forked from Minki/linux
2d074918fb
Conflicts: kernel/events/hw_breakpoint.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
1676 lines
41 KiB
C
1676 lines
41 KiB
C
/*
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* Kprobes-based tracing events
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*
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* Created by Masami Hiramatsu <mhiramat@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#define pr_fmt(fmt) "trace_kprobe: " fmt
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#include <linux/module.h>
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#include <linux/uaccess.h>
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#include <linux/rculist.h>
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#include <linux/error-injection.h>
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#include "trace_probe.h"
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#define KPROBE_EVENT_SYSTEM "kprobes"
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#define KRETPROBE_MAXACTIVE_MAX 4096
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/**
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* Kprobe event core functions
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*/
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struct trace_kprobe {
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struct list_head list;
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struct kretprobe rp; /* Use rp.kp for kprobe use */
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unsigned long __percpu *nhit;
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const char *symbol; /* symbol name */
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struct trace_probe tp;
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};
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#define SIZEOF_TRACE_KPROBE(n) \
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(offsetof(struct trace_kprobe, tp.args) + \
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(sizeof(struct probe_arg) * (n)))
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static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
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{
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return tk->rp.handler != NULL;
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}
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static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
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{
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return tk->symbol ? tk->symbol : "unknown";
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}
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static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
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{
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return tk->rp.kp.offset;
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}
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static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
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{
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return !!(kprobe_gone(&tk->rp.kp));
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}
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static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
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struct module *mod)
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{
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int len = strlen(mod->name);
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const char *name = trace_kprobe_symbol(tk);
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return strncmp(mod->name, name, len) == 0 && name[len] == ':';
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}
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static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
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{
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return !!strchr(trace_kprobe_symbol(tk), ':');
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}
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static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
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{
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unsigned long nhit = 0;
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int cpu;
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for_each_possible_cpu(cpu)
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nhit += *per_cpu_ptr(tk->nhit, cpu);
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return nhit;
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}
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bool trace_kprobe_on_func_entry(struct trace_event_call *call)
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{
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struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
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return kprobe_on_func_entry(tk->rp.kp.addr,
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tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
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tk->rp.kp.addr ? 0 : tk->rp.kp.offset);
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}
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bool trace_kprobe_error_injectable(struct trace_event_call *call)
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{
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struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
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unsigned long addr;
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if (tk->symbol) {
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addr = (unsigned long)
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kallsyms_lookup_name(trace_kprobe_symbol(tk));
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addr += tk->rp.kp.offset;
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} else {
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addr = (unsigned long)tk->rp.kp.addr;
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}
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return within_error_injection_list(addr);
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}
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static int register_kprobe_event(struct trace_kprobe *tk);
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static int unregister_kprobe_event(struct trace_kprobe *tk);
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static DEFINE_MUTEX(probe_lock);
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static LIST_HEAD(probe_list);
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static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
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static int kretprobe_dispatcher(struct kretprobe_instance *ri,
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struct pt_regs *regs);
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/* Memory fetching by symbol */
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struct symbol_cache {
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char *symbol;
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long offset;
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unsigned long addr;
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};
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unsigned long update_symbol_cache(struct symbol_cache *sc)
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{
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sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
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if (sc->addr)
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sc->addr += sc->offset;
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return sc->addr;
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}
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void free_symbol_cache(struct symbol_cache *sc)
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{
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kfree(sc->symbol);
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kfree(sc);
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}
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struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
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{
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struct symbol_cache *sc;
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if (!sym || strlen(sym) == 0)
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return NULL;
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sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
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if (!sc)
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return NULL;
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sc->symbol = kstrdup(sym, GFP_KERNEL);
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if (!sc->symbol) {
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kfree(sc);
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return NULL;
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}
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sc->offset = offset;
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update_symbol_cache(sc);
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return sc;
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}
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/*
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* Kprobes-specific fetch functions
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*/
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#define DEFINE_FETCH_stack(type) \
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static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
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void *offset, void *dest) \
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{ \
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*(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
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(unsigned int)((unsigned long)offset)); \
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} \
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NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
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DEFINE_BASIC_FETCH_FUNCS(stack)
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/* No string on the stack entry */
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#define fetch_stack_string NULL
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#define fetch_stack_string_size NULL
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#define DEFINE_FETCH_memory(type) \
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static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
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void *addr, void *dest) \
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{ \
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type retval; \
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if (probe_kernel_address(addr, retval)) \
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*(type *)dest = 0; \
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else \
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*(type *)dest = retval; \
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} \
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NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
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DEFINE_BASIC_FETCH_FUNCS(memory)
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/*
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* Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
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* length and relative data location.
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*/
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static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
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void *addr, void *dest)
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{
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int maxlen = get_rloc_len(*(u32 *)dest);
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u8 *dst = get_rloc_data(dest);
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long ret;
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if (!maxlen)
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return;
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/*
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* Try to get string again, since the string can be changed while
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* probing.
