[PATCH v4 05/11] tracing: Use tracing error_log with probe events

From: Tom Zanussi
Date: Fri Mar 22 2019 - 11:34:58 EST

From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Use tracing error_log with probe events for logging error more
precisely. This also makes all parse error returns -EINVAL
(except for -ENOMEM), because user can see better error message
in error_log file now.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 77 ++++++++-----
kernel/trace/trace_probe.c | 274 +++++++++++++++++++++++++++++++-------------
kernel/trace/trace_probe.h | 77 ++++++++++++-
kernel/trace/trace_uprobe.c | 44 ++++---
4 files changed, 348 insertions(+), 124 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 63aa0ab56051..6f49c01378ee 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -441,13 +441,8 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
else
ret = register_kprobe(&tk->rp.kp);

- if (ret == 0) {
+ if (ret == 0)
tk->tp.flags |= TP_FLAG_REGISTERED;
- } else if (ret == -EILSEQ) {
- pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
- tk->rp.kp.addr);
- ret = -EINVAL;
- }
return ret;
}

@@ -591,7 +586,7 @@ static int trace_kprobe_create(int argc, const char *argv[])
* Type of args:
* FETCHARG:TYPE : use TYPE instead of unsigned long.
*/
- struct trace_kprobe *tk;
+ struct trace_kprobe *tk = NULL;
int i, len, ret = 0;
bool is_return = false;
char *symbol = NULL, *tmp = NULL;
@@ -615,44 +610,50 @@ static int trace_kprobe_create(int argc, const char *argv[])
if (argc < 2)
return -ECANCELED;

+ trace_probe_log_init("trace_kprobe", argc, argv);
+
event = strchr(&argv[0][1], ':');
if (event)
event++;

if (isdigit(argv[0][1])) {
if (!is_return) {
- pr_info("Maxactive is not for kprobe");
- return -EINVAL;
+ trace_probe_log_err(1, MAXACT_NO_KPROBE);
+ goto parse_error;
}
if (event)
len = event - &argv[0][1] - 1;
else
len = strlen(&argv[0][1]);
- if (len > MAX_EVENT_NAME_LEN - 1)
- return -E2BIG;
+ if (len > MAX_EVENT_NAME_LEN - 1) {
+ trace_probe_log_err(1, BAD_MAXACT);
+ goto parse_error;
+ }
memcpy(buf, &argv[0][1], len);
buf[len] = '\0';
ret = kstrtouint(buf, 0, &maxactive);
if (ret || !maxactive) {
- pr_info("Invalid maxactive number\n");
- return ret;
+ trace_probe_log_err(1, BAD_MAXACT);
+ goto parse_error;
}
/* kretprobes instances are iterated over via a list. The
* maximum should stay reasonable.
*/
if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
- pr_info("Maxactive is too big (%d > %d).\n",
- maxactive, KRETPROBE_MAXACTIVE_MAX);
- return -E2BIG;
+ trace_probe_log_err(1, MAXACT_TOO_BIG);
+ goto parse_error;
}
}

/* try to parse an address. if that fails, try to read the
* input as a symbol. */
if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
+ trace_probe_log_set_index(1);
/* Check whether uprobe event specified */
- if (strchr(argv[1], '/') && strchr(argv[1], ':'))
- return -ECANCELED;
+ if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
+ ret = -ECANCELED;
+ goto error;
+ }
/* a symbol specified */
symbol = kstrdup(argv[1], GFP_KERNEL);
if (!symbol)
@@ -660,23 +661,23 @@ static int trace_kprobe_create(int argc, const char *argv[])
/* TODO: support .init module functions */
ret = traceprobe_split_symbol_offset(symbol, &offset);
if (ret || offset < 0 || offset > UINT_MAX) {
- pr_info("Failed to parse either an address or a symbol.\n");
- goto out;
+ trace_probe_log_err(0, BAD_PROBE_ADDR);
+ goto parse_error;
}
if (kprobe_on_func_entry(NULL, symbol, offset))
flags |= TPARG_FL_FENTRY;
if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
- pr_info("Given offset is not valid for return probe.\n");
- ret = -EINVAL;
- goto out;
+ trace_probe_log_err(0, BAD_RETPROBE);
+ goto parse_error;
}
}
- argc -= 2; argv += 2;

