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2021-12-15malloc: Add Huge Page support for mmapAdhemerval Zanella
With the morecore hook removed, there is not easy way to provide huge pages support on with glibc allocator without resorting to transparent huge pages. And some users and programs do prefer to use the huge pages directly instead of THP for multiple reasons: no splitting, re-merging by the VM, no TLB shootdowns for running processes, fast allocation from the reserve pool, no competition with the rest of the processes unlike THP, no swapping all, etc. This patch extends the 'glibc.malloc.hugetlb' tunable: the value '2' means to use huge pages directly with the system default size, while a positive value means and specific page size that is matched against the supported ones by the system. Currently only memory allocated on sysmalloc() is handled, the arenas still uses the default system page size. To test is a new rule is added tests-malloc-hugetlb2, which run the addes tests with the required GLIBC_TUNABLE setting. On systems without a reserved huge pages pool, is just stress the mmap(MAP_HUGETLB) allocation failure. To improve test coverage it is required to create a pool with some allocated pages. Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15malloc: Add madvise support for Transparent Huge PagesAdhemerval Zanella
Linux Transparent Huge Pages (THP) current supports three different states: 'never', 'madvise', and 'always'. The 'never' is self-explanatory and 'always' will enable THP for all anonymous pages. However, 'madvise' is still the default for some system and for such case THP will be only used if the memory range is explicity advertise by the program through a madvise(MADV_HUGEPAGE) call. To enable it a new tunable is provided, 'glibc.malloc.hugetlb', where setting to a value diffent than 0 enables the madvise call. This patch issues the madvise(MADV_HUGEPAGE) call after a successful mmap() call at sysmalloc() with sizes larger than the default huge page size. The madvise() call is disable is system does not support THP or if it has the mode set to "never" and on Linux only support one page size for THP, even if the architecture supports multiple sizes. To test is a new rule is added tests-malloc-hugetlb1, which run the addes tests with the required GLIBC_TUNABLE setting. Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15Use LFS and 64 bit time for installed programs (BZ #15333)Adhemerval Zanella
The installed programs are built with a combination of different values for MODULE_NAME, as below. To enable both Long File Support and 64 bt time, -D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64 is added for nonlibi, nscd, lddlibc4, libresolv, ldconfig, locale_programs, iconvprogs, libnss_files, libnss_compat, libnss_db, libnss_hesiod, libutil, libpcprofile, and libSegFault. nscd/nscd nscd/nscd.o MODULE_NAME=nscd nscd/connections.o MODULE_NAME=nscd nscd/pwdcache.o MODULE_NAME=nscd nscd/getpwnam_r.o MODULE_NAME=nscd nscd/getpwuid_r.o MODULE_NAME=nscd nscd/grpcache.o MODULE_NAME=nscd nscd/getgrnam_r.o MODULE_NAME=nscd nscd/getgrgid_r.o MODULE_NAME=nscd nscd/hstcache.o MODULE_NAME=nscd nscd/gethstbyad_r.o MODULE_NAME=nscd nscd/gethstbynm3_r.o MODULE_NAME=nscd nscd/getsrvbynm_r.o MODULE_NAME=nscd nscd/getsrvbypt_r.o MODULE_NAME=nscd nscd/servicescache.o MODULE_NAME=nscd nscd/dbg_log.o MODULE_NAME=nscd nscd/nscd_conf.o MODULE_NAME=nscd nscd/nscd_stat.o MODULE_NAME=nscd nscd/cache.o MODULE_NAME=nscd nscd/mem.o MODULE_NAME=nscd nscd/nscd_setup_thread.o MODULE_NAME=nscd nscd/xmalloc.o MODULE_NAME=nscd nscd/xstrdup.o MODULE_NAME=nscd nscd/aicache.o MODULE_NAME=nscd nscd/initgrcache.o MODULE_NAME=nscd nscd/gai.o MODULE_NAME=nscd nscd/res_hconf.o MODULE_NAME=nscd nscd/netgroupcache.o MODULE_NAME=nscd nscd/cachedumper.o MODULE_NAME=nscd elf/lddlibc4 elf/lddlibc4 MODULE_NAME=lddlibc4 elf/pldd elf/pldd.o MODULE_NAME=nonlib elf/xmalloc.o MODULE_NAME=nonlib elf/sln elf/sln.o MODULE_NAME=nonlib elf/static-stubs.o MODULE_NAME=nonlib elf/sprof MODULE_NAME=nonlib elf/ldconfig elf/ldconfig.o MODULE_NAME=ldconfig elf/cache.o MODULE_NAME=nonlib elf/readlib.o MODULE_NAME=nonlib