#include <linux/ptrace.h>
#include <linux/perf_event.h>
#include <linux/stringify.h>
+#include <linux/limits.h>
+#include <linux/uaccess.h>
#include <asm/bitsperlong.h>
#include "trace.h"
#define MAX_TRACE_ARGS 128
#define MAX_ARGSTR_LEN 63
#define MAX_EVENT_NAME_LEN 64
+#define MAX_STRING_SIZE PATH_MAX
#define KPROBE_EVENT_SYSTEM "kprobes"
/* Reserved field names */
};
/* Printing function type */
-typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *);
+typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *,
+ void *);
#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
/* Printing in basic type function template */
#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
- const char *name, void *data)\
+ const char *name, \
+ void *data, void *ent)\
{ \
return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
} \
DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
+/* data_rloc: data relative location, compatible with u32 */
+#define make_data_rloc(len, roffs) \
+ (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
+#define get_rloc_len(dl) ((u32)(dl) >> 16)
+#define get_rloc_offs(dl) ((u32)(dl) & 0xffff)
+
+static inline void *get_rloc_data(u32 *dl)
+{
+ return (u8 *)dl + get_rloc_offs(*dl);
+}
+
+/* For data_loc conversion */
+static inline void *get_loc_data(u32 *dl, void *ent)
+{
+ return (u8 *)ent + get_rloc_offs(*dl);
+}
+
+/*
+ * Convert data_rloc to data_loc:
+ * data_rloc stores the offset from data_rloc itself, but data_loc
+ * stores the offset from event entry.
+ */
+#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
+
+/* For defining macros, define string/string_size types */
+typedef u32 string;
+typedef u32 string_size;
+
+/* Print type function for string type */
+static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
+ const char *name,
+ void *data, void *ent)
+{
+ int len = *(u32 *)data >> 16;
+
+ if (!len)
+ return trace_seq_printf(s, " %s=(fault)", name);
+ else
+ return trace_seq_printf(s, " %s=\"%s\"", name,
+ (const char *)get_loc_data(data, ent));
+}
+static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
+
/* Data fetch function type */
typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
return fprm->fn(regs, fprm->data, dest);
}
-#define FETCH_FUNC_NAME(kind, type) fetch_##kind##_##type
+#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
/*
* Define macro for basic types - we don't need to define s* types, because
* we have to care only about bitwidth at recording time.
*/
-#define DEFINE_BASIC_FETCH_FUNCS(kind) \
-DEFINE_FETCH_##kind(u8) \
-DEFINE_FETCH_##kind(u16) \
-DEFINE_FETCH_##kind(u32) \
-DEFINE_FETCH_##kind(u64)
-
-#define CHECK_BASIC_FETCH_FUNCS(kind, fn) \
- ((FETCH_FUNC_NAME(kind, u8) == fn) || \
- (FETCH_FUNC_NAME(kind, u16) == fn) || \
- (FETCH_FUNC_NAME(kind, u32) == fn) || \
- (FETCH_FUNC_NAME(kind, u64) == fn))
+#define DEFINE_BASIC_FETCH_FUNCS(method) \
+DEFINE_FETCH_##method(u8) \
+DEFINE_FETCH_##method(u16) \
+DEFINE_FETCH_##method(u32) \
+DEFINE_FETCH_##method(u64)
+
+#define CHECK_FETCH_FUNCS(method, fn) \
+ (((FETCH_FUNC_NAME(method, u8) == fn) || \
+ (FETCH_FUNC_NAME(method, u16) == fn) || \
+ (FETCH_FUNC_NAME(method, u32) == fn) || \
+ (FETCH_FUNC_NAME(method, u64) == fn) || \
+ (FETCH_FUNC_NAME(method, string) == fn) || \
+ (FETCH_FUNC_NAME(method, string_size) == fn)) \
+ && (fn != NULL))
/* Data fetch function templates */
#define DEFINE_FETCH_reg(type) \
static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
