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02ca1521ad
Fix kprobe-tracer not to delete a probe if the probe is in use. In that case, delete operation will return -EBUSY. This bug can cause a kernel panic if enabled probes are deleted during perf record. (Add some probes on functions) sh-4.2# perf probe --del probe:\* sh-4.2# exit (kernel panic) This is originally reported on the fedora bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=742383 I've also checked that this problem doesn't happen on tracepoints when module removing because perf event locks target module. $ sudo ./perf record -e xfs:\* -aR sh sh-4.2# rmmod xfs ERROR: Module xfs is in use sh-4.2# exit [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.203 MB perf.data (~8862 samples) ] Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: stable@kernel.org Link: http://lkml.kernel.org/r/20111004104438.14591.6553.stgit@fedora15 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2122 lines
53 KiB
C
2122 lines
53 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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#include <linux/module.h>
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#include <linux/uaccess.h>
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#include <linux/kprobes.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include <linux/smp.h>
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#include <linux/debugfs.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/ptrace.h>
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#include <linux/perf_event.h>
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#include <linux/stringify.h>
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#include <linux/limits.h>
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#include <asm/bitsperlong.h>
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#include "trace.h"
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#include "trace_output.h"
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#define MAX_TRACE_ARGS 128
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#define MAX_ARGSTR_LEN 63
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#define MAX_EVENT_NAME_LEN 64
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#define MAX_STRING_SIZE PATH_MAX
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#define KPROBE_EVENT_SYSTEM "kprobes"
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/* Reserved field names */
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#define FIELD_STRING_IP "__probe_ip"
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#define FIELD_STRING_RETIP "__probe_ret_ip"
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#define FIELD_STRING_FUNC "__probe_func"
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const char *reserved_field_names[] = {
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"common_type",
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"common_flags",
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"common_preempt_count",
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"common_pid",
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"common_tgid",
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FIELD_STRING_IP,
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FIELD_STRING_RETIP,
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FIELD_STRING_FUNC,
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};
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/* Printing function type */
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typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *,
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void *);
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#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
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#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
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/* Printing in basic type function template */
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#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
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static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
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const char *name, \
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void *data, void *ent)\
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{ \
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return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
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} \
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static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
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DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
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DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
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DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
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DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
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DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
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DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
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DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
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DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
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/* data_rloc: data relative location, compatible with u32 */
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#define make_data_rloc(len, roffs) \
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(((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
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#define get_rloc_len(dl) ((u32)(dl) >> 16)
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#define get_rloc_offs(dl) ((u32)(dl) & 0xffff)
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static inline void *get_rloc_data(u32 *dl)
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{
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return (u8 *)dl + get_rloc_offs(*dl);
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}
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/* For data_loc conversion */
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static inline void *get_loc_data(u32 *dl, void *ent)
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{
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return (u8 *)ent + get_rloc_offs(*dl);
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}
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/*
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* Convert data_rloc to data_loc:
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* data_rloc stores the offset from data_rloc itself, but data_loc
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* stores the offset from event entry.
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*/
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#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