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*/
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ret = strncpy_from_unsafe(dst, addr, maxlen);
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if (ret < 0) { /* Failed to fetch string */
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dst[0] = '\0';
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*(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
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} else {
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*(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
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}
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}
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NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));
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/* Return the length of string -- including null terminal byte */
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static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
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void *addr, void *dest)
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{
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mm_segment_t old_fs;
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int ret, len = 0;
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u8 c;
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old_fs = get_fs();
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set_fs(KERNEL_DS);
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pagefault_disable();
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do {
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ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
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len++;
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} while (c && ret == 0 && len < MAX_STRING_SIZE);
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pagefault_enable();
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set_fs(old_fs);
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if (ret < 0) /* Failed to check the length */
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*(u32 *)dest = 0;
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else
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*(u32 *)dest = len;
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}
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NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));
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#define DEFINE_FETCH_symbol(type) \
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void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\
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{ \
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struct symbol_cache *sc = data; \
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if (sc->addr) \
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fetch_memory_##type(regs, (void *)sc->addr, dest); \
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else \
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*(type *)dest = 0; \
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} \
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NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
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DEFINE_BASIC_FETCH_FUNCS(symbol)
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DEFINE_FETCH_symbol(string)
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DEFINE_FETCH_symbol(string_size)
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/* kprobes don't support file_offset fetch methods */
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#define fetch_file_offset_u8 NULL
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#define fetch_file_offset_u16 NULL
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#define fetch_file_offset_u32 NULL
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#define fetch_file_offset_u64 NULL
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#define fetch_file_offset_string NULL
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#define fetch_file_offset_string_size NULL
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/* Fetch type information table */
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static const struct fetch_type kprobes_fetch_type_table[] = {
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/* Special types */
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[FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
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sizeof(u32), 1, "__data_loc char[]"),
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[FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
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string_size, sizeof(u32), 0, "u32"),
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/* Basic types */
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ASSIGN_FETCH_TYPE(u8, u8, 0),
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ASSIGN_FETCH_TYPE(u16, u16, 0),
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ASSIGN_FETCH_TYPE(u32, u32, 0),
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ASSIGN_FETCH_TYPE(u64, u64, 0),
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ASSIGN_FETCH_TYPE(s8, u8, 1),
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ASSIGN_FETCH_TYPE(s16, u16, 1),
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ASSIGN_FETCH_TYPE(s32, u32, 1),
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ASSIGN_FETCH_TYPE(s64, u64, 1),
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ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
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ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
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ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
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ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
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ASSIGN_FETCH_TYPE_END
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};
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/*
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* Allocate new trace_probe and initialize it (including kprobes).
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*/
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static struct trace_kprobe *alloc_trace_kprobe(const char *group,
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const char *event,
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void *addr,
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const char *symbol,
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unsigned long offs,
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int maxactive,
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int nargs, bool is_return)
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{
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struct trace_kprobe *tk;
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int ret = -ENOMEM;
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tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
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if (!tk)
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return ERR_PTR(ret);
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tk->nhit = alloc_percpu(unsigned long);
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if (!tk->nhit)
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goto error;
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if (symbol) {
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tk->symbol = kstrdup(symbol, GFP_KERNEL);
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if (!tk->symbol)
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goto error;
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tk->rp.kp.symbol_name = tk->symbol;
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tk->rp.kp.offset = offs;
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} else
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tk->rp.kp.addr = addr;
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if (is_return)
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tk->rp.handler = kretprobe_dispatcher;
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else
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tk->rp.kp.pre_handler = kprobe_dispatcher;
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tk->rp.maxactive = maxactive;
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if (!event || !is_good_name(event)) {
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ret = -EINVAL;
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goto error;
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}
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tk->tp.call.class = &tk->tp.class;
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tk->tp.call.name = kstrdup(event, GFP_KERNEL);
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if (!tk->tp.call.name)
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goto error;
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if (!group || !is_good_name(group)) {
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ret = -EINVAL;
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goto error;
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}
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tk->tp.class.system = kstrdup(group, GFP_KERNEL);
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if (!tk->tp.class.system)
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goto error;
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INIT_LIST_HEAD(&tk->list);
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INIT_LIST_HEAD(&tk->tp.files);
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return tk;
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error:
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kfree(tk->tp.call.name);
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kfree(tk->symbol);
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free_percpu(tk->nhit);
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kfree(tk);
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return ERR_PTR(ret);
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}
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static void free_trace_kprobe(struct trace_kprobe *tk)
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{
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int i;
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for (i = 0; i < tk->tp.nr_args; i++)
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traceprobe_free_probe_arg(&tk->tp.args[i]);
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kfree(tk->tp.call.class->system);
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kfree(tk->tp.call.name);
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kfree(tk->symbol);
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free_percpu(tk->nhit);
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kfree(tk);
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}
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static struct trace_kprobe *find_trace_kprobe(const char *event,
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const char *group)
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{
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struct trace_kprobe *tk;
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list_for_each_entry(tk, &probe_list, list)
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if (strcmp(trace_event_name(&tk->tp.call), event) == 0 &&
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strcmp(tk->tp.call.class->system, group) == 0)
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return tk;
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return NULL;
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}
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|
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/*
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* Enable trace_probe
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* if the file is NULL, enable "perf" handler, or enable "trace" handler.
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*/
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static int
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enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
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{
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int ret = 0;
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if (file) {
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struct event_file_link *link;
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link = kmalloc(sizeof(*link), GFP_KERNEL);
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if (!link) {
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ret = -ENOMEM;
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goto out;
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}
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link->file = file;
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list_add_tail_rcu(&link->list, &tk->tp.files);
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tk->tp.flags |= TP_FLAG_TRACE;
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} else
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tk->tp.flags |= TP_FLAG_PROFILE;
|
|
|
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if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) {
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if (trace_kprobe_is_return(tk))
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ret = enable_kretprobe(&tk->rp);
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else
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ret = enable_kprobe(&tk->rp.kp);
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}
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out:
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return ret;
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|
}
|
|
|
|
/*
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* Disable trace_probe
|
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* if the file is NULL, disable "perf" handler, or disable "trace" handler.
|
|
*/
|
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static int
|
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disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
|
|
{
|
|
struct event_file_link *link = NULL;
|
|
int wait = 0;
|
|
int ret = 0;
|
|
|
|
if (file) {
|
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link = find_event_file_link(&tk->tp, file);
|
|
if (!link) {
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ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
list_del_rcu(&link->list);
|
|
wait = 1;
|
|
if (!list_empty(&tk->tp.files))
|
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goto out;
|
|
|
|
tk->tp.flags &= ~TP_FLAG_TRACE;
|
|
} else
|
|
tk->tp.flags &= ~TP_FLAG_PROFILE;
|
|
|
|
if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->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->list))
|
|
wait = 0;
|
|
out:
|
|
if (wait) {
|
|
/*
|
|
* 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.
