Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755770Ab0F2SmE (ORCPT ); Tue, 29 Jun 2010 14:42:04 -0400 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:60247 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755727Ab0F2Sl6 (ORCPT ); Tue, 29 Jun 2010 14:41:58 -0400 From: Srikar Dronamraju To: Peter Zijlstra , Ingo Molnar Cc: Mel Gorman , Srikar Dronamraju , Steven Rostedt , Randy Dunlap , Arnaldo Carvalho de Melo , Linus Torvalds , Roland McGrath , "H. Peter Anvin" , Christoph Hellwig , Masami Hiramatsu , Oleg Nesterov , Mark Wielaard , Mathieu Desnoyers , LKML , Jim Keniston , Frederic Weisbecker , "Rafael J. Wysocki" , "Frank Ch. Eigler" , Ananth N Mavinakayanahalli , Andrew Morton , "Paul E. McKenney" Date: Wed, 30 Jun 2010 00:06:34 +0530 Message-Id: <20100629183634.32537.20825.sendpatchset@localhost6.localdomain6> In-Reply-To: <20100629183454.32537.63582.sendpatchset@localhost6.localdomain6> References: <20100629183454.32537.63582.sendpatchset@localhost6.localdomain6> Subject: [PATCHv7 2.6.35-rc3-tip 8/11] trace: Extract out common code for kprobes/uprobes traceevents. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 37355 Lines: 1370 trace: Extract out common code for kprobes/uprobes traceevents. Changelog from v5: Addressed comments from Masami Hiramatsu and Steven Rostedt. Also shared lot more code from kprobes traceevents. Move common parts of trace_kprobe.c and trace_uprobe.c Adjust kernel/trace/trace_kprobe.c after moving common code to kernel/trace/trace_probe.h and kernel/trace/trace_probe.c. TODO: Merge both events to a single probe event. Signed-off-by: Srikar Dronamraju --- kernel/trace/Kconfig | 4 kernel/trace/Makefile | 1 kernel/trace/trace_kprobe.c | 576 +------------------------------------------ kernel/trace/trace_probe.c | 510 ++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 126 +++++++++ 5 files changed, 651 insertions(+), 566 deletions(-) create mode 100644 kernel/trace/trace_probe.c create mode 100644 kernel/trace/trace_probe.h diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index f669092..ab62d9a 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -395,6 +395,7 @@ config KPROBE_EVENT depends on HAVE_REGS_AND_STACK_ACCESS_API bool "Enable kprobes-based dynamic events" select TRACING + select PROBE_EVENTS default y help This allows the user to add tracing events (similar to tracepoints) @@ -407,6 +408,9 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config PROBE_EVENTS + def_bool n + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 469a1c7..5a45910 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -55,5 +55,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o obj-$(CONFIG_KSYM_TRACER) += trace_ksym.o obj-$(CONFIG_EVENT_TRACING) += power-traces.o +obj-$(CONFIG_PROBE_EVENTS) +=trace_probe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 3b831d8..4f11a56 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -19,305 +19,15 @@ #include #include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "trace.h" -#include "trace_output.h" - -#define MAX_TRACE_ARGS 128 -#define MAX_ARGSTR_LEN 63 -#define MAX_EVENT_NAME_LEN 64 -#define KPROBE_EVENT_SYSTEM "kprobes" - -/* Reserved field names */ -#define FIELD_STRING_IP "__probe_ip" -#define FIELD_STRING_RETIP "__probe_ret_ip" -#define FIELD_STRING_FUNC "__probe_func" - -const char *reserved_field_names[] = { - "common_type", - "common_flags", - "common_preempt_count", - "common_pid", - "common_tgid", - "common_lock_depth", - FIELD_STRING_IP, - FIELD_STRING_RETIP, - FIELD_STRING_FUNC, -}; - -/* Printing function type */ -typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *); -#define PRINT_TYPE_FUNC_NAME(type) print_type_##type -#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type - -/* Printing in basic type function template */ -#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ -static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, void *data)\ -{ \ - return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ -} \ -static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; - -DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) -DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) -DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) -DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) -DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) - -/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); - -struct fetch_param { - fetch_func_t fn; - void *data; -}; - -static __kprobes void call_fetch(struct fetch_param *fprm, - struct pt_regs *regs, void *dest) -{ - return fprm->fn(regs, fprm->data, dest); -} - -#define FETCH_FUNC_NAME(kind, type) fetch_##kind##_##type -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(kind) \ -DEFINE_FETCH_##kind(u8) \ -DEFINE_FETCH_##kind(u16) \ -DEFINE_FETCH_##kind(u32) \ -DEFINE_FETCH_##kind(u64) - -#define CHECK_BASIC_FETCH_FUNCS(kind, fn) \ - ((FETCH_FUNC_NAME(kind, u8) == fn) || \ - (FETCH_FUNC_NAME(kind, u16) == fn) || \ - (FETCH_FUNC_NAME(kind, u32) == fn) || \ - (FETCH_FUNC_NAME(kind, u64) == fn)) - -/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_register(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(reg) - -#define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(stack) - -#define DEFINE_FETCH_retval(type) \ -static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ - void *dummy, void *dest) \ -{ \ - *(type *)dest = (type)regs_return_value(regs); \ -} -DEFINE_BASIC_FETCH_FUNCS(retval) - -#define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} -DEFINE_BASIC_FETCH_FUNCS(memory) - -/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -static unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - if (sc->addr) - sc->addr += sc->offset; - return sc->addr; -} - -static void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - - update_symbol_cache(sc); - return sc; -} - -#define DEFINE_FETCH_symbol(type) \ -static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(symbol) - -/* Dereference memory access function */ -struct deref_fetch_param { - struct fetch_param orig; - long offset; -}; - -#define DEFINE_FETCH_deref(type) \ -static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ - void *data, void *dest) \ -{ \ - struct deref_fetch_param *dprm = data; \ - unsigned long addr; \ - call_fetch(&dprm->orig, regs, &addr); \ - if (addr) { \ - addr += dprm->offset; \ - fetch_memory_##type(regs, (void *)addr, dest); \ - } else \ - *(type *)dest = 0; \ -} -DEFINE_BASIC_FETCH_FUNCS(deref) -static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_BASIC_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_BASIC_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} - -/* Default (unsigned long) fetch type */ -#define __DEFAULT_FETCH_TYPE(t) u##t -#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) -#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) -#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) - -#define ASSIGN_FETCH_FUNC(kind, type) \ - .kind = FETCH_FUNC_NAME(kind, type) - -#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ - {.name = #ptype, \ - .size = sizeof(ftype), \ - .is_signed = sign, \ - .print = PRINT_TYPE_FUNC_NAME(ptype), \ - .fmt = PRINT_TYPE_FMT_NAME(ptype), \ -ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ - } +#include "trace_probe.h" -/* Fetch type information table */ -static const struct fetch_type { - const char *name; /* Name of type */ - size_t size; /* Byte size of type */ - int is_signed; /* Signed flag */ - print_type_func_t print; /* Print functions */ - const char *fmt; /* Fromat string */ - /* Fetch functions */ - fetch_func_t reg; - fetch_func_t stack; - fetch_func_t retval; - fetch_func_t memory; - fetch_func_t symbol; - fetch_func_t deref; -} fetch_type_table[] = { - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), -}; - -static