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/* For defining macros, define string/string_size types */
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typedef u32 string;
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typedef u32 string_size;
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/* Print type function for string type */
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static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
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const char *name,
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void *data, void *ent)
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{
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int len = *(u32 *)data >> 16;
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if (!len)
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return trace_seq_printf(s, " %s=(fault)", name);
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else
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return trace_seq_printf(s, " %s=\"%s\"", name,
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(const char *)get_loc_data(data, ent));
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}
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static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
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/* Data fetch function type */
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typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
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struct fetch_param {
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fetch_func_t fn;
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void *data;
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};
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static __kprobes void call_fetch(struct fetch_param *fprm,
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struct pt_regs *regs, void *dest)
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{
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return fprm->fn(regs, fprm->data, dest);
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}
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#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
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/*
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* Define macro for basic types - we don't need to define s* types, because
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* we have to care only about bitwidth at recording time.
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*/
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#define DEFINE_BASIC_FETCH_FUNCS(method) \
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DEFINE_FETCH_##method(u8) \
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DEFINE_FETCH_##method(u16) \
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DEFINE_FETCH_##method(u32) \
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DEFINE_FETCH_##method(u64)
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#define CHECK_FETCH_FUNCS(method, fn) \
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(((FETCH_FUNC_NAME(method, u8) == fn) || \
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(FETCH_FUNC_NAME(method, u16) == fn) || \
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(FETCH_FUNC_NAME(method, u32) == fn) || \
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(FETCH_FUNC_NAME(method, u64) == fn) || \
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(FETCH_FUNC_NAME(method, string) == fn) || \
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(FETCH_FUNC_NAME(method, string_size) == fn)) \
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&& (fn != NULL))
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/* Data fetch function templates */
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#define DEFINE_FETCH_reg(type) \
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static __kprobes void FETCH_FUNC_NAME(reg, 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_register(regs, \
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(unsigned int)((unsigned long)offset)); \
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}
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DEFINE_BASIC_FETCH_FUNCS(reg)
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/* No string on the register */
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#define fetch_reg_string NULL
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#define fetch_reg_string_size NULL
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#define DEFINE_FETCH_stack(type) \
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static __kprobes 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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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_retval(type) \
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static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
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void *dummy, void *dest) \
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{ \
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*(type *)dest = (type)regs_return_value(regs); \
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}
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DEFINE_BASIC_FETCH_FUNCS(retval)
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/* No string on the retval */
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#define fetch_retval_string NULL
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#define fetch_retval_string_size NULL
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#define DEFINE_FETCH_memory(type) \
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static __kprobes 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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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 __kprobes 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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long ret;
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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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u8 *src = addr;
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mm_segment_t old_fs = get_fs();
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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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set_fs(KERNEL_DS);
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pagefault_disable();
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do
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ret = __copy_from_user_inatomic(dst++, src++, 1);
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while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
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dst[-1] = '\0';
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pagefault_enable();
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set_fs(old_fs);
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if (ret < 0) { /* Failed to fetch string */