+ trace_probe_log_set_index(0);
if (event) {
- ret = traceprobe_parse_event_name(&event, &group, buf);
+ ret = traceprobe_parse_event_name(&event, &group, buf,
+ event - argv[0]);
if (ret)
- goto out;
+ goto parse_error;
} else {
/* Make a new event name */
if (symbol)
@@ -691,13 +692,14 @@ static int trace_kprobe_create(int argc, const char *argv[])

/* setup a probe */
tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
- argc, is_return);
+ argc - 2, is_return);
if (IS_ERR(tk)) {
ret = PTR_ERR(tk);
- /* This must return -ENOMEM otherwise there is a bug */
+ /* This must return -ENOMEM, else there is a bug */
WARN_ON_ONCE(ret != -ENOMEM);
- goto out;
+ goto out; /* We know tk is not allocated */
}
+ argc -= 2; argv += 2;

/* parse arguments */
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
@@ -707,19 +709,32 @@ static int trace_kprobe_create(int argc, const char *argv[])
goto error;
}

+ trace_probe_log_set_index(i + 2);
ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
kfree(tmp);
if (ret)
- goto error;
+ goto error; /* This can be -ENOMEM */
}

ret = register_trace_kprobe(tk);
- if (ret)
+ if (ret) {
+ trace_probe_log_set_index(1);
+ if (ret == -EILSEQ)
+ trace_probe_log_err(0, BAD_INSN_BNDRY);
+ else if (ret == -ENOENT)
+ trace_probe_log_err(0, BAD_PROBE_ADDR);
+ else if (ret != -ENOMEM)
+ trace_probe_log_err(0, FAIL_REG_PROBE);
goto error;
+ }
+
out:
+ trace_probe_log_clear();
kfree(symbol);
return ret;

+parse_error:
+ ret = -EINVAL;
error:
free_trace_kprobe(tk);
goto out;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 8f8411e7835f..e11f98c49d72 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -13,6 +13,11 @@

#include "trace_probe.h"

+#undef C
+#define C(a, b) b
+
+static const char *trace_probe_err_text[] = { ERRORS };
+
static const char *reserved_field_names[] = {
"common_type",
"common_flags",
@@ -133,6 +138,60 @@ static const struct fetch_type *find_fetch_type(const char *type)
return NULL;
}

+static struct trace_probe_log trace_probe_log;
+
+void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
+{
+ trace_probe_log.subsystem = subsystem;
+ trace_probe_log.argc = argc;
+ trace_probe_log.argv = argv;
+ trace_probe_log.index = 0;
+}
+
+void trace_probe_log_clear(void)
+{
+ memset(&trace_probe_log, 0, sizeof(trace_probe_log));
+}
+
+void trace_probe_log_set_index(int index)
+{
+ trace_probe_log.index = index;
+}
+
+void __trace_probe_log_err(int offset, int err_type)
+{
+ char *command, *p;
+ int i, len = 0, pos = 0;
+
+ if (!trace_probe_log.argv)
+ return;
+
+ /* Recalcurate the length and allocate buffer */
+ for (i = 0; i < trace_probe_log.argc; i++) {
+ if (i == trace_probe_log.index)
+ pos = len;
+ len += strlen(trace_probe_log.argv[i]) + 1;
+ }
+ command = kzalloc(len, GFP_KERNEL);
+ if (!command)
+ return;
+
+ /* And make a command string from argv array */
+ 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]);
+ p[len] = ' ';
+ p += len + 1;
+ }
+ *(p - 1) = '\0';
+
+ tracing_log_err(trace_probe_log.subsystem, command,
+ trace_probe_err_text, err_type, pos + offset);
+
+ kfree(command);
+}
+
/* Split symbol and offset. */
int traceprobe_split_symbol_offset(char *symbol, long *offset)
{
@@ -156,7 +215,7 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset)

