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2018-03-26RISC-V: add remaining relocationsAndreas Schwab1-12/+56
2018-03-24Add $(tests-execstack-$(have-z-execstack)) after defined [BZ #22998]H.J. Lu1-1/+2
When $(tests-execstack-$(have-z-execstack)) is added to tests before it is defined, it is empty. This patch adds it to tests after it is defined. [BZ #22998] * elf/Makefile (tests): Add $(tests-execstack-$(have-z-execstack)) after it is defined.
2018-03-19Add SHT_X86_64_UNWIND to elf.h (bug 20079).Joseph Myers1-0/+3
As requested in bug 20079, this patch adds SHT_X86_64_UNWIND (a standard value from the x86_64 ABI) to elf.h. Tested for x86_64. [BZ #20079] * elf/elf.h (SHT_X86_64_UNWIND): New macro.
2018-03-11hurd: add gscope supportSamuel Thibault1-0/+3
* elf/dl-support.c [!THREAD_GSCOPE_IN_TCB] (_dl_thread_gscope_count): Define variable. * sysdeps/generic/ldsodefs.h [!THREAD_GSCOPE_IN_TCB] (struct rtld_global): Add _dl_thread_gscope_count member. * sysdeps/mach/hurd/tls.h: Include <atomic.h>. [!defined __ASSEMBLER__] (THREAD_GSCOPE_GLOBAL, THREAD_GSCOPE_SET_FLAG, THREAD_GSCOPE_RESET_FLAG, THREAD_GSCOPE_WAIT): Define macros. * sysdeps/generic/tls.h: Document THREAD_GSCOPE_IN_TCB. * sysdeps/aarch64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/alpha/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/arm/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/hppa/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/i386/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/ia64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/m68k/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/microblaze/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/mips/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/nios2/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/powerpc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/riscv/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/s390/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/sh/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/sparc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/tile/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/x86_64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
2018-02-21ldconfig: Sync temporary files to disk before renaming them [BZ #20890]Florian Weimer1-3/+7
If the system crashes before the file data has been written to disk, the file system recovery upon the next mount may restore a partially rewritten temporary file under the non-temporary (final) name (after the rename operation).
2018-02-21elf: Remove ad-hoc restrictions on dlopen callers [BZ #22787]Florian Weimer5-105/+1
This looks like a post-exploitation hardening measure: If an attacker is able to redirect execution flow, they could use that to load a DSO which contains additional code (or perhaps make the stack executable). However, the checks are not in the correct place to be effective: If they are performed before the critical operation, an attacker with sufficient control over execution flow could simply jump directly to the code which performs the operation, bypassing the check. The check would have to be executed unconditionally after the operation and terminate the process in case a caller violation was detected. Furthermore, in _dl_check_caller, there was a fallback reading global writable data (GL(dl_rtld_map).l_map_start and GL(dl_rtld_map).l_text_end), which could conceivably be targeted by an attacker to disable the check, too. Other critical functions (such as system) remain completely unprotected, so the value of these additional checks does not appear that large. Therefore this commit removes this functionality.
2018-02-06Add elf.h NT_* macros from Linux 4.15 (bug 14890).Joseph Myers1-0/+9
Linux 4.15 adds NT_S390_RI_CB to linux/elf.h (and NT_ARM_SVE, which we already have in glibc). This shows up that various other ELF note values from linux/elf.h are missing from glibc's elf.h. This patch adds the missing values that are relevant to glibc architectures. As elf.h is a general description of the ELF format, not necessarily limited to glibc configurations, there's an argument for having the remaining NT_* values that Linux uses for non-glibc architectures in glibc's elf.h as well, but this patch does not add them. Adding the NT_PRFPREG name is bug 14890. That bug also requests making the NT_FPREGSET name obsolete. Given that elf.h is not just for Linux but can describe ELF for other operating systems, I don't think that a change of name in the Linux kernel is sufficient justification for declaring the other name obsolete; there can be multiple names for the same note value, even with incompatible semantics, if those reflect variants of the ELF format in actual use. For example, FreeBSD appears still to have the name NT_FPREGSET <https://github.com/freebsd/freebsd/blob/master/sys/sys/elf_common.h> (note: I haven't checked whether the FreeBSD kernel actually generates such notes or whether this is actually an other-OS definition present in FreeBSD's header). [BZ #14890] * elf/elf.h (NT_PRFPREG): New macro. (NT_S390_VXRS_LOW): Likewise. (NT_S390_VXRS_HIGH): Likewise. (NT_S390_GS_CB): Likewise. (NT_S390_GS_BC): Likewise. (NT_S390_RI_CB): Likewise.