elf/xmalloc.o MODULE_NAME=nonlib elf/xstrdup.o MODULE_NAME=nonlib elf/chroot_canon.o MODULE_NAME=nonlib elf/static-stubs.o MODULE_NAME=nonlib elf/stringtable.o MODULE_NAME=nonlib io/pwd io/pwd.o MODULE_NAME=nonlib locale/locale locale/locale.o MODULE_NAME=locale_programs locale/locale-spec.o MODULE_NAME=locale_programs locale/charmap-dir.o MODULE_NAME=locale_programs locale/simple-hash.o MODULE_NAME=locale_programs locale/xmalloc.o MODULE_NAME=locale_programs locale/xstrdup.o MODULE_NAME=locale_programs locale/record-status.o MODULE_NAME=locale_programs locale/xasprintf.o MODULE_NAME=locale_programs locale/localedef locale/localedef.o MODULE_NAME=locale_programs locale/ld-ctype.o MODULE_NAME=locale_programs locale/ld-messages.o MODULE_NAME=locale_programs locale/ld-monetary.o MODULE_NAME=locale_programs locale/ld-numeric.o MODULE_NAME=locale_programs locale/ld-time.o MODULE_NAME=locale_programs locale/ld-paper.o MODULE_NAME=locale_programs locale/ld-name.o MODULE_NAME=locale_programs locale/ld-address.o MODULE_NAME=locale_programs locale/ld-telephone.o MODULE_NAME=locale_programs locale/ld-measurement.o MODULE_NAME=locale_programs locale/ld-identification.o MODULE_NAME=locale_programs locale/ld-collate.o MODULE_NAME=locale_programs locale/charmap.o MODULE_NAME=locale_programs locale/linereader.o MODULE_NAME=locale_programs locale/locfile.o MODULE_NAME=locale_programs locale/repertoire.o MODULE_NAME=locale_programs locale/locarchive.o MODULE_NAME=locale_programs locale/md5.o MODULE_NAME=locale_programs locale/charmap-dir.o MODULE_NAME=locale_programs locale/simple-hash.o MODULE_NAME=locale_programs locale/xmalloc.o MODULE_NAME=locale_programs locale/xstrdup.o MODULE_NAME=locale_programs locale/record-status.o MODULE_NAME=locale_programs locale/xasprintf.o MODULE_NAME=locale_programs catgets/gencat catgets/gencat.o MODULE_NAME=nonlib catgets/xmalloc.o MODULE_NAME=nonlib nss/makedb nss/makedb.o MODULE_NAME=nonlib nss/xmalloc.o MODULE_NAME=nonlib nss/hash-string.o MODULE_NAME=nonlib nss/getent nss/getent.o MODULE_NAME=nonlib posix/getconf posix/getconf.o MODULE_NAME=nonlib login/utmpdump login/utmpdump.o MODULE_NAME=nonlib debug/pcprofiledump debug/pcprofiledump.o MODULE_NAME=nonlib timezone/zic timezone/zic.o MODULE_NAME=nonlib timezone/zdump timezone/zdump.o MODULE_NAME=nonlib iconv/iconv_prog iconv/iconv_prog.o MODULE_NAME=nonlib iconv/iconv_charmap.o MODULE_NAME=iconvprogs iconv/charmap.o MODULE_NAME=iconvprogs iconv/charmap-dir.o MODULE_NAME=iconvprogs iconv/linereader.o MODULE_NAME=iconvprogs iconv/dummy-repertoire.o MODULE_NAME=iconvprogs iconv/simple-hash.o MODULE_NAME=iconvprogs iconv/xstrdup.o MODULE_NAME=iconvprogs iconv/xmalloc.o MODULE_NAME=iconvprogs iconv/record-status.o MODULE_NAME=iconvprogs iconv/iconvconfig iconv/iconvconfig.o MODULE_NAME=nonlib iconv/strtab.o MODULE_NAME=iconvprogs iconv/xmalloc.o MODULE_NAME=iconvprogs iconv/hash-string.o MODULE_NAME=iconvprogs nss/libnss_files.so MODULE_NAME=libnss_files nss/libnss_compat.so.2 MODULE_NAME=libnss_compat nss/libnss_db.so MODULE_NAME=libnss_db hesiod/libnss_hesiod.so MODULE_NAME=libnss_hesiod login/libutil.so MODULE_NAME=libutil debug/libpcprofile.so MODULE_NAME=libpcprofile debug/libSegFault.so MODULE_NAME=libSegFault Also, to avoid adding both LFS and 64 bit time support on internal tests they are moved to a newer 'testsuite-internal' module. It should be similar to 'nonlib' regarding internal definition and linking namespace. This patch also enables LFS and 64 bit support of libsupport container programs (echo-container, test-container, shell-container, and true-container). Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-14Support target specific ALIGN for variable alignment test [BZ #28676]H.J. Lu
Add <tst-file-align.h> to support target specific ALIGN for variable alignment test: 1. Alpha: Use 0x10000. 2. MicroBlaze and Nios II: Use 0x8000. 3. All others: Use 0x200000. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-12-14elf: Align argument of __munmap to page size [BZ #28676]H.J. Lu
