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Diffstat (limited to 'kernel/trace/trace_probe.c')
-rw-r--r--kernel/trace/trace_probe.c1388
1 files changed, 1214 insertions, 174 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 01ebabbbe8c9..2f571083ce9e 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -11,6 +11,10 @@
*/
#define pr_fmt(fmt) "trace_probe: " fmt
+#include <linux/bpf.h>
+#include <linux/fs.h>
+
+#include "trace_btf.h"
#include "trace_probe.h"
#undef C
@@ -50,6 +54,7 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
+DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'")
int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
{
@@ -64,7 +69,7 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
int len = *(u32 *)data >> 16;
if (!len)
- trace_seq_puts(s, "(fault)");
+ trace_seq_puts(s, FAULT_STRING);
else
trace_seq_printf(s, "\"%s\"",
(const char *)get_loc_data(data, ent));
@@ -95,6 +100,7 @@ static const struct fetch_type probe_fetch_types[] = {
ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
+ ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0),
ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
ASSIGN_FETCH_TYPE_END
@@ -148,22 +154,30 @@ fail:
}
static struct trace_probe_log trace_probe_log;
+extern struct mutex dyn_event_ops_mutex;
-void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
+const char *trace_probe_log_init(const char *subsystem, int argc, const char **argv)
{
+ lockdep_assert_held(&dyn_event_ops_mutex);
+
trace_probe_log.subsystem = subsystem;
trace_probe_log.argc = argc;
trace_probe_log.argv = argv;
trace_probe_log.index = 0;
+ return subsystem;
}
void trace_probe_log_clear(void)
{
+ lockdep_assert_held(&dyn_event_ops_mutex);
+
memset(&trace_probe_log, 0, sizeof(trace_probe_log));
}
void trace_probe_log_set_index(int index)
{
+ lockdep_assert_held(&dyn_event_ops_mutex);
+
trace_probe_log.index = index;
}
@@ -172,6 +186,8 @@ void __trace_probe_log_err(int offset, int err_type)
char *command, *p;
int i, len = 0, pos = 0;
+ lockdep_assert_held(&dyn_event_ops_mutex);
+
if (!trace_probe_log.argv)
return;
@@ -199,7 +215,7 @@ void __trace_probe_log_err(int offset, int err_type)
p = command;
for (i = 0; i < trace_probe_log.argc; i++) {
len = strlen(trace_probe_log.argv[i]);
- strcpy(p, trace_probe_log.argv[i]);
+ memcpy(p, trace_probe_log.argv[i], len);
p[len] = ' ';
p += len + 1;
}
@@ -232,7 +248,25 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset)
return 0;
}
-/* @buf must has MAX_EVENT_NAME_LEN size */
+/**
+ * traceprobe_parse_event_name() - Parse a string into group and event names
+ * @pevent: A pointer to the string to be parsed.
+ * @pgroup: A pointer to the group name.
+ * @buf: A buffer to store the parsed group name.
+ * @offset: The offset of the string in the original user command, for logging.
+ *
+ * This parses a string with the format `[GROUP/][EVENT]` or `[GROUP.][EVENT]`
+ * (either GROUP or EVENT or both must be specified).
+ * Since the parsed group name is stored in @buf, the caller must ensure @buf
+ * is at least MAX_EVENT_NAME_LEN bytes.
+ *
+ * Return: 0 on success, or -EINVAL on failure.
+ *
+ * If success, *@pevent is updated to point to the event name part of the
+ * original string, or NULL if there is no event name.
+ * Also, *@pgroup is updated to point to the parsed group which is stored
+ * in @buf, or NULL if there is no group name.
+ */
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
char *buf, int offset)
{
@@ -252,7 +286,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
trace_probe_log_err(offset, GROUP_TOO_LONG);
return -EINVAL;
}
- strlcpy(buf, event, slash - event + 1);
+ strscpy(buf, event, slash - event + 1);
if (!is_good_system_name(buf)) {
trace_probe_log_err(offset, BAD_GROUP_NAME);
return -EINVAL;
@@ -270,7 +304,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
}
trace_probe_log_err(offset, NO_EVENT_NAME);
return -EINVAL;
- } else if (len > MAX_EVENT_NAME_LEN) {
+ } else if (len >= MAX_EVENT_NAME_LEN) {
trace_probe_log_err(offset, EVENT_TOO_LONG);
return -EINVAL;
}
@@ -281,69 +315,742 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
return 0;
}
+static int parse_trace_event_arg(char *arg, struct fetch_insn *code,
+ struct traceprobe_parse_context *ctx)
+{
+ struct ftrace_event_field *field;
+ struct list_head *head;
+
+ head = trace_get_fields(ctx->event);
+ list_for_each_entry(field, head, link) {
+ if (!strcmp(arg, field->name)) {
+ code->op = FETCH_OP_TP_ARG;
+ code->data = field;
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
+
+static u32 btf_type_int(const struct btf_type *t)
+{
+ return *(u32 *)(t + 1);
+}
+
+static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type)
+{
+ const struct btf_type *real_type;
+ u32 intdata;
+ s32 tid;
+
+ real_type = btf_type_skip_modifiers(btf, type->type, &tid);
+ if (!real_type)
+ return false;
+
+ if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT)
+ return false;
+
+ intdata = btf_type_int(real_type);
+ return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
+ && BTF_INT_BITS(intdata) == 8;
+}
+
+static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type)
+{
+ const struct btf_type *real_type;
+ const struct btf_array *array;
+ u32 intdata;
+ s32 tid;
+
+ if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY)
+ return false;
+
+ array = (const struct btf_array *)(type + 1);
+
+ real_type = btf_type_skip_modifiers(btf, array->type, &tid);
+
+ intdata = btf_type_int(real_type);
+ return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
+ && BTF_INT_BITS(intdata) == 8;
+}
+
+static int check_prepare_btf_string_fetch(char *typename,
+ struct fetch_insn **pcode,
+ struct traceprobe_parse_context *ctx)
+{
+ struct btf *btf = ctx->btf;
+