2018-02-05Use ADDRIDX with DT_GNU_HASHH.J. Lu3-10/+4
The only differences in ld.so are line numbers for asserts. Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> * elf/dl-addr.c (determine_info): Use ADDRIDX with DT_GNU_HASH. * elf/dl-lookup.c (_dl_setup_hash): Likewise. * elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
2018-02-05Add DT_SYMTAB_SHNDX from gABIH.J. Lu1-1/+2
* elf/elf.h (DT_SYMTAB_SHNDX): New. Set to 34. (DT_NUM): Updated to 35.
2018-01-25Add support for the RISC-V-specific ELF flagsPalmer Dabbelt2-0/+14
The RISC-V port defines ELF flags that enforce compatibility between various objects. This adds the shared support necessary for these flags. 2018-01-25 Palmer Dabbelt <palmer@sifive.com> * elf/cache.c (print_entry): Add FLAG_RISCV_FLOAT_ABI_SOFT and FLAG_RISCV_FLOAT_ABI_DOUBLE. * elf/elf.h (EF_RISCV_RVC): New define. (EF_RISCV_FLOAT_ABI): Likewise. (EF_RISCV_FLOAT_ABI_SOFT): Likewise. (EF_RISCV_FLOAT_ABI_SINGLE): Likewise. (EF_RISCV_FLOAT_ABI_DOUBLE): Likewise. (EF_RISCV_FLOAT_ABI_QUAD): Likewise. * sysdeps/generic/ldconfig.h (FLAG_RISCV_FLOAT_ABI_SOFT): New define. (FLAG_RISCV_FLOAT_ABI_DOUBLE): Likewise.
2018-01-15Add NT_ARM_SVE to elf.hAlan Hayward1-0/+2
This definition is for AArch64 SVE registers in elf core dumps. * elf/elf.h (NT_ARM_SVE): Define.
2018-01-13Synchronize DF_1_* flags with binutils (Bug 22707)Carlos O'Donell1-0/+2
This patch synchronizes DF_1_* flags with binutils and ensures that all DF_1_* flags defined in binutil's include/elf/common.h are also defined glibc's elf/elf.h. This is a user visible change since elf/elf.h is installed by default as /usr/include/elf.h. Signed-off-by: Carlos O'Donell <carlos@redhat.com>
2018-01-06Add RISC-V dynamic relocations to elf.hPalmer Dabbelt1-0/+14
These relocations can appear in shared objects on RISC-V ELF systems. 2018-01-06 Palmer Dabbelt <palmer@sifive.com> * elf/elf.h (R_RISCV_NONE): New define. (R_RISCV_32): Likewise. (R_RISCV_64): Likewise. (R_RISCV_RELATIVE): Likewise. (R_RISCV_COPY): Likewise. (R_RISCV_JUMP_SLOT): Likewise. (R_RISCV_TLS_DTPMOD32): Likewise. (R_RISCV_TLS_DTPMOD64): Likewise. (R_RISCV_TLS_DTPREL32): Likewise. (R_RISCV_TLS_DTPREL64): Likewise. (R_RISCV_TLS_TPREL32): Likewise. (R_RISCV_TLS_TPREL64): Likewise.
2018-01-04elf: Support dlvsym within libc.soFlorian Weimer7-6/+303
This commit adds a new _dl_open_hook entry for dlvsym and implements the function using the existing dl_lookup_symbol_x function supplied by the dynamic loader. A new hook variable, _dl_open_hook2, is introduced, which should make this change suitable for backporting: For old statically linked binaries, __libc_dlvsym will always return NULL.
2018-01-01elf: check for rpath emptiness before making a copy of itDmitry V. Levin1-10/+8
* elf/dl-load.c (decompose_rpath): Check for rpath emptiness before making a copy of it.