|
|
*/
|
|
synchronize_sched();
|
|
kfree(link); /* Ignored if link == NULL */
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Internal register function - just handle k*probes and flags */
|
|
static int __register_trace_kprobe(struct trace_kprobe *tk)
|
|
{
|
|
int i, ret;
|
|
|
|
if (trace_probe_is_registered(&tk->tp))
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < tk->tp.nr_args; i++)
|
|
traceprobe_update_arg(&tk->tp.args[i]);
|
|
|
|
/* Set/clear disabled flag according to tp->flag */
|
|
if (trace_probe_is_enabled(&tk->tp))
|
|
tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
|
|
else
|
|
tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
|
|
|
|
if (trace_kprobe_is_return(tk))
|
|
ret = register_kretprobe(&tk->rp);
|
|
else
|
|
ret = register_kprobe(&tk->rp.kp);
|
|
|
|
if (ret == 0)
|
|
tk->tp.flags |= TP_FLAG_REGISTERED;
|
|
else {
|
|
pr_warn("Could not insert probe at %s+%lu: %d\n",
|
|
trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
|
|
if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
|
|
pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
|
|
ret = 0;
|
|
} else if (ret == -EILSEQ) {
|
|
pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
|
|
tk->rp.kp.addr);
|
|
ret = -EINVAL;
|
|
}
|
|
}
|
|
|
|
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_return(tk))
|
|
unregister_kretprobe(&tk->rp);
|
|
else
|
|
unregister_kprobe(&tk->rp.kp);
|
|
tk->tp.flags &= ~TP_FLAG_REGISTERED;
|
|
/* Cleanup kprobe for reuse */
|
|
if (tk->rp.kp.symbol_name)
|
|
tk->rp.kp.addr = NULL;
|
|
}
|
|
}
|
|
|
|
/* Unregister a trace_probe and probe_event: call with locking probe_lock */
|
|
static int unregister_trace_kprobe(struct trace_kprobe *tk)
|
|
{
|
|
/* Enabled event can not be unregistered */
|
|
if (trace_probe_is_enabled(&tk->tp))
|
|
return -EBUSY;
|
|
|
|
/* Will fail if probe is being used by ftrace or perf */
|
|
if (unregister_kprobe_event(tk))
|
|
return -EBUSY;
|
|
|
|
__unregister_trace_kprobe(tk);
|
|
list_del(&tk->list);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Register a trace_probe and probe_event */
|
|
static int register_trace_kprobe(struct trace_kprobe *tk)
|
|
{
|
|
struct trace_kprobe *old_tk;
|
|
int ret;
|
|
|
|
mutex_lock(&probe_lock);
|
|
|
|
/* Delete old (same name) event if exist */
|
|
old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call),
|
|
tk->tp.call.class->system);
|
|
if (old_tk) {
|
|
ret = unregister_trace_kprobe(old_tk);
|
|
if (ret < 0)
|
|
goto end;
|
|
free_trace_kprobe(old_tk);
|
|
}
|
|
|
|
/* Register new event */
|
|
ret = register_kprobe_event(tk);
|
|
if (ret) {
|
|
pr_warn("Failed to register probe event(%d)\n", ret);
|
|
goto end;
|
|
}
|
|
|
|
/* Register k*probe */
|
|
ret = __register_trace_kprobe(tk);
|
|
if (ret < 0)
|
|
unregister_kprobe_event(tk);
|
|
else
|
|
list_add_tail(&tk->list, &probe_list);
|
|
|
|
end:
|
|
mutex_unlock(&probe_lock);
|
|
return ret;
|
|
}
|
|
|
|
/* Module notifier call back, checking event on the module */
|
|
static int trace_kprobe_module_callback(struct notifier_block *nb,
|
|
unsigned long val, void *data)
|
|
{
|
|
struct module *mod = data;
|
|
struct trace_kprobe *tk;
|
|
int ret;
|
|
|
|
if (val != MODULE_STATE_COMING)
|
|
return NOTIFY_DONE;
|
|
|
|
/* Update probes on coming module */
|
|
mutex_lock(&probe_lock);
|
|
list_for_each_entry(tk, &probe_list, list) {
|
|
if (trace_kprobe_within_module(tk, mod)) {
|
|
/* Don't need to check busy - this should have gone. */
|
|
__unregister_trace_kprobe(tk);
|
|
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),
|
|
mod->name, ret);
|
|
}
|
|
}
|
|
mutex_unlock(&probe_lock);
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block trace_kprobe_module_nb = {
|
|
.notifier_call = trace_kprobe_module_callback,
|
|
.priority = 1 /* Invoked after kprobe module callback */
|
|
};
|
|
|
|
/* Convert certain expected symbols into '_' when generating event names */
|
|
static inline void sanitize_event_name(char *name)
|
|
{
|
|
while (*name++ != '\0')
|
|
if (*name == ':' || *name == '.')
|
|
*name = '_';
|
|
}
|
|
|
|
static int create_trace_kprobe(int argc, char **argv)
|
|
{
|
|
/*
|
|
* Argument syntax:
|
|
* - Add kprobe:
|
|
* p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
|
|
* - Add kretprobe:
|
|
* r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
|
|
* Fetch args:
|
|
* $retval : fetch return value
|
|
* $stack : fetch stack address
|
|
* $stackN : fetch Nth of stack (N:0-)
|
|
* $comm : fetch current task comm
|
|
* @ADDR : fetch memory at ADDR (ADDR should be in kernel)
|
|
* @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
|
|
* %REG : fetch register REG
|
|
* Dereferencing memory fetch:
|
|
* +|-offs(ARG) : fetch memory at ARG +|- offs address.