/* @buf must has MAX_EVENT_NAME_LEN size */
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
- char *buf)
+ char *buf, int offset)
{
const char *slash, *event = *pevent;
int len;
@@ -164,32 +223,33 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
slash = strchr(event, '/');
if (slash) {
if (slash == event) {
- pr_info("Group name is not specified\n");
+ trace_probe_log_err(offset, NO_GROUP_NAME);
return -EINVAL;
}
if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
- pr_info("Group name is too long\n");
- return -E2BIG;
+ trace_probe_log_err(offset, GROUP_TOO_LONG);
+ return -EINVAL;
}
strlcpy(buf, event, slash - event + 1);
if (!is_good_name(buf)) {
- pr_info("Group name must follow the same rules as C identifiers\n");
+ trace_probe_log_err(offset, BAD_GROUP_NAME);
return -EINVAL;
}
*pgroup = buf;
*pevent = slash + 1;
+ offset += slash - event + 1;
event = *pevent;
}
len = strlen(event);
if (len == 0) {
- pr_info("Event name is not specified\n");
+ trace_probe_log_err(offset, NO_EVENT_NAME);
return -EINVAL;
} else if (len > MAX_EVENT_NAME_LEN) {
- pr_info("Event name is too long\n");
- return -E2BIG;
+ trace_probe_log_err(offset, EVENT_TOO_LONG);
+ return -EINVAL;
}
if (!is_good_name(event)) {
- pr_info("Event name must follow the same rules as C identifiers\n");
+ trace_probe_log_err(offset, BAD_EVENT_NAME);
return -EINVAL;
}
return 0;
@@ -198,56 +258,67 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
#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)
+ struct fetch_insn *code, unsigned int flags, int offs)
{
unsigned long param;
int ret = 0;
int len;

if (strcmp(arg, "retval") == 0) {
- if (flags & TPARG_FL_RETURN)
+ if (flags & TPARG_FL_RETURN) {
code->op = FETCH_OP_RETVAL;
- else
+ } else {
+ trace_probe_log_err(offs, RETVAL_ON_PROBE);
ret = -EINVAL;
+ }
} else if ((len = str_has_prefix(arg, "stack"))) {
if (arg[len] == '\0') {
code->op = FETCH_OP_STACKP;
} else if (isdigit(arg[len])) {
ret = kstrtoul(arg + len, 10, &param);
- if (ret || ((flags & TPARG_FL_KERNEL) &&
- param > PARAM_MAX_STACK))
+ 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 {
+ } else {
code->op = FETCH_OP_STACK;
code->param = (unsigned int)param;
}
} else
- ret = -EINVAL;
+ goto inval_var;
} else if (strcmp(arg, "comm") == 0) {
code->op = FETCH_OP_COMM;
#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"))) {
- if (!isdigit(arg[len]))
- return -EINVAL;
ret = kstrtoul(arg + len, 10, &param);
- if (ret || !param || param > PARAM_MAX_STACK)
+ if (ret) {
+ goto inval_var;
+ } else if (!param || param > PARAM_MAX_STACK) {
+ trace_probe_log_err(offs, BAD_ARG_NUM);
return -EINVAL;
+ }
code->op = FETCH_OP_ARG;
code->param = (unsigned int)param - 1;
#endif
} else
- ret = -EINVAL;
+ goto inval_var;

return ret;
+
+inval_var:
+ trace_probe_log_err(offs, BAD_VAR);
+ return -EINVAL;
}

/* Recursive argument parser */
static int
parse_probe_arg(char *arg, const struct fetch_type *type,
struct fetch_insn **pcode, struct fetch_insn *end,
- unsigned int flags)
+ unsigned int flags, int offs)
{
struct fetch_insn *code = *pcode;
unsigned long param;
@@ -257,7 +328,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,

switch (arg[0]) {
case '$':
- ret = parse_probe_vars(arg + 1, type, code, flags);
+ ret = parse_probe_vars(arg + 1, type, code, flags, offs);
break;

case '%': /* named register */
@@ -266,47 +337,57 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->op = FETCH_OP_REG;
code->param = (unsigned int)ret;
ret = 0;
- }
+ } else
+ trace_probe_log_err(offs, BAD_REG_NAME);
break;

