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* rtld: Add glibc.rtld.enable_secure tunable.Joe Simmons-Talbott2024-02-291-0/+2
| | | | | | | | | | Add a tunable for setting __libc_enable_secure to 1. Do not set __libc_enable_secure to 0 if the tunable is set to 0. Ignore all tunables if glib.rtld.enable_secure is set. One use-case for this addition is to enable testing code paths that depend on __libc_enable_secure being set without the need to use setxid binaries. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* x86_64: Suppress false positive valgrind errorH.J. Lu2024-02-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When strcmp-avx2.S is used as the default, elf/tst-valgrind-smoke fails with ==1272761== Conditional jump or move depends on uninitialised value(s) ==1272761== at 0x4022C98: strcmp (strcmp-avx2.S:462) ==1272761== by 0x400B05B: _dl_name_match_p (dl-misc.c:75) ==1272761== by 0x40085F3: _dl_map_object (dl-load.c:1966) ==1272761== by 0x401AEA4: map_doit (rtld.c:644) ==1272761== by 0x4001488: _dl_catch_exception (dl-catch.c:237) ==1272761== by 0x40015AE: _dl_catch_error (dl-catch.c:256) ==1272761== by 0x401B38F: do_preload (rtld.c:816) ==1272761== by 0x401C116: handle_preload_list (rtld.c:892) ==1272761== by 0x401EDF5: dl_main (rtld.c:1842) ==1272761== by 0x401A79E: _dl_sysdep_start (dl-sysdep.c:140) ==1272761== by 0x401BEEE: _dl_start_final (rtld.c:494) ==1272761== by 0x401BEEE: _dl_start (rtld.c:581) ==1272761== by 0x401AD87: ??? (in */elf/ld.so) The assembly codes are: 0x0000000004022c80 <+144>: vmovdqu 0x20(%rdi),%ymm0 0x0000000004022c85 <+149>: vpcmpeqb 0x20(%rsi),%ymm0,%ymm1 0x0000000004022c8a <+154>: vpcmpeqb %ymm0,%ymm15,%ymm2 0x0000000004022c8e <+158>: vpandn %ymm1,%ymm2,%ymm1 0x0000000004022c92 <+162>: vpmovmskb %ymm1,%ecx 0x0000000004022c96 <+166>: inc %ecx => 0x0000000004022c98 <+168>: jne 0x4022c32 <strcmp+66> strcmp-avx2.S has 32-byte vector loads of strings which are shorter than 32 bytes: (gdb) p (char *) ($rdi + 0x20) $6 = 0x1ffeffea20 "memcheck-amd64-linux.so" (gdb) p (char *) ($rsi + 0x20) $7 = 0x4832640 "core-amd64-linux.so" (gdb) call (int) strlen ((char *) ($rsi + 0x20)) $8 = 19 (gdb) call (int) strlen ((char *) ($rdi + 0x20)) $9 = 23 (gdb) It triggers the valgrind error. The above code is safe since the loads don't cross the page boundary. Update tst-valgrind-smoke.sh to accept an optional suppression file and pass a suppression file to valgrind when strcmp-avx2.S is the default implementation of strcmp. Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
* x86: Update _dl_tlsdesc_dynamic to preserve caller-saved registersH.J. Lu2024-02-281-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | Compiler generates the following instruction sequence for GNU2 dynamic TLS access: leaq tls_var@TLSDESC(%rip), %rax call *tls_var@TLSCALL(%rax) or leal tls_var@TLSDESC(%ebx), %eax call *tls_var@TLSCALL(%eax) CALL instruction is transparent to compiler which assumes all registers, except for EFLAGS and RAX/EAX, are unchanged after CALL. When _dl_tlsdesc_dynamic is called, it calls __tls_get_addr on the slow path. __tls_get_addr is a normal function which doesn't preserve any caller-saved registers. _dl_tlsdesc_dynamic saved and restored integer caller-saved registers, but didn't preserve any other caller-saved registers. Add _dl_tlsdesc_dynamic IFUNC functions for FNSAVE, FXSAVE, XSAVE and XSAVEC to save and restore all caller-saved registers. This fixes BZ #31372. Add GLRO(dl_x86_64_runtime_resolve) with GLRO(dl_x86_tlsdesc_dynamic) to optimize elf_machine_runtime_setup. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
* arm: Use _dl_find_object on __gnu_Unwind_Find_exidx (BZ 31405)Adhemerval Zanella2024-02-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of __dl_iterate_phdr. On ARM dlfo_eh_frame/dlfo_eh_count maps to PT_ARM_EXIDX vaddr start / length. On a Neoverse N1 machine with 160 cores, the following program: $ cat test.c #include <stdlib.h> #include <pthread.h> #include <assert.h> enum { niter = 1024, ntimes = 128, }; static void * tf (void *arg) { int a = (int) arg; for (int i = 0; i < niter; i++) { void *p[ntimes]; for (int j = 0; j < ntimes; j++) p[j] = malloc (a * 128); for (int j = 0; j < ntimes; j++) free (p[j]); } return NULL; } int main (int argc, char *argv[]) { enum { nthreads = 16 }; pthread_t t[nthreads]; for (int i = 0; i < nthreads; i ++) assert (pthread_create (&t[i], NULL, tf, (void *) i) == 0); for (int i = 0; i < nthreads; i++) { void *r; assert (pthread_join (t[i], &r) == 0); assert (r == NULL); } return 0; } $ arm-linux-gnueabihf-gcc -fsanitize=address test.c -o test Improves from ~15s to 0.5s. Checked on arm-linux-gnueabihf.
