[tip:perf/core] parse-events: Handle invalid opcode parsing gracefully

From: tip-bot for Vaibhav Nagarnaik
Date: Mon May 21 2012 - 05:39:38 EST

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Commit-ID: d69afed55be1016c2bcfcb3e00cd5365d2f557f6
Gitweb: http://git.kernel.org/tip/d69afed55be1016c2bcfcb3e00cd5365d2f557f6
Author: Vaibhav Nagarnaik <vnagarnaik@xxxxxxxxxx>
AuthorDate: Fri, 6 Apr 2012 00:48:00 +0200
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Wed, 25 Apr 2012 13:35:28 +0200

parse-events: Handle invalid opcode parsing gracefully

If an invalid opcode is encountered, trace-cmd exits with an error.
Instead it can be treated as a soft error where the event's print format
is not parsed and its binary data is dumped out.

This patch adds a return value to arg_num_eval() function to indicate if
the parsing was successful. If not, then the error is considered soft
and the parsing of the offending event fails.

Cc: Michael Rubin <mrubin@xxxxxxxxxx>
Cc: David Sharp <dhsharp@xxxxxxxxxx>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1310785241-3799-2-git-send-email-vnagarnaik@xxxxxxxxxx
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Arun Sharma <asharma@xxxxxx>
Cc: Namhyung Kim <namhyung.kim@xxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
tools/lib/traceevent/event-parse.c | 125 ++++++++++++++++++++++++------------
1 files changed, 83 insertions(+), 42 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 16da20c..ef2c65f 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -1915,90 +1915,120 @@ eval_type(unsigned long long val, struct print_arg *arg, int pointer)
return eval_type_str(val, arg->typecast.type, pointer);
}

-static long long arg_num_eval(struct print_arg *arg)
+static int arg_num_eval(struct print_arg *arg, long long *val)
{
long long left, right;
- long long val = 0;
+ int ret = 1;

switch (arg->type) {
case PRINT_ATOM:
- val = strtoll(arg->atom.atom, NULL, 0);
+ *val = strtoll(arg->atom.atom, NULL, 0);
break;
case PRINT_TYPE:
- val = arg_num_eval(arg->typecast.item);
- val = eval_type(val, arg, 0);
+ ret = arg_num_eval(arg->typecast.item, val);
+ if (!ret)
+ break;
+ *val = eval_type(*val, arg, 0);
break;
case PRINT_OP:
switch (arg->op.op[0]) {
case '|':
- left = arg_num_eval(arg->op.left);
- right = arg_num_eval(arg->op.right);
+ ret = arg_num_eval(arg->op.left, &left);
+ if (!ret)
+ break;
+ ret = arg_num_eval(arg->op.right, &right);
+ if (!ret)
+ break;
if (arg->op.op[1])
- val = left || right;
+ *val = left || right;
else
- val = left | right;
+ *val = left | right;
break;
case '&':
- left = arg_num_eval(arg->op.left);
- right = arg_num_eval(arg->op.right);
+ ret = arg_num_eval(arg->op.left, &left);
+ if (!ret)
+ break;
+ ret = arg_num_eval(arg->op.right, &right);
+ if (!ret)
+ break;
if (arg->op.op[1])
- val = left && right;
+ *val = left && right;
else
- val = left & right;
+ *val = left & right;
break;
case '<':
- left = arg_num_eval(arg->op.left);
- right = arg_num_eval(arg->op.right);
+ ret = arg_num_eval(arg->op.left, &left);
+ if (!ret)
+ break;
+ ret = arg_num_eval(arg->op.right, &right);
+ if (!ret)
+ break;
switch (arg->op.op[1]) {
case 0:
- val = left < right;
+ *val = left < right;
break;
case '<':
- val = left << right;
+ *val = left << right;
break;
case '=':
- val = left <= right;
+ *val = left <= right;
break;
default:
- die("unknown op '%s'", arg->op.op);
+ do_warning("unknown op '%s'", arg->op.op);
+ ret = 0;
}
break;
case '>':
- left = arg_num_eval(arg->op.left);
- right = arg_num_eval(arg->op.right);
+ ret = arg_num_eval(arg->op.left, &left);
+ if (!ret)
+ break;
+ ret = arg_num_eval(arg->op.right, &right);
+ if (!ret)
+ break;
switch (arg->op.op[1]) {
case 0:
- val = left > right;
+ *val = left > right;
break;
case '>':
- val = left >> right;
+ *val = left >> right;
break;
case '=':
- val = left >= right;
+ *val = left >= right;
break;
default:
- die("unknown op '%s'", arg->op.op);
+ do_warning("unknown op '%s'", arg->op.op);
+ ret = 0;
}
break;
case '=':
- left = arg_num_eval(arg->op.left);
- right = arg_num_eval(arg->op.right);
-
- if (arg->op.op[1] != '=')
- die("unknown op '%s'", arg->op.op);
+ ret = arg_num_eval(arg->op.left, &left);
+ if (!ret)
+ break;
+ ret = arg_num_eval(arg->op.right, &right);
+ if (!ret)
+ break;