case '@': /* memory, file-offset or symbol */
if (isdigit(arg[1])) {
ret = kstrtoul(arg + 1, 0, &param);
- if (ret)
+ if (ret) {
+ trace_probe_log_err(offs, BAD_MEM_ADDR);
break;
+ }
/* load address */
code->op = FETCH_OP_IMM;
code->immediate = param;
} else if (arg[1] == '+') {
/* kprobes don't support file offsets */
- if (flags & TPARG_FL_KERNEL)
+ if (flags & TPARG_FL_KERNEL) {
+ trace_probe_log_err(offs, FILE_ON_KPROBE);
return -EINVAL;
-
+ }
ret = kstrtol(arg + 2, 0, &offset);
- if (ret)
+ if (ret) {
+ trace_probe_log_err(offs, BAD_FILE_OFFS);
break;
+ }

code->op = FETCH_OP_FOFFS;
code->immediate = (unsigned long)offset; // imm64?
} else {
/* uprobes don't support symbols */
- if (!(flags & TPARG_FL_KERNEL))
+ if (!(flags & TPARG_FL_KERNEL)) {
+ trace_probe_log_err(offs, SYM_ON_UPROBE);
return -EINVAL;
-
+ }
/* Preserve symbol for updating */
code->op = FETCH_NOP_SYMBOL;
code->data = kstrdup(arg + 1, GFP_KERNEL);
if (!code->data)
return -ENOMEM;
- if (++code == end)
- return -E2BIG;
-
+ if (++code == end) {
+ trace_probe_log_err(offs, TOO_MANY_OPS);
+ return -EINVAL;
+ }
code->op = FETCH_OP_IMM;
code->immediate = 0;
}
/* These are fetching from memory */
- if (++code == end)
- return -E2BIG;
+ if (++code == end) {
+ trace_probe_log_err(offs, TOO_MANY_OPS);
+ return -EINVAL;
+ }
*pcode = code;
code->op = FETCH_OP_DEREF;
code->offset = offset;
@@ -317,28 +398,38 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
/* fall through */
case '-':
tmp = strchr(arg, '(');
- if (!tmp)
+ if (!tmp) {
+ trace_probe_log_err(offs, DEREF_NEED_BRACE);
return -EINVAL;
-
+ }
*tmp = '\0';
ret = kstrtol(arg, 0, &offset);
- if (ret)
+ if (ret) {
+ trace_probe_log_err(offs, BAD_DEREF_OFFS);
break;
-
+ }
+ offs += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
arg = tmp + 1;
tmp = strrchr(arg, ')');
-
- if (tmp) {
+ if (!tmp) {
+ trace_probe_log_err(offs + strlen(arg),
+ DEREF_OPEN_BRACE);
+ return -EINVAL;
+ } else {
const struct fetch_type *t2 = find_fetch_type(NULL);

*tmp = '\0';
- ret = parse_probe_arg(arg, t2, &code, end, flags);
+ ret = parse_probe_arg(arg, t2, &code, end, flags, offs);
if (ret)
break;
- if (code->op == FETCH_OP_COMM)
+ if (code->op == FETCH_OP_COMM) {
+ trace_probe_log_err(offs, COMM_CANT_DEREF);
+ return -EINVAL;
+ }
+ if (++code == end) {
+ trace_probe_log_err(offs, TOO_MANY_OPS);
return -EINVAL;
- if (++code == end)
- return -E2BIG;
+ }
*pcode = code;

code->op = FETCH_OP_DEREF;
@@ -348,6 +439,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
}
if (!ret && code->op == FETCH_OP_NOP) {
/* Parsed, but do not find fetch method */
+ trace_probe_log_err(offs, BAD_FETCH_ARG);
ret = -EINVAL;
}
return ret;
@@ -379,7 +471,7 @@ static int __parse_bitfield_probe_arg(const char *bf,
return -EINVAL;
code++;
if (code->op != FETCH_OP_NOP)
- return -E2BIG;
+ return -EINVAL;
*pcode = code;

code->op = FETCH_OP_MOD_BF;
@@ -392,32 +484,53 @@ static int __parse_bitfield_probe_arg(const char *bf,

/* String length checking wrapper */
static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
- struct probe_arg *parg, unsigned int flags)
+ struct probe_arg *parg, unsigned int flags, int offset)
{
struct fetch_insn *code, *scode, *tmp = NULL;
- char *t, *t2;
+ char *t, *t2, *t3;
int ret, len;