* elf: Fix tst-nodeps2 test failure.Carlos O'Donell2024-01-101-1/+4
| | | | | | | | | | | | | | | | | After 78ca44da0160a0b442f0ca1f253e3360f044b2ec ("elf: Relocate libc.so early during startup and dlmopen (bug 31083)") we start seeing tst-nodeps2 failures when building the testsuite with --enable-hard-coded-path-in-tests. When building the testsuite with --enable-hard-coded-path-in-tests the tst-nodeps2-mod.so is not built with the required DT_RUNPATH values and the test escapes the test framework and loads the system libraries and aborts. The fix is to use the existing $(link-test-modules-rpath-link) variable to set DT_RUNPATH correctly. No regressions on x86_64. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Update copyright dates with scripts/update-copyrightsPaul Eggert2024-01-011-1/+1
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* elf: Add TLS modid reuse test for bug 29039Szabolcs Nagy2023-12-201-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a minimal regression test for bug 29039 which only affects targets with TLSDESC and a reproducer requires that 1) Have modid gaps (closed modules) with old generation. 2) Update a DTV to a newer generation (needs a newer dlopen). 3) But do not update the closed gap entry in that DTV. 4) Reuse the modid gap for a new module (another dlopen). 5) Use dynamic TLSDESC in that new module with old generation (bug). 6) Access TLS via this TLSDESC and the now outdated DTV. However step (3) in practice rarely happens: during DTV update the entries for closed modids are initialized to "unallocated" and then dynamic TLSDESC calls __tls_get_addr independently of its generation. The only exception to this is DTV setup at thread creation (gaps are initialized to NULL instead of unallocated) or DTV resize where the gap entries are outside the previous DTV array (again NULL instead of unallocated, and this requires loading > DTV_SURPLUS modules). So the bug can only cause NULL (+ offset) dereference, not use after free. And the easiest way to get (3) is via thread creation. Note that step (5) requires that the newly loaded module has larger TLS than the remaining optional static TLS. And for (6) there cannot be other TLS access or dlopen in the thread that updates the DTV. Tested on aarch64-linux-gnu. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Fix elf/tst-env-setuid[-static] if test needs to be rerun.Stefan Liebler2023-12-201-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | If /tmp is mounted nosuid and make xcheck is run, then tst-env-setuid fails UNSUPPORTED with "SGID failed: GID and EGID match" and /var/tmp/tst-sonamemove-runmod1.so.profile is created. If you then try to rerun the test with a suid mounted test-dir (the SGID binary is created in test-dir which defaults to /tmp) with something like that: make tst-env-setuid-ENV="TMPDIR=..." t=elf/tst-env-setuid test the test fails as the LD_PROFILE output file is still available from the previous run. Thus this patch removes the LD_PROFILE output file in parent before spawning the SGID binary. Even if LD_PROFILE is not supported anymore in static binaries, use a different library and thus output file for tst-env-setuid and tst-env-setuid-static in order to not interfere if both tests are run in parallel. Furthermore the checks in test_child are now more verbose. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Relocate libc.so early during startup and dlmopen (bug 31083)Florian Weimer2023-11-271-0/+21
| | | | | | | This makes it more likely that objects without dependencies can use IFUNC resolvers in libc.so. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* elf: Remove LD_PROFILE for static binariesAdhemerval Zanella2023-11-211-3/+7
| | | | | | | | | | | The _dl_non_dynamic_init does not parse LD_PROFILE, which does not enable profile for dlopen objects. Since dlopen is deprecated for static objects, it is better to remove the support. It also allows to trim down libc.a of profile support. Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Ignore LD_PROFILE for setuid binariesAdhemerval Zanella2023-11-211-0/+3