|
|
* Alias name of args:
|
|
* NAME=FETCHARG : set NAME as alias of FETCHARG.
|
|
* Type of args:
|
|
* FETCHARG:TYPE : use TYPE instead of unsigned long.
|
|
*/
|
|
struct trace_kprobe *tk;
|
|
int i, ret = 0;
|
|
bool is_return = false, is_delete = false;
|
|
char *symbol = NULL, *event = NULL, *group = NULL;
|
|
int maxactive = 0;
|
|
char *arg;
|
|
long offset = 0;
|
|
void *addr = NULL;
|
|
char buf[MAX_EVENT_NAME_LEN];
|
|
|
|
/* argc must be >= 1 */
|
|
if (argv[0][0] == 'p')
|
|
is_return = false;
|
|
else if (argv[0][0] == 'r')
|
|
is_return = true;
|
|
else if (argv[0][0] == '-')
|
|
is_delete = true;
|
|
else {
|
|
pr_info("Probe definition must be started with 'p', 'r' or"
|
|
" '-'.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
event = strchr(&argv[0][1], ':');
|
|
if (event) {
|
|
event[0] = '\0';
|
|
event++;
|
|
}
|
|
if (is_return && isdigit(argv[0][1])) {
|
|
ret = kstrtouint(&argv[0][1], 0, &maxactive);
|
|
if (ret) {
|
|
pr_info("Failed to parse maxactive.\n");
|
|
return ret;
|
|
}
|
|
/* kretprobes instances are iterated over via a list. The
|
|
* maximum should stay reasonable.
|
|
*/
|
|
if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
|
|
pr_info("Maxactive is too big (%d > %d).\n",
|
|
maxactive, KRETPROBE_MAXACTIVE_MAX);
|
|
return -E2BIG;
|
|
}
|
|
}
|
|
|
|
if (event) {
|
|
if (strchr(event, '/')) {
|
|
group = event;
|
|
event = strchr(group, '/') + 1;
|
|
event[-1] = '\0';
|
|
if (strlen(group) == 0) {
|
|
pr_info("Group name is not specified\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (strlen(event) == 0) {
|
|
pr_info("Event name is not specified\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (!group)
|
|
group = KPROBE_EVENT_SYSTEM;
|
|
|
|
if (is_delete) {
|
|
if (!event) {
|
|
pr_info("Delete command needs an event name.\n");
|
|
return -EINVAL;
|
|
}
|
|
mutex_lock(&probe_lock);
|
|
tk = find_trace_kprobe(event, group);
|
|
if (!tk) {
|
|
mutex_unlock(&probe_lock);
|
|
pr_info("Event %s/%s doesn't exist.\n", group, event);
|
|
return -ENOENT;
|
|
}
|
|
/* delete an event */
|
|
ret = unregister_trace_kprobe(tk);
|
|
if (ret == 0)
|
|
free_trace_kprobe(tk);
|
|
mutex_unlock(&probe_lock);
|
|
return ret;
|
|
}
|
|
|
|
if (argc < 2) {
|
|
pr_info("Probe point is not specified.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* try to parse an address. if that fails, try to read the
|
|
* input as a symbol. */
|
|
if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
|
|
/* a symbol specified */
|
|
symbol = argv[1];
|
|
/* TODO: support .init module functions */
|
|
ret = traceprobe_split_symbol_offset(symbol, &offset);
|
|
if (ret || offset < 0 || offset > UINT_MAX) {
|
|
pr_info("Failed to parse either an address or a symbol.\n");
|
|
return ret;
|
|
}
|
|
if (offset && is_return &&
|
|
!kprobe_on_func_entry(NULL, symbol, offset)) {
|
|
pr_info("Given offset is not valid for return probe.\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
argc -= 2; argv += 2;
|
|
|
|
/* setup a probe */
|
|
if (!event) {
|
|
/* Make a new event name */
|
|
if (symbol)
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
|
|
is_return ? 'r' : 'p', symbol, offset);
|
|
else
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
|
|
is_return ? 'r' : 'p', addr);
|
|
sanitize_event_name(buf);
|
|
event = buf;
|
|
}
|
|
tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
|
|
argc, is_return);
|
|
if (IS_ERR(tk)) {
|
|
pr_info("Failed to allocate trace_probe.(%d)\n",
|
|
(int)PTR_ERR(tk));
|
|
return PTR_ERR(tk);
|
|
}
|
|
|
|
/* parse arguments */
|
|
ret = 0;
|
|
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
|
|
struct probe_arg *parg = &tk->tp.args[i];
|
|
|
|
/* Increment count for freeing args in error case */
|
|
tk->tp.nr_args++;
|
|
|
|
/* Parse argument name */
|
|
arg = strchr(argv[i], '=');
|
|
if (arg) {
|
|
*arg++ = '\0';
|
|
parg->name = kstrdup(argv[i], GFP_KERNEL);
|
|
} else {
|
|
arg = argv[i];
|
|
/* If argument name is omitted, set "argN" */
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
|
|
parg->name = kstrdup(buf, GFP_KERNEL);
|
|
}
|
|
|
|
if (!parg->name) {
|
|
pr_info("Failed to allocate argument[%d] name.\n", i);
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
if (!is_good_name(parg->name)) {
|
|
pr_info("Invalid argument[%d] name: %s\n",
|
|
i, parg->name);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
if (traceprobe_conflict_field_name(parg->name,
|
|
tk->tp.args, i)) {
|
|
pr_info("Argument[%d] name '%s' conflicts with "
|
|
"another field.\n", i, argv[i]);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/* Parse fetch argument */
|
|
ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
|
|
is_return, true,
|
|
kprobes_fetch_type_table);
|
|
if (ret) {
|
|