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((u8 *)get_rloc_data(dest))[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(src - (u8 *)addr,
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get_rloc_offs(*(u32 *)dest));
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}
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/* Return the length of string -- including null terminal byte */
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static __kprobes 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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int ret, len = 0;
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u8 c;
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mm_segment_t 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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/* 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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static 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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static 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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static 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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#define DEFINE_FETCH_symbol(type) \
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static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
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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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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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/* Dereference memory access function */
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struct deref_fetch_param {
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struct fetch_param orig;
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long offset;
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};
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#define DEFINE_FETCH_deref(type) \
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static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
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void *data, void *dest) \
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{ \
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struct deref_fetch_param *dprm = data; \
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unsigned long addr; \
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call_fetch(&dprm->orig, regs, &addr); \
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if (addr) { \
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addr += dprm->offset; \
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fetch_memory_##type(regs, (void *)addr, dest); \
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} else \
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*(type *)dest = 0; \
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}
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DEFINE_BASIC_FETCH_FUNCS(deref)
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DEFINE_FETCH_deref(string)
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DEFINE_FETCH_deref(string_size)
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static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
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{
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if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
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update_deref_fetch_param(data->orig.data);
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else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
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update_symbol_cache(data->orig.data);
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}
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static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
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{
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if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
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free_deref_fetch_param(data->orig.data);
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else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
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free_symbol_cache(data->orig.data);
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kfree(data);
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}
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/* Bitfield fetch function */
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struct bitfield_fetch_param {
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struct fetch_param orig;
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unsigned char hi_shift;
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unsigned char low_shift;
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};
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#define DEFINE_FETCH_bitfield(type) \
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static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
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void *data, void *dest) \
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{ \
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struct bitfield_fetch_param *bprm = data; \
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type buf = 0; \
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call_fetch(&bprm->orig, regs, &buf); \
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if (buf) { \
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buf <<= bprm->hi_shift; \
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buf >>= bprm->low_shift; \
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} \
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*(type *)dest = buf; \
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}
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DEFINE_BASIC_FETCH_FUNCS(bitfield)
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#define fetch_bitfield_string NULL
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#define fetch_bitfield_string_size NULL
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static __kprobes void
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update_bitfield_fetch_param(struct bitfield_fetch_param *data)
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{
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/*
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* Don't check the bitfield itself, because this must be the
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* last fetch function.
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*/
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if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
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update_deref_fetch_param(data->orig.data);
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else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
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update_symbol_cache(data->orig.data);