- void *offset, void *dest) \
+ void *offset, void *dest) \
{ \
*(type *)dest = (type)regs_get_register(regs, \
(unsigned int)((unsigned long)offset)); \
}
DEFINE_BASIC_FETCH_FUNCS(reg)
+/* No string on the register */
+#define fetch_reg_string NULL
+#define fetch_reg_string_size NULL
#define DEFINE_FETCH_stack(type) \
static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
(unsigned int)((unsigned long)offset)); \
}
DEFINE_BASIC_FETCH_FUNCS(stack)
+/* No string on the stack entry */
+#define fetch_stack_string NULL
+#define fetch_stack_string_size NULL
#define DEFINE_FETCH_retval(type) \
static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
*(type *)dest = (type)regs_return_value(regs); \
}
DEFINE_BASIC_FETCH_FUNCS(retval)
+/* No string on the retval */
+#define fetch_retval_string NULL
+#define fetch_retval_string_size NULL
#define DEFINE_FETCH_memory(type) \
static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
*(type *)dest = retval; \
}
DEFINE_BASIC_FETCH_FUNCS(memory)
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
+ * length and relative data location.
+ */
+static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
+ void *addr, void *dest)
+{
+ long ret;
+ int maxlen = get_rloc_len(*(u32 *)dest);
+ u8 *dst = get_rloc_data(dest);
+ u8 *src = addr;
+ mm_segment_t old_fs = get_fs();
+ if (!maxlen)
+ return;
+ /*
+ * Try to get string again, since the string can be changed while
+ * probing.
+ */
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+ do
+ ret = __copy_from_user_inatomic(dst++, src++, 1);
+ while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
+ dst[-1] = '\0';
+ pagefault_enable();
+ set_fs(old_fs);
+
+ if (ret < 0) { /* Failed to fetch string */
+ ((u8 *)get_rloc_data(dest))[0] = '\0';
+ *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
+ } else
+ *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
+ get_rloc_offs(*(u32 *)dest));
+}
+/* Return the length of string -- including null terminal byte */
+static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
+ void *addr, void *dest)
+{
+ int ret, len = 0;
+ u8 c;
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+ do {
+ ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
+ len++;
+ } while (c && ret == 0 && len < MAX_STRING_SIZE);
+ pagefault_enable();
+ set_fs(old_fs);
+
+ if (ret < 0) /* Failed to check the length */
+ *(u32 *)dest = 0;
+ else
+ *(u32 *)dest = len;
+}
/* Memory fetching by symbol */
struct symbol_cache {
*(type *)dest = 0; \
}
DEFINE_BASIC_FETCH_FUNCS(symbol)
+DEFINE_FETCH_symbol(string)
+DEFINE_FETCH_symbol(string_size)
/* Dereference memory access function */
struct deref_fetch_param {
*(type *)dest = 0; \
}
DEFINE_BASIC_FETCH_FUNCS(deref)
+DEFINE_FETCH_deref(string)
+DEFINE_FETCH_deref(string_size)
static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
{
- if (CHECK_BASIC_FETCH_FUNCS(deref, data->orig.fn))
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
free_deref_fetch_param(data->orig.data);
- else if (CHECK_BASIC_FETCH_FUNCS(symbol, data->orig.fn))
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
free_symbol_cache(data->orig.data);
kfree(data);
}
#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
-#define ASSIGN_FETCH_FUNC(kind, type) \
- .kind = FETCH_FUNC_NAME(kind, type)
-
-#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
- {.name = #ptype, \
- .size = sizeof(ftype), \
- .is_signed = sign, \
- .print = PRINT_TYPE_FUNC_NAME(ptype), \