+ if (!btf || !ctx->last_type)
+ return 0;
+
+ /* char [] does not need any change. */
+ if (btf_type_is_char_array(btf, ctx->last_type))
+ return 0;
+
+ /* char * requires dereference the pointer. */
+ if (btf_type_is_char_ptr(btf, ctx->last_type)) {
+ struct fetch_insn *code = *pcode + 1;
+
+ if (code->op == FETCH_OP_END) {
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
+ return -E2BIG;
+ }
+ if (typename[0] == 'u')
+ code->op = FETCH_OP_UDEREF;
+ else
+ code->op = FETCH_OP_DEREF;
+ code->offset = 0;
+ *pcode = code;
+ return 0;
+ }
+ /* Other types are not available for string */
+ trace_probe_log_err(ctx->offset, BAD_TYPE4STR);
+ return -EINVAL;
+}
+
+static const char *fetch_type_from_btf_type(struct btf *btf,
+ const struct btf_type *type,
+ struct traceprobe_parse_context *ctx)
+{
+ u32 intdata;
+
+ /* TODO: const char * could be converted as a string */
+ switch (BTF_INFO_KIND(type->info)) {
+ case BTF_KIND_ENUM:
+ /* enum is "int", so convert to "s32" */
+ return "s32";
+ case BTF_KIND_ENUM64:
+ return "s64";
+ case BTF_KIND_PTR:
+ /* pointer will be converted to "x??" */
+ if (IS_ENABLED(CONFIG_64BIT))
+ return "x64";
+ else
+ return "x32";
+ case BTF_KIND_INT:
+ intdata = btf_type_int(type);
+ if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) {
+ switch (BTF_INT_BITS(intdata)) {
+ case 8:
+ return "s8";
+ case 16:
+ return "s16";
+ case 32:
+ return "s32";
+ case 64:
+ return "s64";
+ }
+ } else { /* unsigned */
+ switch (BTF_INT_BITS(intdata)) {
+ case 8:
+ return "u8";
+ case 16:
+ return "u16";
+ case 32:
+ return "u32";
+ case 64:
+ return "u64";
+ }
+ /* bitfield, size is encoded in the type */
+ ctx->last_bitsize = BTF_INT_BITS(intdata);
+ ctx->last_bitoffs += BTF_INT_OFFSET(intdata);
+ return "u64";
+ }
+ }
+ /* TODO: support other types */
+
+ return NULL;
+}
+
+static int query_btf_context(struct traceprobe_parse_context *ctx)
+{
+ const struct btf_param *param;
+ const struct btf_type *type;
+ struct btf *btf;
+ s32 nr;
+
+ if (ctx->btf)
+ return 0;
+
+ if (!ctx->funcname)
+ return -EINVAL;
+
+ type = btf_find_func_proto(ctx->funcname, &btf);
+ if (!type)
+ return -ENOENT;
+
+ ctx->btf = btf;
+ ctx->proto = type;
+
+ /* ctx->params is optional, since func(void) will not have params. */
+ nr = 0;
+ param = btf_get_func_param(type, &nr);
+ if (!IS_ERR_OR_NULL(param)) {
+ /* Hide the first 'data' argument of tracepoint */
+ if (ctx->flags & TPARG_FL_TPOINT) {
+ nr--;
+ param++;
+ }
+ }
+
+ if (nr > 0) {
+ ctx->nr_params = nr;
+ ctx->params = param;
+ } else {
+ ctx->nr_params = 0;
+ ctx->params = NULL;
+ }
+
+ return 0;
+}
+
+static void clear_btf_context(struct traceprobe_parse_context *ctx)
+{
+ if (ctx->btf) {
+ btf_put(ctx->btf);
+ ctx->btf = NULL;
+ ctx->proto = NULL;
+ ctx->params = NULL;
+ ctx->nr_params = 0;
+ }
+}
+
+/* Return 1 if the field separator is arrow operator ('->') */
+static int split_next_field(char *varname, char **next_field,
+ struct traceprobe_parse_context *ctx)
+{
+ char *field;
+ int ret = 0;
+
+ field = strpbrk(varname, ".-");
+ if (field) {
+ if (field[0] == '-' && field[1] == '>') {
+ field[0] = '\0';
+ field += 2;
+ ret = 1;
+ } else if (field[0] == '.') {
+ field[0] = '\0';
+ field += 1;
+ } else {
+ trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN);
+ return -EINVAL;
+ }
+ *next_field = field;
+ }
+
+ return ret;
+}
+
+/*
+ * Parse the field of data structure. The @type must be a pointer type
+ * pointing the target data structure type.
+ */
+static int parse_btf_field(char *fieldname, const struct btf_type *type,
+ struct fetch_insn **pcode, struct fetch_insn *end,
+ struct traceprobe_parse_context *ctx)
+{
+ struct fetch_insn *code = *pcode;
+ const struct btf_member *field;
+ u32 bitoffs, anon_offs;
+ char *next;
+ int is_ptr;
+ s32 tid;
+
+ do {
+ /* Outer loop for solving arrow operator ('->') */
+ if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) {
+ trace_probe_log_err(ctx->offset, NO_PTR_STRCT);
+ return -EINVAL;
+ }
+ /* Convert a struct pointer type to a struct type */
+ type = btf_type_skip_modifiers(ctx->btf, type->type, &tid);
+ if (!type) {
+ trace_probe_log_err(ctx->offset, BAD_BTF_TID);
+ return -EINVAL;
+ }
+
+ bitoffs = 0;
+ do {
+ /* Inner loop for solving dot operator ('.') */
+ next = NULL;
+ is_ptr = split_next_field(fieldname, &next, ctx);
+ if (is_ptr < 0)
+ return is_ptr;
+
+ anon_offs = 0;
+ field = btf_find_struct_member(ctx->btf, type, fieldname,
+ &anon_offs);
+ if (IS_ERR(field)) {
+ trace_probe_log_err(ctx->offset, BAD_BTF_TID);
+ return PTR_ERR(field);
+ }
+ if (!field) {
+ trace_probe_log_err(ctx->offset, NO_BTF_FIELD);
+ return -ENOENT;
+ }
+ /* Add anonymous structure/union offset */
+ bitoffs += anon_offs;
+
+ /* Accumulate the bit-offsets of the dot-connected fields */
+ if (btf_type_kflag(type)) {
+ bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset);
+ ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset);
+ } else {
+ bitoffs += field->offset;
+ ctx->last_bitsize = 0;
+ }
+
+ type = btf_type_skip_modifiers(ctx->btf, field->type, &tid);
+ if (!type) {
+ trace_probe_log_err(ctx->offset, BAD_BTF_TID);
+ return -EINVAL;
+ }
+
+ ctx->offset += next - fieldname;
+ fieldname = next;
+ } while (!is_ptr && fieldname);
+
+ if (++code == end) {
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
+ return -EINVAL;
+ }
+ code->op = FETCH_OP_DEREF; /* TODO: user deref support */
+ code->offset = bitoffs / 8;
+ *pcode = code;
+
+ ctx->last_bitoffs = bitoffs % 8;
+ ctx->last_type = type;
+ } while (fieldname);
+
+ return 0;
+}
+
+static int __store_entry_arg(struct trace_probe *tp, int argnum);
+
+static int parse_btf_arg(char *varname,
+ struct fetch_insn **pcode, struct fetch_insn *end,
+ struct traceprobe_parse_context *ctx)
+{