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}
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static __kprobes void
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free_bitfield_fetch_param(struct bitfield_fetch_param *data)
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{
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/*
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* Don't check the bitfield itself, because this must be the
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* last fetch function.
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*/
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if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
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free_deref_fetch_param(data->orig.data);
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else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
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free_symbol_cache(data->orig.data);
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kfree(data);
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}
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/* Default (unsigned long) fetch type */
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#define __DEFAULT_FETCH_TYPE(t) u##t
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#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
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#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
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#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
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/* Fetch types */
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enum {
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FETCH_MTD_reg = 0,
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FETCH_MTD_stack,
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FETCH_MTD_retval,
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FETCH_MTD_memory,
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FETCH_MTD_symbol,
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FETCH_MTD_deref,
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FETCH_MTD_bitfield,
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FETCH_MTD_END,
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};
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#define ASSIGN_FETCH_FUNC(method, type) \
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[FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
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#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
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{.name = _name, \
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.size = _size, \
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.is_signed = sign, \
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.print = PRINT_TYPE_FUNC_NAME(ptype), \
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.fmt = PRINT_TYPE_FMT_NAME(ptype), \
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.fmttype = _fmttype, \
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.fetch = { \
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ASSIGN_FETCH_FUNC(reg, ftype), \
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ASSIGN_FETCH_FUNC(stack, ftype), \
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ASSIGN_FETCH_FUNC(retval, ftype), \
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ASSIGN_FETCH_FUNC(memory, ftype), \
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ASSIGN_FETCH_FUNC(symbol, ftype), \
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ASSIGN_FETCH_FUNC(deref, ftype), \
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ASSIGN_FETCH_FUNC(bitfield, ftype), \
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} \
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}
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#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
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__ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
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#define FETCH_TYPE_STRING 0
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#define FETCH_TYPE_STRSIZE 1
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/* Fetch type information table */
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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 */
|
|
const char *fmttype; /* Name in format file */
|
|
/* Fetch functions */
|
|
fetch_func_t fetch[FETCH_MTD_END];
|
|
} fetch_type_table[] = {
|
|
/* Special types */
|
|
[FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
|
|
sizeof(u32), 1, "__data_loc char[]"),
|
|
[FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
|
|
string_size, sizeof(u32), 0, "u32"),
|
|
/* Basic types */
|
|
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;
|
|
|
|
/* Special case: bitfield */
|
|
if (*type == 'b') {
|
|
unsigned long bs;
|
|
type = strchr(type, '/');
|
|
if (!type)
|
|
goto fail;
|
|
type++;
|
|
if (strict_strtoul(type, 0, &bs))
|
|
goto fail;
|
|
switch (bs) {
|
|
case 8:
|
|
return find_fetch_type("u8");
|
|
case 16:
|
|
return find_fetch_type("u16");
|
|
case 32:
|
|
return find_fetch_type("u32");
|
|
case 64:
|
|
return find_fetch_type("u64");
|
|
default:
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
|
|
if (strcmp(type, fetch_type_table[i].name) == 0)
|
|
return &fetch_type_table[i];
|
|
fail:
|
|
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);
|
|
}
|
|
|
|
static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
|
|
fetch_func_t orig_fn)
|
|
{
|
|
int i;
|
|
|
|
if (type != &fetch_type_table[FETCH_TYPE_STRING])
|
|
return NULL; /* Only string type needs size function */
|
|
for (i = 0; i < FETCH_MTD_END; i++)
|
|
if (type->fetch[i] == orig_fn)
|
|
return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
|
|
|
|
WARN_ON(1); /* This should not happen */
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* Kprobe event core functions
|
|
*/
|
|
|
|
struct probe_arg {
|
|
struct fetch_param fetch;
|
|
struct fetch_param fetch_size;
|
|
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
|
|
#define TP_FLAG_REGISTERED 4
|
|
|
|
struct trace_probe {
|
|
struct list_head list;
|
|
struct kretprobe rp; /* Use rp.kp for kprobe use */
|
|
unsigned long nhit;
|
|
unsigned int flags; /* For TP_FLAG_* */
|
|
const char *symbol; /* symbol name */
|
|
struct ftrace_event_class class;
|
|
struct ftrace_event_call call;
|
|
ssize_t size; /* trace entry size */
|
|
unsigned int nr_args;
|
|
struct probe_arg args[];
|
|
};
|
|
|
|
#define SIZEOF_TRACE_PROBE(n) \
|
|
(offsetof(struct trace_probe, args) + \
|
|
(sizeof(struct probe_arg) * (n)))
|
|
|
|
|
|
static __kprobes int trace_probe_is_return(struct trace_probe *tp)
|
|
{
|
|
return tp->rp.handler != NULL;
|
|
}
|
|
|
|
static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
|
|
{
|
|
return tp->symbol ? tp->symbol : "unknown";
|
|
}
|
|
|
|
static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
|
|
{
|
|
return tp->rp.kp.offset;
|
|
}
|
|
|
|
static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
|
|
{
|
|
