glibc/elf/dl-tunable-types.h
Siddhesh Poyarekar ad2f35cb39 tunables: Add support for tunables of uint64_t type
Recognize the uint64_t type in addition to the current int32_t and
size_t.  This allows addition of tunables of uint64_t types.  In
addition to adding the uint64_t type, this patch also consolidates
validation and reading of integer types in tunables.

One notable change is that of overflow computation in
tunables_strtoul.  The function was lifted from __internal_strtoul,
but it does not need the boundary condition check (i.e. result ==
ULONG_MAX) since it does not need to set errno.  As a result the check
can be simplified, which I have now done.

	* elf/dl-tunable-types.h (tunable_type_code_t): New type
	TUNABLE_TYPE_UINT_64.
	* elf/dl-tunables.c (tunables_strtoul): Return uint64_t.
	Simplify computation of overflow.
	(tunable_set_val_if_valid_range_signed,
	tunable_set_val_if_valid_range_unsigned): Remove and replace
	with this...
	(TUNABLE_SET_VAL_IF_VALID_RANGE): ... New macro.
	(tunable_initialize): Adjust.  Add uint64_t support.
	(__tunable_set_val): Add uint64_t support.
	* README.tunables: Document it.
2017-05-17 13:11:55 +05:30

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C

/* Tunable type information.
Copyright (C) 2016-2017 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
<http://www.gnu.org/licenses/>. */
#ifndef _TUNABLE_TYPES_H_
# define _TUNABLE_TYPES_H_
#include <stddef.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;
int64_t min;
int64_t max;
} tunable_type_t;
typedef union
{
int64_t numval;
const char *strval;
} tunable_val_t;
typedef void (*tunable_callback_t) (tunable_val_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;
#endif