On Linux/x86-64, for elf/tst-align3, we now get munmap(0x7f88f9401000, 1126424) = 0 instead of munmap(0x7f1615200018, 544768) = -1 EINVAL (Invalid argument) Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-12-14elf: Use new dependency sorting algorithm by defaultFlorian Weimer
The default has to change eventually, and there are no known failures that require a delay. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-12-10elf: Use errcode instead of (unset) errno in rtld_chain_loadFlorian Weimer
2021-12-10Add a testcase to check alignment of PT_LOAD segment [BZ #28676]H.J. Lu
2021-12-10elf: Properly align PT_LOAD segments [BZ #28676]Rongwei Wang
When PT_LOAD segment alignment > the page size, allocate enough space to ensure that the segment can be properly aligned. This change helps code segments use huge pages become simple and available. This fixes [BZ #28676]. Signed-off-by: Xu Yu <xuyu@linux.alibaba.com> Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>
2021-12-10elf: Install a symbolic link to ld.so as /usr/bin/ld.soFlorian Weimer
This makes ld.so features such as --preload, --audit, and --list-diagnostics more accessible to end users because they do not need to know the ABI name of the dynamic loader. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-12-09Remove TLS_TCB_ALIGN and TLS_INIT_TCB_ALIGNFlorian Weimer
TLS_INIT_TCB_ALIGN is not actually used. TLS_TCB_ALIGN was likely introduced to support a configuration where the thread pointer has not the same alignment as THREAD_SELF. Only ia64 seems to use that, but for the stack/pointer guard, not for storing tcbhead_t. Some ports use TLS_TCB_OFFSET and TLS_PRE_TCB_SIZE to shift the thread pointer, potentially landing in a different residue class modulo the alignment, but the changes should not impact that. In general, given that TLS variables have their own alignment requirements, having different alignment for the (unshifted) thread pointer and struct pthread would potentially result in dynamic offsets, leading to more complexity. hppa had different values before: __alignof__ (tcbhead_t), which seems to be 4, and __alignof__ (struct pthread), which was 8 (old default) and is now 32. However, it defines THREAD_SELF as: /* Return the thread descriptor for the current thread. */ # define THREAD_SELF \ ({ struct pthread *__self; \ __self = __get_cr27(); \ __self - 1; \ }) So the thread pointer points after struct pthread (hence __self - 1), and they have to have the same alignment on hppa as well. Similarly, on ia64, the definitions were different. We have: # define TLS_PRE_TCB_SIZE \ (sizeof (struct pthread) \ + (PTHREAD_STRUCT_END_PADDING < 2 * sizeof (uintptr_t) \ ? ((2 * sizeof (uintptr_t) + __alignof__ (struct pthread) - 1) \ & ~(__alignof__ (struct pthread) - 1)) \ : 0)) # define THREAD_SELF \ ((struct pthread *) ((char *) __thread_self - TLS_PRE_TCB_SIZE)) And TLS_PRE_TCB_SIZE is a multiple of the struct pthread alignment (confirmed by the new _Static_assert in sysdeps/ia64/libc-tls.c). On m68k, we have a larger gap between tcbhead_t and struct pthread. But as far as I can tell, the port is fine with that. The definition of TCB_OFFSET is sufficient to handle the shifted TCB scenario. This fixes commit 23c77f60181eb549f11ec2f913b4270af29eee38 ("nptl: Increase default TCB alignment to 32"). Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-12-05elf: execve statically linked programs instead of crashing [BZ #28648]Florian Weimer
Programs without dynamic dependencies and without a program interpreter are now run via execve. Previously, the dynamic linker either crashed while attempting to read a non-existing dynamic segment (looking for DT_AUDIT/DT_DEPAUDIT data), or the self-relocated in the static PIE executable crashed because the outer dynamic linker had already applied RELRO protection. <dl-execve.h> is needed because execve is not available in the dynamic loader on Hurd. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-12-02elf: add definition for ELF_NOTE_FDO and NT_FDO_PACKAGING_METADATA noteLuca Boccassi
As defined on: https://systemd.io/COREDUMP_PACKAGE_METADATA/ this note will be used starting from Fedora 36. Signed-off-by: Luca Boccassi <bluca@debian.org>
2021-11-30elf: Include <stdbool.h> in tst-tls20.cFlorian Weimer
The test uses the bool type.