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
ret = register_trace_kprobe(tk);
|
|
if (ret)
|
|
goto error;
|
|
return 0;
|
|
|
|
error:
|
|
free_trace_kprobe(tk);
|
|
return ret;
|
|
}
|
|
|
|
static int release_all_trace_kprobes(void)
|
|
{
|
|
struct trace_kprobe *tk;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&probe_lock);
|
|
/* Ensure no probe is in use. */
|
|
list_for_each_entry(tk, &probe_list, list)
|
|
if (trace_probe_is_enabled(&tk->tp)) {
|
|
ret = -EBUSY;
|
|
goto end;
|
|
}
|
|
/* TODO: Use batch unregistration */
|
|
while (!list_empty(&probe_list)) {
|
|
tk = list_entry(probe_list.next, struct trace_kprobe, list);
|
|
ret = unregister_trace_kprobe(tk);
|
|
if (ret)
|
|
goto end;
|
|
free_trace_kprobe(tk);
|
|
}
|
|
|
|
end:
|
|
mutex_unlock(&probe_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Probes listing interfaces */
|
|
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
mutex_lock(&probe_lock);
|
|
return seq_list_start(&probe_list, *pos);
|
|
}
|
|
|
|
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
return seq_list_next(v, &probe_list, pos);
|
|
}
|
|
|
|
static void probes_seq_stop(struct seq_file *m, void *v)
|
|
{
|
|
mutex_unlock(&probe_lock);
|
|
}
|
|
|
|
static int probes_seq_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_kprobe *tk = v;
|
|
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));
|
|
|
|
if (!tk->symbol)
|
|
seq_printf(m, " 0x%p", tk->rp.kp.addr);
|
|
else if (tk->rp.kp.offset)
|
|
seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
|
|
tk->rp.kp.offset);
|
|
else
|
|
seq_printf(m, " %s", trace_kprobe_symbol(tk));
|
|
|
|
for (i = 0; i < tk->tp.nr_args; i++)
|
|
seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations probes_seq_op = {
|
|
.start = probes_seq_start,
|
|
.next = probes_seq_next,
|
|
.stop = probes_seq_stop,
|
|
.show = probes_seq_show
|
|
};
|
|
|
|
static int probes_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret;
|
|
|
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
|
|
ret = release_all_trace_kprobes();
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return seq_open(file, &probes_seq_op);
|
|
}
|
|
|
|
static ssize_t probes_write(struct file *file, const char __user *buffer,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return trace_parse_run_command(file, buffer, count, ppos,
|
|
create_trace_kprobe);
|
|
}
|
|
|
|
static const struct file_operations kprobe_events_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = probes_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
.write = probes_write,
|
|
};
|
|
|
|
/* Probes profiling interfaces */
|
|
static int probes_profile_seq_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_kprobe *tk = v;
|
|
|
|
seq_printf(m, " %-44s %15lu %15lu\n",
|
|
trace_event_name(&tk->tp.call),
|
|
trace_kprobe_nhit(tk),
|
|
tk->rp.kp.nmissed);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations profile_seq_op = {
|
|
.start = probes_seq_start,
|
|
.next = probes_seq_next,
|
|
.stop = probes_seq_stop,
|
|
.show = probes_profile_seq_show
|
|
};
|
|
|
|
static int profile_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &profile_seq_op);
|
|
}
|
|
|
|
static const struct file_operations kprobe_profile_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = profile_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
/* Kprobe handler */
|
|
static nokprobe_inline void
|
|
__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
|
|
struct trace_event_file *trace_file)
|
|
{
|
|
struct kprobe_trace_entry_head *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
int size, dsize, pc;
|
|
unsigned long irq_flags;
|
|
struct trace_event_call *call = &tk->tp.call;
|
|
|
|
WARN_ON(call != trace_file->event_call);
|
|
|
|
if (trace_trigger_soft_disabled(trace_file))
|
|
return;
|
|
|
|
local_save_flags(irq_flags);
|
|
pc = preempt_count();
|
|
|
|
dsize = __get_data_size(&tk->tp, regs);
|
|
size = sizeof(*entry) + tk->tp.size + dsize;
|
|
|
|
event = trace_event_buffer_lock_reserve(&buffer, trace_file,
|
|
call->event.type,
|
|
size, irq_flags, pc);
|
|
if (!event)
|
|
return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->ip = (unsigned long)tk->rp.kp.addr;
|
|
store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
|
|
|
|
event_trigger_unlock_commit_regs(trace_file, buffer, event,
|
|
entry, irq_flags, pc, regs);
|
|
}
|
|
|
|
static void
|
|
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)
|
|
__kprobe_trace_func(tk, regs, link->file);
|
|
}
|
|
NOKPROBE_SYMBOL(kprobe_trace_func);
|
|
|
|
/* Kretprobe handler */
|
|
static nokprobe_inline void
|
|
__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
|
|
struct pt_regs *regs,
|
|
struct trace_event_file *trace_file)
|
|
{
|
|