| | | | | | | | | | | | | | | | | | Loader does not ignore LD_PROFILE in secure-execution mode (different than man-page states [1]), rather it uses a different path (/var/profile) and ignore LD_PROFILE_OUTPUT. Allowing secure-execution profiling is already a non good security boundary, since it enables different code paths and extra OS access by the process. But by ignoring LD_PROFILE_OUTPUT, the resulting profile file might also be acceded in a racy manner since the file name does not use any process-specific information (such as pid, timing, etc.). Another side-effect is it forces lazy binding even on libraries that might be with DF_BIND_NOW. [1] https://man7.org/linux/man-pages/man8/ld.so.8.html Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Add all malloc tunable to unsecvarsAdhemerval Zanella2023-11-211-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | Some environment variables allow alteration of allocator behavior across setuid boundaries, where a setuid program may ignore the tunable, but its non-setuid child can read it and adjust the memory allocator behavior accordingly. Most library behavior tunings is limited to the current process and does not bleed in scope; so it is unclear how pratical this misfeature is. If behavior change across privilege boundaries is desirable, it would be better done with a wrapper program around the non-setuid child that sets these envvars, instead of using the setuid process as the messenger. The patch as fixes tst-env-setuid, where it fail if any unsecvars is set. It also adds a dynamic test, although it requires --enable-hardcoded-path-in-tests so kernel correctly sets the setuid bit (using the loader command directly would require to set the setuid bit on the loader itself, which is not a usual deployment). Co-authored-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
* elf: Ignore GLIBC_TUNABLES for setuid/setgid binariesAdhemerval Zanella2023-11-211-1/+4
| | | | | | | | | | | | | | | | | | | | The tunable privilege levels were a retrofit to try and keep the malloc tunable environment variables' behavior unchanged across security boundaries. However, CVE-2023-4911 shows how tricky can be tunable parsing in a security-sensitive environment. Not only parsing, but the malloc tunable essentially changes some semantics on setuid/setgid processes. Although it is not a direct security issue, allowing users to change setuid/setgid semantics is not a good security practice, and requires extra code and analysis to check if each tunable is safe to use on all security boundaries. It also means that security opt-in features, like aarch64 MTE, would need to be explicit enabled by an administrator with a wrapper script or with a possible future system-wide tunable setting. Co-authored-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: DJ Delorie <dj@redhat.com>
* elf: Handle non-directory name in search path (BZ 31035)Adhemerval Zanella2023-11-161-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The open_path stops if a relative path in search path contains a component that is a non directory (for instance, if the component is an existing file). For instance: $ cat > lib.c <<EOF > void foo (void) {} > EOF $ gcc -shared -fPIC -o lib.so lib.c $ cat > main.c <<EOF extern void foo (); int main () { foo (); return 0; } EOF $ gcc -o main main.c lib.so $ LD_LIBRARY_PATH=. ./main $ LD_LIBRARY_PATH=non-existing/path:. ./main $ LD_LIBRARY_PATH=$(pwd)/main:. ./main $ LD_LIBRARY_PATH=./main:. ./main ./main: error while loading shared libraries: lib.so: cannot open shared object file: No such file or directory The invalid './main' should be ignored as a non-existent one, instead as a valid but non accessible file. Absolute paths do not trigger this issue because their status are initialized as 'unknown' and open_path check if this is a directory. Checked on x86_64-linux-gnu. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* test: Run the tst-tls-allocation-failure-static-patched with test-wrapper.Yanzhang Wang2023-11-131-1/+1
| | | | If we use cross test with ssh, this test needs to be ran on the remote.