- val = left == right;
+ if (arg->op.op[1] != '=') {
+ do_warning("unknown op '%s'", arg->op.op);
+ ret = 0;
+ } else
+ *val = left == right;
break;
case '!':
- left = arg_num_eval(arg->op.left);
- right = arg_num_eval(arg->op.right);
+ ret = arg_num_eval(arg->op.left, &left);
+ if (!ret)
+ break;
+ ret = arg_num_eval(arg->op.right, &right);
+ if (!ret)
+ break;

switch (arg->op.op[1]) {
case '=':
- val = left != right;
+ *val = left != right;
break;
default:
- die("unknown op '%s'", arg->op.op);
+ do_warning("unknown op '%s'", arg->op.op);
+ ret = 0;
}
break;
case '-':
@@ -2006,12 +2036,17 @@ static long long arg_num_eval(struct print_arg *arg)
if (arg->op.left->type == PRINT_NULL)
left = 0;
else
- left = arg_num_eval(arg->op.left);
- right = arg_num_eval(arg->op.right);
- val = left - right;
+ ret = arg_num_eval(arg->op.left, &left);
+ if (!ret)
+ break;
+ ret = arg_num_eval(arg->op.right, &right);
+ if (!ret)
+ break;
+ *val = left - right;
break;
default:
- die("unknown op '%s'", arg->op.op);
+ do_warning("unknown op '%s'", arg->op.op);
+ ret = 0;
}
break;

@@ -2020,10 +2055,11 @@ static long long arg_num_eval(struct print_arg *arg)
case PRINT_STRING:
case PRINT_BSTRING:
default:
- die("invalid eval type %d", arg->type);
+ do_warning("invalid eval type %d", arg->type);
+ ret = 0;

}
- return val;
+ return ret;
}

static char *arg_eval (struct print_arg *arg)
@@ -2037,7 +2073,8 @@ static char *arg_eval (struct print_arg *arg)
case PRINT_TYPE:
return arg_eval(arg->typecast.item);
case PRINT_OP:
- val = arg_num_eval(arg);
+ if (!arg_num_eval(arg, &val))
+ break;
sprintf(buf, "%lld", val);
return buf;

@@ -2079,6 +2116,8 @@ process_fields(struct event_format *event, struct print_flag_sym **list, char **
memset(field, 0, sizeof(*field));

value = arg_eval(arg);
+ if (value == NULL)
+ goto out_free;
field->value = strdup(value);

free_arg(arg);
@@ -2090,6 +2129,8 @@ process_fields(struct event_format *event, struct print_flag_sym **list, char **
goto out_free;

value = arg_eval(arg);
+ if (value == NULL)
+ goto out_free;
field->str = strdup(value);
free_arg(arg);
arg = NULL;
--
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Next message: Richard Zhao: "Re: [PATCH 2/2] mfd: anatop: permit adata be NULL when accessregister"
Previous message: Johannes Weiner: "Re: [PATCH] mm: consider all swapped back pages in used-once logic"
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