+ struct fetch_insn *code = *pcode;
+ const struct btf_param *params;
+ const struct btf_type *type;
+ char *field = NULL;
+ int i, is_ptr, ret;
+ u32 tid;
+
+ if (WARN_ON_ONCE(!ctx->funcname))
+ return -EINVAL;
+
+ is_ptr = split_next_field(varname, &field, ctx);
+ if (is_ptr < 0)
+ return is_ptr;
+ if (!is_ptr && field) {
+ /* dot-connected field on an argument is not supported. */
+ trace_probe_log_err(ctx->offset + field - varname,
+ NOSUP_DAT_ARG);
+ return -EOPNOTSUPP;
+ }
+
+ if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) {
+ code->op = FETCH_OP_RETVAL;
+ /* Check whether the function return type is not void */
+ if (query_btf_context(ctx) == 0) {
+ if (ctx->proto->type == 0) {
+ trace_probe_log_err(ctx->offset, NO_RETVAL);
+ return -ENOENT;
+ }
+ tid = ctx->proto->type;
+ goto found;
+ }
+ if (field) {
+ trace_probe_log_err(ctx->offset + field - varname,
+ NO_BTF_ENTRY);
+ return -ENOENT;
+ }
+ return 0;
+ }
+
+ if (!ctx->btf) {
+ ret = query_btf_context(ctx);
+ if (ret < 0 || ctx->nr_params == 0) {
+ trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
+ return -ENOENT;
+ }
+ }
+ params = ctx->params;
+
+ for (i = 0; i < ctx->nr_params; i++) {
+ const char *name = btf_name_by_offset(ctx->btf, params[i].name_off);
+
+ if (name && !strcmp(name, varname)) {
+ if (tparg_is_function_entry(ctx->flags)) {
+ code->op = FETCH_OP_ARG;
+ if (ctx->flags & TPARG_FL_TPOINT)
+ code->param = i + 1;
+ else
+ code->param = i;
+ } else if (tparg_is_function_return(ctx->flags)) {
+ code->op = FETCH_OP_EDATA;
+ ret = __store_entry_arg(ctx->tp, i);
+ if (ret < 0) {
+ /* internal error */
+ return ret;
+ }
+ code->offset = ret;
+ }
+ tid = params[i].type;
+ goto found;
+ }
+ }
+ trace_probe_log_err(ctx->offset, NO_BTFARG);
+ return -ENOENT;
+
+found:
+ type = btf_type_skip_modifiers(ctx->btf, tid, &tid);
+ if (!type) {
+ trace_probe_log_err(ctx->offset, BAD_BTF_TID);
+ return -EINVAL;
+ }
+ /* Initialize the last type information */
+ ctx->last_type = type;
+ ctx->last_bitoffs = 0;
+ ctx->last_bitsize = 0;
+ if (field) {
+ ctx->offset += field - varname;
+ return parse_btf_field(field, type, pcode, end, ctx);
+ }
+ return 0;
+}
+
+static const struct fetch_type *find_fetch_type_from_btf_type(
+ struct traceprobe_parse_context *ctx)
+{
+ struct btf *btf = ctx->btf;
+ const char *typestr = NULL;
+
+ if (btf && ctx->last_type)
+ typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx);
+
+ return find_fetch_type(typestr, ctx->flags);
+}
+
+static int parse_btf_bitfield(struct fetch_insn **pcode,
+ struct traceprobe_parse_context *ctx)
+{
+ struct fetch_insn *code = *pcode;
+
+ if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0)
+ return 0;
+
+ code++;
+ if (code->op != FETCH_OP_NOP) {
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
+ return -EINVAL;
+ }
+ *pcode = code;
+
+ code->op = FETCH_OP_MOD_BF;
+ code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs);
+ code->rshift = 64 - ctx->last_bitsize;
+ code->basesize = 64 / 8;
+ return 0;
+}
+
+#else
+static void clear_btf_context(struct traceprobe_parse_context *ctx)
+{
+ ctx->btf = NULL;
+}
+
+static int query_btf_context(struct traceprobe_parse_context *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
+static int parse_btf_arg(char *varname,
+ struct fetch_insn **pcode, struct fetch_insn *end,
+ struct traceprobe_parse_context *ctx)
+{
+ trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
+ return -EOPNOTSUPP;
+}
+
+static int parse_btf_bitfield(struct fetch_insn **pcode,
+ struct traceprobe_parse_context *ctx)
+{
+ trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
+ return -EOPNOTSUPP;
+}
+
+#define find_fetch_type_from_btf_type(ctx) \
+ find_fetch_type(NULL, ctx->flags)
+
+static int check_prepare_btf_string_fetch(char *typename,
+ struct fetch_insn **pcode,
+ struct traceprobe_parse_context *ctx)
+{
+ return 0;
+}
+
+#endif
+
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+
+static void store_entry_arg_at(struct fetch_insn *code, int argnum, int offset)
+{
+ code[0].op = FETCH_OP_ARG;
+ code[0].param = argnum;
+ code[1].op = FETCH_OP_ST_EDATA;
+ code[1].offset = offset;
+}
+
+static int get_entry_arg_max_offset(struct probe_entry_arg *earg)
+{
+ int i, max_offset = 0;
+
+ /*
+ * earg->code[] array has an operation sequence which is run in
+ * the entry handler.
+ * The sequence stopped by FETCH_OP_END and each data stored in
+ * the entry data buffer by FETCH_OP_ST_EDATA. The FETCH_OP_ST_EDATA
+ * stores the data at the data buffer + its offset, and all data are
+ * "unsigned long" size. The offset must be increased when a data is
+ * stored. Thus we need to find the last FETCH_OP_ST_EDATA in the
+ * code array.
+ */
+ for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i++) {
+ if (earg->code[i].op == FETCH_OP_ST_EDATA)
+ if (earg->code[i].offset > max_offset)
+ max_offset = earg->code[i].offset;
+ }
+ return max_offset;
+}
+
+/*
+ * Add the entry code to store the 'argnum'th parameter and return the offset
+ * in the entry data buffer where the data will be stored.
+ */
+static int __store_entry_arg(struct trace_probe *tp, int argnum)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ int i, offset, last_offset = 0;
+
+ if (!earg) {
+ earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL);
+ if (!earg)
+ return -ENOMEM;
+ earg->size = 2 * tp->nr_args + 1;
+ earg->code = kcalloc(earg->size, sizeof(struct fetch_insn),
+ GFP_KERNEL);
+ if (!earg->code) {
+ kfree(earg);
+ return -ENOMEM;
+ }
+ /* Fill the code buffer with 'end' to simplify it */
+ for (i = 0; i < earg->size; i++)
+ earg->code[i].op = FETCH_OP_END;
+ tp->entry_arg = earg;
+ store_entry_arg_at(earg->code, argnum, 0);
+ return 0;
+ }
+
+ /*
+ * NOTE: if anyone change the following rule, please rewrite this.