return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
|
|
}
|
|
|
|
static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
|
|
{
|
|
return !!(tp->flags & TP_FLAG_REGISTERED);
|
|
}
|
|
|
|
static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
|
|
{
|
|
return !!(kprobe_gone(&tp->rp.kp));
|
|
}
|
|
|
|
static __kprobes bool trace_probe_within_module(struct trace_probe *tp,
|
|
struct module *mod)
|
|
{
|
|
int len = strlen(mod->name);
|
|
const char *name = trace_probe_symbol(tp);
|
|
return strncmp(mod->name, name, len) == 0 && name[len] == ':';
|
|
}
|
|
|
|
static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
|
|
{
|
|
return !!strchr(trace_probe_symbol(tp), ':');
|
|
}
|
|
|
|
static int register_probe_event(struct trace_probe *tp);
|
|
static void unregister_probe_event(struct trace_probe *tp);
|
|
|
|
static DEFINE_MUTEX(probe_lock);
|
|
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/fields */
|
|
static int is_good_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).
|
|
*/
|
|
static struct trace_probe *alloc_trace_probe(const char *group,
|
|
const char *event,
|
|
void *addr,
|
|
const char *symbol,
|
|
unsigned long offs,
|
|
int nargs, int is_return)
|
|
{
|
|
struct trace_probe *tp;
|
|
int ret = -ENOMEM;
|
|
|
|
tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
|
|
if (!tp)
|
|
return ERR_PTR(ret);
|
|
|
|
if (symbol) {
|
|
tp->symbol = kstrdup(symbol, GFP_KERNEL);
|
|
if (!tp->symbol)
|
|
goto error;
|
|
tp->rp.kp.symbol_name = tp->symbol;
|
|
tp->rp.kp.offset = offs;
|
|
} else
|
|
tp->rp.kp.addr = addr;
|
|
|
|
if (is_return)
|
|
tp->rp.handler = kretprobe_dispatcher;
|
|
else
|
|
tp->rp.kp.pre_handler = kprobe_dispatcher;
|
|
|
|
if (!event || !is_good_name(event)) {
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
tp->call.class = &tp->class;
|
|
tp->call.name = kstrdup(event, GFP_KERNEL);
|
|
if (!tp->call.name)
|
|
goto error;
|
|
|
|
if (!group || !is_good_name(group)) {
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
tp->class.system = kstrdup(group, GFP_KERNEL);
|
|
if (!tp->class.system)
|
|
goto error;
|
|
|
|
INIT_LIST_HEAD(&tp->list);
|
|
return tp;
|
|
error:
|
|
kfree(tp->call.name);
|
|
kfree(tp->symbol);
|
|
kfree(tp);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static void update_probe_arg(struct probe_arg *arg)
|
|
{
|
|
if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
|
|
update_bitfield_fetch_param(arg->fetch.data);
|
|
else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
|
|
update_deref_fetch_param(arg->fetch.data);
|
|
else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
|
|
update_symbol_cache(arg->fetch.data);
|
|
}
|
|
|
|
static void free_probe_arg(struct probe_arg *arg)
|
|
{
|
|
if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
|
|
free_bitfield_fetch_param(arg->fetch.data);
|
|
else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
|
|
free_deref_fetch_param(arg->fetch.data);
|
|
else if (CHECK_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]);
|
|
|
|
kfree(tp->call.class->system);
|
|
kfree(tp->call.name);
|
|
kfree(tp->symbol);
|
|
kfree(tp);
|
|
}
|
|
|
|
static struct trace_probe *find_trace_probe(const char *event,
|
|
const char *group)
|
|
{
|
|
struct trace_probe *tp;
|
|
|
|
list_for_each_entry(tp, &probe_list, list)
|
|
if (strcmp(tp->call.name, event) == 0 &&
|
|
strcmp(tp->call.class->system, group) == 0)
|
|
return tp;
|
|
return NULL;
|
|
}
|
|
|
|
/* Enable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
|
|
static int enable_trace_probe(struct trace_probe *tp, int flag)
|
|
{
|
|
int ret = 0;
|
|
|
|
tp->flags |= flag;
|
|
if (trace_probe_is_enabled(tp) && trace_probe_is_registered(tp) &&
|
|
!trace_probe_has_gone(tp)) {
|
|
if (trace_probe_is_return(tp))
|
|
ret = enable_kretprobe(&tp->rp);
|
|
else
|
|
ret = enable_kprobe(&tp->rp.kp);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Disable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
|
|
static void disable_trace_probe(struct trace_probe *tp, int flag)
|
|
{
|
|
tp->flags &= ~flag;
|
|
if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) {
|
|
if (trace_probe_is_return(tp))
|
|
disable_kretprobe(&tp->rp);
|
|
else
|
|
disable_kprobe(&tp->rp.kp);
|
|
}
|
|
}
|
|
|
|
/* Internal register function - just handle k*probes and flags */
|
|
static int __register_trace_probe(struct trace_probe *tp)
|
|
{
|
|
int i, ret;
|
|
|
|
if (trace_probe_is_registered(tp))
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
update_probe_arg(&tp->args[i]);
|
|
|
|
/* Set/clear disabled flag according to tp->flag */
|
|
if (trace_probe_is_enabled(tp))
|
|
tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
|
|
else
|
|
tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
|
|
|
|
if (trace_probe_is_return(tp))
|
|
ret = register_kretprobe(&tp->rp);
|
|
else
|
|
ret = register_kprobe(&tp->rp.kp);
|
|
|
|
if (ret == 0)
|
|
tp->flags |= TP_FLAG_REGISTERED;
|
|
else {
|
|
pr_warning("Could not insert probe at %s+%lu: %d\n",
|
|
trace_probe_symbol(tp), trace_probe_offset(tp), ret);
|
|
if (ret == -ENOENT && trace_probe_is_on_module(tp)) {
|
|
pr_warning("This probe might be able to register after"
|
|
"target module is loaded. Continue.\n");
|
|
ret = 0;
|
|
} else if (ret == -EILSEQ) {
|
|
pr_warning("Probing address(0x%p) is not an "
|
|
"instruction boundary.\n",
|
|
tp->rp.kp.addr);
|
|
ret = -EINVAL;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Internal unregister function - just handle k*probes and flags */
|
|
static void __unregister_trace_probe(struct trace_probe *tp)
|
|
{
|
|
if (trace_probe_is_registered(tp)) {
|
|
if (trace_probe_is_return(tp))
|
|
unregister_kretprobe(&tp->rp);
|
|
else
|
|
unregister_kprobe(&tp->rp.kp);
|
|
tp->flags &= ~TP_FLAG_REGISTERED;
|
|
/* Cleanup kprobe for reuse */
|
|
if (tp->rp.kp.symbol_name)
|
|
tp->rp.kp.addr = NULL;
|
|
}
|
|
}
|
|
|
|
/* Unregister a trace_probe and probe_event: call with locking probe_lock */
|
|
static int unregister_trace_probe(struct trace_probe *tp)
|
|
{
|
|
/* Enabled event can not be unregistered */
|
|
if (trace_probe_is_enabled(tp))
|
|
return -EBUSY;
|
|
|
|
__unregister_trace_probe(tp);
|
|
list_del(&tp->list);
|
|
unregister_probe_event(tp);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Register a trace_probe and probe_event */
|
|
static int register_trace_probe(struct trace_probe *tp)
|
|
{
|
|
struct trace_probe *old_tp;
|
|
int ret;
|
|
|
|
mutex_lock(&probe_lock);
|
|
|
|
/* Delete old (same name) event if exist */
|
|
old_tp = find_trace_probe(tp->call.name, tp->call.class->system);
|
|
if (old_tp) {
|
|
ret = unregister_trace_probe(old_tp);
|
|
if (ret < 0)
|
|
goto end;
|
|
free_trace_probe(old_tp);
|
|
}
|
|
|
|
/* Register new event */
|
|
ret = register_probe_event(tp);
|
|
if (ret) {
|
|
pr_warning("Failed to register probe event(%d)\n", ret);
|
|
goto end;
|
|
}
|
|
|
|
/* Register k*probe */
|
|
ret = __register_trace_probe(tp);
|
|
if (ret < 0)
|
|
unregister_probe_event(tp);
|
|
else
|
|
list_add_tail(&tp->list, &probe_list);
|
|
|
|
end:
|
|
mutex_unlock(&probe_lock);
|
|
return ret;
|
|
}
|
|
|
|
/* Module notifier call back, checking event on the module */
|
|
static int trace_probe_module_callback(struct notifier_block *nb,
|
|
unsigned long val, void *data)
|
|
{
|
|