const struct fetch_type *find_fetch_type(const char *type) -{ - int i; - - if (!type) - type = DEFAULT_FETCH_TYPE_STR; - - for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) - if (strcmp(type, fetch_type_table[i].name) == 0) - return &fetch_type_table[i]; - return NULL; -} - -/* Special function : only accept unsigned long */ -static __kprobes void fetch_stack_address(struct pt_regs *regs, - void *dummy, void *dest) -{ - *(unsigned long *)dest = kernel_stack_pointer(regs); -} +#define KPROBE_EVENT_SYSTEM "kprobes" /** * Kprobe event core functions */ -struct probe_arg { - struct fetch_param fetch; - unsigned int offset; /* Offset from argument entry */ - const char *name; /* Name of this argument */ - const char *comm; /* Command of this argument */ - const struct fetch_type *type; /* Type of this argument */ -}; - -/* Flags for trace_probe */ -#define TP_FLAG_TRACE 1 -#define TP_FLAG_PROFILE 2 - struct trace_probe { struct list_head list; struct kretprobe rp; /* Use rp.kp for kprobe use */ @@ -355,19 +65,6 @@ static LIST_HEAD(probe_list); static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); - -/* Check the name is good for event/group */ -static int check_event_name(const char *name) -{ - if (!isalpha(*name) && *name != '_') - return 0; - while (*++name != '\0') { - if (!isalpha(*name) && !isdigit(*name) && *name != '_') - return 0; - } - return 1; -} - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -427,22 +124,12 @@ error: return ERR_PTR(ret); } -static void free_probe_arg(struct probe_arg *arg) -{ - if (CHECK_BASIC_FETCH_FUNCS(deref, arg->fetch.fn)) - free_deref_fetch_param(arg->fetch.data); - else if (CHECK_BASIC_FETCH_FUNCS(symbol, arg->fetch.fn)) - free_symbol_cache(arg->fetch.data); - kfree(arg->name); - kfree(arg->comm); -} - static void free_trace_probe(struct trace_probe *tp) { int i; for (i = 0; i < tp->nr_args; i++) - free_probe_arg(&tp->args[i]); + traceprobe_free_probe_arg(&tp->args[i]); kfree(tp->call.class->system); kfree(tp->call.name); @@ -516,181 +203,6 @@ end: return ret; } -/* Split symbol and offset. */ -static int split_symbol_offset(char *symbol, unsigned long *offset) -{ - char *tmp; - int ret; - - if (!offset) - return -EINVAL; - - tmp = strchr(symbol, '+'); - if (tmp) { - /* skip sign because strict_strtol doesn't accept '+' */ - ret = strict_strtoul(tmp + 1, 0, offset); - if (ret) - return ret; - *tmp = '\0'; - } else - *offset = 0; - return 0; -} - -#define PARAM_MAX_ARGS 16 -#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) - -static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) -{ - int ret = 0; - unsigned long param; - - if (strcmp(arg, "retval") == 0) { - if (is_return) - f->fn = t->retval; - else - ret = -EINVAL; - } else if (strncmp(arg, "stack", 5) == 0) { - if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) - f->fn = fetch_stack_address; - else - ret = -EINVAL; - } else if (isdigit(arg[5])) { - ret = strict_strtoul(arg + 5, 10, ¶m); - if (ret || param > PARAM_MAX_STACK) - ret = -EINVAL; - else { - f->fn = t->stack; - f->data = (void *)param; - } - } else - ret = -EINVAL; - } else - ret = -EINVAL; - return ret; -} - -/* Recursive argument parser */ -static int __parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, int is_return) -{ - int ret = 0; - unsigned long param; - long offset; - char *tmp; - - switch (arg[0]) { - case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return); - break; - case '%': /* named register */ - ret = regs_query_register_offset(arg + 1); - if (ret >= 0) { - f->fn = t->reg; - f->data = (void *)(unsigned long)ret; - ret = 0; - } - break; - case '@': /* memory or symbol */ - if (isdigit(arg[1])) { - ret = strict_strtoul(arg + 1, 0, ¶m); - if (ret) - break; - f->fn = t->memory; - f->data = (void *)param; - } else { - ret = split_symbol_offset(arg + 1, &offset); - if (ret) - break; - f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) - f->fn = t->symbol; - } - break; - case '+': /* deref memory */ - case '-': - tmp = strchr(arg, '('); - if (!tmp) - break; - *tmp = '\0'; - ret = strict_strtol(arg + 1, 0, &offset); - if (ret) - break; - if (arg[0] == '-') - offset = -offset; - arg = tmp + 1; - tmp = strrchr(arg, ')'); - if (tmp) { - struct deref_fetch_param *dprm; - const struct fetch_type *t2 = find_fetch_type(NULL); - *tmp = '\0'; - dprm = kzalloc(sizeof(struct deref_fetch_param), - GFP_KERNEL); - if (!dprm) - return -ENOMEM; - dprm->offset = offset; - ret = __parse_probe_arg(arg, t2, &dprm->orig, - is_return); - if (ret) - kfree(dprm); - else { - f->fn = t->deref; - f->data = (void *)dprm; - } - } - break; - } - if (!ret && !f->fn) - ret = -EINVAL; - return ret; -} - -/* String length checking wrapper */ -static int parse_probe_arg(char *arg, struct trace_probe *tp, - struct probe_arg *parg, int is_return) -{ - const char *t; - - if (strlen(arg) > MAX_ARGSTR_LEN) { - pr_info("Argument is too long.: %s\n", arg); - return -ENOSPC; - } - parg->comm = kstrdup(arg, GFP_KERNEL); - if (!parg->comm) { - pr_info("Failed to allocate memory for command '%s'.\n", arg); - return -ENOMEM; - } - t = strchr(parg->comm, ':'); - if (t) { - arg[t - parg->comm] = '\0'; - t++; - } - parg->type = find_fetch_type(t); - if (!parg->type) { - pr_info("Unsupported type: %s\n", t); - return -EINVAL; - } - parg->offset = tp->size; - tp->size += parg->type->size; - return __parse_probe_arg(arg, parg->type, &parg->fetch, is_return); -} - -/* Return 1 if name is reserved or already used by another argument */ -static int conflict_field_name(const char *name, - struct probe_arg *args, int narg) -{ - int i; - for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) - if (strcmp(reserved_field_names[i], name) == 0) - return 1; - for (i = 0; i < narg; i++) - if (strcmp(args[i].name, name) == 0) - return 1; - return 0; -} - static int create_trace_probe(int argc, char **argv) { /* @@ -787,7 +299,7 @@ static int create_trace_probe(int argc, char **argv) /* a symbol specified */ symbol = argv[1]; /* TODO: support .init module functions */ - ret = split_symbol_offset(symbol, &offset); + ret = traceprobe_split_symbol_offset(symbol, &offset); if (ret) { pr_info("Failed to parse symbol.\n"); return ret; @@ -839,7 +351,8 @@ static int create_trace_probe(int argc, char **argv) if (tmp) *tmp = '_'; /* convert : to _ */ - if (conflict_field_name(tp->args[i].name, tp->args, i)) { + if (traceprobe_conflict_field_name(tp->args[i].name, + tp->args, i)) { pr_info("Argument%d name '%s' conflicts with " "another field.\n", i, argv[i]); ret = -EINVAL; @@ -847,7 +360,8 @@ static int create_trace_probe(int argc, char **argv) } /* Parse fetch argument */ - ret = parse_probe_arg(arg, tp, &tp->args[i], is_return); + ret = traceprobe_parse_probe_arg(arg, &tp->size, + &tp->args[i], is_return, true); if (ret) { pr_info("Parse error at argument%d. (%d)\n", i, ret); kfree(tp->args[i].name); @@ -937,70 +451,11 @@ static int probes_open(struct inode *inode, struct file *file) return seq_open(file, &probes_seq_op); } -static int command_trace_probe(const char *buf) -{ - char **argv; - int argc = 0, ret = 0; - - argv = argv_split(GFP_KERNEL, buf, &argc); - if (!argv) - return -ENOMEM; - - if (argc) - ret = create_trace_probe(argc, argv); - - argv_free(argv); - return ret; -} - -#define WRITE_BUFSIZE 128 - static ssize_t probes_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { - char *kbuf, *tmp; - int ret; - size_t done; - size_t size; - - kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); - if (!kbuf) - return -ENOMEM; - - ret = done = 0; - while (done < count) { - size = count - done; - if (size >= WRITE_BUFSIZE) - size = WRITE_BUFSIZE - 1; - if (copy_from_user(kbuf, buffer + done, size)) { - ret = -EFAULT; - goto out; - } - kbuf[size] = '\0'; - tmp = strchr(kbuf, '\n'); - if (tmp) { - *tmp = '\0'; - size = tmp - kbuf + 