tracing: Extract out common code for kprobes/uprobes trace events
Move parts of trace_kprobe.c that can be shared with upcoming
trace_uprobe.c. Common code to kernel/trace/trace_probe.h and
kernel/trace/trace_probe.c. There are no functional changes.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120409091144.8343.76218.sendpatchset@srdronam.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
new file mode 100644
index 0000000..8e526b9
--- /dev/null
+++ b/kernel/trace/trace_probe.c
@@ -0,0 +1,833 @@
+/*
+ * Common code for probe-based Dynamic events.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * This code was copied from kernel/trace/trace_kprobe.c written by
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Updates to make this generic:
+ * Copyright (C) IBM Corporation, 2010-2011
+ * Author: Srikar Dronamraju
+ */
+
+#include "trace_probe.h"
+
+const char *reserved_field_names[] = {
+ "common_type",
+ "common_flags",
+ "common_preempt_count",
+ "common_pid",
+ "common_tgid",
+ FIELD_STRING_IP,
+ FIELD_STRING_RETIP,
+ FIELD_STRING_FUNC,
+};
+
+/* Printing function type */
+#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
+#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
+
+/* Printing in basic type function template */
+#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
+static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
+ const char *name, \
+ void *data, void *ent)\
+{ \
+ return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
+} \
+static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
+
+DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
+
+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);
+}
+
+/* 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\\\"";
+
+#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(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) \
+{ \
+ *(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,\
+ void *offset, void *dest) \
+{ \
+ *(type *)dest = (type)regs_get_kernel_stack_nth(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,\
+ void *dummy, void *dest) \
+{ \
+ *(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,\
+ void *addr, void *dest) \
+{ \
+ type retval; \
+ if (probe_kernel_address(addr, retval)) \
+ *(type *)dest = 0; \
+ else \
+ *(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)
+{
+ mm_segment_t old_fs;
+ int ret, len = 0;
+ u8 c;
+
+ 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 {
+ char *symbol;
+ long offset;
+ unsigned long addr;
+};
+
+static unsigned long update_symbol_cache(struct symbol_cache *sc)
+{
+ sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
+
+ if (sc->addr)
+ sc->addr += sc->offset;
+
+ return sc->addr;
+}
+
+static void free_symbol_cache(struct symbol_cache *sc)
+{
+ kfree(sc->symbol);
+ kfree(sc);
+}
+
+static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
+{
+ struct symbol_cache *sc;
+
+ if (!sym || strlen(sym) == 0)
+ return NULL;
+
+ sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
+ if (!sc)
+ return NULL;
+
+ sc->symbol = kstrdup(sym, GFP_KERNEL);
+ if (!sc->symbol) {
+ kfree(sc);
+ return NULL;
+ }
+ sc->offset = offset;
+ update_symbol_cache(sc);
+
+ return sc;
+}
+
+#define DEFINE_FETCH_symbol(type) \
+static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct symbol_cache *sc = data; \
+ if (sc->addr) \
+ fetch_memory_##type(regs, (void *)sc->addr, dest); \
+ else \
+ *(type *)dest = 0; \
+}
+DEFINE_BASIC_FETCH_FUNCS(symbol)
+DEFINE_FETCH_symbol(string)
+DEFINE_FETCH_symbol(string_size)
+
+/* Dereference memory access function */
+struct deref_fetch_param {
+ struct fetch_param orig;
+ long offset;
+};
+
+#define DEFINE_FETCH_deref(type) \
+static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct deref_fetch_param *dprm = data; \
+ unsigned long addr; \
+ call_fetch(&dprm->orig, regs, &addr); \
+ if (addr) { \
+ addr += dprm->offset; \
+ fetch_memory_##type(regs, (void *)addr, dest); \
+ } else \
+ *(type *)dest = 0; \
+}
+DEFINE_BASIC_FETCH_FUNCS(deref)
+DEFINE_FETCH_deref(string)
+DEFINE_FETCH_deref(string_size)
+
+static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
+{
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ update_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ update_symbol_cache(data->orig.data);
+}
+
+static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
+{
+ 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);
+}
+
+/* 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
+update_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))
+ update_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ update_symbol_cache(data->orig.data);
+}
+
+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)
+#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
+#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
+
+#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), \
+ASSIGN_FETCH_FUNC(bitfield, 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 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;
+}
+
+/* Split symbol and offset. */
+int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
+{
+ char *tmp;
+ int ret;
+
+ if (!offset)
+ return -EINVAL;
+
+ tmp = strchr(symbol, '+');
+ if (tmp) {
+ /* skip sign because strict_strtol doesn't accept '+' */
+ ret = strict_strtoul(tmp + 1, 0, offset);
+ if (ret)
+ return ret;
+
+ *tmp = '\0';
+ } else
+ *offset = 0;
+
+ return 0;
+}
+
+#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
+
+static int parse_probe_vars(char *arg, const struct fetch_type *t,
+ struct fetch_param *f, bool 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, bool is_return)
+{
+ unsigned long param;
+ long offset;
+ char *tmp;
+ int ret;
+
+ ret = 0;
+ 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 = traceprobe_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;
+
+ 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 */
+int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
+ struct probe_arg *parg, bool 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 = *size;
+ *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 */
+int traceprobe_conflict_field_name(const char *name,
+ struct probe_arg *args, int narg)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
+ if (strcmp(reserved_field_names[i], name) == 0)
+ return 1;
+
+ for (i = 0; i < narg; i++)
+ if (strcmp(args[i].name, name) == 0)
+ return 1;
+
+ return 0;
+}
+
+void traceprobe_update_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);
+}
+
+void traceprobe_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);
+}
+
+int traceprobe_command(const char *buf, int (*createfn)(int, char **))
+{
+ char **argv;
+ int argc, ret;
+
+ argc = 0;
+ ret = 0;
+ argv = argv_split(GFP_KERNEL, buf, &argc);
+ if (!argv)
+ return -ENOMEM;
+
+ if (argc)
+ ret = createfn(argc, argv);
+
+ argv_free(argv);
+
+ return ret;
+}
+
+#define WRITE_BUFSIZE 4096
+
+ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos,
+ int (*createfn)(int, char **))
+{
+ char *kbuf, *tmp;
+ int ret = 0;
+ size_t done = 0;
+ size_t size;
+
+ kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ while (done < count) {
+ size = count - done;
+
+ if (size >= WRITE_BUFSIZE)
+ size = WRITE_BUFSIZE - 1;
+
+ if (copy_from_user(kbuf, buffer + done, size)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ kbuf[size] = '\0';
+ tmp = strchr(kbuf, '\n');
+
+ if (tmp) {
+ *tmp = '\0';
+ size = tmp - kbuf + 1;
+ } else if (done + size < count) {
+ pr_warning("Line length is too long: "
+ "Should be less than %d.", WRITE_BUFSIZE);
+ ret = -EINVAL;
+ goto out;
+ }
+ done += size;
+ /* Remove comments */
+ tmp = strchr(kbuf, '#');
+
+ if (tmp)
+ *tmp = '\0';
+
+ ret = traceprobe_command(kbuf, createfn);
+ if (ret)
+ goto out;
+ }
+ ret = done;
+
+out:
+ kfree(kbuf);
+
+ return ret;
+}