+ * The entry code array is filled with the pair of
+ *
+ * [FETCH_OP_ARG(argnum)]
+ * [FETCH_OP_ST_EDATA(offset of entry data buffer)]
+ *
+ * and the rest of entries are filled with [FETCH_OP_END].
+ * The offset should be incremented, thus the last pair should
+ * have the largest offset.
+ */
+
+ /* Search the offset for the sprcified argnum. */
+ for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i += 2) {
+ if (WARN_ON_ONCE(earg->code[i].op != FETCH_OP_ARG))
+ return -EINVAL;
+
+ if (earg->code[i].param != argnum)
+ continue;
+
+ if (WARN_ON_ONCE(earg->code[i + 1].op != FETCH_OP_ST_EDATA))
+ return -EINVAL;
+
+ return earg->code[i + 1].offset;
+ }
+ /* Not found, append new entry if possible. */
+ if (i >= earg->size - 1)
+ return -ENOSPC;
+
+ /* The last entry must have the largest offset. */
+ if (i != 0) {
+ if (WARN_ON_ONCE(earg->code[i - 1].op != FETCH_OP_ST_EDATA))
+ return -EINVAL;
+ last_offset = earg->code[i - 1].offset;
+ }
+
+ offset = last_offset + sizeof(unsigned long);
+ store_entry_arg_at(&earg->code[i], argnum, offset);
+ return offset;
+}
+
+int traceprobe_get_entry_data_size(struct trace_probe *tp)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+
+ if (!earg)
+ return 0;
+
+ return get_entry_arg_max_offset(earg) + sizeof(unsigned long);
+}
+
+void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ unsigned long val = 0;
+ int i;
+
+ if (!earg)
+ return;
+
+ for (i = 0; i < earg->size; i++) {
+ struct fetch_insn *code = &earg->code[i];
+
+ switch (code->op) {
+ case FETCH_OP_ARG:
+ val = regs_get_kernel_argument(regs, code->param);
+ break;
+ case FETCH_OP_ST_EDATA:
+ *(unsigned long *)((unsigned long)edata + code->offset) = val;
+ break;
+ case FETCH_OP_END:
+ goto end;
+ default:
+ break;
+ }
+ }
+end:
+ return;
+}
+NOKPROBE_SYMBOL(store_trace_entry_data)
+#endif
+
#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
-static int parse_probe_vars(char *arg, const struct fetch_type *t,
- struct fetch_insn *code, unsigned int flags, int offs)
+/* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */
+static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
+ struct fetch_insn **pcode,
+ struct fetch_insn *end,
+ struct traceprobe_parse_context *ctx)
{
+ struct fetch_insn *code = *pcode;
+ int err = TP_ERR_BAD_VAR;
+ char *arg = orig_arg + 1;
unsigned long param;
int ret = 0;
int len;
- if (flags & TPARG_FL_TPOINT) {
+ if (ctx->flags & TPARG_FL_TEVENT) {
if (code->data)
return -EFAULT;
- code->data = kstrdup(arg, GFP_KERNEL);
- if (!code->data)
- return -ENOMEM;
- code->op = FETCH_OP_TP_ARG;
- } else if (strcmp(arg, "retval") == 0) {
- if (flags & TPARG_FL_RETURN) {
+ ret = parse_trace_event_arg(arg, code, ctx);
+ if (!ret)
+ return 0;
+ if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
+ code->op = FETCH_OP_COMM;
+ return 0;
+ }
+ /* backward compatibility */
+ ctx->offset = 0;
+ goto inval;
+ }
+
+ if (str_has_prefix(arg, "retval")) {
+ if (!(ctx->flags & TPARG_FL_RETURN)) {
+ err = TP_ERR_RETVAL_ON_PROBE;
+ goto inval;
+ }
+ if (!(ctx->flags & TPARG_FL_KERNEL) ||
+ !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
code->op = FETCH_OP_RETVAL;
- } else {
- trace_probe_log_err(offs, RETVAL_ON_PROBE);
- ret = -EINVAL;
+ return 0;
}
- } else if ((len = str_has_prefix(arg, "stack"))) {
+ return parse_btf_arg(orig_arg, pcode, end, ctx);
+ }
+
+ len = str_has_prefix(arg, "stack");
+ if (len) {
+
if (arg[len] == '\0') {
code->op = FETCH_OP_STACKP;
- } else if (isdigit(arg[len])) {
+ return 0;
+ }
+
+ if (isdigit(arg[len])) {
ret = kstrtoul(arg + len, 10, &param);
- if (ret) {
- goto inval_var;
- } else if ((flags & TPARG_FL_KERNEL) &&
- param > PARAM_MAX_STACK) {
- trace_probe_log_err(offs, BAD_STACK_NUM);
- ret = -EINVAL;
- } else {
- code->op = FETCH_OP_STACK;
- code->param = (unsigned int)param;
+ if (ret)
+ goto inval;
+
+ if ((ctx->flags & TPARG_FL_KERNEL) &&
+ param > PARAM_MAX_STACK) {
+ err = TP_ERR_BAD_STACK_NUM;
+ goto inval;
}
- } else
- goto inval_var;
- } else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
+ code->op = FETCH_OP_STACK;
+ code->param = (unsigned int)param;
+ return 0;
+ }
+ goto inval;
+ }
+
+ if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
code->op = FETCH_OP_COMM;
+ return 0;
+ }
+
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
- } else if (((flags & TPARG_FL_MASK) ==
- (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
- (len = str_has_prefix(arg, "arg"))) {
+ len = str_has_prefix(arg, "arg");
+ if (len) {
ret = kstrtoul(arg + len, 10, &param);
- if (ret) {
- goto inval_var;
- } else if (!param || param > PARAM_MAX_STACK) {
- trace_probe_log_err(offs, BAD_ARG_NUM);
- return -EINVAL;
+ if (ret)
+ goto inval;
+
+ if (!param || param > PARAM_MAX_STACK) {
+ err = TP_ERR_BAD_ARG_NUM;
+ goto inval;
}
- code->op = FETCH_OP_ARG;
- code->param = (unsigned int)param - 1;
-#endif
- } else
- goto inval_var;
+ param--; /* argN starts from 1, but internal arg[N] starts from 0 */
- return ret;
+ if (tparg_is_function_entry(ctx->flags)) {
+ code->op = FETCH_OP_ARG;
+ code->param = (unsigned int)param;
+ /*
+ * The tracepoint probe will probe a stub function, and the
+ * first parameter of the stub is a dummy and should be ignored.