2018-01-01Update copyright dates not handled by scripts/update-copyrights.Joseph Myers5-5/+5
I've updated copyright dates in glibc for 2018. This is the patch for the changes not generated by scripts/update-copyrights and subsequent build / regeneration of generated files. Please remember to include 2018 in the dates for any new files added in future (which means updating any existing uncommitted patches you have that add new files to use the new copyright dates in them). * NEWS: Update copyright dates. * catgets/gencat.c (print_version): Likewise. * csu/version.c (banner): Likewise. * debug/catchsegv.sh: Likewise. * debug/pcprofiledump.c (print_version): Likewise. * debug/xtrace.sh (do_version): Likewise. * elf/ldconfig.c (print_version): Likewise. * elf/ldd.bash.in: Likewise. * elf/pldd.c (print_version): Likewise. * elf/sotruss.sh: Likewise. * elf/sprof.c (print_version): Likewise. * iconv/iconv_prog.c (print_version): Likewise. * iconv/iconvconfig.c (print_version): Likewise. * locale/programs/locale.c (print_version): Likewise. * locale/programs/localedef.c (print_version): Likewise. * login/programs/pt_chown.c (print_version): Likewise. * malloc/memusage.sh (do_version): Likewise. * malloc/memusagestat.c (print_version): Likewise. * malloc/mtrace.pl: Likewise. * manual/libc.texinfo: Likewise. * nptl/version.c (banner): Likewise. * nscd/nscd.c (print_version): Likewise. * nss/getent.c (print_version): Likewise. * nss/makedb.c (print_version): Likewise. * posix/getconf.c (main): Likewise. * scripts/test-installation.pl: Likewise. * sysdeps/unix/sysv/linux/lddlibc4.c (main): Likewise.
2018-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers139-139/+139
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
2017-12-30elf: Check for empty tokens before dynamic string token expansion [BZ #22625]Aurelien Jarno1-16/+33
The fillin_rpath function in elf/dl-load.c loops over each RPATH or RUNPATH tokens and interprets empty tokens as the current directory ("./"). In practice the check for empty token is done *after* the dynamic string token expansion. The expansion process can return an empty string for the $ORIGIN token if __libc_enable_secure is set or if the path of the binary can not be determined (/proc not mounted). Fix that by moving the check for empty tokens before the dynamic string token expansion. In addition, check for NULL pointer or empty strings return by expand_dynamic_string_token. The above changes highlighted a bug in decompose_rpath, an empty array is represented by the first element being NULL at the fillin_rpath level, but by using a -1 pointer in decompose_rpath and other functions. Changelog: [BZ #22625] * elf/dl-load.c (fillin_rpath): Check for empty tokens before dynamic string token expansion. Check for NULL pointer or empty string possibly returned by expand_dynamic_string_token. (decompose_rpath): Check for empty path after dynamic string token expansion.
2017-12-27elf: remove redundant is_path argumentDmitry V. Levin3-22/+18
is_path argument is no longer used and could be safely removed. * elf/dl-dst.h (DL_DST_COUNT): Remove is_path argument, all callers updated. * elf/dl-load.c (is_dst, _dl_dst_count, _dl_dst_substitute, expand_dynamic_string_token): Likewise. * sysdeps/generic/ldsodefs.h (_dl_dst_count, _dl_dst_substitute): Remove is_path argument.
2017-12-27elf: remove redundant code from is_dstDmitry V. Levin1-5/+3
is_dst is called either by _dl_dst_count or by _dl_dst_substitute. _dl_dst_count is called by DL_DST_COUNT only. DL_DST_COUNT is called either by expand_dst with is_path == 0 or by expand_dynamic_string_token. _dl_dst_substitute is called either from expand_dst with is_path == 0 or from expand_dynamic_string_token. The latter function is called either from _dl_map_object with is_path == 0 or from fillin_rpath with is_path == 1 and name containing no ':'. In any case (is_path && name[i] == ':') is always false and all code depending on it can be safely removed. * elf/dl-load.c (is_dst): Remove checks that is_path is set and name contains ':', and all code depending on these checks.
2017-12-27elf: remove redundant code from _dl_dst_substituteDmitry V. Levin1-20/+1
There are just two users of _dl_dst_substitute: one is expand_dst that sets is_path argument to 0, another one is expand_dynamic_string_token. The latter function also has just two users: one is _dl_map_object that sets is_path argument to 0, another one is fillin_rpath that sets is_path argument to 1 and name argument contains no ':'. In any case (is_path && name[i] == ':') is always false and all code depending on it can be safely removed. * elf/dl-load.c (_dl_dst_substitute): Remove checks that is_path is set and name contains ':', and all code depending on these checks.