* elf: Add glibc.mem.decorate_maps tunableAdhemerval Zanella2023-11-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PR_SET_VMA_ANON_NAME support is only enabled through a configurable kernel switch, mainly because assigning a name to a anonymous virtual memory area might prevent that area from being merged with adjacent virtual memory areas. For instance, with the following code: void *p1 = mmap (NULL, 1024 * 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); void *p2 = mmap (p1 + (1024 * 4096), 1024 * 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); The kernel will potentially merge both mappings resulting in only one segment of size 0x800000. If the segment is names with PR_SET_VMA_ANON_NAME with different names, it results in two mappings. Although this will unlikely be an issue for pthread stacks and malloc arenas (since for pthread stacks the guard page will result in a PROT_NONE segment, similar to the alignment requirement for the arena block), it still might prevent the mmap memory allocated for detail malloc. There is also another potential scalability issue, where the prctl requires to take the mmap global lock which is still not fully fixed in Linux [1] (for pthread stacks and arenas, it is mitigated by the stack cached and the arena reuse). So this patch disables anonymous mapping annotations as default and add a new tunable, glibc.mem.decorate_maps, can be used to enable it. [1] https://lwn.net/Articles/906852/ Checked on x86_64-linux-gnu and aarch64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
* malloc: Decorate malloc mapsAdhemerval Zanella2023-11-071-0/+4
| | | | | | | | | | | | | | | Add anonymous mmap annotations on loader malloc, malloc when it allocates memory with mmap, and on malloc arena. The /proc/self/maps will now print: [anon: glibc: malloc arena] [anon: glibc: malloc] [anon: glibc: loader malloc] On arena allocation, glibc annotates only the read/write mapping. Checked on x86_64-linux-gnu and aarch64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
* nptl: Decorate thread stack on pthread_createAdhemerval Zanella2023-11-071-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 4.5 removed thread stack annotations due to the complexity of computing them [1], and Linux added PR_SET_VMA_ANON_NAME on 5.17 as a way to name anonymous virtual memory areas. This patch adds decoration on the stack created and used by pthread_create, for glibc crated thread stack the /proc/self/maps will now show: [anon: glibc: pthread stack: <tid>] And for user-provided stacks: [anon: glibc: pthread user stack: <tid>] The guard page is not decorated, and the mapping name is cleared when the thread finishes its execution (so the cached stack does not have any name associated). Checked on x86_64-linux-gnu aarch64 aarch64-linux-gnu. [1] https://github.com/torvalds/linux/commit/65376df582174ffcec9e6471bf5b0dd79ba05e4a Co-authored-by: Ian Rogers <irogers@google.com> Reviewed-by: DJ Delorie <dj@redhat.com>
* crypt: Remove libcrypt supportAdhemerval Zanella2023-10-301-38/+0
| | | | | | | | | | | | | | | | | | All the crypt related functions, cryptographic algorithms, and make requirements are removed, with only the exception of md5 implementation which is moved to locale folder since it is required by localedef for integrity protection (libc's locale-reading code does not check these, but localedef does generate them). Besides thec code itself, both internal documentation and the manual is also adjusted. This allows to remove both --enable-crypt and --enable-nss-crypt configure options. Checked with a build for all affected ABIs. Co-authored-by: Zack Weinberg <zack@owlfolio.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* elf: Check that --list-diagnostics output has the expected syntaxFlorian Weimer2023-08-251-0/+9