- if (strlen(arg) > MAX_ARGSTR_LEN) {
- pr_info("Argument is too long.: %s\n", arg);
- return -ENOSPC;
+ len = strlen(arg);
+ if (len > MAX_ARGSTR_LEN) {
+ trace_probe_log_err(offset, ARG_TOO_LONG);
+ return -EINVAL;
+ } else if (len == 0) {
+ trace_probe_log_err(offset, NO_ARG_BODY);
+ return -EINVAL;
}
+
parg->comm = kstrdup(arg, GFP_KERNEL);
- if (!parg->comm) {
- pr_info("Failed to allocate memory for command '%s'.\n", arg);
+ if (!parg->comm)
return -ENOMEM;
- }
+
t = strchr(arg, ':');
if (t) {
*t = '\0';
t2 = strchr(++t, '[');
if (t2) {
- *t2 = '\0';
- parg->count = simple_strtoul(t2 + 1, &t2, 0);
- if (strcmp(t2, "]") || parg->count == 0)
+ *t2++ = '\0';
+ t3 = strchr(t2, ']');
+ if (!t3) {
+ offset += t2 + strlen(t2) - arg;
+ trace_probe_log_err(offset,
+ ARRAY_NO_CLOSE);
+ return -EINVAL;
+ } else if (t3[1] != '\0') {
+ trace_probe_log_err(offset + t3 + 1 - arg,
+ BAD_ARRAY_SUFFIX);
+ return -EINVAL;
+ }
+ *t3 = '\0';
+ if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
+ trace_probe_log_err(offset + t2 - arg,
+ BAD_ARRAY_NUM);
return -EINVAL;
- if (parg->count > MAX_ARRAY_LEN)
- return -E2BIG;
+ }
+ if (parg->count > MAX_ARRAY_LEN) {
+ trace_probe_log_err(offset + t2 - arg,
+ ARRAY_TOO_BIG);
+ return -EINVAL;
+ }
}
}
/*
@@ -429,7 +542,7 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
else
parg->type = find_fetch_type(t);
if (!parg->type) {
- pr_info("Unsupported type: %s\n", t);
+ trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE);
return -EINVAL;
}
parg->offset = *size;
@@ -450,7 +563,7 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;

ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
- flags);
+ flags, offset);
if (ret)
goto fail;

@@ -458,7 +571,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
if (!strcmp(parg->type->name, "string")) {
if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM &&
code->op != FETCH_OP_COMM) {
- pr_info("string only accepts memory or address.\n");
+ trace_probe_log_err(offset + (t ? (t - arg) : 0),
+ BAD_STRING);
ret = -EINVAL;
goto fail;
}
@@ -470,7 +584,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
*/
code++;
if (code->op != FETCH_OP_NOP) {
- ret = -E2BIG;
+ trace_probe_log_err(offset, TOO_MANY_OPS);
+ ret = -EINVAL;
goto fail;
}
}
@@ -483,7 +598,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
} else {
code++;
if (code->op != FETCH_OP_NOP) {
- ret = -E2BIG;
+ trace_probe_log_err(offset, TOO_MANY_OPS);
+ ret = -EINVAL;
goto fail;
}
code->op = FETCH_OP_ST_RAW;
@@ -493,20 +609,24 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
/* Modify operation */
if (t != NULL) {
ret = __parse_bitfield_probe_arg(t, parg->type, &code);
- if (ret)
+ if (ret) {
+ trace_probe_log_err(offset + t - arg, BAD_BITFIELD);
goto fail;
+ }
}
/* Loop(Array) operation */
if (parg->count) {
if (scode->op != FETCH_OP_ST_MEM &&
scode->op != FETCH_OP_ST_STRING) {
- pr_info("array only accepts memory or address\n");
+ trace_probe_log_err(offset + (t ? (t - arg) : 0),
+ BAD_STRING);
ret = -EINVAL;
goto fail;
}
code++;
if (code->op != FETCH_OP_NOP) {
- ret = -E2BIG;
+ trace_probe_log_err(offset, TOO_MANY_OPS);
+ ret = -EINVAL;
goto fail;
}
code->op = FETCH_OP_LP_ARRAY;
@@ -555,15 +675,19 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
{
struct probe_arg *parg = &tp->args[i];
char *body;
- int ret;