- .fmt = PRINT_TYPE_FMT_NAME(ptype), \
-ASSIGN_FETCH_FUNC(reg, ftype), \
-ASSIGN_FETCH_FUNC(stack, ftype), \
-ASSIGN_FETCH_FUNC(retval, ftype), \
-ASSIGN_FETCH_FUNC(memory, ftype), \
-ASSIGN_FETCH_FUNC(symbol, ftype), \
-ASSIGN_FETCH_FUNC(deref, ftype), \
+/* Fetch types */
+enum {
+ FETCH_MTD_reg = 0,
+ FETCH_MTD_stack,
+ FETCH_MTD_retval,
+ FETCH_MTD_memory,
+ FETCH_MTD_symbol,
+ FETCH_MTD_deref,
+ FETCH_MTD_END,
+};
+
+#define ASSIGN_FETCH_FUNC(method, type) \
+ [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
+
+#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
+ {.name = _name, \
+ .size = _size, \
+ .is_signed = sign, \
+ .print = PRINT_TYPE_FUNC_NAME(ptype), \
+ .fmt = PRINT_TYPE_FMT_NAME(ptype), \
+ .fmttype = _fmttype, \
+ .fetch = { \
+ASSIGN_FETCH_FUNC(reg, ftype), \
+ASSIGN_FETCH_FUNC(stack, ftype), \
+ASSIGN_FETCH_FUNC(retval, ftype), \
+ASSIGN_FETCH_FUNC(memory, ftype), \
+ASSIGN_FETCH_FUNC(symbol, ftype), \
+ASSIGN_FETCH_FUNC(deref, ftype), \
+ } \
}
+#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
+ __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
+
+#define FETCH_TYPE_STRING 0
+#define FETCH_TYPE_STRSIZE 1
+
/* Fetch type information table */
static const struct fetch_type {
const char *name; /* Name 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 reg;
- fetch_func_t stack;
- fetch_func_t retval;
- fetch_func_t memory;
- fetch_func_t symbol;
- fetch_func_t deref;
+ 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),
*(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 */
static void free_probe_arg(struct probe_arg *arg)
{
- if (CHECK_BASIC_FETCH_FUNCS(deref, arg->fetch.fn))
+ if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
free_deref_fetch_param(arg->fetch.data);
- else if (CHECK_BASIC_FETCH_FUNCS(symbol, arg->fetch.fn))
+ else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
free_symbol_cache(arg->fetch.data);
kfree(arg->name);
kfree(arg->comm);
if (strcmp(arg, "retval") == 0) {
if (is_return)
- f->fn = t->retval;
+ f->fn = t->fetch[FETCH_MTD_retval];
else
ret = -EINVAL;
} else if (strncmp(arg, "stack", 5) == 0) {
if (ret || param > PARAM_MAX_STACK)
ret = -EINVAL;
else {
- f->fn = t->stack;
+ f->fn = t->fetch[FETCH_MTD_stack];
f->data = (void *)param;
}
} else
case '%': /* named register */
ret = regs_query_register_offset(arg + 1);
if (ret >= 0) {
- f->fn = t->reg;
+ f->fn = t->fetch[FETCH_MTD_reg];
f->data = (void *)(unsigned long)ret;
ret = 0;
}
ret = strict_strtoul(arg + 1, 0, ¶m);
if (ret)
break;
- f->fn = t->memory;
+ f->fn = t->fetch[FETCH_MTD_memory];
f->data = (void *)param;
} else {
ret = split_symbol_offset(arg + 1, &offset);
break;
f->data = alloc_symbol_cache(arg + 1, offset);
if (f->data)
- f->fn = t->symbol;
+ f->fn = t->fetch[FETCH_MTD_symbol];
}
break;
case '+': /* deref memory */
if (ret)
kfree(dprm);
else {
- f->fn = t->deref;
+ f->fn = t->fetch[FETCH_MTD_deref];
f->data = (void *)dprm;
}
}
break;
}
- if (!ret && !f->fn)
+ 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;
}
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);
}
parg->offset = tp->size;
tp->size += parg->type->size;
- return __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
+ ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
+ 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 */
.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 kprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
- u8 *data;
- int size, i, pc;