1; - } else if (done + size < count) { - pr_warning("Line length is too long: " - "Should be less than %d.", WRITE_BUFSIZE); - ret = -EINVAL; - goto out; - } - done += size; - /* Remove comments */ - tmp = strchr(kbuf, '#'); - if (tmp) - *tmp = '\0'; - - ret = command_trace_probe(kbuf); - if (ret) - goto out; - } - ret = done; -out: - kfree(kbuf); - return ret; + return traceprobe_probes_write(file, buffer, count, ppos, + create_trace_probe); } static const struct file_operations kprobe_events_ops = { @@ -1214,17 +669,6 @@ static void probe_event_disable(struct ftrace_event_call *call) } } -#undef DEFINE_FIELD -#define DEFINE_FIELD(type, item, name, is_signed) \ - do { \ - ret = trace_define_field(event_call, #type, name, \ - offsetof(typeof(field), item), \ - sizeof(field.item), is_signed, \ - FILTER_OTHER); \ - if (ret) \ - return ret; \ - } while (0) - static int kprobe_event_define_fields(struct ftrace_event_call *event_call) { int ret, i; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c new file mode 100644 index 0000000..9d6caad --- /dev/null +++ b/kernel/trace/trace_probe.c @@ -0,0 +1,510 @@ +/* + * Common code for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010 + * Author: Srikar Dronamraju + * + * Derived from kernel/trace/trace_kprobe.c written by + * Masami Hiramatsu + */ + +#include "trace_probe.h" + +const char *reserved_field_names[] = { + "common_type", + "common_flags", + "common_preempt_count", + "common_pid", + "common_tgid", + "common_lock_depth", + FIELD_STRING_IP, + FIELD_STRING_RETIP, + FIELD_STRING_FUNC, +}; + +/* Printing function type */ +#define PRINT_TYPE_FUNC_NAME(type) print_type_##type +#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type + +/* Printing in basic type function template */ +#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ +static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ + const char *name, void *data)\ +{ \ + return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ +} \ +static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; + +DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) +DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) +DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) +DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) +DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) + +#define FETCH_FUNC_NAME(kind, type) fetch_##kind##_##type +/* + * Define macro for basic types - we don't need to define s* types, because + * we have to care only about bitwidth at recording time. + */ +#define DEFINE_BASIC_FETCH_FUNCS(kind) \ +DEFINE_FETCH_##kind(u8) \ +DEFINE_FETCH_##kind(u16) \ +DEFINE_FETCH_##kind(u32) \ +DEFINE_FETCH_##kind(u64) + +#define CHECK_BASIC_FETCH_FUNCS(kind, fn) \ + ((FETCH_FUNC_NAME(kind, u8) == fn) || \ + (FETCH_FUNC_NAME(kind, u16) == fn) || \ + (FETCH_FUNC_NAME(kind, u32) == fn) || \ + (FETCH_FUNC_NAME(kind, u64) == fn)) + +/* Data fetch function templates */ +#define DEFINE_FETCH_reg(type) \ +static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_register(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(reg) + +#define DEFINE_FETCH_stack(type) \ +static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ + void *offset, void *dest) \ +{ \ + *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ + (unsigned int)((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(stack) + +#define DEFINE_FETCH_retval(type) \ +static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ + void *dummy, void *dest) \ +{ \ + *(type *)dest = (type)regs_return_value(regs); \ +} +DEFINE_BASIC_FETCH_FUNCS(retval) + +#define DEFINE_FETCH_memory(type) \ +static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ + void *addr, void *dest) \ +{ \ + type retval; \ + if (probe_kernel_address(addr, retval)) \ + *(type *)dest = 0; \ + else \ + *(type *)dest = retval; \ +} +DEFINE_BASIC_FETCH_FUNCS(memory) + +/* Memory fetching by symbol */ +struct symbol_cache { + char *symbol; + long offset; + unsigned long addr; +}; + +static unsigned long update_symbol_cache(struct symbol_cache *sc) +{ + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); + if (sc->addr) + sc->addr += sc->offset; + return sc->addr; +} + +static void free_symbol_cache(struct symbol_cache *sc) +{ + kfree(sc->symbol); + kfree(sc); +} + +static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) +{ + struct symbol_cache *sc; + + if (!sym || strlen(sym) == 0) + return NULL; + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); + if (!sc) + return NULL; + + sc->symbol = kstrdup(sym, GFP_KERNEL); + if (!sc->symbol) { + kfree(sc); + return NULL; + } + sc->offset = offset; + + update_symbol_cache(sc); + return sc; +} + +#define DEFINE_FETCH_symbol(type) \ +static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct symbol_cache *sc = data; \ + if (sc->addr) \ + fetch_memory_##type(regs, (void *)sc->addr, dest); \ + else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(symbol) + +/* Dereference memory access function */ +struct deref_fetch_param { + struct fetch_param orig; + long offset; +}; + +#define DEFINE_FETCH_deref(type) \ +static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct deref_fetch_param *dprm = data; \ + unsigned long addr; \ + call_fetch(&dprm->orig, regs, &addr); \ + if (addr) { \ + addr += dprm->offset; \ + fetch_memory_##type(regs, (void *)addr, dest); \ + } else \ + *(type *)dest = 0; \ +} +DEFINE_BASIC_FETCH_FUNCS(deref) + +static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) +{ + if (CHECK_BASIC_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_BASIC_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + kfree(data); +} + +/* Default (unsigned long) fetch type */ +#define __DEFAULT_FETCH_TYPE(t) u##t +#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) +#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) +#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) + +#define ASSIGN_FETCH_FUNC(kind, type) \ + .kind = FETCH_FUNC_NAME(kind, type) + +#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ + {.name = #ptype, \ + .size = sizeof(ftype), \ + .is_signed = sign, \ + .print = PRINT_TYPE_FUNC_NAME(ptype), \ + .fmt = PRINT_TYPE_FMT_NAME(ptype), \ +ASSIGN_FETCH_FUNC(reg, ftype), \ +ASSIGN_FETCH_FUNC(stack, ftype), \ +ASSIGN_FETCH_FUNC(retval, ftype), \ +ASSIGN_FETCH_FUNC(memory, ftype), \ +ASSIGN_FETCH_FUNC(symbol, ftype), \ +ASSIGN_FETCH_FUNC(deref, ftype), \ + } + +/* Fetch type information table */ +static const struct fetch_type fetch_type_table[] = { + ASSIGN_FETCH_TYPE(u8, u8, 0), + ASSIGN_FETCH_TYPE(u16, u16, 0), + ASSIGN_FETCH_TYPE(u32, u32, 0), + ASSIGN_FETCH_TYPE(u64, u64, 0), + ASSIGN_FETCH_TYPE(s8, u8, 1), + ASSIGN_FETCH_TYPE(s16, u16, 1), + ASSIGN_FETCH_TYPE(s32, u32, 1), + ASSIGN_FETCH_TYPE(s64, u64, 1), +}; + +static const struct fetch_type *find_fetch_type(const char *type) +{ + int i; + + if (!type) + type = DEFAULT_FETCH_TYPE_STR; + + for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) + if (strcmp(type, fetch_type_table[i].name) == 0) + return &fetch_type_table[i]; + return NULL; +} + +/* Special function : only accept unsigned long */ +static __kprobes void fetch_stack_address(struct pt_regs *regs, + void *dummy, void *dest) +{ + *(unsigned long *)dest = kernel_stack_pointer(regs); +} + +/* Split symbol and offset. */ +int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +{ + char *tmp; + int ret; + + if (!offset) + return -EINVAL; + + tmp = strchr(symbol, '+'); + if (tmp) { + /* skip sign because strict_strtol doesn't accept '+' */ + ret = strict_strtoul(tmp + 1, 0, offset); + if (ret) + return ret; + *tmp = '\0'; + } else + *offset = 0; + return 0; +} + + +#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) + +static int parse_probe_vars(char *arg, const struct fetch_type *t, + struct fetch_param *f, int is_return) +{ + int ret = 