Commit Graph

4 Commits

Author SHA1 Message Date
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
Siddhesh Poyarekar
d13103074a tunables: Specify a default value for tunables
Enhance dl-tunables.list to allow specifying a default value for a
tunable that it would be initialized to.

	* scripts/gen-tunables.awk: Recognize 'default' keyword in
	dl-tunables.list.
	* README.tunables: Document it.
2017-05-17 13:11:00 +05:30
Sunyeop Lee
65eff7fbdb Update old tunables framework document/script.
Since commit 8b9e9c3c0b, security_level replaces
is_secure. There were some old files need to be updated.

2017-03-23  Sunyeop Lee  <sunyeop97@gmail.com>

	* README.tunables: Updated descriptions.
	* elf/dl-tunables.list: Fixed typo: SXID_NONE -> NONE.
	* scripts/gen-tunables.awk: Updated the code related to the commit.
2017-03-24 11:08:28 +05:30
Siddhesh Poyarekar
67e58f3941 Add framework for tunables
The tunables framework allows us to uniformly manage and expose global
variables inside glibc as switches to users.  tunables/README has
instructions for glibc developers to add new tunables.

Tunables support can be enabled by passing the --enable-tunables
configure flag to the configure script.  This patch only adds a
framework and does not pose any limitations on how tunable values are
read from the user.  It also adds environment variables used in malloc
behaviour tweaking to the tunables framework as a PoC of the
compatibility interface.

	* manual/install.texi: Add --enable-tunables option.
	* INSTALL: Regenerate.
	* README.tunables: New file.
	* Makeconfig (CPPFLAGS): Define TOP_NAMESPACE.
	(before-compile): Generate dl-tunable-list.h early.
	* config.h.in: Add HAVE_TUNABLES.
	* config.make.in: Add have-tunables.
	* configure.ac: Add --enable-tunables option.
	* configure: Regenerate.
	* csu/init-first.c (__libc_init_first): Move
	__libc_init_secure earlier...
	* csu/init-first.c (LIBC_START_MAIN):... to here.
	Include dl-tunables.h, libc-internal.h.
	(LIBC_START_MAIN) [!SHARED]: Initialize tunables for static
	binaries.
	* elf/Makefile (dl-routines): Add dl-tunables.
	* elf/Versions (ld): Add __tunable_set_val to GLIBC_PRIVATE
	namespace.
	* elf/dl-support (_dl_nondynamic_init): Unset MALLOC_CHECK_
	only when !HAVE_TUNABLES.
	* elf/rtld.c (process_envvars): Likewise.
	* elf/dl-sysdep.c [HAVE_TUNABLES]: Include dl-tunables.h
	(_dl_sysdep_start): Call __tunables_init.
	* elf/dl-tunable-types.h: New file.
	* elf/dl-tunables.c: New file.
	* elf/dl-tunables.h: New file.
	* elf/dl-tunables.list: New file.
	* malloc/tst-malloc-usable-static.c: New test case.
	* malloc/Makefile (tests-static): Add it.
	* malloc/arena.c [HAVE_TUNABLES]: Include dl-tunables.h.
	Define TUNABLE_NAMESPACE.
	(DL_TUNABLE_CALLBACK (set_mallopt_check)): New function.
	(DL_TUNABLE_CALLBACK_FNDECL): New macro.  Use it to define
	callback functions.
	(ptmalloc_init): Set tunable values.
	* scripts/gen-tunables.awk: New file.
	* sysdeps/mach/hurd/dl-sysdep.c: Include dl-tunables.h.
	(_dl_sysdep_start): Call __tunables_init.
2016-12-31 23:49:24 +05:30