2021-11-30elf: Include <stdint.h> in tst-tls20.cFlorian Weimer
The test uses standard integer types.
2021-11-18elf: Move la_activity (LA_ACT_ADD) after _dl_add_to_namespace_list() (BZ #28062)Adhemerval Zanella
It ensures that the the namespace is guaranteed to not be empty. Checked on x86_64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-11-17elf: Introduce GLRO (dl_libc_freeres), called from __libc_freeresFlorian Weimer
This will be used to deallocate memory allocated using the non-minimal malloc. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-11-16elf: hidden visibility for __minimal_malloc functionsAdhemerval Zanella
Since b05fae4d8e34, __minimal malloc code is used during static startup before PIE self-relocation (_dl_relocate_static_pie). So it requires the same fix done for other objects by 47618209d05a. Checked on aarch64, x86_64, and i686 with and without static-pie.
2021-11-16elf: Use a temporary file to generate Makefile fragments [BZ #28550]H.J. Lu
1. Use a temporary file to generate Makefile fragments for DSO sorting tests and use -include on them. 2. Add Makefile fragments to postclean-generated so that a "make clean" removes the autogenerated fragments and a subsequent "make" regenerates them. This partially fixes BZ #28550. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-11-15elf: Move LAV_CURRENT to link_lavcurrent.hAdhemerval Zanella
No functional change.
2021-11-09Fix build a chec failures after b05fae4d8e34Adhemerval Zanella
The include cleanup on dl-minimal.c removed too much for some targets. Also for Hurd, __sbrk is removed from localplt.data now that tunables allocated memory through mmap. Checked with a build for all affected architectures.
2021-11-09elf: Use the minimal malloc on tunables_strdupAdhemerval Zanella
The rtld_malloc functions are moved to its own file so it can be used on csu code. Also, the functiosn are renamed to __minimal_* (since there are now used not only on loader code). Using the __minimal_malloc on tunables_strdup() avoids potential issues with sbrk() calls while processing the tunables (I see sporadic elf/tst-dso-ordering9 on powerpc64le with different tests failing due ASLR). Also, using __minimal_malloc over plain mmap optimizes the memory allocation on both static and dynamic case (since it will any unused space in either the last page of data segments, avoiding mmap() call, or from the previous mmap() call). Checked on x86_64-linux-gnu, i686-linux-gnu, and powerpc64le-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-11-05elf: Earlier missing dynamic segment check in _dl_map_object_from_fdFlorian Weimer
Separated debuginfo files have PT_DYNAMIC with p_filesz == 0. We need to check for that before the _dl_map_segments call because that could attempt to write to mappings that extend beyond the end of the file, resulting in SIGBUS. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-11-03elf: Do not run DSO sorting if tunables is not enabledAdhemerval Zanella
Since the argorithm selection requires tunables. Checked on x86_64-linux-gnu with --enable-tunables=no.
2021-11-02elf: Assume disjointed .rela.dyn and .rela.plt for loaderAdhemerval Zanella
The patch removes the the ELF_DURING_STARTUP optimization and assume both .rel.dyn and .rel.plt might not be subsequent. This allows some code simplification since relocation will be handled independently where it is done on bootstrap. At least on x86_64_64, I can not measure any performance implications. Running 10000 time the command LD_DEBUG=statistics ./elf/ld.so ./libc.so And filtering the "total startup time in dynamic loader" result, the geometric mean is: patched master Ryzen 7 5900x 24140 24952 i7-4510U 45957 45982 (The results do show some variation, I did not make any statistical analysis). It also allows build arm with lld, since it inserts ".ARM.exidx" between ".rel.dyn" and ".rel.plt" for the loader. Checked on x86_64-linux-gnu and arm-linux-gnueabihf. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-10-29elf: Disable ifuncmain{1,5,5pic,5pie} when using LLDAdhemerval Zanella
These tests takes the address of a protected symbol (foo_protected) and lld does not support copy relocations on protected data symbols. Checked on x86_64-linux-gnu. Reviewed-by: Fangrui Song <maskray@google.com>
2021-10-25elf: Make global.out depend on reldepmod4.so [BZ #28457]H.J. Lu
The global test is linked with globalmod1.so which dlopens reldepmod4.so. Make global.out depend on reldepmod4.so. This fixes BZ #28457. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-10-21elf: Fix slow DSO sorting behavior in dynamic loader (BZ #17645)Chung-Lin Tang