0; + unsigned long param; + + if (strcmp(arg, "retval") == 0) { + if (is_return) + f->fn = t->retval; + else + ret = -EINVAL; + } else if (strncmp(arg, "stack", 5) == 0) { + if (arg[5] == '\0') { + if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) + f->fn = fetch_stack_address; + else + ret = -EINVAL; + } else if (isdigit(arg[5])) { + ret = strict_strtoul(arg + 5, 10, ¶m); + if (ret || param > PARAM_MAX_STACK) + ret = -EINVAL; + else { + f->fn = t->stack; + f->data = (void *)param; + } + } else + ret = -EINVAL; + } else + ret = -EINVAL; + return ret; +} + +/* Recursive argument parser */ +static int parse_probe_arg(char *arg, const struct fetch_type *t, + struct fetch_param *f, int is_return, bool is_kprobe) +{ + int ret = 0; + unsigned long param; + long offset; + char *tmp; + + /* Until uprobe_events supports only reg arguments */ + if (!is_kprobe && arg[0] != '%') + return -EINVAL; + + switch (arg[0]) { + case '$': + ret = parse_probe_vars(arg + 1, t, f, is_return); + break; + case '%': /* named register */ + ret = regs_query_register_offset(arg + 1); + if (ret >= 0) { + f->fn = t->reg; + f->data = (void *)(unsigned long)ret; + ret = 0; + } + break; + case '@': /* memory or symbol */ + if (isdigit(arg[1])) { + ret = strict_strtoul(arg + 1, 0, ¶m); + if (ret) + break; + f->fn = t->memory; + f->data = (void *)param; + } else { + ret = traceprobe_split_symbol_offset(arg + 1, &offset); + if (ret) + break; + f->data = alloc_symbol_cache(arg + 1, offset); + if (f->data) + f->fn = t->symbol; + } + break; + case '+': /* deref memory */ + case '-': + tmp = strchr(arg, '('); + if (!tmp) + break; + *tmp = '\0'; + ret = strict_strtol(arg + 1, 0, &offset); + if (ret) + break; + if (arg[0] == '-') + offset = -offset; + arg = tmp + 1; + tmp = strrchr(arg, ')'); + if (tmp) { + struct deref_fetch_param *dprm; + const struct fetch_type *t2 = find_fetch_type(NULL); + *tmp = '\0'; + dprm = kzalloc(sizeof(struct deref_fetch_param), + GFP_KERNEL); + if (!dprm) + return -ENOMEM; + dprm->offset = offset; + ret = parse_probe_arg(arg, t2, &dprm->orig, + is_return, is_kprobe); + if (ret) + kfree(dprm); + else { + f->fn = t->deref; + f->data = (void *)dprm; + } + } + break; + } + if (!ret && !f->fn) + ret = -EINVAL; + return ret; +} + +/* String length checking wrapper */ +int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, int is_return, bool is_kprobe) +{ + const char *t; + + if (strlen(arg) > MAX_ARGSTR_LEN) { + pr_info("Argument is too long.: %s\n", arg); + return -ENOSPC; + } + parg->comm = kstrdup(arg, GFP_KERNEL); + if (!parg->comm) { + pr_info("Failed to allocate memory for command '%s'.\n", arg); + return -ENOMEM; + } + t = strchr(parg->comm, ':'); + if (t) { + arg[t - parg->comm] = '\0'; + t++; + } + parg->type = find_fetch_type(t); + if (!parg->type) { + pr_info("Unsupported type: %s\n", t); + return -EINVAL; + } + parg->offset = *size; + *size += parg->type->size; + return parse_probe_arg(arg, parg->type, &parg->fetch, + is_return, is_kprobe); +} + +/* Return 1 if name is reserved or already used by another argument */ +int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg) +{ + int i; + for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) + if (strcmp(reserved_field_names[i], name) == 0) + return 1; + for (i = 0; i < narg; i++) + if (strcmp(args[i].name, name) == 0) + return 1; + return 0; +} + +void traceprobe_free_probe_arg(struct probe_arg *arg) +{ + if (CHECK_BASIC_FETCH_FUNCS(deref, arg->fetch.fn)) + free_deref_fetch_param(arg->fetch.data); + else if (CHECK_BASIC_FETCH_FUNCS(symbol, arg->fetch.fn)) + free_symbol_cache(arg->fetch.data); + kfree(arg->name); + kfree(arg->comm); +} + +static int command_trace_probe(const char *buf, + int (*createfn)(int, char**)) +{ + char **argv; + int argc = 0, ret = 0; + + argv = argv_split(GFP_KERNEL, buf, &argc); + if (!argv) + return -ENOMEM; + + if (argc) + ret = createfn(argc, argv); + + argv_free(argv); + return