diff options
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 111 |
1 files changed, 106 insertions, 5 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 2dec9bc..8435b43 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -353,6 +353,43 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) kfree(data); } +/* Bitfield fetch function */ +struct bitfield_fetch_param { + struct fetch_param orig; + unsigned char hi_shift; + unsigned char low_shift; +}; + +#define DEFINE_FETCH_bitfield(type) \ +static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct bitfield_fetch_param *bprm = data; \ + type buf = 0; \ + call_fetch(&bprm->orig, regs, &buf); \ + if (buf) { \ + buf <<= bprm->hi_shift; \ + buf >>= bprm->low_shift; \ + } \ + *(type *)dest = buf; \ +} +DEFINE_BASIC_FETCH_FUNCS(bitfield) +#define fetch_bitfield_string NULL +#define fetch_bitfield_string_size NULL + +static __kprobes void +free_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + kfree(data); +} /* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) u##t #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) @@ -367,6 +404,7 @@ enum { FETCH_MTD_memory, FETCH_MTD_symbol, FETCH_MTD_deref, + FETCH_MTD_bitfield, FETCH_MTD_END, }; @@ -387,6 +425,7 @@ ASSIGN_FETCH_FUNC(retval, ftype), \ ASSIGN_FETCH_FUNC(memory, ftype), \ ASSIGN_FETCH_FUNC(symbol, ftype), \ ASSIGN_FETCH_FUNC(deref, ftype), \ +ASSIGN_FETCH_FUNC(bitfield, ftype), \ } \ } @@ -430,9 +469,33 @@ static const struct fetch_type *find_fetch_type(const char *type) 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; } @@ -586,7 +649,9 @@ error: static void free_probe_arg(struct probe_arg *arg) { - if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + 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); @@ -767,16 +832,15 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t, } break; case '+': /* deref memory */ + arg++; /* Skip '+', because strict_strtol() rejects it. */ case '-': tmp = strchr(arg, '('); if (!tmp) break; *tmp = '\0'; - ret = strict_strtol(arg + 1, 0, &offset); + ret = strict_strtol(arg, 0, &offset); if (ret) break; - if (arg[0] == '-') - offset = -offset; arg = tmp + 1; tmp = strrchr(arg, ')'); if (tmp) { @@ -807,6 +871,41 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t, 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) @@ -836,6 +935,8 @@ static int parse_probe_arg(char *arg, struct trace_probe *tp, 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); @@ -1130,7 +1231,7 @@ static int command_trace_probe(const char *buf) return ret; } -#define WRITE_BUFSIZE 128 +#define WRITE_BUFSIZE 4096 static ssize_t probes_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) |