struct module *mod = data;
|
|
struct trace_probe *tp;
|
|
int ret;
|
|
|
|
if (val != MODULE_STATE_COMING)
|
|
return NOTIFY_DONE;
|
|
|
|
/* Update probes on coming module */
|
|
mutex_lock(&probe_lock);
|
|
list_for_each_entry(tp, &probe_list, list) {
|
|
if (trace_probe_within_module(tp, mod)) {
|
|
/* Don't need to check busy - this should have gone. */
|
|
__unregister_trace_probe(tp);
|
|
ret = __register_trace_probe(tp);
|
|
if (ret)
|
|
pr_warning("Failed to re-register probe %s on"
|
|
"%s: %d\n",
|
|
tp->call.name, mod->name, ret);
|
|
}
|
|
}
|
|
mutex_unlock(&probe_lock);
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block trace_probe_module_nb = {
|
|
.notifier_call = trace_probe_module_callback,
|
|
.priority = 1 /* Invoked after kprobe module callback */
|
|
};
|
|
|
|
/* 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->fetch[FETCH_MTD_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->fetch[FETCH_MTD_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->fetch[FETCH_MTD_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->fetch[FETCH_MTD_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->fetch[FETCH_MTD_symbol];
|
|
}
|
|
break;
|
|
case '+': /* deref memory */
|
|
arg++; /* Skip '+', because strict_strtol() rejects it. */
|
|
case '-':
|
|
tmp = strchr(arg, '(');
|
|
if (!tmp)
|
|
break;
|
|
*tmp = '\0';
|
|
ret = strict_strtol(arg, 0, &offset);
|
|
if (ret)
|
|
break;
|
|
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->fetch[FETCH_MTD_deref];
|
|
f->data = (void *)dprm;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
|
|
pr_info("%s type has no corresponding fetch method.\n",
|
|
t->name);
|
|
ret = -EINVAL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
|
|
|
|
/* Bitfield type needs to be parsed into a fetch function */
|
|
static int __parse_bitfield_probe_arg(const char *bf,
|
|
const struct fetch_type *t,
|
|
struct fetch_param *f)
|
|
{
|
|
struct bitfield_fetch_param *bprm;
|
|
unsigned long bw, bo;
|
|
char *tail;
|
|
|
|
if (*bf != 'b')
|
|
return 0;
|
|
|
|
bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
|
|
if (!bprm)
|
|
return -ENOMEM;
|
|
bprm->orig = *f;
|
|
f->fn = t->fetch[FETCH_MTD_bitfield];
|
|
f->data = (void *)bprm;
|
|
|
|
bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
|
|
if (bw == 0 || *tail != '@')
|
|
return -EINVAL;
|
|
|
|
bf = tail + 1;
|
|
bo = simple_strtoul(bf, &tail, 0);
|
|
if (tail == bf || *tail != '/')
|
|
return -EINVAL;
|
|
|
|
bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
|
|
bprm->low_shift = bprm->hi_shift + bo;
|
|
return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
|
|
}
|
|
|
|
/* 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;
|
|
int ret;
|
|
|
|
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;
|
|
ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
|
|
if (ret >= 0 && t != NULL)
|
|
ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
|
|
if (ret >= 0) {
|
|
parg->fetch_size.fn = get_fetch_size_function(parg->type,
|
|
parg->fetch.fn);
|
|
parg->fetch_size.data = parg->fetch.data;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
/*
|
|
* Argument syntax:
|
|
* - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
|
|
* - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
|
|
* Fetch args:
|
|
* $retval : fetch return value
|
|
* $stack : fetch stack address
|
|
* $stackN : fetch Nth of stack (N:0-)
|
|
* @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_probe *tp;
|
|
int i, ret = 0;
|
|
int is_return = 0, is_delete = 0;
|
|
char *symbol = NULL, *event = NULL, *group = NULL;
|
|
char *arg;
|
|
unsigned long offset = 0;
|
|
void *addr = NULL;
|
|
char buf[MAX_EVENT_NAME_LEN];
|
|
|
|
/* argc must be >= 1 */
|
|
if (argv[0][0] == 'p')
|
|
is_return = 0;
|
|
else if (argv[0][0] == 'r')
|
|
is_return = 1;
|
|
else if (argv[0][0] == '-')
|
|
is_delete = 1;
|
|
else {
|
|
pr_info("Probe definition must be started with 'p', 'r' or"
|
|
" '-'.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (argv[0][1] == ':') {
|
|
event = &argv[0][2];
|
|
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);
|
|
tp = find_trace_probe(event, group);
|
|
if (!tp) {
|
|
mutex_unlock(&probe_lock);
|
|
pr_info("Event %s/%s doesn't exist.\n", group, event);
|
|
return -ENOENT;
|
|
}
|
|
/* delete an event */
|
|
ret = unregister_trace_probe(tp);
|
|
if (ret == 0)
|
|
free_trace_probe(tp);
|
|
mutex_unlock(&probe_lock);
|
|
return ret;
|
|
}
|
|
|
|
if (argc < 2) {
|
|
pr_info("Probe point is not specified.\n");
|
|
return -EINVAL;
|
|
}
|
|
if (isdigit(argv[1][0])) {
|
|
if (is_return) {
|
|
pr_info("Return probe point must be a symbol.\n");
|
|
return -EINVAL;
|
|
}
|
|
/* an address specified */
|
|
ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
|
|
if (ret) {
|
|
pr_info("Failed to parse address.\n");
|
|
return ret;
|
|
}
|
|
} else {
|
|
/* a symbol specified */
|
|
symbol = argv[1];
|
|
/* TODO: support .init module functions */
|
|
ret = split_symbol_offset(symbol, &offset);
|
|
if (ret) {
|
|
pr_info("Failed to parse symbol.\n");
|
|
return ret;
|
|
}
|
|
if (offset && is_return) {
|
|
pr_info("Return probe must be used without offset.\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);
|
|
event = buf;
|
|
}
|
|
tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
|
|
is_return);
|
|
if (IS_ERR(tp)) {
|
|
pr_info("Failed to allocate trace_probe.(%d)\n",
|
|
(int)PTR_ERR(tp));
|
|
return PTR_ERR(tp);
|
|
}
|
|
|
|
/* parse arguments */
|
|
ret = 0;
|
|
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
|
|
/* Increment count for freeing args in error case */
|
|
tp->nr_args++;
|
|
|
|
/* Parse argument name */
|
|
arg = strchr(argv[i], '=');
|
|
if (arg) {
|
|
*arg++ = '\0';
|
|
tp->args[i].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);
|
|
tp->args[i].name = kstrdup(buf, GFP_KERNEL);
|
|
}
|
|
|
|
if (!tp->args[i].name) {
|
|
pr_info("Failed to allocate argument[%d] name.\n", i);
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
if (!is_good_name(tp->args[i].name)) {
|
|
pr_info("Invalid argument[%d] name: %s\n",
|
|
i, tp->args[i].name);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
if (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;
|
|
goto error;
|
|
}
|
|
|
|
/* Parse fetch argument */
|
|
ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
|
|
if (ret) {
|
|
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
ret = register_trace_probe(tp);
|
|
if (ret)
|
|
goto error;
|
|
return 0;
|
|
|
|
error:
|
|
free_trace_probe(tp);
|
|
return ret;
|
|
}
|
|
|
|
static int release_all_trace_probes(void)
|
|
{
|
|
struct trace_probe *tp;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&probe_lock);
|
|
/* Ensure no probe is in use. */
|
|
list_for_each_entry(tp, &probe_list, list)
|
|
if (trace_probe_is_enabled(tp)) {
|
|
ret = -EBUSY;
|
|
goto end;
|
|
}
|
|
/* TODO: Use batch unregistration */
|
|
while (!list_empty(&probe_list)) {
|
|
tp = list_entry(probe_list.next, struct trace_probe, list);
|
|
unregister_trace_probe(tp);
|
|
free_trace_probe(tp);
|
|
}
|
|
|
|
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_probe *tp = v;
|
|
int i;
|
|
|
|
seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p');
|
|
seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
|
|
|
|