+ */
+ if (ctx->flags & TPARG_FL_TPOINT)
+ code->param++;
+ } else if (tparg_is_function_return(ctx->flags)) {
+ /* function entry argument access from return probe */
+ ret = __store_entry_arg(ctx->tp, param);
+ if (ret < 0) /* This error should be an internal error */
+ return ret;
+
+ code->op = FETCH_OP_EDATA;
+ code->offset = ret;
+ } else {
+ err = TP_ERR_NOFENTRY_ARGS;
+ goto inval;
+ }
+ return 0;
+ }
+#endif
-inval_var:
- trace_probe_log_err(offs, BAD_VAR);
+inval:
+ __trace_probe_log_err(ctx->offset, err);
return -EINVAL;
}
@@ -376,7 +1083,7 @@ static int __parse_imm_string(char *str, char **pbuf, int offs)
static int
parse_probe_arg(char *arg, const struct fetch_type *type,
struct fetch_insn **pcode, struct fetch_insn *end,
- unsigned int flags, int offs)
+ struct traceprobe_parse_context *ctx)
{
struct fetch_insn *code = *pcode;
unsigned long param;
@@ -387,13 +1094,13 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
switch (arg[0]) {
case '$':
- ret = parse_probe_vars(arg + 1, type, code, flags, offs);
+ ret = parse_probe_vars(arg, type, pcode, end, ctx);
break;
case '%': /* named register */
- if (flags & TPARG_FL_TPOINT) {
- /* eprobes do not handle registers */
- trace_probe_log_err(offs, BAD_VAR);
+ if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) {
+ /* eprobe and fprobe do not handle registers */
+ trace_probe_log_err(ctx->offset, BAD_VAR);
break;
}
ret = regs_query_register_offset(arg + 1);
@@ -402,14 +1109,14 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->param = (unsigned int)ret;
ret = 0;
} else
- trace_probe_log_err(offs, BAD_REG_NAME);
+ trace_probe_log_err(ctx->offset, BAD_REG_NAME);
break;
case '@': /* memory, file-offset or symbol */
if (isdigit(arg[1])) {
ret = kstrtoul(arg + 1, 0, &param);
if (ret) {
- trace_probe_log_err(offs, BAD_MEM_ADDR);
+ trace_probe_log_err(ctx->offset, BAD_MEM_ADDR);
break;
}
/* load address */
@@ -417,13 +1124,13 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->immediate = param;
} else if (arg[1] == '+') {
/* kprobes don't support file offsets */
- if (flags & TPARG_FL_KERNEL) {
- trace_probe_log_err(offs, FILE_ON_KPROBE);
+ if (ctx->flags & TPARG_FL_KERNEL) {
+ trace_probe_log_err(ctx->offset, FILE_ON_KPROBE);
return -EINVAL;
}
ret = kstrtol(arg + 2, 0, &offset);
if (ret) {
- trace_probe_log_err(offs, BAD_FILE_OFFS);
+ trace_probe_log_err(ctx->offset, BAD_FILE_OFFS);
break;
}
@@ -431,8 +1138,8 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->immediate = (unsigned long)offset; // imm64?
} else {
/* uprobes don't support symbols */
- if (!(flags & TPARG_FL_KERNEL)) {
- trace_probe_log_err(offs, SYM_ON_UPROBE);
+ if (!(ctx->flags & TPARG_FL_KERNEL)) {
+ trace_probe_log_err(ctx->offset, SYM_ON_UPROBE);
return -EINVAL;
}
/* Preserve symbol for updating */
@@ -441,7 +1148,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
if (!code->data)
return -ENOMEM;
if (++code == end) {
- trace_probe_log_err(offs, TOO_MANY_OPS);
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
return -EINVAL;
}
code->op = FETCH_OP_IMM;
@@ -449,7 +1156,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
}
/* These are fetching from memory */
if (++code == end) {
- trace_probe_log_err(offs, TOO_MANY_OPS);
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
return -EINVAL;
}
*pcode = code;
@@ -468,47 +1175,51 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
arg++; /* Skip '+', because kstrtol() rejects it. */
tmp = strchr(arg, '(');
if (!tmp) {
- trace_probe_log_err(offs, DEREF_NEED_BRACE);
+ trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE);
return -EINVAL;
}
*tmp = '\0';
ret = kstrtol(arg, 0, &offset);
if (ret) {
- trace_probe_log_err(offs, BAD_DEREF_OFFS);
+ trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS);
break;
}
- offs += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
+ ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
arg = tmp + 1;
tmp = strrchr(arg, ')');
if (!tmp) {
- trace_probe_log_err(offs + strlen(arg),
+ trace_probe_log_err(ctx->offset + strlen(arg),
DEREF_OPEN_BRACE);
return -EINVAL;
} else {
- const struct fetch_type *t2 = find_fetch_type(NULL, flags);
+ const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags);
+ int cur_offs = ctx->offset;
*tmp = '\0';
- ret = parse_probe_arg(arg, t2, &code, end, flags, offs);
+ ret = parse_probe_arg(arg, t2, &code, end, ctx);
if (ret)
break;
+ ctx->offset = cur_offs;
if (code->op == FETCH_OP_COMM ||
code->op == FETCH_OP_DATA) {
- trace_probe_log_err(offs, COMM_CANT_DEREF);
+ trace_probe_log_err(ctx->offset, COMM_CANT_DEREF);
return -EINVAL;
}
if (++code == end) {
- trace_probe_log_err(offs, TOO_MANY_OPS);
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
return -EINVAL;
}
*pcode = code;
code->op = deref;
code->offset = offset;
+ /* Reset the last type if used */
+ ctx->last_type = NULL;
}
break;
case '\\': /* Immediate value */
if (arg[1] == '"') { /* Immediate string */
- ret = __parse_imm_string(arg + 2, &tmp, offs + 2);
+ ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2);
if (ret)
break;
code->op = FETCH_OP_DATA;
@@ -516,22 +1227,30 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
} else {
ret = str_to_immediate(arg + 1, &code->immediate);
if (ret)
- trace_probe_log_err(offs + 1, BAD_IMM);
+ trace_probe_log_err(ctx->offset + 1, BAD_IMM);
else
code->op = FETCH_OP_IMM;
}
break;
+ default:
+ if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
+ if (!tparg_is_function_entry(ctx->flags) &&
+ !tparg_is_function_return(ctx->flags)) {
+ trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
+ return -EINVAL;
+ }
+ ret = parse_btf_arg(arg, pcode, end, ctx);