This second patch contains the actual implementation of a new sorting algorithm for shared objects in the dynamic loader, which solves the slow behavior that the current "old" algorithm falls into when the DSO set contains circular dependencies. The new algorithm implemented here is simply depth-first search (DFS) to obtain the Reverse-Post Order (RPO) sequence, a topological sort. A new l_visited:1 bitfield is added to struct link_map to more elegantly facilitate such a search. The DFS algorithm is applied to the input maps[nmap-1] backwards towards maps[0]. This has the effect of a more "shallow" recursion depth in general since the input is in BFS. Also, when combined with the natural order of processing l_initfini[] at each node, this creates a resulting output sorting closer to the intuitive "left-to-right" order in most cases. Another notable implementation adjustment related to this _dl_sort_maps change is the removing of two char arrays 'used' and 'done' in _dl_close_worker to represent two per-map attributes. This has been changed to simply use two new bit-fields l_map_used:1, l_map_done:1 added to struct link_map. This also allows discarding the clunky 'used' array sorting that _dl_sort_maps had to sometimes do along the way. Tunable support for switching between different sorting algorithms at runtime is also added. A new tunable 'glibc.rtld.dynamic_sort' with current valid values 1 (old algorithm) and 2 (new DFS algorithm) has been added. At time of commit of this patch, the default setting is 1 (old algorithm). Signed-off-by: Chung-Lin Tang <cltang@codesourcery.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-21elf: Testing infrastructure for ld.so DSO sorting (BZ #17645)Chung-Lin Tang
This is the first of a 2-part patch set that fixes slow DSO sorting behavior in the dynamic loader, as reported in BZ #17645. In order to facilitate such a large modification to the dynamic loader, this first patch implements a testing framework for validating shared object sorting behavior, to enable comparison between old/new sorting algorithms, and any later enhancements. This testing infrastructure consists of a Python script scripts/dso-ordering-test.py' which takes in a description language, consisting of strings that describe a set of link dependency relations between DSOs, and generates testcase programs and Makefile fragments to automatically test the described situation, for example: a->b->c->d # four objects linked one after another a->[bc]->d;b->c # a depends on b and c, which both depend on d, # b depends on c (b,c linked to object a in fixed order) a->b->c;{+a;%a;-a} # a, b, c serially dependent, main program uses # dlopen/dlsym/dlclose on object a a->b->c;{}!->[abc] # a, b, c serially dependent; multiple tests generated # to test all permutations of a, b, c ordering linked # to main program (Above is just a short description of what the script can do, more documentation is in the script comments.) Two files containing several new tests, elf/dso-sort-tests-[12].def are added, including test scenarios for BZ #15311 and Redhat issue #1162810 [1]. Due to the nature of dynamic loader tests, where the sorting behavior and test output occurs before/after main(), generating testcases to use support/test-driver.c does not suffice to control meaningful timeout for ld.so. Therefore a new utility program 'support/test-run-command', based on test-driver.c/support_test_main.c has been added. This does the same testcase control, but for a program specified through a command-line rather than at the source code level. This utility is used to run the dynamic loader testcases generated by dso-ordering-test.py. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1162810 Signed-off-by: Chung-Lin Tang <cltang@codesourcery.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-20Correct access attribute on memfrob (bug 28475)Joseph Myers
As noted in bug 28475, the access attribute on memfrob in <string.h> is incorrect: the function both reads and writes the memory pointed to by its argument, so it needs to use __read_write__, not __write_only__. This incorrect attribute results in a build failure for accessing uninitialized memory for s390x-linux-gnu-O3 with build-many-glibcs.py using GCC mainline. Correct the attribute. Fixing this shows up that some calls to memfrob in elf/ tests are reading uninitialized memory; I'm not entirely sure of the purpose of those calls, but guess they are about ensuring that the stack space is indeed allocated at that point in the function, and so it matters that they are calling a function whose semantics are unknown to the compiler. Thus, change the first memfrob call in those tests to use explicit_bzero instead, as suggested by Florian in <https://sourceware.org/pipermail/libc-alpha/2021-October/132119.html>, to avoid the use of uninitialized memory. Tested for x86_64, and with build-many-glibcs.py (GCC mainline) for s390x-linux-gnu-O3.
2021-10-19ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340]H.J. Lu
1. Define DL_RO_DYN_SECTION to initalize bootstrap_map.l_ld_readonly before calling elf_get_dynamic_info to get dynamic info in bootstrap_map, 2. Define a single static inline bool dl_relocate_ld (const struct link_map *l) { /* Don't relocate dynamic section if it is readonly */ return !(l->l_ld_readonly || DL_RO_DYN_SECTION); } This updates BZ #28340 fix.