2017-12-19elf: remove redundant __libc_enable_secure check from fillin_rpathDmitry V. Levin1-30/+3
There are just two users of fillin_rpath: one is decompose_rpath that sets check_trusted argument to 0, another one is _dl_init_paths that sets check_trusted argument to __libc_enable_secure and invokes fillin_rpath only when LD_LIBRARY_PATH is non-empty. Starting with commit glibc-2.25.90-512-gf6110a8fee2ca36f8e2d2abecf3cba9fa7b8ea7d, LD_LIBRARY_PATH is ignored for __libc_enable_secure executables, so check_trusted argument of fillin_rpath is always zero. * elf/dl-load.c (is_trusted_path): Remove. (fillin_rpath): Remove check_trusted argument and its use, all callers changed.
2017-12-19Replece LDFLAGS-* = $(no-pie-ldflag) with tst-*-no-pie = yes [BZ #22630]H.J. Lu1-3/+3
After commit 9d7a3741c9e59eba87fb3ca6b9f979befce07826 Author: H.J. Lu <hjl.tools@gmail.com> Date: Fri Dec 15 16:59:33 2017 -0800 Add --enable-static-pie configure option to build static PIE [BZ #19574] and commit 00c714df398b63934540d95ce3792596f7a94a6c Author: H.J. Lu <hjl.tools@gmail.com> Date: Mon Dec 18 12:24:26 2017 -0800 Pass -no-pie to GCC only if GCC defaults to PIE [BZ #22614] $(no-pie-ldflag) is no longer effective since no-pie-ldflag is defined to -no-pie only if GCC defaults to PIE. When --enable-static-pie is used to configure glibc build and GCC doesn't default to PIE. no-pie-ldflag is undefined and these tests: elf/Makefile:LDFLAGS-tst-dlopen-aout = $(no-pie-ldflag) elf/Makefile:LDFLAGS-tst-prelink = $(no-pie-ldflag) elf/Makefile:LDFLAGS-tst-main1 = $(no-pie-ldflag) gmon/Makefile:LDFLAGS-tst-gmon := $(no-pie-ldflag) may fail to link. This patch replaces "-pie" with $(if $($(@F)-no-pie),$(no-pie-ldflag),-pie) and repleces LDFLAGS-* = $(no-pie-ldflag) with tst-*-no-pie = yes so that tst-dlopen-aout, tst-prelink, tst-main1 and tst-gmon are always built as non-PIE, with and without --enable-static-pie, regardless if GCC defaults to PIE or non-PIE. Tested with build-many-glibcs.py without --enable-static-pie as well as with --enable-static-pie for x86_64, x32 and i686. [BZ #22630] * Makeconfig (link-pie-before-libc): Replace -pie with $(if $($(@F)-no-pie),$(no-pie-ldflag),-pie). * elf/Makefile (LDFLAGS-tst-dlopen-aout): Removed. (tst-dlopen-aout-no-pie): New. (LDFLAGS-tst-prelink): Removed. (tst-prelink-no-pie): New. (LDFLAGS-tst-main1): Removed. (tst-main1-no-pie): New. * gmon/Makefile (LDFLAGS-tst-gmon): Removed. (tst-gmon-no-pie): New.
2017-12-18ld.so: Examine GLRO to detect inactive loader [BZ #20204]Florian Weimer2-4/+6
GLRO (_rtld_global_ro) is read-only after initialization and can therefore not be patched at run time, unlike the hook table addresses and their contents, so this is a desirable hardening feature. The hooks are only needed if ld.so has not been initialized, and this happens only after static dlopen (dlmopen uses a single ld.so object across all namespaces). Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2017-12-18elf: do not substitute dst in $LD_LIBRARY_PATH twice [BZ #22627]Dmitry V. Levin1-19/+1
Starting with commit glibc-2.18.90-470-g2a939a7e6d81f109d49306bc2e10b4ac9ceed8f9 that introduced substitution of dynamic string tokens in fillin_rpath, _dl_init_paths invokes _dl_dst_substitute for $LD_LIBRARY_PATH twice: the first time it's called directly, the second time the result is passed on to fillin_rpath which calls expand_dynamic_string_token which in turn calls _dl_dst_substitute, leading to the following behaviour: $ mkdir -p /tmp/'$ORIGIN' && cd /tmp/'$ORIGIN' && echo 'int main(){}' |gcc -xc - && strace -qq -E LD_LIBRARY_PATH='$ORIGIN' -e /open ./a.out open("/tmp//tmp/$ORIGIN/tls/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/tmp//tmp/$ORIGIN/tls/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/tmp//tmp/$ORIGIN/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/tmp//tmp/$ORIGIN/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3 open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3 Fix this by removing the direct _dl_dst_substitute invocation. * elf/dl-load.c (_dl_init_paths): Remove _dl_dst_substitute preparatory code and invocation.