+ break;
+ }
}
if (!ret && code->op == FETCH_OP_NOP) {
/* Parsed, but do not find fetch method */
- trace_probe_log_err(offs, BAD_FETCH_ARG);
+ trace_probe_log_err(ctx->offset, BAD_FETCH_ARG);
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,
@@ -567,126 +1286,101 @@ static int __parse_bitfield_probe_arg(const char *bf,
return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
}
-/* String length checking wrapper */
-static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
- struct probe_arg *parg, unsigned int flags, int offset)
+/* Split type part from @arg and return it. */
+static char *parse_probe_arg_type(char *arg, struct probe_arg *parg,
+ struct traceprobe_parse_context *ctx)
{
- struct fetch_insn *code, *scode, *tmp = NULL;
- char *t, *t2, *t3;
- char *arg;
- int ret, len;
+ char *t = NULL, *t2, *t3;
+ int offs;
- arg = kstrdup(argv, GFP_KERNEL);
- if (!arg)
- return -ENOMEM;
-
- ret = -EINVAL;
- len = strlen(arg);
- if (len > MAX_ARGSTR_LEN) {
- trace_probe_log_err(offset, ARG_TOO_LONG);
- goto out;
- } else if (len == 0) {
- trace_probe_log_err(offset, NO_ARG_BODY);
- goto out;
- }
-
- ret = -ENOMEM;
- parg->comm = kstrdup(arg, GFP_KERNEL);
- if (!parg->comm)
- goto out;
-
- ret = -EINVAL;
t = strchr(arg, ':');
if (t) {
- *t = '\0';
- t2 = strchr(++t, '[');
+ *t++ = '\0';
+ t2 = strchr(t, '[');
if (t2) {
*t2++ = '\0';
t3 = strchr(t2, ']');
if (!t3) {
- offset += t2 + strlen(t2) - arg;
- trace_probe_log_err(offset,
+ offs = t2 + strlen(t2) - arg;
+
+ trace_probe_log_err(ctx->offset + offs,
ARRAY_NO_CLOSE);
- goto out;
+ return ERR_PTR(-EINVAL);
} else if (t3[1] != '\0') {
- trace_probe_log_err(offset + t3 + 1 - arg,
+ trace_probe_log_err(ctx->offset + t3 + 1 - arg,
BAD_ARRAY_SUFFIX);
- goto out;
+ return ERR_PTR(-EINVAL);
}
*t3 = '\0';
if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
- trace_probe_log_err(offset + t2 - arg,
+ trace_probe_log_err(ctx->offset + t2 - arg,
BAD_ARRAY_NUM);
- goto out;
+ return ERR_PTR(-EINVAL);
}
if (parg->count > MAX_ARRAY_LEN) {
- trace_probe_log_err(offset + t2 - arg,
+ trace_probe_log_err(ctx->offset + t2 - arg,
ARRAY_TOO_BIG);
- goto out;
+ return ERR_PTR(-EINVAL);
}
}
}
+ offs = t ? t - arg : 0;
/*
* Since $comm and immediate string can not be dereferenced,
* we can find those by strcmp. But ignore for eprobes.
*/
- if (!(flags & TPARG_FL_TPOINT) &&
+ if (!(ctx->flags & TPARG_FL_TEVENT) &&
(strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
strncmp(arg, "\\\"", 2) == 0)) {
- /* The type of $comm must be "string", and not an array. */
- if (parg->count || (t && strcmp(t, "string")))
- goto out;
- parg->type = find_fetch_type("string", flags);
+ /* The type of $comm must be "string", and not an array type. */
+ if (parg->count || (t && strcmp(t, "string"))) {
+ trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE);
+ return ERR_PTR(-EINVAL);
+ }
+ parg->type = find_fetch_type("string", ctx->flags);
} else
- parg->type = find_fetch_type(t, flags);
- if (!parg->type) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE);
- goto out;
- }
- parg->offset = *size;
- *size += parg->type->size * (parg->count ?: 1);
+ parg->type = find_fetch_type(t, ctx->flags);
- ret = -ENOMEM;
- if (parg->count) {
- len = strlen(parg->type->fmttype) + 6;
- parg->fmt = kmalloc(len, GFP_KERNEL);
- if (!parg->fmt)
- goto out;
- snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
- parg->count);
+ if (!parg->type) {
+ trace_probe_log_err(ctx->offset + offs, BAD_TYPE);
+ return ERR_PTR(-EINVAL);
}
- code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
- if (!code)
- goto out;
- code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
+ return t;
+}
- ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
- flags, offset);
- if (ret)
- goto fail;
+/* After parsing, adjust the fetch_insn according to the probe_arg */
+static int finalize_fetch_insn(struct fetch_insn *code,
+ struct probe_arg *parg,
+ char *type,
+ int type_offset,
+ struct traceprobe_parse_context *ctx)
+{
+ struct fetch_insn *scode;
+ int ret;
- ret = -EINVAL;
/* Store operation */
if (parg->type->is_string) {
+ /* Check bad combination of the type and the last fetch_insn. */
if (!strcmp(parg->type->name, "symstr")) {
if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0),
+ trace_probe_log_err(ctx->offset + type_offset,
BAD_SYMSTRING);
- goto fail;
+ return -EINVAL;
}
} else {
if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0),
+ trace_probe_log_err(ctx->offset + type_offset,
BAD_STRING);
- goto fail;
+ return -EINVAL;
}
}
+
if (!strcmp(parg->type->name, "symstr") ||
(code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
@@ -701,10 +1395,11 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
*/
code++;
if (code->op != FETCH_OP_NOP) {
- trace_probe_log_err(offset, TOO_MANY_OPS);
- goto fail;
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
+ return -EINVAL;
}
}
+
/* If op == DEREF, replace it with STRING */
if (!strcmp(parg->type->name, "ustring") ||
code->op == FETCH_OP_UDEREF)
@@ -724,43 +1419,129 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
} else {
code++;
if (code->op != FETCH_OP_NOP) {
- trace_probe_log_err(offset, TOO_MANY_OPS);
- goto fail;
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
+ return -E2BIG;
}
code->op = FETCH_OP_ST_RAW;
code->size = parg->type->size;
}
+
+ /* Save storing fetch_insn. */
scode = code;
+
/* Modify operation */
- if (t != NULL) {
- ret = __parse_bitfield_probe_arg(t, parg->type, &code);
+ if (type != NULL) {
+ /* Bitfield needs a special fetch_insn. */
+ ret = __parse_bitfield_probe_arg(type, parg->type, &code);
if (ret) {