/* Increment count for freeing args in error case */
tp->nr_args++;

body = strchr(arg, '=');
if (body) {
- if (body - arg > MAX_ARG_NAME_LEN || body == arg)
+ if (body - arg > MAX_ARG_NAME_LEN) {
+ trace_probe_log_err(0, ARG_NAME_TOO_LONG);
+ return -EINVAL;
+ } else if (body == arg) {
+ trace_probe_log_err(0, NO_ARG_NAME);
return -EINVAL;
+ }
parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
body++;
} else {
@@ -575,22 +699,16 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
return -ENOMEM;

if (!is_good_name(parg->name)) {
- pr_info("Invalid argument[%d] name: %s\n",
- i, parg->name);
+ trace_probe_log_err(0, BAD_ARG_NAME);
return -EINVAL;
}
-
if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
- pr_info("Argument[%d]: '%s' conflicts with another field.\n",
- i, parg->name);
+ trace_probe_log_err(0, USED_ARG_NAME);
return -EINVAL;
}
-
/* Parse fetch argument */
- ret = traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags);
- if (ret)
- pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
- return ret;
+ return traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags,
+ body - arg);
}

void traceprobe_free_probe_arg(struct probe_arg *arg)
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 2177c206de15..b7737666c1a8 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -280,8 +280,8 @@ extern int traceprobe_update_arg(struct probe_arg *arg);
extern void traceprobe_free_probe_arg(struct probe_arg *arg);

extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
-extern int traceprobe_parse_event_name(const char **pevent,
- const char **pgroup, char *buf);
+int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
+ char *buf, int offset);

extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);

@@ -298,3 +298,76 @@ extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
#endif
extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
size_t offset, struct trace_probe *tp);
+
+#undef ERRORS
+#define ERRORS \
+ C(FILE_NOT_FOUND, "Failed to find the given file"), \
+ C(NO_REGULAR_FILE, "Not a regular file"), \
+ C(BAD_REFCNT, "Invalid reference counter offset"), \
+ C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \
+ C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \
+ C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \
+ C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \
+ C(BAD_MAXACT, "Invalid maxactive number"), \
+ C(MAXACT_TOO_BIG, "Maxactive is too big"), \
+ C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
+ C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
+ C(NO_GROUP_NAME, "Group name is not specified"), \
+ C(GROUP_TOO_LONG, "Group name is too long"), \
+ C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \
+ C(NO_EVENT_NAME, "Event name is not specified"), \
+ C(EVENT_TOO_LONG, "Event name is too long"), \
+ C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \
+ C(RETVAL_ON_PROBE, "$retval is not available on probe"), \
+ C(BAD_STACK_NUM, "Invalid stack number"), \
+ C(BAD_ARG_NUM, "Invalid argument number"), \
+ C(BAD_VAR, "Invalid $-valiable specified"), \
+ C(BAD_REG_NAME, "Invalid register name"), \
+ C(BAD_MEM_ADDR, "Invalid memory address"), \
+ C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \
+ C(BAD_FILE_OFFS, "Invalid file offset value"), \
+ C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \
+ C(TOO_MANY_OPS, "Dereference is too much nested"), \
+ C(DEREF_NEED_BRACE, "Dereference needs a brace"), \
+ C(BAD_DEREF_OFFS, "Invalid dereference offset"), \
+ C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \
+ C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \
+ C(BAD_FETCH_ARG, "Invalid fetch argument"), \
+ C(ARRAY_NO_CLOSE, "Array is not closed"), \
+ C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \
+ C(BAD_ARRAY_NUM, "Invalid array size"), \
+ C(ARRAY_TOO_BIG, "Array number is too big"), \
+ C(BAD_TYPE, "Unknown type is specified"), \
+ C(BAD_STRING, "String accepts only memory argument"), \
+ C(BAD_BITFIELD, "Invalid bitfield"), \
+ C(ARG_NAME_TOO_LONG, "Argument name is too long"), \
+ C(NO_ARG_NAME, "Argument name is not specified"), \
+ C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \
+ C(USED_ARG_NAME, "This argument name is already used"), \
+ C(ARG_TOO_LONG, "Argument expression is too long"), \
+ C(NO_ARG_BODY, "No argument expression"), \
+ C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\
+ C(FAIL_REG_PROBE, "Failed to register probe event"),
+
+#undef C
+#define C(a, b) TP_ERR_##a
+
+/* Define TP_ERR_ */
+enum { ERRORS };
+
+/* Error text is defined in trace_probe.c */
+
+struct trace_probe_log {
+ const char *subsystem;
+ const char **argv;
+ int argc;
+ int index;
+};
+
+void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
+void trace_probe_log_set_index(int index);
+void trace_probe_log_clear(void);
+void __trace_probe_log_err(int offset, int err);
+
+#define trace_probe_log_err(offs, err) \
+ __trace_probe_log_err(offs, TP_ERR_##err)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index b54137ec7810..9fb1f8a5c154 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -450,13 +450,19 @@ static int trace_uprobe_create(int argc, const char **argv)
return -ECANCELED;
}