| | | | | | | | | | Parts of elf/tst-rtld-list-diagnostics.py have been copied from scripts/tst-ld-trace.py. The abnf module is entirely optional and used to verify the ABNF grammar as included in the manual. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Sort Makefile variables.Carlos O'Donell2023-06-021-1/+1
| | | | | | | | | Sort Makefile variables using scrips/sort-makefile-lines.py. No code generation changes observed in non-test binary artifacts. No regressions on x86_64 and i686. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Make more functions available for binding during dlclose (bug 30425)Florian Weimer2023-05-301-0/+8
| | | | | | | | | | | | | Previously, after destructors for a DSO have been invoked, ld.so refused to bind against that DSO in all cases. Relax this restriction somewhat if the referencing object is itself a DSO that is being unloaded. This assumes that the symbol reference is not going to be stored anywhere. The situation in the test case can arise fairly easily with C++ and objects that are built with different optimization levels and therefore define different functions with vague linkage. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Fix misspellings in elf/ -- BZ 25337Paul Pluzhnikov2023-05-291-4/+4
| | | | | | | Applying this commit results in bit-identical libc.so.6. The elf/ld-linux-x86-64.so.2 does change, but only in .note.gnu.build-id Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* elf: add test for dl-printfRoy Eldar2023-05-251-0/+1
| | | | | | | | This patch checks _dl_debug_vdprintf, by passing various inputs to _dl_dprintf and comparing the output with invocations of snprintf. Signed-off-by: Roy Eldar <royeldar0@gmail.com> Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add test for locating libraries in root dir (bug 30435)Qixing ksyx Xue2023-05-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When dlopen is being called, efforts have been made to improve future lookup performance. This includes marking a search path as non-existent using `stat`. However, if the root directory is given as a search path, there exists a bug which erroneously marks it as non-existing. The bug is reproduced under the following sequence: 1. dlopen is called to open a shared library, with at least: 1) a dependency 'A.so' not directly under the '/' directory (e.g. /lib/A.so), and 2) another dependency 'B.so' resides in '/'. 2. for this bug to reproduce, 'A.so' should be searched *before* 'B.so'. 3. it first tries to find 'A.so' in /, (e.g. /A.so): - this will (obviously) fail, - since it's the first time we have seen the '/' directory, its 'status' is 'unknown'. 4. `buf[buflen - namelen - 1] = '\0'` is executed: - it intends to remove the leaf and its final slash, - because of the speciality of '/', its buflen == namelen + 1, - it erroneously clears the entire buffer. 6. it then calls 'stat' with the empty buffer: - which will result in an error. 7. so it marks '/' as 'nonexisting', future lookups will not consider this path. 8. while /B.so *does* exist, failure to look it up in the '/' directory leads to a 'cannot open shared object file' error. This patch fixes the bug by preventing 'buflen', an index to put '\0', from being set to 0, so that the root '/' is always kept. Relative search paths are always considered as 'existing' so this wont be affected. Writeup by Moody Liu <mooodyhunter@outlook.com> Suggested-by: Carlos O'Donell <carlos@redhat.com> Signed-off-by: Qixing ksyx Xue <qixingxue@outlook.com> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Adjust tests in Makefile.Carlos O'Donell2023-05-181-10/+10
| | | | | | | | | Sort tests against updated scripts/sort-makefile-lines.py. No changes in generated code. No regressions on x86_64 and i686. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Reformat Makefile.Carlos O'Donell2023-05-161-35/+35
| | | | | | | | Fix list terminator whitspace. Sort using scripts/sort-makefile-lines.py. No code generation changes observed in binary artifacts. No regressions on x86_64 and i686.
