Instead of ignoring ill-formatted tunable strings, first, check all the
tunable definitions are correct and then set each tunable value. It
means that partially invalid strings, like "key1=value1:key2=key2=value'
or 'key1=value':key2=value2=value2' do not enable 'key1=value1'. It
avoids possible user-defined errors in tunable definitions.
Checked on x86_64-linux-gnu.
---
elf/dl-tunables.c | 50 +++++++++++++++++++++++++++++++++++-----------
elf/tst-tunables.c | 13 ++++++++----
2 files changed, 47 insertions(+), 16 deletions(-)
@@ -154,17 +154,29 @@ __tunable_set_val (tunable_id_t id, tunable_val_t *valp, tunable_num_t *minp,
do_tunable_update_val (cur, valp, minp, maxp);
}
-/* Parse the tunable string VALSTRING. VALSTRING is a duplicated values,
- where delimiters ':' are replaced with '\0', so string tunables are null
- terminated. */
-static void
-parse_tunables (char *valstring)
+struct tunable_toset_t
+{
+ tunable_t *t;
+ const char *value;
+};
+
+enum { tunables_list_size = array_length (tunable_list) };
+
+/* Parse the tunable string VALSTRING and set TUNABLES with the found tunables
+ and their respectibles values. VALSTRING is a duplicated values, where
+ delimiters ':' are replaced with '\0', so string tunables are null
+ terminated.
+ Return the number of tunables found (including 0 if the string is empty)
+ or -1 if for a ill-formatted definition. */
+static int
+parse_tunables_string (char *valstring, struct tunable_toset_t *tunables)
{
if (valstring == NULL || *valstring == '\0')
- return;
+ return 0;
char *p = valstring;
bool done = false;
+ int ntunables = 0;
while (!done)
{
@@ -177,7 +189,7 @@ parse_tunables (char *valstring)
/* If we reach the end of the string before getting a valid name-value
pair, bail out. */
if (*p == '\0')
- break;
+ return -1;
/* We did not find a valid name-value pair before encountering the
colon. */
@@ -190,30 +202,44 @@ parse_tunables (char *valstring)
/* Skip the ':' or '='. */
p++;
- const char *value = p;
+ char *value = p;
while (*p != '=' && *p != ':' && *p != '\0')
p++;
if (*p == '=')
- break;
+ return -1;
else if (*p == '\0')
done = true;
else
*p++ = '\0';
/* Add the tunable if it exists. */
- for (size_t i = 0; i < sizeof (tunable_list) / sizeof (tunable_t); i++)
+ for (size_t i = 0; i < tunables_list_size; i++)
{
tunable_t *cur = &tunable_list[i];
if (tunable_is_name (cur->name, name))
{
- tunable_initialize (cur, value);
+ tunables[ntunables++] = (struct tunable_toset_t) { cur, value };
break;
}
}
}
+
+ return ntunables;
+}
+
+static void
+parse_tunables (char *valstring)
+{
+ struct tunable_toset_t tunables[tunables_list_size];
+ int ntunables = parse_tunables_string (valstring, tunables);
+ if (ntunables == -1)
+ return;
+
+ for (int i = 0; i < ntunables; i++)
+ tunable_initialize (tunables[i].t, tunables[i].value);
}
/* Initialize the tunables list from the environment. For now we only use the
@@ -240,7 +266,7 @@ __tunables_init (char **envp)
continue;
}
- for (int i = 0; i < sizeof (tunable_list) / sizeof (tunable_t); i++)
+ for (int i = 0; i < tunables_list_size; i++)
{
tunable_t *cur = &tunable_list[i];
@@ -160,7 +160,7 @@ static const struct test_t
0,
0,
},
- /* If there is a ill-formatted key=value, everything after is also ignored. */
+ /* Ill-formatted tunables string is not parsed. */
{
"glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096:glibc.malloc.check=2",
0,
@@ -185,13 +185,18 @@ static const struct test_t
0,
0,
},
- /* Valid tunables set before ill-formatted ones are set. */
{
"glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096",
- 2,
0,
0,
- }
+ 0,
+ },
+ {
+ "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096",
+ 0,
+ 0,
+ 0,
+ },
};
static int