2021-10-18elf: Fix elf_get_dynamic_info() for bootstrapAdhemerval Zanella
THe d6d89608ac8c broke powerpc for --enable-bind-now because it turned out that different than patch assumption rtld elf_get_dynamic_info() does require to handle RTLD_BOOTSTRAP to avoid DT_FLAGS and DT_RUNPATH (more specially the GLRO usage which is not reallocate yet). This patch fixes by passing two arguments to elf_get_dynamic_info() to inform that by rtld (bootstrap) or static pie initialization (static_pie_bootstrap). I think using explicit argument is way more clear and burried C preprocessor, and compiler should remove the dead code. I checked on x86_64 and i686 with default options, --enable-bind-now, and --enable-bind-now and --enable--static-pie. I also check on aarch64, armhf, powerpc64, and powerpc with default and --enable-bind-now.
2021-10-14elf: Fix dynamic-link.h usage on rtld.cAdhemerval Zanella
The 4af6982e4c fix does not fully handle RTLD_BOOTSTRAP usage on rtld.c due two issues: 1. RTLD_BOOTSTRAP is also used on dl-machine.h on various architectures and it changes the semantics of various machine relocation functions. 2. The elf_get_dynamic_info() change was done sideways, previously to 490e6c62aa get-dynamic-info.h was included by the first dynamic-link.h include *without* RTLD_BOOTSTRAP being defined. It means that the code within elf_get_dynamic_info() that uses RTLD_BOOTSTRAP is in fact unused. To fix 1. this patch now includes dynamic-link.h only once with RTLD_BOOTSTRAP defined. The ELF_DYNAMIC_RELOCATE call will now have the relocation fnctions with the expected semantics for the loader. And to fix 2. part of 4af6982e4c is reverted (the check argument elf_get_dynamic_info() is not required) and the RTLD_BOOTSTRAP pieces are removed. To reorganize the includes the static TLS definition is moved to its own header to avoid a circular dependency (it is defined on dynamic-link.h and dl-machine.h requires it at same time other dynamic-link.h definition requires dl-machine.h defitions). Also ELF_MACHINE_NO_REL, ELF_MACHINE_NO_RELA, and ELF_MACHINE_PLT_REL are moved to its own header. Only ancient ABIs need special values (arm, i386, and mips), so a generic one is used as default. The powerpc Elf64_FuncDesc is also moved to its own header, since csu code required its definition (which would require either include elf/ folder or add a full path with elf/). Checked on x86_64, i686, aarch64, armhf, powerpc64, powerpc32, and powerpc64le. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-10-12elf: Update audit tests to not depend on stdoutStafford Horne
The tst-audit14, tst-audit15 and tst-audit16 tests all have audit modules that write to stdout; the test reads from stdout to confirm what was written. This assumes the stdout is a file which is not the case when run over ssh. This patch updates the tests to use a post run cmp command to compare the output against and .exp file. This is similar to how many other tests work and it fixes the stdout limitation. Also, this means the test code can be greatly simplified. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-12elf: Fix elf_get_dynamic_info definitionAdhemerval Zanella
Before to 490e6c62aa31a8a ('elf: Avoid nested functions in the loader [BZ #27220]'), elf_get_dynamic_info() was defined twice on rtld.c: on the first dynamic-link.h include and later within _dl_start(). The former definition did not define DONT_USE_BOOTSTRAP_MAP and it is used on setup_vdso() (since it is a global definition), while the former does define DONT_USE_BOOTSTRAP_MAP and it is used on loader self-relocation. With the commit change, the function is now included and defined once instead of defined as a nested function. So rtld.c defines without defining RTLD_BOOTSTRAP and it brokes at least powerpc32. This patch fixes by moving the get-dynamic-info.h include out of dynamic-link.h, which then the caller can corirectly set the expected semantic by defining STATIC_PIE_BOOTSTRAP, RTLD_BOOTSTRAP, and/or RESOLVE_MAP. It also required to enable some asserts only for the loader bootstrap to avoid issues when called from setup_vdso(). As a side note, this is another issues with nested functions: it is not clear from pre-processed output (-E -dD) how the function will be build and its semantic (since nested function will be local and extra C defines may change it). I checked on x86_64-linux-gnu (w/o --enable-static-pie), i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4, aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and s390x-linux-gnu. Reviewed-by: Fangrui Song <maskray@google.com>
2021-10-07elf: Avoid nested functions in the loader [BZ #27220]Fangrui Song
