - if (trace_probe_is_registered(&tk->tp)) { + if (trace_kprobe_is_registered(tk)) { if (trace_kprobe_is_return(tk)) unregister_kretprobe(&tk->rp); else unregister_kprobe(&tk->rp.kp); - trace_probe_clear_flag(&tk->tp, TP_FLAG_REGISTERED); - /* Cleanup kprobe for reuse */ + /* Cleanup kprobe for reuse and mark it unregistered */ + INIT_HLIST_NODE(&tk->rp.kp.hlist); + INIT_LIST_HEAD(&tk->rp.kp.list); if (tk->rp.kp.symbol_name) tk->rp.kp.addr = NULL; } -- cgit v1.2.3