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2017-05-17tunables: Add support for tunables of uint64_t typeSiddhesh Poyarekar1-1/+2
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.
2017-05-17tunables: Specify a default value for tunablesSiddhesh Poyarekar1-0/+2
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.
2017-03-24Update old tunables framework document/script.Sunyeop Lee1-7/+7
Since commit 8b9e9c3c0bae497ad5e2d0ae2f333f62feddcc12, 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.
2016-12-31Add framework for tunablesSiddhesh Poyarekar1-0/+85
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.