dynamic-link.h is included more than once in some elf/ files (rtld.c, dl-conflict.c, dl-reloc.c, dl-reloc-static-pie.c) and uses GCC nested functions. This harms readability and the nested functions usage is the biggest obstacle prevents Clang build (Clang doesn't support GCC nested functions). The key idea for unnesting is to add extra parameters (struct link_map *and struct r_scope_elm *[]) to RESOLVE_MAP, ELF_MACHINE_BEFORE_RTLD_RELOC, ELF_DYNAMIC_RELOCATE, elf_machine_rel[a], elf_machine_lazy_rel, and elf_machine_runtime_setup. (This is inspired by Stan Shebs' ppc64/x86-64 implementation in the google/grte/v5-2.27/master which uses mixed extra parameters and static variables.) Future simplification: * If mips elf_machine_runtime_setup no longer needs RESOLVE_GOTSYM, elf_machine_runtime_setup can drop the `scope` parameter. * If TLSDESC no longer need to be in elf_machine_lazy_rel, elf_machine_lazy_rel can drop the `scope` parameter. Tested on aarch64, i386, x86-64, powerpc64le, powerpc64, powerpc32, sparc64, sparcv9, s390x, s390, hppa, ia64, armhf, alpha, and mips64. In addition, tested build-many-glibcs.py with {arc,csky,microblaze,nios2}-linux-gnu and riscv64-linux-gnu-rv64imafdc-lp64d. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-07Add run-time check for indirect external accessH.J. Lu
When performing symbol lookup for references in executable without indirect external access: 1. Disallow copy relocations in executable against protected data symbols in a shared object with indirect external access. 2. Disallow non-zero symbol values of undefined function symbols in executable, which are used as the function pointer, against protected function symbols in a shared object with indirect external access. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-07Initial support for GNU_PROPERTY_1_NEEDEDH.J. Lu
1. Add GNU_PROPERTY_1_NEEDED: #define GNU_PROPERTY_1_NEEDED GNU_PROPERTY_UINT32_OR_LO to indicate the needed properties by the object file. 2. Add GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS: #define GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS (1U << 0) to indicate that the object file requires canonical function pointers and cannot be used with copy relocation. 3. Scan GNU_PROPERTY_1_NEEDED property and store it in l_1_needed. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-06ld.so: Don't fill the DT_DEBUG entry in ld.so [BZ #28129]H.J. Lu
Linker creates the DT_DEBUG entry only in executables. Don't fill the non-existent DT_DEBUG entry in ld.so with the run-time address of the r_debug structure. This fixes BZ #28129.
2021-10-04elf: Avoid deadlock between pthread_create and ctors [BZ #28357]Szabolcs Nagy
The fix for bug 19329 caused a regression such that pthread_create can deadlock when concurrent ctors from dlopen are waiting for it to finish. Use a new GL(dl_load_tls_lock) in pthread_create that is not taken around ctors in dlopen. The new lock is also used in __tls_get_addr instead of GL(dl_load_lock). The new lock is held in _dl_open_worker and _dl_close_worker around most of the logic before/after the init/fini routines. When init/fini routines are running then TLS is in a consistent, usable state. In _dl_open_worker the new lock requires catching and reraising dlopen failures that happen in the critical section. The new lock is reinitialized in a fork child, to keep the existing behaviour and it is kept recursive in case malloc interposition or TLS access from signal handlers can retake it. It is not obvious if this is necessary or helps, but avoids changing the preexisting behaviour. The new lock may be more appropriate for dl_iterate_phdr too than GL(dl_load_write_lock), since TLS state of an incompletely loaded module may be accessed. If the new lock can replace the old one, that can be a separate change. Fixes bug 28357. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-09-30elf: Replace nsid with args.nsid [BZ #27609]H.J. Lu
commit ec935dea6332cb22f9881cd1162bad156173f4b0 Author: Florian Weimer <fweimer@redhat.com> Date: Fri Apr 24 22:31:15 2020 +0200 elf: Implement __libc_early_init has @@ -856,6 +876,11 @@ no more namespaces available for dlmopen()")); /* See if an error occurred during loading. */ if (__glibc_unlikely (exception.errstring != NULL)) { + /* Avoid keeping around a dangling reference to the libc.so link + map in case it has been cached in libc_map. */ + if (!args.libc_already_loaded) + GL(dl_ns)[nsid].libc_map = NULL; + do_dlopen calls _dl_open with nsid == __LM_ID_CALLER (-2), which calls dl_open_worker with args.nsid = nsid. dl_open_worker updates args.nsid if it is __LM_ID_CALLER. After dl_open_worker returns, it is wrong to use nsid. Replace nsid with args.nsid after dl_open_worker returns. This fixes BZ #27609.