* dlopen: skip debugger notification for DSO loaded from sprof (bug 30258)Andreas Schwab2023-05-091-0/+11
| | | | Avoid inconsistent state in the debugger interface.
* Remove --enable-tunables configure optionAdhemerval Zanella Netto2023-03-291-8/+1
| | | | | | | | | | | | And make always supported. The configure option was added on glibc 2.25 and some features require it (such as hwcap mask, huge pages support, and lock elisition tuning). It also simplifies the build permutations. Changes from v1: * Remove glibc.rtld.dynamic_sort changes, it is orthogonal and needs more discussion. * Cleanup more code. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Take into account ${sysconfdir} in elf/tst-ldconfig-p.shRomain Geissler2023-03-271-1/+1
| | | | | | Take into account ${sysconfdir} in elf/tst-ldconfig-p.sh. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Remove --with-default-link configure optionAdhemerval Zanella Netto2023-03-271-2/+0
| | | | | | | Now that there is no need to use a special linker script to hardening internal data structures, remove the --with-default-link configure option and associated definitions. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* libio: Remove the usage of __libc_IO_vtablesAdhemerval Zanella Netto2023-03-271-15/+1
| | | | | | | | | | | | | | Instead of using a special ELF section along with a linker script directive to put the IO vtables within the RELRO section, the libio vtables are all moved to an array marked as data.relro (so linker will place in the RELRO segment without the need of extra directives). To avoid static linking namespace issues and including all vtable referenced objects, all required function pointers are set to weak alias. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* elf: Add missing dependency between resolvfail and testobj1.soArsen Arsenović2023-03-101-0/+1
| | | | | | | | It was possible to run this test individually and have it fail because it can't find testobj1.so. This patch adds that dependency, to prevent such issues. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add -z lazy to some more testsArsen Arsenović2023-03-101-0/+19
| | | | | | | Some toolchains, such as that used on Gentoo Hardened, set -z now out of the box. This trips up a couple of tests. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Restore ldconfig libc6 implicit soname logic [BZ #30125]Joan Bruguera2023-02-201-0/+14
| | | | | | | | | | | | | | | | | | | | | | While cleaning up old libc version support, the deprecated libc4 code was accidentally kept in `implicit_soname`, instead of the libc6 code. This causes additional symlinks to be created by `ldconfig` for libraries without a soname, e.g. a library `libsomething.123.456.789` without a soname will create a `libsomething.123` -> `libsomething.123.456.789` symlink. As the libc6 version of the `implicit_soname` code is a trivial `xstrdup`, just inline it and remove `implicit_soname` altogether. Some further simplification looks possible (e.g. the call to `create_links` looks like a no-op if `soname == NULL`, other than the verbose printfs), but logic is kept as-is for now. Fixes: BZ #30125 Fixes: 8ee878592c4a ("Assume only FLAG_ELF_LIBC6 suport") Signed-off-by: Joan Bruguera <joanbrugueram@gmail.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Smoke-test ldconfig -p against system /etc/ld.so.cacheFlorian Weimer2023-02-081-0/+6
| | | | | | | | The test is sufficient to detect the ldconfig bug fixed in commit 9fe6f6363886aae6b2b210cae3ed1f5921299083 ("elf: Fix 64 time_t support for installed statically binaries"). Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Update copyright dates with scripts/update-copyrightsJoseph Myers2023-01-061-1/+1
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* libio: Convert __vswprintf_internal to buffers (bug 27857)Florian Weimer2022-12-191-1/+0
| | | | | | | Always null-terminate the buffer and set E2BIG if the buffer is too small. This fixes bug 27857. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* libio: Convert __obstack_vprintf_internal to buffers (bug 27124)Florian Weimer2022-12-191-1/+0
| | | | | | This fixes bug 27124 because the problematic built-in vtable is gone. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* libio: Convert __vsprintf_internal to buffersFlorian Weimer2022-12-191-1/+0
| | | | Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* stdio-common: Convert vfprintf and related functions to buffersFlorian Weimer2022-12-191-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vfprintf is entangled with vfwprintf (of course), __printf_fp, __printf_fphex, __vstrfmon_l_internal, and the strfrom family of functions. The latter use the internal snprintf functionality, so vsnprintf is converted as well. The simples conversion is __printf_fphex, followed by __vstrfmon_l_internal and __printf_fp, and finally __vfprintf_internal and __vfwprintf_internal. __vsnprintf_internal and strfrom* are mostly consuming the new interfaces, so they are comparatively simple. __printf_fp is a public symbol, so the FILE *-based interface had to preserved. The __printf_fp rewrite does not change the actual binary-to-decimal conversion algorithm, and digits are still not emitted directly to the target buffer. However, the staging buffer now uses bytes instead of wide characters, and one buffer copy is eliminated. The changes are at least performance-neutral in my testing. Floating point printing and snprintf improved measurably, so that this Lua script for i=1,5000000 do print(i, i * math.pi) end runs about 5% faster for me. To preserve fprintf performance for a simple "%d" format, this commit has some logic changes under LABEL (unsigned_number) to avoid additional function calls. There are certainly some very easy performance improvements here: binary, octal and hexadecimal formatting can easily avoid the temporary work buffer (the number of digits can be computed ahead-of-time using one of the __builtin_clz* built-ins). Decimal formatting can use a specialized version of _itoa_word for base 10. The existing (inconsistent) width handling between strfmon and printf is preserved here. __print_fp_buffer_1 would have to use __translated_number_width to achieve ISO conformance for printf. Test expectations in libio/tst-vtables-common.c are adjusted because the internal staging buffer merges all virtual function calls into one. In general, stack buffer usage is greatly reduced, particularly for unbuffered input streams. __printf_fp can still use a large buffer in binary128 mode for %g, though. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* stdio-common: Introduce buffers for implementing printfFlorian Weimer2022-12-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | These buffers will eventually be used instead of FILE * objects to implement printf functions. The multibyte buffer is struct __printf_buffer, the wide buffer is struct __wprintf_buffer. To enable writing type-generic code, the header files printf_buffer-char.h and printf_buffer-wchar_t.h define the Xprintf macro differently, enabling Xprintf (buffer) to stand for __printf_buffer and __wprintf_buffer as appropriate. For common cases, macros like Xprintf_buffer are provided as a more syntactically convenient shortcut. Buffer-specific flush callbacks are implemented with a switch statement instead of a function pointer, to avoid hardening issues similar to those of libio vtables. struct __printf_buffer_as_file is needed to support custom printf specifiers because the public interface for that requires passing a FILE *, which is why there is a trapdoor back from these buffers to FILE * streams. Since the immediate user of these interfaces knows when processing has finished, there is no flush callback for the end of processing, only a flush callback for the intermediate buffer flush. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Rework exception handling in the dynamic loader [BZ #25486]Florian Weimer2022-11-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | The old exception handling implementation used function interposition to replace the dynamic loader implementation (no TLS support) with the libc implementation (TLS support). This results in problems if the link order between the dynamic loader and libc is reversed (bug 25486). The new implementation moves the entire implementation of the exception handling functions back into the dynamic loader, using THREAD_GETMEM and THREAD_SETMEM for thread-local data support. These depends on Hurd support for these macros, added in commit b65a82e4e757c1e6cb7073916 ("hurd: Add THREAD_GET/SETMEM/_NC"). One small obstacle is that the exception handling facilities are used before the TCB has been set up, so a check is needed if the TCB is available. If not, a regular global variable is used to store the exception handling information. Also rename dl-error.c to dl-catch.c, to avoid confusion with the dlerror function. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Build tst-relr-mod[34]a.so with $(LDFLAGS-rpath-ORIGIN)H.J. Lu2022-10-311-2/+2
