glibc/elf/dl-tunable-types.h
Siddhesh Poyarekar d1a3dcabf2 tunables: Fix comparison of tunable values
The simplification of tunable_set interfaces took care of
signed/unsigned conversions while setting values, but comparison with
bounds ended up being incorrect; comparing TUNABLE_SIZE_T values for
example will fail because SIZE_MAX is seen as -1.

Add comparison helpers that take tunable types into account and use
them to do comparison instead.
2021-04-07 14:06:18 +05:30

102 lines
2.9 KiB
C

/* Internal representation of tunables.
Copyright (C) 2016-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _TUNABLE_TYPES_H_
#define _TUNABLE_TYPES_H_
/* Note: This header is included in the generated dl-tunables-list.h and
only used internally in the tunables implementation in dl-tunables.c. */
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
typedef enum
{
TUNABLE_TYPE_INT_32,
TUNABLE_TYPE_UINT_64,
TUNABLE_TYPE_SIZE_T,
TUNABLE_TYPE_STRING
} tunable_type_code_t;
typedef struct
{
tunable_type_code_t type_code;
tunable_num_t min;
tunable_num_t max;
} tunable_type_t;
/* Security level for tunables. This decides what to do with individual
tunables for AT_SECURE binaries. */
typedef enum
{
/* Erase the tunable for AT_SECURE binaries so that child processes don't
read it. */
TUNABLE_SECLEVEL_SXID_ERASE = 0,
/* Ignore the tunable for AT_SECURE binaries, but don't erase it, so that
child processes can read it. */
TUNABLE_SECLEVEL_SXID_IGNORE = 1,
/* Read the tunable. */
TUNABLE_SECLEVEL_NONE = 2,
} tunable_seclevel_t;
/* A tunable. */
struct _tunable
{
const char name[TUNABLE_NAME_MAX]; /* Internal name of the tunable. */
tunable_type_t type; /* Data type of the tunable. */
tunable_val_t val; /* The value. */
bool initialized; /* Flag to indicate that the tunable is
initialized. */
tunable_seclevel_t security_level; /* Specify the security level for the
tunable with respect to AT_SECURE
programs. See description of
tunable_seclevel_t to see a
description of the values.
Note that even if the tunable is
read, it may not get used by the
target module if the value is
considered unsafe. */
/* Compatibility elements. */
const char env_alias[TUNABLE_ALIAS_MAX]; /* The compatibility environment
variable name. */
};
typedef struct _tunable tunable_t;
static __always_inline bool
unsigned_tunable_type (tunable_type_code_t t)
{
switch (t)
{
case TUNABLE_TYPE_INT_32:
return false;
case TUNABLE_TYPE_UINT_64:
case TUNABLE_TYPE_SIZE_T:
return true;
case TUNABLE_TYPE_STRING:
default:
break;
}
__builtin_unreachable ();
}
#endif