2017-12-16ldconfig: set LC_COLLATE to C [BZ #22505]Aurelien Jarno1-0/+4
ldconfig supports `include' directives and use the glob function to process them. The glob function sort entries according to the LC_COLLATE category. When using a standard "include /etc/ld.so.conf.d/*.conf" entry in /etc/ld.so.conf, the order therefore depends on the locale used to run ldconfig. A few examples of locale specific order that might be disturbing in that context compared to the C locale: - The cs_CZ and sk_SK locales sort the digits after the letters. - The et_EE locale sorts the 'z' between 's' and 't'. This patch fixes that by setting LC_COLLATE to C in order to process files in deterministic order, independently of the locale used to launch ldconfig. NOTE: This should NOT be backported to older release branches. Changelog: [BZ #22505] * elf/ldconfig.c (main): Call setlocale to force LC_COLLATE to C.
2017-12-15Fix tst-leaks1 (bug 14681)Carlos O'Donell1-3/+18
The test tst-leaks1 exercises calling dlopen with a $ORIGIN DST. This results in a theoretical leak e.g. Memory not freed: ----------------- Address Size Caller 0x0000000001d766c0 0x21 at 0x7fb1bd8bf4ab Or as seen via valgrind: ==27582== 33 bytes in 1 blocks are still reachable in loss record 1 of 1 ==27582== at 0x4C2CB6B: malloc (vg_replace_malloc.c:299) ==27582== by 0x40124AA: _dl_get_origin (dl-origin.c:50) ==27582== by 0x4007DB9: expand_dynamic_string_token (dl-load.c:382) ==27582== by 0x400899C: _dl_map_object (dl-load.c:2160) ==27582== by 0x4013020: dl_open_worker (dl-open.c:224) ==27582== by 0x5166F9B: _dl_catch_exception (dl-error-skeleton.c:198) ==27582== by 0x4012BD9: _dl_open (dl-open.c:594) ==27582== by 0x4E39EF5: dlopen_doit (dlopen.c:66) ==27582== by 0x5166F9B: _dl_catch_exception (dl-error-skeleton.c:198) ==27582== by 0x516700E: _dl_catch_error (dl-error-skeleton.c:217) ==27582== by 0x4E3A514: _dlerror_run (dlerror.c:162) ==27582== by 0x4E39F70: dlopen@@GLIBC_2.2.5 (dlopen.c:87) There is no real leak. The calling link map (the executable's link map) has it's l_origin expanded for future use as part of _dl_get_origin, and that results in the main executable link map having a N-byte allocation for l->l_origin that is never freed since the executable's link map is just a part of the process. To take this into account we do one dlopen with $ORIGIN before calling mtrace to force the initialization of the executable link map. Signed-off-by: Carlos O'Donell <carlos@redhat.com>
2017-12-15Add --enable-static-pie configure option to build static PIE [BZ #19574]H.J. Lu5-6/+72
Static PIE extends address space layout randomization to static executables. It provides additional security hardening benefits at the cost of some memory and performance. Dynamic linker, ld.so, is a standalone program which can be loaded at any address. This patch adds a configure option, --enable-static-pie, to embed the part of ld.so in static executable to create static position independent executable (static PIE). A static PIE is similar to static executable, but can be loaded at any address without help from a dynamic linker. When --enable-static-pie is used to configure glibc, libc.a is built as PIE and all static executables, including tests, are built as static PIE. The resulting libc.a can be used together with GCC 8 or above to build static PIE with the compiler option, -static-pie. But GCC 8 isn't required to build glibc with --enable-static-pie. Only GCC with PIE support is needed. When an older GCC is used to build glibc with --enable-static-pie, proper input files are passed to linker to create static executables as static PIE, together with "-z text" to prevent dynamic relocations in read-only segments, which are not allowed in static PIE. The following changes are made for static PIE: 1. Add a new function, _dl_relocate_static_pie, to: a. Get the run-time load address. b. Read the dynamic section. c. Perform dynamic relocations. Dynamic linker also performs these steps. But static PIE doesn't load any shared objects. 