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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 /scripts | |
| parent | 592d5c75392e1da170050a4999af0618c4865aed (diff) | |
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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 'scripts')
| -rw-r--r-- | scripts/gen-tunables.awk | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/scripts/gen-tunables.awk b/scripts/gen-tunables.awk index ccdd0c6c71..622199061a 100644 --- a/scripts/gen-tunables.awk +++ b/scripts/gen-tunables.awk @@ -1,6 +1,14 @@ # Generate dl-tunable-list.h from dl-tunables.list BEGIN { + min_of["STRING"]="0" + max_of["STRING"]="0" + min_of["INT_32"]="INT32_MIN" + max_of["INT_32"]="INT32_MAX" + min_of["UINT_64"]="0" + max_of["UINT_64"]="UINT64_MAX" + min_of["SIZE_T"]="0" + max_of["SIZE_T"]="SIZE_MAX" tunable="" ns="" top_ns="" @@ -43,10 +51,10 @@ $1 == "}" { types[top_ns,ns,tunable] = "STRING" } if (!minvals[top_ns,ns,tunable]) { - minvals[top_ns,ns,tunable] = "0" + minvals[top_ns,ns,tunable] = min_of[types[top_ns,ns,tunable]] } if (!maxvals[top_ns,ns,tunable]) { - maxvals[top_ns,ns,tunable] = "0" + maxvals[top_ns,ns,tunable] = max_of[types[top_ns,ns,tunable]] } if (!env_alias[top_ns,ns,tunable]) { env_alias[top_ns,ns,tunable] = "NULL" |