+ int size, dsize, pc;
unsigned long irq_flags;
struct ftrace_event_call *call = &tp->call;
local_save_flags(irq_flags);
pc = preempt_count();
- size = sizeof(*entry) + tp->size;
+ 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);
entry = ring_buffer_event_data(event);
entry->ip = (unsigned long)kp->addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ 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(buffer, event, irq_flags, pc);
struct kretprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
- u8 *data;
- int size, i, pc;
+ int size, pc, dsize;
unsigned long irq_flags;
struct ftrace_event_call *call = &tp->call;
local_save_flags(irq_flags);
pc = preempt_count();
- size = sizeof(*entry) + tp->size;
+ 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);
entry = ring_buffer_event_data(event);
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ 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(buffer, event, irq_flags, pc);
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))
+ data + tp->args[i].offset, field))
goto partial;
if (!trace_seq_puts(s, "\n"))
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))
+ data + tp->args[i].offset, field))
goto partial;
if (!trace_seq_puts(s, "\n"))
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->name,
+ 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,
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->name,
+ 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,
pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
for (i = 0; i < tp->nr_args; i++) {
- pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
- tp->args[i].name);
+ 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
struct ftrace_event_call *call = &tp->call;
struct kprobe_trace_entry_head *entry;
struct hlist_head *head;
- u8 *data;
- int size, __size, i;
+ int size, __size, dsize;
int rctx;
- __size = sizeof(*entry) + tp->size;
+ 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,
return;
entry->ip = (unsigned long)kp->addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ 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);
struct ftrace_event_call *call = &tp->call;
struct kretprobe_trace_entry_head *entry;
struct hlist_head *head;
- u8 *data;
- int size, __size, i;
+ int size, __size, dsize;
int rctx;
- __size = sizeof(*entry) + tp->size;
+ 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,
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ 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);
* Probe finder related functions
*/
+static struct kprobe_trace_arg_ref *alloc_trace_arg_ref(long offs)
+{
+ struct kprobe_trace_arg_ref *ref;
+ ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
+ if (ref != NULL)
+ ref->offset = offs;
+ return ref;
+}
+
/* Show a location */
-static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
+static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
{
+ Dwarf_Attribute attr;
+ Dwarf_Op *op;
+ size_t nops;
unsigned int regn;
Dwarf_Word offs = 0;
bool ref = false;
const char *regs;
struct kprobe_trace_arg *tvar = pf->tvar;
+ int ret;
+
+ /* TODO: handle more than 1 exprs */
+ if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
+ dwarf_getlocation_addr(&attr, pf->addr, &op, &nops, 1) <= 0 ||
+ nops == 0) {
+ /* TODO: Support const_value */
+ pr_err("Failed to find the location of %s at this address.\n"
+ " Perhaps, it has been optimized out.\n", pf->pvar->var);
+ return -ENOENT;
+ }
+