2. Call _dl_relocate_static_pie at entrance of LIBC_START_MAIN in libc.a. crt1.o, which is used to create dynamic and non-PIE static executables, is updated to include a dummy _dl_relocate_static_pie. rcrt1.o is added to create static PIE, which will link in the real _dl_relocate_static_pie. grcrt1.o is also added to create static PIE with -pg. GCC 8 has been updated to support rcrt1.o and grcrt1.o for static PIE. Static PIE can work on all architectures which support PIE, provided: 1. Target must support accessing of local functions without dynamic relocations, which is needed in start.S to call __libc_start_main with function addresses of __libc_csu_init, __libc_csu_fini and main. All functions in static PIE are local functions. If PIE start.S can't reach main () defined in a shared object, the code sequence: pass address of local_main to __libc_start_main ... local_main: tail call to main via PLT can be used. 2. start.S is updated to check PIC instead SHARED for PIC code path and avoid dynamic relocation, when PIC is defined and SHARED isn't defined, to support static PIE. 3. All assembly codes are updated check PIC instead SHARED for PIC code path to avoid dynamic relocations in read-only sections. 4. All assembly codes are updated check SHARED instead PIC for static symbol name. 5. elf_machine_load_address in dl-machine.h are updated to support static PIE. 6. __brk works without TLS nor dynamic relocations in read-only section so that it can be used by __libc_setup_tls to initializes TLS in static PIE. NB: When glibc is built with GCC defaulted to PIE, libc.a is compiled with -fPIE, regardless if --enable-static-pie is used to configure glibc. When glibc is configured with --enable-static-pie, libc.a is compiled with -fPIE, regardless whether GCC defaults to PIE or not. The same libc.a can be used to build both static executable and static PIE. There is no need for separate PIE copy of libc.a. On x86-64, the normal static sln: text data bss dec hex filename 625425 8284 5456 639165 9c0bd elf/sln the static PIE sln: text data bss dec hex filename 657626 20636 5392 683654 a6e86 elf/sln The code size is increased by 5% and the binary size is increased by 7%. Linker requirements to build glibc with --enable-static-pie: 1. Linker supports --no-dynamic-linker to remove PT_INTERP segment from static PIE. 2. Linker can create working static PIE. The x86-64 linker needs the fix for https://sourceware.org/bugzilla/show_bug.cgi?id=21782 The i386 linker needs to be able to convert "movl main@GOT(%ebx), %eax" to "leal main@GOTOFF(%ebx), %eax" if main is defined locally. Binutils 2.29 or above are OK for i686 and x86-64. But linker status for other targets need to be verified. 