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| author |   Alexey Makhalov <amakhalov@vmware.com> | 2017-09-27 02:44:09 +0530 |
|---|---|---|
| committer |   Siddhesh Poyarekar <siddhesh@sourceware.org> | 2017-09-27 02:44:09 +0530 |
| commit | cebcb9f864d4ca29e155363e71b7de6826d13cf1 (patch) | |
| tree | 5e2b25a46cbcb31b4a5e280db71641b8d7df22bf /elf | |
| parent | Skip PT_DYNAMIC segment with p_filesz == 0 [BZ #22101] (diff) | |
| download | glibc-cebcb9f864d4ca29e155363e71b7de6826d13cf1.tar.gz glibc-cebcb9f864d4ca29e155363e71b7de6826d13cf1.tar.bz2 glibc-cebcb9f864d4ca29e155363e71b7de6826d13cf1.zip | |
Fix range check in do_tunable_update_val
Current implementation of tunables does not set arena_max and arena_test
values. Any value provided by glibc.malloc.arena_max and
glibc.malloc.arena_test parameters is ignored.
These tunables have minval value set to 1 (see elf/dl-tunables.list file)
and undefined maxval value. In that case default value (which is 0. see
scripts/gen-tunables.awk) is being used to set maxval.
For instance, generated tunable_list[] entry for arena_max is:
(gdb) p *cur
$1 = {name = 0x7ffff7df6217 "glibc.malloc.arena_max",
type = {type_code = TUNABLE_TYPE_SIZE_T, min = 1, max = 0},
val = {numval = 0, strval = 0x0}, initialized = false,
security_level = TUNABLE_SECLEVEL_SXID_IGNORE,
env_alias = 0x7ffff7df622e "MALLOC_ARENA_MAX"}
As a result, any value of glibc.malloc.arena_max is ignored by
TUNABLE_SET_VAL_IF_VALID_RANGE macro
__type min = (__cur)->type.min; <- initialized to 1
__type max = (__cur)->type.max; <- initialized to 0!
if (min == max) <- false
{
min = __default_min;
max = __default_max;
}
if ((__type) (__val) >= min && (__type) (val) <= max) <- false
{
(__cur)->val.numval = val;
(__cur)->initialized = true;
}
Assigning correct min/max values at a build time fixes a problem.
Plus, a bit of optimization: Setting of default min/max values for the
given type at a run time might be eliminated.
* elf/dl-tunables.c (do_tunable_update_val): Range checking fix.
* scripts/gen-tunables.awk: Set unspecified minval and/or maxval
values to correct default value for given type.
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/dl-tunables.c | 15 |
1 files changed, 4 insertions, 11 deletions
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index b964a09413..cc2c637543 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -89,18 +89,11 @@ get_next_env (char **envp, char **name, size_t *namelen, char **val, return NULL; } -#define TUNABLE_SET_VAL_IF_VALID_RANGE(__cur, __val, __type, __default_min, \ - __default_max) \ +#define TUNABLE_SET_VAL_IF_VALID_RANGE(__cur, __val, __type) \ ({ \ __type min = (__cur)->type.min; \ __type max = (__cur)->type.max; \ \ - if (min == max) \ - { \ - min = __default_min; \ - max = __default_max; \ - } \ - \ if ((__type) (__val) >= min && (__type) (val) <= max) \ { \ (__cur)->val.numval = val; \ @@ -120,17 +113,17 @@ do_tunable_update_val (tunable_t *cur, const void *valp) { case TUNABLE_TYPE_INT_32: { - TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, int64_t, INT32_MIN, INT32_MAX); + TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, int64_t); break; } case TUNABLE_TYPE_UINT_64: { - TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, uint64_t, 0, UINT64_MAX); + TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, uint64_t); break; } case TUNABLE_TYPE_SIZE_T: { - TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, uint64_t, 0, SIZE_MAX); + TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, uint64_t); break; } case TUNABLE_TYPE_STRING: |