| | | | | | | | | | When --enable-hardcoded-path-in-tests is used only with DT_RUNPATH, elf/tst-relr3 and elf/tst-relr4 failed to run. Their dependency libraries, tst-relr-mod3a.so and tst-relr-mod4a.so, are failed to load since DT_RUNPATH on executable doesn't apply to them. Build tst-relr-mod3a.so and tst-relr-mod4a.so with $(LDFLAGS-rpath-ORIGIN) to add DT_RUNPATH for their dependency libraries. Reviewed-by: Fangrui Song <maskray@google.com>
* elf: Introduce to _dl_call_finiFlorian Weimer2022-10-271-0/+1
| | | | | | | | | | This consolidates the destructor invocations from _dl_fini and dlclose. Remove the micro-optimization that avoids calling _dl_call_fini if they are no destructors (as dlclose is quite expensive anyway). The debug log message is now printed unconditionally. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Remove -fno-tree-loop-distribute-patterns usage on dl-supportAdhemerval Zanella2022-10-101-5/+0
| | | | | | | | | | | | | | Besides the option being gcc specific, this approach is still fragile and not future proof since we do not know if this will be the only optimization option gcc will add that transforms loops to memset (or any libcall). This patch adds a new header, dl-symbol-redir-ifunc.h, that can b used to redirect the compiler generated libcalls to port the generic memset implementation if required. Checked on x86_64-linux-gnu and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* elf: Remove legacy hwcaps support from the dynamic loaderJavier Pello2022-10-061-6/+0
| | | | | | | | Remove support for the legacy hwcaps subdirectories from the dynamic loader. Signed-off-by: Javier Pello <devel@otheo.eu> Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Call __libc_early_init for reused namespaces (bug 29528)Florian Weimer2022-08-261-0/+7
| | | | | | | | | | libc_map is never reset to NULL, neither during dlclose nor on a dlopen call which reuses the namespace structure. As a result, if a namespace is reused, its libc is not initialized properly. The most visible result is a crash in the <ctype.h> functions. To prevent similar bugs on namespace reuse from surfacing, unconditionally initialize the chosen namespace to zero using memset.
* Revert "Detect ld.so and libc.so version inconsistency during startup"Florian Weimer2022-08-251-1/+1
| | | | | | | | | | | | | | | | This reverts commit 6f85dbf102ad7982409ba0fe96886caeb6389fef. Once this change hits the release branches, it will require relinking of all statically linked applications before static dlopen works again, for the majority of updates on release branches: The NEWS file is regularly updated with bug references, so the __libc_early_init suffix changes, and static dlopen cannot find the function anymore. While this ABI check is still technically correct (we do require rebuilding & relinking after glibc updates to keep static dlopen working), it is too drastic for stable release branches. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Detect ld.so and libc.so version inconsistency during startupFlorian Weimer2022-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The files NEWS, include/link.h, and sysdeps/generic/ldsodefs.h contribute to the version fingerprint used for detection. The fingerprint can be further refined using the --with-extra-version-id configure argument. _dl_call_libc_early_init is replaced with _dl_lookup_libc_early_init. The new function is used store a pointer to libc.so's __libc_early_init function in the libc_map_early_init member of the ld.so namespace structure. This function pointer can then be called directly, so the separate invocation function is no longer needed. The versioned symbol lookup needs the symbol versioning data structures, so the initialization of libc_map and libc_map_early_init is now done from _dl_check_map_versions, after this information becomes available. (_dl_map_object_from_fd does not set this up in time, so the initialization code had to be moved from there.) This means that the separate initialization code can be removed from dl_main because _dl_check_map_versions covers all maps, including the initial executable loaded by the kernel. The lookup still happens before relocation and the invocation of IFUNC resolvers, so IFUNC resolvers are protected from ABI mismatch. The __libc_early_init function pointer is not protected because so little code runs between the pointer write and the invocation (only dynamic linker code and IFUNC resolvers). Reviewed-by: Carlos O'Donell <carlos@redhat.com>
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-15 13:24:11 +0000