if (!tp->symbol)
|
|
seq_printf(m, " 0x%p", tp->rp.kp.addr);
|
|
else if (tp->rp.kp.offset)
|
|
seq_printf(m, " %s+%u", trace_probe_symbol(tp),
|
|
tp->rp.kp.offset);
|
|
else
|
|
seq_printf(m, " %s", trace_probe_symbol(tp));
|
|
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
|
|
seq_printf(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_probes();
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
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 4096
|
|
|
|
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;
|
|
}
|
|
|
|
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_probe *tp = v;
|
|
|
|
seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
|
|
tp->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,
|
|
};
|
|
|
|
/* Sum up total data length for dynamic arraies (strings) */
|
|
static __kprobes int __get_data_size(struct trace_probe *tp,
|
|
struct pt_regs *regs)
|
|
{
|
|
int i, ret = 0;
|
|
u32 len;
|
|
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
if (unlikely(tp->args[i].fetch_size.fn)) {
|
|
call_fetch(&tp->args[i].fetch_size, regs, &len);
|
|
ret += len;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Store the value of each argument */
|
|
static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
|
|
struct pt_regs *regs,
|
|
u8 *data, int maxlen)
|
|
{
|
|
int i;
|
|
u32 end = tp->size;
|
|
u32 *dl; /* Data (relative) location */
|
|
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
if (unlikely(tp->args[i].fetch_size.fn)) {
|
|
/*
|
|
* First, we set the relative location and
|
|
* maximum data length to *dl
|
|
*/
|
|
dl = (u32 *)(data + tp->args[i].offset);
|
|
*dl = make_data_rloc(maxlen, end - tp->args[i].offset);
|
|
/* Then try to fetch string or dynamic array data */
|
|
call_fetch(&tp->args[i].fetch, regs, dl);
|
|
/* Reduce maximum length */
|
|
end += get_rloc_len(*dl);
|
|
maxlen -= get_rloc_len(*dl);
|
|
/* Trick here, convert data_rloc to data_loc */
|
|
*dl = convert_rloc_to_loc(*dl,
|
|
ent_size + tp->args[i].offset);
|
|
} else
|
|
/* Just fetching data normally */
|
|
call_fetch(&tp->args[i].fetch, regs,
|
|
data + tp->args[i].offset);
|
|
}
|
|
}
|
|
|
|
/* Kprobe handler */
|
|
static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
|
|
struct kprobe_trace_entry_head *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
int size, dsize, pc;
|
|
unsigned long irq_flags;
|
|
struct ftrace_event_call *call = &tp->call;
|
|
|
|
tp->nhit++;
|
|
|
|
local_save_flags(irq_flags);
|
|
pc = preempt_count();
|
|
|
|
dsize = __get_data_size(tp, regs);
|
|
size = sizeof(*entry) + tp->size + dsize;
|
|
|
|
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
|
|
size, irq_flags, pc);
|
|
if (!event)
|
|
return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->ip = (unsigned long)kp->addr;
|
|
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
|
|
|
|
if (!filter_current_check_discard(buffer, call, entry, event))
|
|
trace_nowake_buffer_unlock_commit_regs(buffer, event,
|
|
irq_flags, pc, regs);
|
|
}
|
|
|
|
/* Kretprobe handler */
|
|
static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
|
|
struct kretprobe_trace_entry_head *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
int size, pc, dsize;
|
|
unsigned long irq_flags;
|
|
struct ftrace_event_call *call = &tp->call;
|
|
|
|
local_save_flags(irq_flags);
|
|
pc = preempt_count();
|
|
|
|
dsize = __get_data_size(tp, regs);
|
|
size = sizeof(*entry) + tp->size + dsize;
|
|
|
|
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
|
|
size, irq_flags, pc);
|
|
if (!event)
|
|
return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->func = (unsigned long)tp->rp.kp.addr;
|
|
entry->ret_ip = (unsigned long)ri->ret_addr;
|
|
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
|
|
|
|
if (!filter_current_check_discard(buffer, call, entry, event))
|
|
trace_nowake_buffer_unlock_commit_regs(buffer, event,
|
|
irq_flags, pc, regs);
|
|
}
|
|
|
|
/* Event entry printers */
|
|
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);
|
|
|
|
if (!trace_seq_printf(s, "%s: (", tp->call.name))
|
|
goto partial;
|
|
|
|
if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, ")"))
|
|
goto partial;
|
|
|
|
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 partial;
|
|
|
|
if (!trace_seq_puts(s, "\n"))
|
|
goto partial;
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
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);
|
|
|
|
if (!trace_seq_printf(s, "%s: (", tp->call.name))
|
|
goto partial;
|
|
|
|
if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, " <- "))
|
|
goto partial;
|
|
|
|
if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, ")"))
|
|
goto partial;
|
|
|
|
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 partial;
|
|
|
|
if (!trace_seq_puts(s, "\n"))
|
|
goto partial;
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
#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;
|
|
struct kprobe_trace_entry_head field;
|
|
struct trace_probe *tp = (struct trace_probe *)event_call->data;
|
|
|
|
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
|
|
/* Set argument names as fields */
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
ret = trace_define_field(event_call, tp->args[i].type->fmttype,
|
|
tp->args[i].name,
|
|
sizeof(field) + tp->args[i].offset,
|
|
tp->args[i].type->size,
|
|
tp->args[i].type->is_signed,
|
|
FILTER_OTHER);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
|
|
{
|
|
int ret, i;
|
|
struct kretprobe_trace_entry_head field;
|
|
struct trace_probe *tp = (struct trace_probe *)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 < tp->nr_args; i++) {
|
|
ret = trace_define_field(event_call, tp->args[i].type->fmttype,
|
|
tp->args[i].name,
|
|
sizeof(field) + tp->args[i].offset,
|
|
tp->args[i].type->size,
|
|
tp->args[i].type->is_signed,
|
|
FILTER_OTHER);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
|
|
{
|
|
int i;
|
|
int pos = 0;
|
|
|
|
const char *fmt, *arg;
|
|
|
|
if (!trace_probe_is_return(tp)) {
|
|
fmt = "(%lx)";
|
|
arg = "REC->" FIELD_STRING_IP;
|
|
} else {
|
|
fmt = "(%lx <- %lx)";
|
|
arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
|
|
}
|
|
|
|
/* When len=0, we just calculate the needed length */
|
|
#define LEN_OR_ZERO (len ? len - pos : 0)
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
|
|
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
|
|
tp->args[i].name, tp->args[i].type->fmt);
|
|
}
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
|
|
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
if (strcmp(tp->args[i].type->name, "string") == 0)
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO,
|
|
", __get_str(%s)",
|
|
tp->args[i].name);
|
|
else
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
|
|
tp->args[i].name);
|
|
}
|
|
|
|
#undef LEN_OR_ZERO
|
|
|
|
/* return the length of print_fmt */
|
|
return pos;
|
|
}
|
|
|
|
static int set_print_fmt(struct trace_probe *tp)
|
|
{
|
|
int len;
|
|
char *print_fmt;
|
|
|
|
/* First: called with 0 length to calculate the needed length */
|
|
len = __set_print_fmt(tp, NULL, 0);
|
|
print_fmt = kmalloc(len + 1, GFP_KERNEL);
|
|
if (!print_fmt)
|
|
return -ENOMEM;
|
|
|
|
/* Second: actually write the @print_fmt */
|
|
__set_print_fmt(tp, print_fmt, len + 1);
|
|