struct kretprobe_trace_entry_head *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
int size, pc, dsize;
|
|
unsigned long irq_flags;
|
|
struct trace_event_call *call = &tk->tp.call;
|
|
|
|
WARN_ON(call != trace_file->event_call);
|
|
|
|
if (trace_trigger_soft_disabled(trace_file))
|
|
return;
|
|
|
|
local_save_flags(irq_flags);
|
|
pc = preempt_count();
|
|
|
|
dsize = __get_data_size(&tk->tp, regs);
|
|
size = sizeof(*entry) + tk->tp.size + dsize;
|
|
|
|
event = trace_event_buffer_lock_reserve(&buffer, trace_file,
|
|
call->event.type,
|
|
size, irq_flags, pc);
|
|
if (!event)
|
|
return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->func = (unsigned long)tk->rp.kp.addr;
|
|
entry->ret_ip = (unsigned long)ri->ret_addr;
|
|
store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
|
|
|
|
event_trigger_unlock_commit_regs(trace_file, buffer, event,
|
|
entry, irq_flags, pc, regs);
|
|
}
|
|
|
|
static void
|
|
kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct event_file_link *link;
|
|
|
|
list_for_each_entry_rcu(link, &tk->tp.files, list)
|
|
__kretprobe_trace_func(tk, ri, regs, link->file);
|
|
}
|
|
NOKPROBE_SYMBOL(kretprobe_trace_func);
|
|
|
|
/* Event entry printers */
|
|
static enum print_line_t
|
|
print_kprobe_event(struct trace_iterator *iter, int flags,
|
|
struct trace_event *event)
|
|
{
|
|
struct kprobe_trace_entry_head *field;
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_probe *tp;
|
|
u8 *data;
|
|
int i;
|
|
|
|
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));
|
|
|
|
if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
|
|
goto out;
|
|
|
|
trace_seq_putc(s, ')');
|
|
|
|
data = (u8 *)&field[1];
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
if (!tp->args[i].type->print(s, tp->args[i].name,
|
|
data + tp->args[i].offset, field))
|
|
goto out;
|
|
|
|
trace_seq_putc(s, '\n');
|
|
out:
|
|
return trace_handle_return(s);
|
|
}
|
|
|
|
static enum print_line_t
|
|
print_kretprobe_event(struct trace_iterator *iter, int flags,
|
|
struct trace_event *event)
|
|
{
|
|
struct kretprobe_trace_entry_head *field;
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_probe *tp;
|
|
u8 *data;
|
|
int i;
|
|
|
|
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));
|
|
|
|
if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
|
|
goto out;
|
|
|
|
trace_seq_puts(s, " <- ");
|
|
|
|
if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
|
|
goto out;
|
|
|
|
trace_seq_putc(s, ')');
|
|
|
|
data = (u8 *)&field[1];
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
if (!tp->args[i].type->print(s, tp->args[i].name,
|
|
data + tp->args[i].offset, field))
|
|
goto out;
|
|
|
|
trace_seq_putc(s, '\n');
|
|
|
|
out:
|
|
return trace_handle_return(s);
|
|
}
|
|
|
|
|
|
static int kprobe_event_define_fields(struct trace_event_call *event_call)
|
|
{
|
|
int ret, i;
|
|
struct kprobe_trace_entry_head field;
|
|
struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
|
|
|
|
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
|
|
/* Set argument names as fields */
|
|
for (i = 0; i < tk->tp.nr_args; i++) {
|
|
struct probe_arg *parg = &tk->tp.args[i];
|
|
|
|
ret = trace_define_field(event_call, parg->type->fmttype,
|
|
parg->name,
|
|
sizeof(field) + parg->offset,
|
|
parg->type->size,
|
|
parg->type->is_signed,
|
|
FILTER_OTHER);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int kretprobe_event_define_fields(struct trace_event_call *event_call)
|
|
{
|
|
int ret, i;
|
|
struct kretprobe_trace_entry_head field;
|
|
struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
|
|
|
|
DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
|
|
DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
|
|
/* Set argument names as fields */
|
|
for (i = 0; i < tk->tp.nr_args; i++) {
|
|
struct probe_arg *parg = &tk->tp.args[i];
|
|
|
|
ret = trace_define_field(event_call, parg->type->fmttype,
|
|
parg->name,
|
|
sizeof(field) + parg->offset,
|
|
parg->type->size,
|
|
parg->type->is_signed,
|
|
FILTER_OTHER);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
|
|
/* Kprobe profile handler */
|
|
static int
|
|
kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
|
|
{
|
|
struct trace_event_call *call = &tk->tp.call;
|
|
struct kprobe_trace_entry_head *entry;
|
|
struct hlist_head *head;
|
|
int size, __size, dsize;
|
|
int rctx;
|
|
|
|
if (bpf_prog_array_valid(call)) {
|
|
unsigned long orig_ip = instruction_pointer(regs);
|
|
int ret;
|
|
|
|
ret = trace_call_bpf(call, regs);
|
|
|
|
/*
|
|
* We need to check and see if we modified the pc of the
|
|
* pt_regs, and if so clear the kprobe and return 1 so that we
|
|
* don't do the single stepping.
|
|
* The ftrace kprobe handler leaves it up to us to re-enable
|
|
* preemption here before returning if we've modified the ip.