+ trace_probe_log_init("trace_uprobe", argc, argv);
+ trace_probe_log_set_index(1); /* filename is the 2nd argument */
+
*arg++ = '\0';
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret) {
+ trace_probe_log_err(0, FILE_NOT_FOUND);
kfree(filename);
+ trace_probe_log_clear();
return ret;
}
if (!d_is_reg(path.dentry)) {
+ trace_probe_log_err(0, NO_REGULAR_FILE);
ret = -EINVAL;
goto fail_address_parse;
}
@@ -465,9 +471,16 @@ static int trace_uprobe_create(int argc, const char **argv)
rctr = strchr(arg, '(');
if (rctr) {
rctr_end = strchr(rctr, ')');
- if (rctr > rctr_end || *(rctr_end + 1) != 0) {
+ if (!rctr_end) {
+ ret = -EINVAL;
+ rctr_end = rctr + strlen(rctr);
+ trace_probe_log_err(rctr_end - filename,
+ REFCNT_OPEN_BRACE);
+ goto fail_address_parse;
+ } else if (rctr_end[1] != '\0') {
ret = -EINVAL;
- pr_info("Invalid reference counter offset.\n");
+ trace_probe_log_err(rctr_end + 1 - filename,
+ BAD_REFCNT_SUFFIX);
goto fail_address_parse;
}

@@ -475,22 +488,23 @@ static int trace_uprobe_create(int argc, const char **argv)
*rctr_end = '\0';
ret = kstrtoul(rctr, 0, &ref_ctr_offset);
if (ret) {
- pr_info("Invalid reference counter offset.\n");
+ trace_probe_log_err(rctr - filename, BAD_REFCNT);
goto fail_address_parse;
}
}

/* Parse uprobe offset. */
ret = kstrtoul(arg, 0, &offset);
- if (ret)
+ if (ret) {
+ trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
goto fail_address_parse;
-
- argc -= 2;
- argv += 2;
+ }

/* setup a probe */
+ trace_probe_log_set_index(0);
if (event) {
- ret = traceprobe_parse_event_name(&event, &group, buf);
+ ret = traceprobe_parse_event_name(&event, &group, buf,
+ event - argv[0]);
if (ret)
goto fail_address_parse;
} else {
@@ -512,6 +526,9 @@ static int trace_uprobe_create(int argc, const char **argv)
kfree(tail);
}

+ argc -= 2;
+ argv += 2;
+
tu = alloc_trace_uprobe(group, event, argc, is_return);
if (IS_ERR(tu)) {
ret = PTR_ERR(tu);
@@ -532,6 +549,7 @@ static int trace_uprobe_create(int argc, const char **argv)
goto error;
}

+ trace_probe_log_set_index(i + 2);
ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
is_return ? TPARG_FL_RETURN : 0);
kfree(tmp);
@@ -540,20 +558,20 @@ static int trace_uprobe_create(int argc, const char **argv)
}

ret = register_trace_uprobe(tu);
- if (ret)
- goto error;
- return 0;
+ if (!ret)
+ goto out;

error:
free_trace_uprobe(tu);
+out:
+ trace_probe_log_clear();
return ret;

fail_address_parse:
+ trace_probe_log_clear();
path_put(&path);
kfree(filename);

- pr_info("Failed to parse address or file.\n");
-
return ret;
}

--
2.14.1