+ if (op->atom == DW_OP_addr) {
+ /* Static variables on memory (not stack), make @varname */
+ ret = strlen(dwarf_diename(vr_die));
+ tvar->value = zalloc(ret + 2);
+ if (tvar->value == NULL)
+ return -ENOMEM;
+ snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
+ tvar->ref = alloc_trace_arg_ref((long)offs);
+ if (tvar->ref == NULL)
+ return -ENOMEM;
+ return 0;
+ }
/* If this is based on frame buffer, set the offset */
if (op->atom == DW_OP_fbreg) {
return -ENOMEM;
if (ref) {
- tvar->ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
+ tvar->ref = alloc_trace_arg_ref((long)offs);
if (tvar->ref == NULL)
return -ENOMEM;
- tvar->ref->offset = (long)offs;
}
return 0;
}
static int convert_variable_type(Dwarf_Die *vr_die,
- struct kprobe_trace_arg *targ)
+ struct kprobe_trace_arg *tvar,
+ const char *cast)
{
+ struct kprobe_trace_arg_ref **ref_ptr = &tvar->ref;
Dwarf_Die type;
char buf[16];
int ret;
+ /* TODO: check all types */
+ if (cast && strcmp(cast, "string") != 0) {
+ /* Non string type is OK */
+ tvar->type = strdup(cast);
+ return (tvar->type == NULL) ? -ENOMEM : 0;
+ }
+
if (die_get_real_type(vr_die, &type) == NULL) {
pr_warning("Failed to get a type information of %s.\n",
dwarf_diename(vr_die));
return -ENOENT;
}
+ pr_debug("%s type is %s.\n",
+ dwarf_diename(vr_die), dwarf_diename(&type));
+
+ if (cast && strcmp(cast, "string") == 0) { /* String type */
+ ret = dwarf_tag(&type);
+ if (ret != DW_TAG_pointer_type &&
+ ret != DW_TAG_array_type) {
+ pr_warning("Failed to cast into string: "
+ "%s(%s) is not a pointer nor array.",
+ dwarf_diename(vr_die), dwarf_diename(&type));
+ return -EINVAL;
+ }
+ if (ret == DW_TAG_pointer_type) {
+ if (die_get_real_type(&type, &type) == NULL) {
+ pr_warning("Failed to get a type information.");
+ return -ENOENT;
+ }
+ while (*ref_ptr)
+ ref_ptr = &(*ref_ptr)->next;
+ /* Add new reference with offset +0 */
+ *ref_ptr = zalloc(sizeof(struct kprobe_trace_arg_ref));
+ if (*ref_ptr == NULL) {
+ pr_warning("Out of memory error\n");
+ return -ENOMEM;
+ }
+ }
+ if (die_compare_name(&type, "char") != 0 &&
+ die_compare_name(&type, "unsigned char") != 0) {
+ pr_warning("Failed to cast into string: "
+ "%s is not (unsigned) char *.",
+ dwarf_diename(vr_die));
+ return -EINVAL;
+ }
+ tvar->type = strdup(cast);
+ return (tvar->type == NULL) ? -ENOMEM : 0;
+ }
+
ret = die_get_byte_size(&type) * 8;
if (ret) {
/* Check the bitwidth */
strerror(-ret));
return ret;
}
- targ->type = strdup(buf);
- if (targ->type == NULL)
+ tvar->type = strdup(buf);
+ if (tvar->type == NULL)
return -ENOMEM;
}
return 0;
struct kprobe_trace_arg_ref *ref = *ref_ptr;
Dwarf_Die type;
Dwarf_Word offs;
- int ret;
+ int ret, tag;
pr_debug("converting %s in %s\n", field->name, varname);
if (die_get_real_type(vr_die, &type) == NULL) {
pr_warning("Failed to get the type of %s.\n", varname);
return -ENOENT;
}
-
- /* Check the pointer and dereference */
- if (dwarf_tag(&type) == DW_TAG_pointer_type) {
+ pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
+ tag = dwarf_tag(&type);
+
+ if (field->name[0] == '[' &&
+ (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
+ if (field->next)
+ /* Save original type for next field */
+ memcpy(die_mem, &type, sizeof(*die_mem));
+ /* Get the type of this array */
+ if (die_get_real_type(&type, &type) == NULL) {
+ pr_warning("Failed to get the type of %s.\n", varname);
+ return -ENOENT;
+ }
+ pr_debug2("Array real type: (%x)\n",
+ (unsigned)dwarf_dieoffset(&type));
