diff options
Diffstat (limited to 'kernel/trace/trace_eprobe.c')
| -rw-r--r-- | kernel/trace/trace_eprobe.c | 357 |
1 files changed, 133 insertions, 224 deletions
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 352b65e2b910..3ee39715d5e4 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -9,14 +9,15 @@ * Copyright (C) 2021, VMware Inc, Tzvetomir Stoyanov tz.stoyanov@gmail.com> * */ +#include <linux/cleanup.h> +#include <linux/ftrace.h> #include <linux/module.h> #include <linux/mutex.h> -#include <linux/ftrace.h> #include "trace_dynevent.h" #include "trace_probe.h" -#include "trace_probe_tmpl.h" #include "trace_probe_kernel.h" +#include "trace_probe_tmpl.h" #define EPROBE_EVENT_SYSTEM "eprobes" @@ -41,6 +42,10 @@ struct eprobe_data { struct trace_eprobe *ep; }; + +#define for_each_trace_eprobe_tp(ep, _tp) \ + list_for_each_entry(ep, trace_probe_probe_list(_tp), tp.list) + static int __trace_eprobe_create(int argc, const char *argv[]); static void trace_event_probe_cleanup(struct trace_eprobe *ep) @@ -56,6 +61,9 @@ static void trace_event_probe_cleanup(struct trace_eprobe *ep) kfree(ep); } +DEFINE_FREE(trace_event_probe_cleanup, struct trace_eprobe *, + if (!IS_ERR_OR_NULL(_T)) trace_event_probe_cleanup(_T)) + static struct trace_eprobe *to_trace_eprobe(struct dyn_event *ev) { return container_of(ev, struct trace_eprobe, devent); @@ -192,10 +200,10 @@ static struct trace_eprobe *alloc_event_probe(const char *group, struct trace_event_call *event, int nargs) { - struct trace_eprobe *ep; + struct trace_eprobe *ep __free(trace_event_probe_cleanup) = NULL; const char *event_name; const char *sys_name; - int ret = -ENOMEM; + int ret; if (!event) return ERR_PTR(-ENODEV); @@ -206,56 +214,22 @@ static struct trace_eprobe *alloc_event_probe(const char *group, ep = kzalloc(struct_size(ep, tp.args, nargs), GFP_KERNEL); if (!ep) { trace_event_put_ref(event); - goto error; + return ERR_PTR(-ENOMEM); } ep->event = event; ep->event_name = kstrdup(event_name, GFP_KERNEL); if (!ep->event_name) - goto error; + return ERR_PTR(-ENOMEM); ep->event_system = kstrdup(sys_name, GFP_KERNEL); if (!ep->event_system) - goto error; + return ERR_PTR(-ENOMEM); - ret = trace_probe_init(&ep->tp, this_event, group, false); + ret = trace_probe_init(&ep->tp, this_event, group, false, nargs); if (ret < 0) - goto error; + return ERR_PTR(ret); dyn_event_init(&ep->devent, &eprobe_dyn_event_ops); - return ep; -error: - trace_event_probe_cleanup(ep); - return ERR_PTR(ret); -} - -static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) -{ - struct probe_arg *parg = &ep->tp.args[i]; - struct ftrace_event_field *field; - struct list_head *head; - int ret = -ENOENT; - - head = trace_get_fields(ep->event); - list_for_each_entry(field, head, link) { - if (!strcmp(parg->code->data, field->name)) { - kfree(parg->code->data); - parg->code->data = field; - return 0; - } - } - - /* - * Argument not found on event. But allow for comm and COMM - * to be used to get the current->comm. - */ - if (strcmp(parg->code->data, "COMM") == 0 || - strcmp(parg->code->data, "comm") == 0) { - parg->code->op = FETCH_OP_COMM; - ret = 0; - } - - kfree(parg->code->data); - parg->code->data = NULL; - return ret; + return_ptr(ep); } static int eprobe_event_define_fields(struct trace_event_call *event_call) @@ -311,7 +285,7 @@ print_eprobe_event(struct trace_iterator *iter, int flags, trace_seq_putc(s, ')'); - if (print_probe_args(s, tp->args, tp->nr_args, + if (trace_probe_print_args(s, tp->args, tp->nr_args, (u8 *)&field[1], field) < 0) goto out; @@ -320,7 +294,8 @@ print_eprobe_event(struct trace_iterator *iter, int flags, return trace_handle_return(s); } -static unsigned long get_event_field(struct fetch_insn *code, void *rec) +static nokprobe_inline unsigned long +get_event_field(struct fetch_insn *code, void *rec) { struct ftrace_event_field *field = code->data; unsigned long val; @@ -369,10 +344,15 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec) val = *(unsigned int *)addr; break; default: - if (field->is_signed) - val = *(long *)addr; - else - val = *(unsigned long *)addr; + if (field->size == sizeof(long)) { + if (field->is_signed) + val = *(long *)addr; + else + val = *(unsigned long *)addr; + break; + } + /* This is an array, point to the addr itself */ + val = (unsigned long)addr; break; } return val; @@ -395,20 +375,12 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec) case FETCH_OP_TP_ARG: val = get_event_field(code, rec); break; - case FETCH_OP_IMM: - val = code->immediate; - break; - case FETCH_OP_COMM: - val = (unsigned long)current->comm; - break; - case FETCH_OP_DATA: - val = (unsigned long)code->data; - break; case FETCH_NOP_SYMBOL: /* Ignore a place holder */ code++; goto retry; default: - continue; + if (process_common_fetch_insn(code, &val) < 0) + continue; } code++; len = process_fetch_insn_bottom(code, val, NULL, NULL); @@ -424,88 +396,30 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec) /* 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, void *rec, void *dest, - void *base) +process_fetch_insn(struct fetch_insn *code, void *rec, void *edata, + void *dest, void *base) { unsigned long val; + int ret; retry: switch (code->op) { case FETCH_OP_TP_ARG: val = get_event_field(code, rec); break; - case FETCH_OP_IMM: - val = code->immediate; - break; - case FETCH_OP_COMM: - val = (unsigned long)current->comm; - break; - case FETCH_OP_DATA: - val = (unsigned long)code->data; - break; case FETCH_NOP_SYMBOL: /* Ignore a place holder */ code++; goto retry; default: - return -EILSEQ; + ret = process_common_fetch_insn(code, &val); + if (ret < 0) + return ret; } code++; return process_fetch_insn_bottom(code, val, dest, base); } NOKPROBE_SYMBOL(process_fetch_insn) -/* Return the length of string -- including null terminal byte */ -static nokprobe_inline int -fetch_store_strlen_user(unsigned long addr) -{ - return kern_fetch_store_strlen_user(addr); -} - -/* Return the length of string -- including null terminal byte */ -static nokprobe_inline int -fetch_store_strlen(unsigned long addr) -{ - return kern_fetch_store_strlen(addr); -} - -/* - * 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) -{ - return kern_fetch_store_string_user(addr, dest, base); -} - -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max - * length and relative data location. - */ -static nokprobe_inline int -fetch_store_string(unsigned long addr, void *dest, void *base) -{ - return kern_fetch_store_string(addr, dest, base); -} - -static nokprobe_inline int -probe_mem_read_user(void *dest, void *src, size_t size) -{ - const void __user *uaddr = (__force const void __user *)src; - - return copy_from_user_nofault(dest, uaddr, size); -} - -static nokprobe_inline int -probe_mem_read(void *dest, void *src, size_t size) -{ -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - if ((unsigned long)src < TASK_SIZE) - return probe_mem_read_user(dest, src, size); -#endif - return copy_from_kernel_nofault(dest, src, size); -} - /* eprobe handler */ static inline void __eprobe_trace_func(struct eprobe_data *edata, void *rec) @@ -530,7 +444,7 @@ __eprobe_trace_func(struct eprobe_data *edata, void *rec) return; entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event); - store_trace_args(&entry[1], &edata->ep->tp, rec, sizeof(*entry), dsize); + store_trace_args(&entry[1], &edata->ep->tp, rec, NULL, sizeof(*entry), dsize); trace_event_buffer_commit(&fbuffer); } @@ -570,13 +484,6 @@ static void eprobe_trigger_func(struct event_trigger_data *data, __eprobe_trace_func(edata, rec); } -static struct event_trigger_ops eprobe_trigger_ops = { - .trigger = eprobe_trigger_func, - .print = eprobe_trigger_print, - .init = eprobe_trigger_init, - .free = eprobe_trigger_free, -}; - static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops, struct trace_event_file *file, char *glob, char *cmd, @@ -599,12 +506,6 @@ static void eprobe_trigger_unreg_func(char *glob, } -static struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd, - char *param) -{ - return &eprobe_trigger_ops; -} - static struct event_command event_trigger_cmd = { .name = "eprobe", .trigger_type = ETT_EVENT_EPROBE, @@ -613,8 +514,11 @@ static struct event_command event_trigger_cmd = { .reg = eprobe_trigger_reg_func, .unreg = eprobe_trigger_unreg_func, .unreg_all = NULL, - .get_trigger_ops = eprobe_trigger_get_ops, .set_filter = NULL, + .trigger = eprobe_trigger_func, + .print = eprobe_trigger_print, + .init = eprobe_trigger_init, + .free = eprobe_trigger_free, }; static struct event_trigger_data * @@ -634,7 +538,6 @@ new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file) trigger->flags = EVENT_TRIGGER_FL_PROBE; trigger->count = -1; - trigger->ops = &eprobe_trigger_ops; /* * EVENT PROBE triggers are not registered as commands with @@ -736,10 +639,11 @@ static int disable_eprobe(struct trace_eprobe *ep, static int enable_trace_eprobe(struct trace_event_call *call, struct trace_event_file *file) { - struct trace_probe *pos, *tp; + struct trace_probe *tp; struct trace_eprobe *ep; bool enabled; int ret = 0; + int cnt = 0; tp = trace_probe_primary_from_call(call); if (WARN_ON_ONCE(!tp)) @@ -757,18 +661,29 @@ static int enable_trace_eprobe(struct trace_event_call *call, if (enabled) return 0; - list_for_each_entry(pos, trace_probe_probe_list(tp), list) { - ep = container_of(pos, struct trace_eprobe, tp); + for_each_trace_eprobe_tp(ep, tp) { ret = enable_eprobe(ep, file); if (ret) break; enabled = true; + cnt++; } if (ret) { /* Failed to enable one of them. Roll back all */ - if (enabled) - disable_eprobe(ep, file->tr); + if (enabled) { + /* + * It's a bug if one failed for something other than memory + * not being available but another eprobe succeeded. + */ + WARN_ON_ONCE(ret != -ENOMEM); + + for_each_trace_eprobe_tp(ep, tp) { + disable_eprobe(ep, file->tr); + if (!--cnt) + break; + } + } if (file) trace_probe_remove_file(tp, file); else @@ -781,7 +696,7 @@ static int enable_trace_eprobe(struct trace_event_call *call, static int disable_trace_eprobe(struct trace_event_call *call, struct trace_event_file *file) { - struct trace_probe *pos, *tp; + struct trace_probe *tp; struct trace_eprobe *ep; tp = trace_probe_primary_from_call(call); @@ -798,10 +713,8 @@ static int disable_trace_eprobe(struct trace_event_call *call, trace_probe_clear_flag(tp, TP_FLAG_PROFILE); if (!trace_probe_is_enabled(tp)) { - list_for_each_entry(pos, trace_probe_probe_list(tp), list) { - ep = container_of(pos, struct trace_eprobe, tp); + for_each_trace_eprobe_tp(ep, tp) disable_eprobe(ep, file->tr); - } } out: @@ -870,38 +783,13 @@ find_and_get_event(const char *system, const char *event_name) name = trace_event_name(tp_event); if (!name || strcmp(event_name, name)) continue; - if (!trace_event_try_get_ref(tp_event)) { + if (!trace_event_try_get_ref(tp_event)) return NULL; - break; - } return tp_event; - break; } return NULL; } -static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[], int i) -{ - unsigned int flags = TPARG_FL_KERNEL | TPARG_FL_TPOINT; - int ret; - - ret = traceprobe_parse_probe_arg(&ep->tp, i, argv[i], flags); - if (ret) - return ret; - - if (ep->tp.args[i].code->op == FETCH_OP_TP_ARG) { - ret = trace_eprobe_tp_arg_update(ep, i); - if (ret) - trace_probe_log_err(0, BAD_ATTACH_ARG); - } - - /* Handle symbols "@" */ - if (!ret) - ret = traceprobe_update_arg(&ep->tp.args[i]); - - return ret; -} - static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const char *argv[]) { struct event_filter *dummy = NULL; @@ -923,17 +811,13 @@ static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const ch p = ep->filter_str; for (i = 0; i < argc; i++) { - ret = snprintf(p, len, "%s ", argv[i]); - if (ret < 0) - goto error; - if (ret > len) { - ret = -E2BIG; - goto error; - } + if (i) + ret = snprintf(p, len, " %s", argv[i]); + else + ret = snprintf(p, len, "%s", argv[i]); p += ret; len -= ret; } - p[-1] = '\0'; /* * Ensure the filter string can be parsed correctly. Note, this @@ -942,13 +826,10 @@ static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const ch ret = create_event_filter(top_trace_array(), ep->event, ep->filter_str, true, &dummy); free_event_filter(dummy); - if (ret) - goto error; - - return 0; -error: - kfree(ep->filter_str); - ep->filter_str = NULL; + if (ret) { + kfree(ep->filter_str); + ep->filter_str = NULL; + } return ret; } @@ -960,40 +841,52 @@ static int __trace_eprobe_create(int argc, const char *argv[]) * Fetch args (no