tp->call.print_fmt = print_fmt;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
|
|
/* Kprobe profile handler */
|
|
static __kprobes void kprobe_perf_func(struct kprobe *kp,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
|
|
struct ftrace_event_call *call = &tp->call;
|
|
struct kprobe_trace_entry_head *entry;
|
|
struct hlist_head *head;
|
|
int size, __size, dsize;
|
|
int rctx;
|
|
|
|
dsize = __get_data_size(tp, regs);
|
|
__size = sizeof(*entry) + tp->size + dsize;
|
|
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
|
size -= sizeof(u32);
|
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
|
|
"profile buffer not large enough"))
|
|
return;
|
|
|
|
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
|
|
if (!entry)
|
|
return;
|
|
|
|
entry->ip = (unsigned long)kp->addr;
|
|
memset(&entry[1], 0, dsize);
|
|
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
|
|
|
|
head = this_cpu_ptr(call->perf_events);
|
|
perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
|
|
}
|
|
|
|
/* Kretprobe profile handler */
|
|
static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
|
|
struct ftrace_event_call *call = &tp->call;
|
|
struct kretprobe_trace_entry_head *entry;
|
|
struct hlist_head *head;
|
|
int size, __size, dsize;
|
|
int rctx;
|
|
|
|
dsize = __get_data_size(tp, regs);
|
|
__size = sizeof(*entry) + tp->size + dsize;
|
|
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
|
size -= sizeof(u32);
|
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
|
|
"profile buffer not large enough"))
|
|
return;
|
|
|
|
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
|
|
if (!entry)
|
|
return;
|
|
|
|
entry->func = (unsigned long)tp->rp.kp.addr;
|
|
entry->ret_ip = (unsigned long)ri->ret_addr;
|
|
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
|
|
|
|
head = this_cpu_ptr(call->perf_events);
|
|
perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
static __kprobes
|
|
int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)
|
|
{
|
|
struct trace_probe *tp = (struct trace_probe *)event->data;
|
|
|
|
switch (type) {
|
|
case TRACE_REG_REGISTER:
|
|
return enable_trace_probe(tp, TP_FLAG_TRACE);
|
|
case TRACE_REG_UNREGISTER:
|
|
disable_trace_probe(tp, TP_FLAG_TRACE);
|
|
return 0;
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
case TRACE_REG_PERF_REGISTER:
|
|
return enable_trace_probe(tp, TP_FLAG_PROFILE);
|
|
case TRACE_REG_PERF_UNREGISTER:
|
|
disable_trace_probe(tp, TP_FLAG_PROFILE);
|
|
return 0;
|
|
#endif
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static __kprobes
|
|
int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
|
|
|
|
if (tp->flags & TP_FLAG_TRACE)
|
|
kprobe_trace_func(kp, regs);
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tp->flags & TP_FLAG_PROFILE)
|
|
kprobe_perf_func(kp, regs);
|
|
#endif
|
|
return 0; /* We don't tweek kernel, so just return 0 */
|
|
}
|
|
|
|
static __kprobes
|
|
int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
|
|
|
|
if (tp->flags & TP_FLAG_TRACE)
|
|
kretprobe_trace_func(ri, regs);
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tp->flags & TP_FLAG_PROFILE)
|
|
kretprobe_perf_func(ri, regs);
|
|
#endif
|
|
return 0; /* We don't tweek kernel, so just return 0 */
|
|
}
|
|
|
|
static struct trace_event_functions kretprobe_funcs = {
|
|
.trace = print_kretprobe_event
|
|
};
|
|
|
|
static struct trace_event_functions kprobe_funcs = {
|
|
.trace = print_kprobe_event
|
|
};
|
|
|
|
static int register_probe_event(struct trace_probe *tp)
|
|
{
|
|
struct ftrace_event_call *call = &tp->call;
|
|
int ret;
|
|
|
|
/* Initialize ftrace_event_call */
|
|
INIT_LIST_HEAD(&call->class->fields);
|
|
if (trace_probe_is_return(tp)) {
|
|
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;
|
|
}
|
|
if (set_print_fmt(tp) < 0)
|
|
return -ENOMEM;
|
|
ret = register_ftrace_event(&call->event);
|
|
if (!ret) {
|
|
kfree(call->print_fmt);
|
|
return -ENODEV;
|
|
}
|
|
call->flags = 0;
|
|
call->class->reg = kprobe_register;
|
|
call->data = tp;
|
|
ret = trace_add_event_call(call);
|
|
if (ret) {
|
|
pr_info("Failed to register kprobe event: %s\n", call->name);
|
|
kfree(call->print_fmt);
|
|
unregister_ftrace_event(&call->event);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void unregister_probe_event(struct trace_probe *tp)
|
|
{
|
|
/* tp->event is unregistered in trace_remove_event_call() */
|
|
trace_remove_event_call(&tp->call);
|
|
kfree(tp->call.print_fmt);
|
|
}
|
|
|
|
/* Make a debugfs interface for controlling probe points */
|
|
static __init int init_kprobe_trace(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
struct dentry *entry;
|
|
|
|
if (register_module_notifier(&trace_probe_module_nb))
|
|
return -EINVAL;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return 0;
|
|
|
|
entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
|
|
NULL, &kprobe_events_ops);
|
|
|
|
/* Event list interface */
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'kprobe_events' entry\n");
|
|
|
|
/* Profile interface */
|
|
entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
|
|
NULL, &kprobe_profile_ops);
|
|
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'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.
|
|
*/
|
|
static __used 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 int kprobe_trace_self_tests_init(void)
|
|
{
|
|
int ret, warn = 0;
|
|
int (*target)(int, int, int, int, int, int);
|
|
struct trace_probe *tp;
|
|
|
|
target = kprobe_trace_selftest_target;
|
|
|
|
pr_info("Testing kprobe tracing: ");
|
|
|
|
ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
|
|
"$stack $stack0 +0($stack)");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on probing function entry.\n");
|
|
warn++;
|
|
} else {
|
|
/* Enable trace point */
|
|
tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tp == NULL)) {
|
|
pr_warning("error on getting new probe.\n");
|
|
warn++;
|
|
} else
|
|
enable_trace_probe(tp, TP_FLAG_TRACE);
|
|
}
|
|
|
|
ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
|
|
"$retval");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on probing function return.\n");
|
|
warn++;
|
|
} else {
|
|
/* Enable trace point */
|
|
tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tp == NULL)) {
|
|
pr_warning("error on getting new probe.\n");
|
|
warn++;
|
|
} else
|
|
enable_trace_probe(tp, TP_FLAG_TRACE);
|
|
}
|
|
|
|
if (warn)
|
|
goto end;
|
|
|
|
ret = target(1, 2, 3, 4, 5, 6);
|
|
|
|
/* Disable trace points before removing it */
|
|
tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tp == NULL)) {
|
|
pr_warning("error on getting test probe.\n");
|
|
warn++;
|
|
} else
|
|
disable_trace_probe(tp, TP_FLAG_TRACE);
|
|
|
|
tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tp == NULL)) {
|
|
pr_warning("error on getting 2nd test probe.\n");
|
|
warn++;
|
|
} else
|
|
disable_trace_probe(tp, TP_FLAG_TRACE);
|
|
|
|
ret = command_trace_probe("-:testprobe");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on deleting a probe.\n");
|
|
warn++;
|
|
}
|
|
|
|
ret = command_trace_probe("-:testprobe2");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on deleting a probe.\n");
|
|
warn++;
|
|
}
|
|
|
|
end:
|
|
release_all_trace_probes();
|
|
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
|