ret; +} + +#define WRITE_BUFSIZE 128 + +ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos, int (*createfn)(int, char**)) +{ + char *kbuf, *tmp; + int ret = 0; + size_t done = 0; + size_t size; + + kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + while (done < count) { + size = count - done; + if (size >= WRITE_BUFSIZE) + size = WRITE_BUFSIZE - 1; + if (copy_from_user(kbuf, buffer + done, size)) { + ret = -EFAULT; + goto out; + } + kbuf[size] = '\0'; + tmp = strchr(kbuf, '\n'); + if (tmp) { + *tmp = '\0'; + size = tmp - kbuf + 1; + } else if (done + size < count) { + pr_warning("Line length is too long: " + "Should be less than %d.", WRITE_BUFSIZE); + ret = -EINVAL; + goto out; + } + done += size; + /* Remove comments */ + tmp = strchr(kbuf, '#'); + if (tmp) + *tmp = '\0'; + + ret = command_trace_probe(kbuf, createfn); + if (ret) + goto out; + } + ret = done; +out: + kfree(kbuf); + return ret; +} + diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h new file mode 100644 index 0000000..5f5703b --- /dev/null +++ b/kernel/trace/trace_probe.h @@ -0,0 +1,126 @@ +/* + * Common header file for probe-based Dynamic events. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Copyright (C) IBM Corporation, 2010 + * Author: Srikar Dronamraju + * + * Derived from kernel/trace/trace_kprobe.c written by + * Masami Hiramatsu + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "trace.h" +#include "trace_output.h" + +#define MAX_TRACE_ARGS 128 +#define MAX_ARGSTR_LEN 63 +#define MAX_EVENT_NAME_LEN 64 + +/* Reserved field names */ +#define FIELD_STRING_IP "__probe_ip" +#define FIELD_STRING_RETIP "__probe_ret_ip" +#define FIELD_STRING_FUNC "__probe_func" + +#undef DEFINE_FIELD +#define DEFINE_FIELD(type, item, name, is_signed) \ + do { \ + ret = trace_define_field(event_call, #type, name, \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed, \ + FILTER_OTHER); \ + if (ret) \ + return ret; \ + } while (0) + + +/* Flags for trace_probe */ +#define TP_FLAG_TRACE 1 +#define TP_FLAG_PROFILE 2 + +/* Data fetch function type */ +typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); +typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *); + +/* Fetch type information table */ +struct fetch_type { + const char *name; /* Name of type */ + size_t size; /* Byte size of type */ + int is_signed; /* Signed flag */ + print_type_func_t print; /* Print functions */ + const char *fmt; /* Fromat string */ + /* Fetch functions */ + fetch_func_t reg; + fetch_func_t stack; + fetch_func_t retval; + fetch_func_t memory; + fetch_func_t symbol; + fetch_func_t deref; +}; + +struct fetch_param { + fetch_func_t fn; + void *data; +}; + +struct probe_arg { + struct fetch_param fetch; + unsigned int offset; /* Offset from argument entry */ + const char *name; /* Name of this argument */ + const char *comm; /* Command of this argument */ + const struct fetch_type *type; /* Type of this argument */ +}; + +static inline __kprobes void call_fetch(struct fetch_param *fprm, + struct pt_regs *regs, void *dest) +{ + return fprm->fn(regs, fprm->data, dest); +} + +/* Check the name is good for event/group */ +static inline int check_event_name(const char *name) +{ + if (!isalpha(*name) && *name != '_') + return 0; + while (*++name != '\0') { + if (!isalpha(*name) && !isdigit(*name) && *name != '_') + return 0; + } + return 1; +} + +extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, + struct probe_arg *parg, int is_return, bool is_kprobe); + +extern int traceprobe_conflict_field_name(const char *name, + struct probe_arg *args, int narg); + +extern void traceprobe_free_probe_arg(struct probe_arg *arg); + +extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); + +extern ssize_t traceprobe_probes_write(struct file *file, + const char __user *buffer, size_t count, loff_t *ppos, + int (*createfn)(int, char**)); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/