space): * <name>=$<field>[:TYPE] */ + struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) = NULL; + struct trace_eprobe *ep __free(trace_event_probe_cleanup) = NULL; + const char *trlog __free(trace_probe_log_clear) = NULL; const char *event = NULL, *group = EPROBE_EVENT_SYSTEM; const char *sys_event = NULL, *sys_name = NULL; struct trace_event_call *event_call; - struct trace_eprobe *ep = NULL; - char buf1[MAX_EVENT_NAME_LEN]; - char buf2[MAX_EVENT_NAME_LEN]; - char gbuf[MAX_EVENT_NAME_LEN]; + char *buf1 __free(kfree) = NULL; + char *buf2 __free(kfree) = NULL; + char *gbuf __free(kfree) = NULL; int ret = 0, filter_idx = 0; int i, filter_cnt; if (argc < 2 || argv[0][0] != 'e') return -ECANCELED; - trace_probe_log_init("event_probe", argc, argv); + trlog = trace_probe_log_init("event_probe", argc, argv); event = strchr(&argv[0][1], ':'); if (event) { + gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL); + if (!gbuf) + return -ENOMEM; event++; ret = traceprobe_parse_event_name(&event, &group, gbuf, event - argv[0]); if (ret) - goto parse_error; + return -EINVAL; } trace_probe_log_set_index(1); sys_event = argv[1]; + + buf2 = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL); + if (!buf2) + return -ENOMEM; + ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0); if (ret || !sys_event || !sys_name) { trace_probe_log_err(0, NO_EVENT_INFO); - goto parse_error; + return -EINVAL; } if (!event) { - strscpy(buf1, sys_event, MAX_EVENT_NAME_LEN); + buf1 = kstrdup(sys_event, GFP_KERNEL); + if (!buf1) + return -ENOMEM; event = buf1; } @@ -1006,10 +899,16 @@ static int __trace_eprobe_create(int argc, const char *argv[]) } } - mutex_lock(&event_mutex); - event_call = find_and_get_event(sys_name, sys_event); - ep = alloc_event_probe(group, event, event_call, argc - 2); - mutex_unlock(&event_mutex); + if (argc - 2 > MAX_TRACE_ARGS) { + trace_probe_log_set_index(2); + trace_probe_log_err(0, TOO_MANY_ARGS); + return -E2BIG; + } + + scoped_guard(mutex, &event_mutex) { + event_call = find_and_get_event(sys_name, sys_event); + ep = alloc_event_probe(group, event, event_call, argc - 2); + } if (IS_ERR(ep)) { ret = PTR_ERR(ep); @@ -1017,47 +916,57 @@ static int __trace_eprobe_create(int argc, const char *argv[]) trace_probe_log_err(0, BAD_ATTACH_EVENT); /* This must return -ENOMEM or missing event, else there is a bug */ WARN_ON_ONCE(ret != -ENOMEM && ret != -ENODEV); - ep = NULL; - goto error; + return ret; } if (filter_idx) { trace_probe_log_set_index(filter_idx); ret = trace_eprobe_parse_filter(ep, filter_cnt, argv + filter_idx); if (ret) - goto parse_error; + return -EINVAL; } else ep->filter_str = NULL; + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + ctx->event = ep->event; + ctx->flags = TPARG_FL_KERNEL | TPARG_FL_TEVENT; + argc -= 2; argv += 2; /* parse arguments */ - for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + for (i = 0; i < argc; i++) { trace_probe_log_set_index(i + 2); - ret = trace_eprobe_tp_update_arg(ep, argv, i); + + ret = traceprobe_parse_probe_arg(&ep->tp, i, argv[i], ctx); + /* Handle symbols "@" */ + if (!ret) + ret = traceprobe_update_arg(&ep->tp.args[i]); if (ret) - goto error; + return ret; } ret = traceprobe_set_print_fmt(&ep->tp, PROBE_PRINT_EVENT); if (ret < 0) - goto error; + return ret; + init_trace_eprobe_call(ep); - mutex_lock(&event_mutex); - ret = trace_probe_register_event_call(&ep->tp); - if (ret) { - if (ret == -EEXIST) { - trace_probe_log_set_index(0); - trace_probe_log_err(0, EVENT_EXIST); + scoped_guard(mutex, &event_mutex) { + ret = trace_probe_register_event_call(&ep->tp); + if (ret) { + if (ret == -EEXIST) { + trace_probe_log_set_index(0); + trace_probe_log_err(0, EVENT_EXIST); + } + return ret; } - mutex_unlock(&event_mutex); - goto error; + ret = dyn_event_add(&ep->devent, &ep->tp.event->call); + if (ret < 0) { + trace_probe_unregister_event_call(&ep->tp); + return ret; + } + /* To avoid freeing registered eprobe event, clear ep. */ + ep = NULL; } - ret = dyn_event_add(&ep->devent, &ep->tp.event->call); - mutex_unlock(&event_mutex); - return ret; -parse_error: - ret = -EINVAL; -error: - trace_event_probe_cleanup(ep); return ret; } |