- trace_probe_log_err(offset + t - arg, BAD_BITFIELD);
- goto fail;
+ trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD);
+ return ret;
}
+ } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
+ ctx->last_type) {
+ /* If user not specified the type, try parsing BTF bitfield. */
+ ret = parse_btf_bitfield(&code, ctx);
+ if (ret)
+ return ret;
}
- ret = -EINVAL;
+
/* Loop(Array) operation */
if (parg->count) {
if (scode->op != FETCH_OP_ST_MEM &&
scode->op != FETCH_OP_ST_STRING &&
scode->op != FETCH_OP_ST_USTRING) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0),
- BAD_STRING);
- goto fail;
+ trace_probe_log_err(ctx->offset + type_offset, BAD_STRING);
+ return -EINVAL;
}
code++;
if (code->op != FETCH_OP_NOP) {
- trace_probe_log_err(offset, TOO_MANY_OPS);
- goto fail;
+ trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
+ return -E2BIG;
}
code->op = FETCH_OP_LP_ARRAY;
code->param = parg->count;
}
+
+ /* Finalize the fetch_insn array. */
code++;
code->op = FETCH_OP_END;
- ret = 0;
+ return 0;
+}
+
+/* String length checking wrapper */
+static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
+ struct probe_arg *parg,
+ struct traceprobe_parse_context *ctx)
+{
+ struct fetch_insn *code, *tmp = NULL;
+ char *type, *arg __free(kfree) = NULL;
+ int ret, len;
+
+ len = strlen(argv);
+ if (len > MAX_ARGSTR_LEN) {
+ trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
+ return -E2BIG;
+ } else if (len == 0) {
+ trace_probe_log_err(ctx->offset, NO_ARG_BODY);
+ return -EINVAL;
+ }
+
+ arg = kstrdup(argv, GFP_KERNEL);
+ if (!arg)
+ return -ENOMEM;
+
+ parg->comm = kstrdup(arg, GFP_KERNEL);
+ if (!parg->comm)
+ return -ENOMEM;
+
+ type = parse_probe_arg_type(arg, parg, ctx);
+ if (IS_ERR(type))
+ return PTR_ERR(type);
+
+ code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
+ if (!code)
+ return -ENOMEM;
+ code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
+
+ ctx->last_type = NULL;
+ ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
+ ctx);
+ if (ret < 0)
+ goto fail;
+
+ /* Update storing type if BTF is available */
+ if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
+ ctx->last_type) {
+ if (!type) {
+ parg->type = find_fetch_type_from_btf_type(ctx);
+ } else if (strstr(type, "string")) {
+ ret = check_prepare_btf_string_fetch(type, &code, ctx);
+ if (ret)
+ goto fail;
+ }
+ }
+ parg->offset = *size;
+ *size += parg->type->size * (parg->count ?: 1);
+
+ if (parg->count) {
+ len = strlen(parg->type->fmttype) + 6;
+ parg->fmt = kmalloc(len, GFP_KERNEL);
+ if (!parg->fmt) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
+ parg->count);
+ }
+
+ ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx);
+ if (ret < 0)
+ goto fail;
+
+ for (; code < tmp + FETCH_INSN_MAX; code++)
+ if (code->op == FETCH_OP_END)
+ break;
/* Shrink down the code buffer */
parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
if (!parg->code)
@@ -769,15 +1550,13 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
fail:
- if (ret) {
+ if (ret < 0) {
for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
if (code->op == FETCH_NOP_SYMBOL ||
code->op == FETCH_OP_DATA)
kfree(code->data);
}
kfree(tmp);
-out:
- kfree(arg);
return ret;
}
@@ -799,15 +1578,40 @@ static int traceprobe_conflict_field_name(const char *name,
return 0;
}
+static char *generate_probe_arg_name(const char *arg, int idx)
+{
+ char *name = NULL;
+ const char *end;
+
+ /*
+ * If argument name is omitted, try arg as a name (BTF variable)
+ * or "argN".
+ */
+ if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
+ end = strchr(arg, ':');
+ if (!end)
+ end = arg + strlen(arg);
+
+ name = kmemdup_nul(arg, end - arg, GFP_KERNEL);
+ if (!name || !is_good_name(name)) {
+ kfree(name);
+ name = NULL;
+ }
+ }
+
+ if (!name)
+ name = kasprintf(GFP_KERNEL, "arg%d", idx + 1);
+
+ return name;
+}
+
int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
- unsigned int flags)
+ struct traceprobe_parse_context *ctx)
{
struct probe_arg *parg = &tp->args[i];
const char *body;
- /* Increment count for freeing args in error case */
- tp->nr_args++;
-
+ ctx->tp = tp;
body = strchr(arg, '=');
if (body) {
if (body - arg > MAX_ARG_NAME_LEN) {
@@ -820,8 +1624,7 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
body++;
} else {
- /* If argument name is omitted, set "argN" */
- parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
+ parg->name = generate_probe_arg_name(arg, i);
body = arg;
}
if (!parg->name)
@@ -835,9 +1638,9 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
trace_probe_log_err(0, USED_ARG_NAME);
return -EINVAL;
}
+ ctx->offset = body - arg;
/* Parse fetch argument */
- return traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags,
- body - arg);
+ return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx);
}
void traceprobe_free_probe_arg(struct probe_arg *arg)
@@ -856,6 +1659,205 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
kfree(arg->fmt);
}
+static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
+ struct traceprobe_parse_context *ctx)
+{
+ int i, found = 0;
+
+ for (i = 0; i < argc; i++)
+ if (str_has_prefix(argv[i], "$arg")) {
+ trace_probe_log_set_index(i + 2);
+
+ if (!tparg_is_function_entry(ctx->flags) &&
+ !tparg_is_function_return(ctx->flags)) {
+ trace_probe_log_err(0, NOFENTRY_ARGS);
+ return -EINVAL;
+ }
+
+ if (isdigit(argv[i][4])) {
+ found = 1;
+ continue;
+ }
+
+ if (argv[i][4] != '*') {
+ trace_probe_log_err(0, BAD_VAR);
+ return -EINVAL;
+ }
+
+ if (*args_idx >= 0 && *args_idx < argc) {
+ trace_probe_log_err(0, DOUBLE_ARGS);
+ return -EINVAL;
+ }
+ found = 1;
+ *args_idx = i;
+ }
+
+ return found;
+}
+