3. Linker should resolve undefined weak symbols to 0 in static PIE: https://sourceware.org/bugzilla/show_bug.cgi?id=22269 4. Many ELF backend linkers incorrectly check bfd_link_pic for TLS relocations, which should check bfd_link_executable instead: https://sourceware.org/bugzilla/show_bug.cgi?id=22263 Tested on aarch64, i686 and x86-64. Using GCC 7 and binutils master branch, build-many-glibcs.py with --enable-static-pie with all patches for static PIE applied have the following build successes: PASS: glibcs-aarch64_be-linux-gnu build PASS: glibcs-aarch64-linux-gnu build PASS: glibcs-armeb-linux-gnueabi-be8 build PASS: glibcs-armeb-linux-gnueabi build PASS: glibcs-armeb-linux-gnueabihf-be8 build PASS: glibcs-armeb-linux-gnueabihf build PASS: glibcs-arm-linux-gnueabi build PASS: glibcs-arm-linux-gnueabihf build PASS: glibcs-arm-linux-gnueabihf-v7a build PASS: glibcs-arm-linux-gnueabihf-v7a-disable-multi-arch build PASS: glibcs-m68k-linux-gnu build PASS: glibcs-microblazeel-linux-gnu build PASS: glibcs-microblaze-linux-gnu build PASS: glibcs-mips64el-linux-gnu-n32 build PASS: glibcs-mips64el-linux-gnu-n32-nan2008 build PASS: glibcs-mips64el-linux-gnu-n32-nan2008-soft build PASS: glibcs-mips64el-linux-gnu-n32-soft build PASS: glibcs-mips64el-linux-gnu-n64 build PASS: glibcs-mips64el-linux-gnu-n64-nan2008 build PASS: glibcs-mips64el-linux-gnu-n64-nan2008-soft build PASS: glibcs-mips64el-linux-gnu-n64-soft build PASS: glibcs-mips64-linux-gnu-n32 build PASS: glibcs-mips64-linux-gnu-n32-nan2008 build PASS: glibcs-mips64-linux-gnu-n32-nan2008-soft build PASS: glibcs-mips64-linux-gnu-n32-soft build PASS: glibcs-mips64-linux-gnu-n64 build PASS: glibcs-mips64-linux-gnu-n64-nan2008 build PASS: glibcs-mips64-linux-gnu-n64-nan2008-soft build PASS: glibcs-mips64-linux-gnu-n64-soft build PASS: glibcs-mipsel-linux-gnu build PASS: glibcs-mipsel-linux-gnu-nan2008 build PASS: glibcs-mipsel-linux-gnu-nan2008-soft build PASS: glibcs-mipsel-linux-gnu-soft build PASS: glibcs-mips-linux-gnu build PASS: glibcs-mips-linux-gnu-nan2008 build PASS: glibcs-mips-linux-gnu-nan2008-soft build PASS: glibcs-mips-linux-gnu-soft build PASS: glibcs-nios2-linux-gnu build PASS: glibcs-powerpc64le-linux-gnu build PASS: glibcs-powerpc64-linux-gnu build PASS: glibcs-tilegxbe-linux-gnu-32 build PASS: glibcs-tilegxbe-linux-gnu build PASS: glibcs-tilegx-linux-gnu-32 build PASS: glibcs-tilegx-linux-gnu build PASS: glibcs-tilepro-linux-gnu build and the following build failures: FAIL: glibcs-alpha-linux-gnu build elf/sln is failed to link due to: assertion fail bfd/elf64-alpha.c:4125 This is caused by linker bug and/or non-PIC code in PIE libc.a. FAIL: glibcs-hppa-linux-gnu build elf/sln is failed to link due to: collect2: fatal error: ld terminated with signal 11 [Segmentation fault] https://sourceware.org/bugzilla/show_bug.cgi?id=22537 FAIL: glibcs-ia64-linux-gnu build elf/sln is failed to link due to: collect2: fatal error: ld terminated with signal 11 [Segmentation fault] FAIL: glibcs-powerpc-linux-gnu build FAIL: glibcs-powerpc-linux-gnu-soft build FAIL: glibcs-powerpc-linux-gnuspe build FAIL: glibcs-powerpc-linux-gnuspe-e500v1 build elf/sln is failed to link due to: ld: read-only segment has dynamic relocations. This is caused by linker bug and/or non-PIC code in PIE libc.a. See: https://sourceware.org/bugzilla/show_bug.cgi?id=22264 FAIL: glibcs-powerpc-linux-gnu-power4 build elf/sln is failed to link due to: findlocale.c:96:(.text+0x22c): @local call to ifunc memchr This is caused by linker bug and/or non-PIC code in PIE libc.a. FAIL: glibcs-s390-linux-gnu build elf/sln is failed to link due to: collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped assertion fail bfd/elflink.c:14299 This is caused by linker bug and/or non-PIC code in PIE libc.a. FAIL: glibcs-sh3eb-linux-gnu build FAIL: glibcs-sh3-linux-gnu build FAIL: glibcs-sh4eb-linux-gnu build FAIL: glibcs-sh4eb-linux-gnu-soft build FAIL: glibcs-sh4-linux-gnu build FAIL: glibcs-sh4-linux-gnu-soft build elf/sln is failed to link due to: ld: read-only segment has dynamic relocations. This