|
|
*/
|
|
if (orig_ip != instruction_pointer(regs)) {
|
|
reset_current_kprobe();
|
|
preempt_enable_no_resched();
|
|
return 1;
|
|
}
|
|
if (!ret)
|
|
return 0;
|
|
}
|
|
|
|
head = this_cpu_ptr(call->perf_events);
|
|
if (hlist_empty(head))
|
|
return 0;
|
|
|
|
dsize = __get_data_size(&tk->tp, regs);
|
|
__size = sizeof(*entry) + tk->tp.size + dsize;
|
|
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
|
size -= sizeof(u32);
|
|
|
|
entry = perf_trace_buf_alloc(size, NULL, &rctx);
|
|
if (!entry)
|
|
return 0;
|
|
|
|
entry->ip = (unsigned long)tk->rp.kp.addr;
|
|
memset(&entry[1], 0, dsize);
|
|
store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
|
|
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
|
|
head, NULL);
|
|
return 0;
|
|
}
|
|
NOKPROBE_SYMBOL(kprobe_perf_func);
|
|
|
|
/* Kretprobe profile handler */
|
|
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 kretprobe_trace_entry_head *entry;
|
|
struct hlist_head *head;
|
|
int size, __size, dsize;
|
|
int rctx;
|
|
|
|
if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
|
|
return;
|
|
|
|
head = this_cpu_ptr(call->perf_events);
|
|
if (hlist_empty(head))
|
|
return;
|
|
|
|
dsize = __get_data_size(&tk->tp, regs);
|
|
__size = sizeof(*entry) + tk->tp.size + dsize;
|
|
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
|
size -= sizeof(u32);
|
|
|
|
entry = perf_trace_buf_alloc(size, NULL, &rctx);
|
|
if (!entry)
|
|
return;
|
|
|
|
entry->func = (unsigned long)tk->rp.kp.addr;
|
|
entry->ret_ip = (unsigned long)ri->ret_addr;
|
|
store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
|
|
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
|
|
head, NULL);
|
|
}
|
|
NOKPROBE_SYMBOL(kretprobe_perf_func);
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
/*
|
|
* called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
|
|
*
|
|
* kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
|
|
* lockless, but we can't race with this __init function.
|
|
*/
|
|
static int kprobe_register(struct trace_event_call *event,
|
|
enum trace_reg type, void *data)
|
|
{
|
|
struct trace_kprobe *tk = (struct trace_kprobe *)event->data;
|
|
struct trace_event_file *file = data;
|
|
|
|
switch (type) {
|
|
case TRACE_REG_REGISTER:
|
|
return enable_trace_kprobe(tk, file);
|
|
case TRACE_REG_UNREGISTER:
|
|
return disable_trace_kprobe(tk, file);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
case TRACE_REG_PERF_REGISTER:
|
|
return enable_trace_kprobe(tk, NULL);
|
|
case TRACE_REG_PERF_UNREGISTER:
|
|
return disable_trace_kprobe(tk, NULL);
|
|
case TRACE_REG_PERF_OPEN:
|
|
case TRACE_REG_PERF_CLOSE:
|
|
case TRACE_REG_PERF_ADD:
|
|
case TRACE_REG_PERF_DEL:
|
|
return 0;
|
|
#endif
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
|
|
{
|
|
struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
|
|
int ret = 0;
|
|
|
|
raw_cpu_inc(*tk->nhit);
|
|
|
|
if (tk->tp.flags & TP_FLAG_TRACE)
|
|
kprobe_trace_func(tk, regs);
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tk->tp.flags & TP_FLAG_PROFILE)
|
|
ret = kprobe_perf_func(tk, regs);
|
|
#endif
|
|
return ret;
|
|
}
|
|
NOKPROBE_SYMBOL(kprobe_dispatcher);
|
|
|
|
static int
|
|
kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
|
|
{
|
|
struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
|
|
|
|
raw_cpu_inc(*tk->nhit);
|
|
|
|
if (tk->tp.flags & TP_FLAG_TRACE)
|
|
kretprobe_trace_func(tk, ri, regs);
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tk->tp.flags & TP_FLAG_PROFILE)
|
|
kretprobe_perf_func(tk, ri, regs);
|
|
#endif
|
|
return 0; /* We don't tweek kernel, so just return 0 */
|
|
}
|
|
NOKPROBE_SYMBOL(kretprobe_dispatcher);
|
|
|
|
static struct trace_event_functions kretprobe_funcs = {
|
|
.trace = print_kretprobe_event
|
|
};
|
|
|
|
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)
|
|
{
|
|
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;
|
|
} else {
|
|
call->event.funcs = &kprobe_funcs;
|
|
call->class->define_fields = kprobe_event_define_fields;
|
|
}
|
|
|
|
call->flags = TRACE_EVENT_FL_KPROBE;
|
|
call->class->reg = kprobe_register;
|
|
call->data = 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);
|
|
|
|
if (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);
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
/* create a trace_kprobe, but don't add it to global lists */
|
|
struct trace_event_call *
|
|
create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
|
|
bool is_return)
|
|
{
|
|
struct trace_kprobe *tk;
|
|
int ret;
|
|
char *event;
|
|
|
|
/*
|
|
* local trace_kprobes are not added to probe_list, so they are never
|
|
* searched in find_trace_kprobe(). Therefore, there is no concern of
|
|
* duplicated name here.
|
|
*/
|
|
event = func ? func : "DUMMY_EVENT";
|
|
|
|
tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
|
|
offs, 0 /* maxactive */, 0 /* nargs */,
|
|
is_return);
|
|
|
|
if (IS_ERR(tk)) {
|
|
pr_info("Failed to allocate trace_probe.(%d)\n",
|
|
(int)PTR_ERR(tk));
|
|
return ERR_CAST(tk);
|
|
}
|
|
|
|
init_trace_event_call(tk, &tk->tp.call);
|
|
|
|
if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
ret = __register_trace_kprobe(tk);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
return &tk->tp.call;
|
|
error:
|
|
free_trace_kprobe(tk);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
void destroy_local_trace_kprobe(struct trace_event_call *event_call)
|
|
{
|
|
struct trace_kprobe *tk;
|
|
|
|
tk = container_of(event_call, struct trace_kprobe, tp.call);
|
|
|
|
if (trace_probe_is_enabled(&tk->tp)) {
|
|
WARN_ON(1);
|
|
return;
|
|
}
|
|
|
|
__unregister_trace_kprobe(tk);
|
|
free_trace_kprobe(tk);
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
/* Make a tracefs interface for controlling probe points */
|
|
static __init int init_kprobe_trace(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
struct dentry *entry;
|
|
|
|
if (register_module_notifier(&trace_kprobe_module_nb))
|
|
return -EINVAL;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (IS_ERR(d_tracer))
|
|
return 0;
|
|
|
|
entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
|
|
NULL, &kprobe_events_ops);
|
|
|
|
/* Event list interface */
|
|
if (!entry)
|
|
pr_warn("Could not create tracefs 'kprobe_events' entry\n");
|
|
|
|
/* Profile interface */
|
|
entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
|
|
NULL, &kprobe_profile_ops);
|
|
|
|
if (!entry)
|
|
pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
|
|
return 0;
|
|
}
|
|
fs_initcall(init_kprobe_trace);
|
|
|
|
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
|
/*
|
|
* The "__used" keeps gcc from removing the function symbol
|
|
* from the kallsyms table. 'noinline' makes sure that there
|
|
* isn't an inlined version used by the test method below
|
|
*/
|
|
static __used __init noinline int
|
|
kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int a5, int a6)
|
|
{
|
|
return a1 + a2 + a3 + a4 + a5 + a6;
|
|
}
|
|
|
|
static __init struct trace_event_file *
|
|
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)
|
|
return file;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
|
|
* stage, we can do this lockless.