+static int sprint_nth_btf_arg(int idx, const char *type,
+ char *buf, int bufsize,
+ struct traceprobe_parse_context *ctx)
+{
+ const char *name;
+ int ret;
+
+ if (idx >= ctx->nr_params) {
+ trace_probe_log_err(0, NO_BTFARG);
+ return -ENOENT;
+ }
+ name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off);
+ if (!name) {
+ trace_probe_log_err(0, NO_BTF_ENTRY);
+ return -ENOENT;
+ }
+ ret = snprintf(buf, bufsize, "%s%s", name, type);
+ if (ret >= bufsize) {
+ trace_probe_log_err(0, ARGS_2LONG);
+ return -E2BIG;
+ }
+ return ret;
+}
+
+/* Return new_argv which must be freed after use */
+const char **traceprobe_expand_meta_args(int argc, const char *argv[],
+ int *new_argc, char *buf, int bufsize,
+ struct traceprobe_parse_context *ctx)
+{
+ const struct btf_param *params = NULL;
+ int i, j, n, used, ret, args_idx = -1;
+ const char **new_argv __free(kfree) = NULL;
+
+ ret = argv_has_var_arg(argc, argv, &args_idx, ctx);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ if (!ret) {
+ *new_argc = argc;
+ return NULL;
+ }
+
+ ret = query_btf_context(ctx);
+ if (ret < 0 || ctx->nr_params == 0) {
+ if (args_idx != -1) {
+ /* $arg* requires BTF info */
+ trace_probe_log_err(0, NOSUP_BTFARG);
+ return (const char **)params;
+ }
+ *new_argc = argc;
+ return NULL;
+ }
+
+ if (args_idx >= 0)
+ *new_argc = argc + ctx->nr_params - 1;
+ else
+ *new_argc = argc;
+
+ new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL);
+ if (!new_argv)
+ return ERR_PTR(-ENOMEM);
+
+ used = 0;
+ for (i = 0, j = 0; i < argc; i++) {
+ trace_probe_log_set_index(i + 2);
+ if (i == args_idx) {
+ for (n = 0; n < ctx->nr_params; n++) {
+ ret = sprint_nth_btf_arg(n, "", buf + used,
+ bufsize - used, ctx);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ new_argv[j++] = buf + used;
+ used += ret + 1;
+ }
+ continue;
+ }
+
+ if (str_has_prefix(argv[i], "$arg")) {
+ char *type = NULL;
+
+ n = simple_strtoul(argv[i] + 4, &type, 10);
+ if (type && !(*type == ':' || *type == '\0')) {
+ trace_probe_log_err(0, BAD_VAR);
+ return ERR_PTR(-ENOENT);
+ }
+ /* Note: $argN starts from $arg1 */
+ ret = sprint_nth_btf_arg(n - 1, type, buf + used,
+ bufsize - used, ctx);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ new_argv[j++] = buf + used;
+ used += ret + 1;
+ } else
+ new_argv[j++] = argv[i];
+ }
+
+ return_ptr(new_argv);
+}
+
+/* @buf: *buf must be equal to NULL. Caller must to free *buf */
+int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf)
+{
+ int i, used, ret;
+ const int bufsize = MAX_DENTRY_ARGS_LEN;
+ char *tmpbuf __free(kfree) = NULL;
+
+ if (*buf)
+ return -EINVAL;
+
+ used = 0;
+ for (i = 0; i < argc; i++) {
+ char *tmp __free(kfree) = NULL;
+ char *equal;
+ size_t arg_len;
+
+ if (!glob_match("*:%p[dD]", argv[i]))
+ continue;
+
+ if (!tmpbuf) {
+ tmpbuf = kmalloc(bufsize, GFP_KERNEL);
+ if (!tmpbuf)
+ return -ENOMEM;
+ }
+
+ tmp = kstrdup(argv[i], GFP_KERNEL);
+ if (!tmp)
+ return -ENOMEM;
+
+ equal = strchr(tmp, '=');
+ if (equal)
+ *equal = '\0';
+ arg_len = strlen(argv[i]);
+ tmp[arg_len - 4] = '\0';
+ if (argv[i][arg_len - 1] == 'd')
+ ret = snprintf(tmpbuf + used, bufsize - used,
+ "%s%s+0x0(+0x%zx(%s)):string",
+ equal ? tmp : "", equal ? "=" : "",
+ offsetof(struct dentry, d_name.name),
+ equal ? equal + 1 : tmp);
+ else
+ ret = snprintf(tmpbuf + used, bufsize - used,
+ "%s%s+0x0(+0x%zx(+0x%zx(%s))):string",
+ equal ? tmp : "", equal ? "=" : "",
+ offsetof(struct dentry, d_name.name),
+ offsetof(struct file, f_path.dentry),
+ equal ? equal + 1 : tmp);
+
+ if (ret >= bufsize - used)
+ return -ENOMEM;
+ argv[i] = tmpbuf + used;
+ used += ret + 1;
+ }
+
+ *buf = no_free_ptr(tmpbuf);
+ return 0;
+}
+
+void traceprobe_finish_parse(struct traceprobe_parse_context *ctx)
+{
+ clear_btf_context(ctx);
+}
+
int traceprobe_update_arg(struct probe_arg *arg)
{
struct fetch_insn *code = arg->code;
@@ -1043,12 +2045,18 @@ void trace_probe_cleanup(struct trace_probe *tp)
for (i = 0; i < tp->nr_args; i++)
traceprobe_free_probe_arg(&tp->args[i]);
+ if (tp->entry_arg) {
+ kfree(tp->entry_arg->code);
+ kfree(tp->entry_arg);
+ tp->entry_arg = NULL;
+ }
+
if (tp->event)
trace_probe_unlink(tp);
}
int trace_probe_init(struct trace_probe *tp, const char *event,
- const char *group, bool alloc_filter)
+ const char *group, bool alloc_filter, int nargs)
{
struct trace_event_call *call;
size_t size = sizeof(struct trace_probe_event);
@@ -1084,6 +2092,11 @@ int trace_probe_init(struct trace_probe *tp, const char *event,
goto error;
}
+ tp->nr_args = nargs;
+ /* Make sure pointers in args[] are NULL */
+ if (nargs)
+ memset(tp->args, 0, sizeof(tp->args[0]) * nargs);
+
return 0;
error:
@@ -1170,7 +2183,7 @@ int trace_probe_remove_file(struct trace_probe *tp,
return -ENOENT;
list_del_rcu(&link->list);
- kvfree_rcu(link);
+ kvfree_rcu_mightsleep(link);
if (list_empty(&tp->event->files))
trace_probe_clear_flag(tp, TP_FLAG_TRACE);
@@ -1237,3 +2250,30 @@ int trace_probe_create(const char *raw_command, int (*createfn)(int, const char
return ret;
}
+
+int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
+ u8 *data, void *field)
+{
+ void *p;
+ int i, j;
+
+ for (i = 0; i < nr_args; i++) {
+ struct probe_arg *a = args + i;
+
+ trace_seq_printf(s, " %s=", a->name);
+ if (likely(!a->count)) {
+ if (!a->type->print(s, data + a->offset, field))
+ return -ENOMEM;
+ continue;
+ }
+ trace_seq_putc(s, '{');
+ p = data + a->offset;
+ for (j = 0; j < a->count; j++) {
+ if (!a->type->print(s, p, field))
+ return -ENOMEM;
+ trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
+ p += a->type->size;
+ }
+ }
+ return 0;
+}
generated by cgit (git 2.34.1) at 2025-12-21 20:27:37 +0000