is caused by linker bug and/or non-PIC code in PIE libc.a. See: https://sourceware.org/bugzilla/show_bug.cgi?id=22263 Also TLS code sequence in SH assembly syscalls in glibc doesn't match TLS code sequence expected by ld: https://sourceware.org/bugzilla/show_bug.cgi?id=22270 FAIL: glibcs-sparc64-linux-gnu build FAIL: glibcs-sparcv9-linux-gnu build FAIL: glibcs-tilegxbe-linux-gnu build FAIL: glibcs-tilegxbe-linux-gnu-32 build FAIL: glibcs-tilegx-linux-gnu build FAIL: glibcs-tilegx-linux-gnu-32 build FAIL: glibcs-tilepro-linux-gnu build elf/sln is failed to link due to: ld: read-only segment has dynamic relocations. This is caused by linker bug and/or non-PIC code in PIE libc.a. See: https://sourceware.org/bugzilla/show_bug.cgi?id=22263 [BZ #19574] * INSTALL: Regenerated. * Makeconfig (real-static-start-installed-name): New. (pic-default): Updated for --enable-static-pie. (pie-default): New for --enable-static-pie. (default-pie-ldflag): Likewise. (+link-static-before-libc): Replace $(DEFAULT-LDFLAGS-$(@F)) with $(if $($(@F)-no-pie),$(no-pie-ldflag),$(default-pie-ldflag)). Replace $(static-start-installed-name) with $(real-static-start-installed-name). (+prectorT): Updated for --enable-static-pie. (+postctorT): Likewise. (CFLAGS-.o): Add $(pie-default). (CFLAGS-.op): Likewise. * NEWS: Mention --enable-static-pie. * config.h.in (ENABLE_STATIC_PIE): New. * configure.ac (--enable-static-pie): New configure option. (have-no-dynamic-linker): New LIBC_CONFIG_VAR. (have-static-pie): Likewise. Enable static PIE if linker supports --no-dynamic-linker. (ENABLE_STATIC_PIE): New AC_DEFINE. (enable-static-pie): New LIBC_CONFIG_VAR. * configure: Regenerated. * csu/Makefile (omit-deps): Add r$(start-installed-name) and gr$(start-installed-name) for --enable-static-pie. (extra-objs): Likewise. (install-lib): Likewise. (extra-objs): Add static-reloc.o and static-reloc.os ($(objpfx)$(start-installed-name)): Also depend on $(objpfx)static-reloc.o. ($(objpfx)r$(start-installed-name)): New. ($(objpfx)g$(start-installed-name)): Also depend on $(objpfx)static-reloc.os. ($(objpfx)gr$(start-installed-name)): New. * csu/libc-start.c (LIBC_START_MAIN): Call _dl_relocate_static_pie in libc.a. * csu/libc-tls.c (__libc_setup_tls): Add main_map->l_addr to initimage. * csu/static-reloc.c: New file. * elf/Makefile (routines): Add dl-reloc-static-pie. (elide-routines.os): Likewise. (DEFAULT-LDFLAGS-tst-tls1-static-non-pie): Removed. (tst-tls1-static-non-pie-no-pie): New. * elf/dl-reloc-static-pie.c: New file. * elf/dl-support.c (_dl_get_dl_main_map): New function. * elf/dynamic-link.h (ELF_DURING_STARTUP): Also check STATIC_PIE_BOOTSTRAP. * elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise. * gmon/Makefile (tests): Add tst-gmon-static-pie. (tests-static): Likewise. (DEFAULT-LDFLAGS-tst-gmon-static): Removed. (tst-gmon-static-no-pie): New. (CFLAGS-tst-gmon-static-pie.c): Likewise. (CRT-tst-gmon-static-pie): Likewise. (tst-gmon-static-pie-ENV): Likewise. (tests-special): Likewise. ($(objpfx)tst-gmon-static-pie.out): Likewise. (clean-tst-gmon-static-pie-data): Likewise. ($(objpfx)tst-gmon-static-pie-gprof.out): Likewise. * gmon/tst-gmon-static-pie.c: New file. * manual/install.texi: Document --enable-static-pie. * sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New. (_dl_get_dl_main_map): Likewise. * sysdeps/i386/configure.ac: Check if linker supports static PIE. * sysdeps/x86_64/configure.ac: Likewise. * sysdeps/i386/configure: Regenerated. * sysdeps/x86_64/configure: Likewise. * sysdeps/mips/Makefile (ASFLAGS-.o): Add $(pie-default). (ASFLAGS-.op): Likewise.