2021-09-29elf: Copy l_addr/l_ld when adding ld.so to a new namespaceH.J. Lu
When add ld.so to a new namespace, we don't actually load ld.so. We create a new link map and refers the real one for almost everything. Copy l_addr and l_ld from the real ld.so link map to avoid GDB warning: warning: .dynamic section for ".../elf/ld-linux-x86-64.so.2" is not at the expected address (wrong library or version mismatch?) when handling shared library loaded by dlmopen. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-09-25Avoid warning: overriding recipe for .../tst-ro-dynamic-mod.soH.J. Lu
Add tst-ro-dynamic-mod to modules-names-nobuild to avoid ../Makerules:767: warning: ignoring old recipe for target '.../elf/tst-ro-dynamic-mod.so' This updates BZ #28340 fix.
2021-09-22ld.so: Replace DL_RO_DYN_SECTION with dl_relocate_ld [BZ #28340]H.J. Lu
We can't relocate entries in dynamic section if it is readonly: 1. Add a l_ld_readonly field to struct link_map to indicate if dynamic section is readonly and set it based on p_flags of PT_DYNAMIC segment. 2. Replace DL_RO_DYN_SECTION with dl_relocate_ld to decide if dynamic section should be relocated. 3. Remove DL_RO_DYN_TEMP_CNT. 4. Don't use a static dynamic section to make readonly dynamic section in vDSO writable. 5. Remove the temp argument from elf_get_dynamic_info. This fixes BZ #28340. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-09-20elf: Include <sysdep.h> in elf/dl-debug-symbols.SFlorian Weimer
This is necessary to generate assembler marker sections on some targets. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-09-19Extend struct r_debug to support multiple namespaces [BZ #15971]H.J. Lu
Glibc does not provide an interface for debugger to access libraries loaded in multiple namespaces via dlmopen. The current rtld-debugger interface is described in the file: elf/rtld-debugger-interface.txt under the "Standard debugger interface" heading. This interface only provides access to the first link-map (LM_ID_BASE). 1. Bump r_version to 2 when multiple namespaces are used. This triggers the GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236 2. Add struct r_debug_extended to extend struct r_debug into a linked-list, where each element correlates to an unique namespace. 3. Initialize the r_debug_extended structure. Bump r_version to 2 for the new namespace and add the new namespace to the namespace linked list. 4. Add _dl_debug_update to return the address of struct r_debug' of a namespace. 5. Add a hidden symbol, _r_debug_extended, for struct r_debug_extended. 6. Provide the symbol, _r_debug, with size of struct r_debug, as an alias of _r_debug_extended, for programs which reference _r_debug. This fixes BZ #15971. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-09-16elf: Remove THREAD_GSCOPE_IN_TCBSergey Bugaev
All the ports now have THREAD_GSCOPE_IN_TCB set to 1. Remove all support for !THREAD_GSCOPE_IN_TCB, along with the definition itself. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20210915171110.226187-4-bugaevc@gmail.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2021-09-15elf: Replace most uses of THREAD_GSCOPE_IN_TCBSergey Bugaev
While originally this definition was indeed used to distinguish between the cases where the GSCOPE flag was stored in TCB or not, it has since become used as a general way to distinguish between HTL and NPTL. THREAD_GSCOPE_IN_TCB will be removed in the following commits, as HTL, which currently is the only port that does not put the flag into TCB, will get ported to put the GSCOPE flag into the TCB as well. To prepare for that change, migrate all code that wants to distinguish between HTL and NPTL to use PTHREAD_IN_LIBC instead, which is a better choice since the distinction mostly has to do with whether libc has access to the list of thread structures and therefore can initialize thread-local storage. The parts of code that actually depend on whether the GSCOPE flag is in TCB are left unchanged. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20210907133325.255690-2-bugaevc@gmail.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2021-09-03Remove "Contributed by" linesSiddhesh Poyarekar
We stopped adding "Contributed by" or similar lines in sources in 2012 in favour of git logs and keeping the Contributors section of the glibc manual up to date. Removing these lines makes the license header a bit more consistent across files and also removes the possibility of error in attribution when license blocks or files are copied across since the contributed-by lines don't actually reflect reality in those cases. Move all "Contributed by" and similar lines (Written by, Test by, etc.) into a new file CONTRIBUTED-BY to retain record of these contributions. These contributors are also mentioned in manual/contrib.texi, so we just maintain this additional record as a courtesy to the earlier developers. The following scripts were used to filter a list of files to edit in place and to clean up the CONTRIBUTED-BY file respectively. These were not added to the glibc sources because they're not expected to be of any use in future given that this is a one time task: https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-08-24elf: Skip tst-auditlogmod-* if the linker doesn't support --depaudit [BZ #28151]Fangrui Song
gold and ld.lld do not support --audit or --depaudit. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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