|
|
*/
|
|
static __init int kprobe_trace_self_tests_init(void)
|
|
{
|
|
int ret, warn = 0;
|
|
int (*target)(int, int, int, int, int, int);
|
|
struct trace_kprobe *tk;
|
|
struct trace_event_file *file;
|
|
|
|
if (tracing_is_disabled())
|
|
return -ENODEV;
|
|
|
|
target = kprobe_trace_selftest_target;
|
|
|
|
pr_info("Testing kprobe tracing: ");
|
|
|
|
ret = trace_run_command("p:testprobe kprobe_trace_selftest_target "
|
|
"$stack $stack0 +0($stack)",
|
|
create_trace_kprobe);
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warn("error on probing function entry.\n");
|
|
warn++;
|
|
} else {
|
|
/* Enable trace point */
|
|
tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tk == NULL)) {
|
|
pr_warn("error on getting new probe.\n");
|
|
warn++;
|
|
} else {
|
|
file = find_trace_probe_file(tk, top_trace_array());
|
|
if (WARN_ON_ONCE(file == NULL)) {
|
|
pr_warn("error on getting probe file.\n");
|
|
warn++;
|
|
} else
|
|
enable_trace_kprobe(tk, file);
|
|
}
|
|
}
|
|
|
|
ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target "
|
|
"$retval", create_trace_kprobe);
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warn("error on probing function return.\n");
|
|
warn++;
|
|
} else {
|
|
/* Enable trace point */
|
|
tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tk == NULL)) {
|
|
pr_warn("error on getting 2nd new probe.\n");
|
|
warn++;
|
|
} else {
|
|
file = find_trace_probe_file(tk, top_trace_array());
|
|
if (WARN_ON_ONCE(file == NULL)) {
|
|
pr_warn("error on getting probe file.\n");
|
|
warn++;
|
|
} else
|
|
enable_trace_kprobe(tk, file);
|
|
}
|
|
}
|
|
|
|
if (warn)
|
|
goto end;
|
|
|
|
ret = target(1, 2, 3, 4, 5, 6);
|
|
|
|
/*
|
|
* Not expecting an error here, the check is only to prevent the
|
|
* optimizer from removing the call to target() as otherwise there
|
|
* are no side-effects and the call is never performed.
|
|
*/
|
|
if (ret != 21)
|
|
warn++;
|
|
|
|
/* Disable trace points before removing it */
|
|
tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tk == NULL)) {
|
|
pr_warn("error on getting test probe.\n");
|
|
warn++;
|
|
} else {
|
|
if (trace_kprobe_nhit(tk) != 1) {
|
|
pr_warn("incorrect number of testprobe hits\n");
|
|
warn++;
|
|
}
|
|
|
|
file = find_trace_probe_file(tk, top_trace_array());
|
|
if (WARN_ON_ONCE(file == NULL)) {
|
|
pr_warn("error on getting probe file.\n");
|
|
warn++;
|
|
} else
|
|
disable_trace_kprobe(tk, file);
|
|
}
|
|
|
|
tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tk == NULL)) {
|
|
pr_warn("error on getting 2nd test probe.\n");
|
|
warn++;
|
|
} else {
|
|
if (trace_kprobe_nhit(tk) != 1) {
|
|
pr_warn("incorrect number of testprobe2 hits\n");
|
|
warn++;
|
|
}
|
|
|
|
file = find_trace_probe_file(tk, top_trace_array());
|
|
if (WARN_ON_ONCE(file == NULL)) {
|
|
pr_warn("error on getting probe file.\n");
|
|
warn++;
|
|
} else
|
|
disable_trace_kprobe(tk, file);
|
|
}
|
|
|
|
ret = trace_run_command("-:testprobe", create_trace_kprobe);
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warn("error on deleting a probe.\n");
|
|
warn++;
|
|
}
|
|
|
|
ret = trace_run_command("-:testprobe2", create_trace_kprobe);
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warn("error on deleting a probe.\n");
|
|
warn++;
|
|
}
|
|
|
|
end:
|
|
release_all_trace_kprobes();
|
|
/*
|
|
* Wait for the optimizer work to finish. Otherwise it might fiddle
|
|
* with probes in already freed __init text.
|
|
*/
|
|
wait_for_kprobe_optimizer();
|
|
if (warn)
|
|
pr_cont("NG: Some tests are failed. Please check them.\n");
|
|
else
|
|
pr_cont("OK\n");
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(kprobe_trace_self_tests_init);
|
|
|
|
#endif
|