+ if (tag == DW_TAG_pointer_type) {
+ ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
+ if (ref == NULL)
+ return -ENOMEM;
+ if (*ref_ptr)
+ (*ref_ptr)->next = ref;
+ else
+ *ref_ptr = ref;
+ }
+ ref->offset += die_get_byte_size(&type) * field->index;
+ if (!field->next)
+ /* Save vr_die for converting types */
+ memcpy(die_mem, vr_die, sizeof(*die_mem));
+ goto next;
+ } else if (tag == DW_TAG_pointer_type) {
+ /* Check the pointer and dereference */
if (!field->ref) {
pr_err("Semantic error: %s must be referred by '->'\n",
field->name);
*ref_ptr = ref;
} else {
/* Verify it is a data structure */
- if (dwarf_tag(&type) != DW_TAG_structure_type) {
+ if (tag != DW_TAG_structure_type) {
pr_warning("%s is not a data structure.\n", varname);
return -EINVAL;
}
+ if (field->name[0] == '[') {
+ pr_err("Semantic error: %s is not a pointor nor array.",
+ varname);
+ return -EINVAL;
+ }
if (field->ref) {
pr_err("Semantic error: %s must be referred by '.'\n",
field->name);
}
ref->offset += (long)offs;
+next:
/* Converting next field */
if (field->next)
return convert_variable_fields(die_mem, field->name,
/* Show a variables in kprobe event format */
static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
{
- Dwarf_Attribute attr;
Dwarf_Die die_mem;
- Dwarf_Op *expr;
- size_t nexpr;
int ret;
- if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
- goto error;
- /* TODO: handle more than 1 exprs */
- ret = dwarf_getlocation_addr(&attr, pf->addr, &expr, &nexpr, 1);
- if (ret <= 0 || nexpr == 0)
- goto error;
+ pr_debug("Converting variable %s into trace event.\n",
+ dwarf_diename(vr_die));
- ret = convert_location(expr, pf);
+ ret = convert_variable_location(vr_die, pf);
if (ret == 0 && pf->pvar->field) {
ret = convert_variable_fields(vr_die, pf->pvar->var,
pf->pvar->field, &pf->tvar->ref,
&die_mem);
vr_die = &die_mem;
}
- if (ret == 0) {
- if (pf->pvar->type) {
- pf->tvar->type = strdup(pf->pvar->type);
- if (pf->tvar->type == NULL)
- ret = -ENOMEM;
- } else
- ret = convert_variable_type(vr_die, pf->tvar);
- }
+ if (ret == 0)
+ ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
/* *expr will be cached in libdw. Don't free it. */
return ret;
-error:
- /* TODO: Support const_value */
- pr_err("Failed to find the location of %s at this address.\n"
- " Perhaps, it has been optimized out.\n", pf->pvar->var);
- return -ENOENT;
}
/* Find a variable in a subprogram die */
static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
{
- Dwarf_Die vr_die;
+ Dwarf_Die vr_die, *scopes;
char buf[32], *ptr;
- int ret;
+ int ret, nscopes;
- /* TODO: Support arrays */
if (pf->pvar->name)
pf->tvar->name = strdup(pf->pvar->name);
else {
pr_debug("Searching '%s' variable in context.\n",
pf->pvar->var);
/* Search child die for local variables and parameters. */
- if (!die_find_variable(sp_die, pf->pvar->var, &vr_die)) {
+ if (die_find_variable(sp_die, pf->pvar->var, &vr_die))
+ ret = convert_variable(&vr_die, pf);
+ else {
+ /* Search upper class */
+ nscopes = dwarf_getscopes_die(sp_die, &scopes);
+ if (nscopes > 0) {
+ ret = dwarf_getscopevar(scopes, nscopes, pf->pvar->var,
+ 0, NULL, 0, 0, &vr_die);
+ if (ret >= 0)
+ ret = convert_variable(&vr_die, pf);
+ else
+ ret = -ENOENT;
+ free(scopes);
+ } else
+ ret = -ENOENT;
+ }
+ if (ret < 0)
pr_warning("Failed to find '%s' in this function.\n",
pf->pvar->var);
- return -ENOENT;
- }
- return convert_variable(&vr_die, pf);
+ return ret;
}
/* Show a probe point to output buffer */