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* elf: correct relocation statistics for !ELF_MACHINE_START_ADDRESSAndreas Schwab2024-01-291-4/+3
| | | | Fixes: 6628c742b2 ("elf: Remove prelink support")
* Update copyright dates with scripts/update-copyrightsPaul Eggert2024-01-011-1/+1
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* elf: Initialize GLRO(dl_lazy) before relocating libc in dynamic startupFlorian Weimer2023-12-081-3/+3
| | | | | | | | | | | GLRO(dl_lazy) is used to set the parameters for the early _dl_relocate_object call, so the consider_profiling setting has to be applied before the call. Fixes commit 78ca44da0160a0b442f0ca1f253e3360f044b2ec ("elf: Relocate libc.so early during startup and dlmopen (bug 31083)"). Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* elf: Refactor process_envvarsAdhemerval Zanella2023-12-051-48/+84
| | | | | | | | | | It splits between process_envvars_secure and process_envvars_default, with the former used to process arguments for __libc_enable_secure. It does not have any semantic change, just simplify the code so there is no need to handle __libc_enable_secure on each len switch. Checked on x86_64-linux-gnu and aarch64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Ignore LD_BIND_NOW and LD_BIND_NOT for setuid binariesAdhemerval Zanella2023-12-051-2/+6
| | | | | | | | To avoid any environment variable to change setuid binaries semantics. Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Ignore loader debug env vars for setuidAdhemerval Zanella2023-12-051-8/+14
| | | | | | | | | | | | | Loader already ignores LD_DEBUG, LD_DEBUG_OUTPUT, and LD_TRACE_LOADED_OBJECTS. Both LD_WARN and LD_VERBOSE are similar to LD_DEBUG, in the sense they enable additional checks and debug information, so it makes sense to disable them. Also add both LD_VERBOSE and LD_WARN on filtered environment variables for setuid binaries. Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Relocate libc.so early during startup and dlmopen (bug 31083)Florian Weimer2023-11-271-2/+8
| | | | | | | 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: Add comments on how LD_AUDIT and LD_PRELOAD handle __libc_enable_secureAdhemerval Zanella2023-11-211-1/+8
| | | | | To make explicit why __libc_enable_secure is not checked. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Remove any_debug from dl_main_stateAdhemerval Zanella2023-11-211-3/+1
| | | | | Its usage can be implied by the GLRO(dl_debug_mask). Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Ignore LD_PROFILE for setuid binariesAdhemerval Zanella2023-11-211-5/+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: Remove /etc/suid-debug supportAdhemerval Zanella2023-11-211-2/+1
| | | | | | | | | | | | | | | | Since malloc debug support moved to a different library (libc_malloc_debug.so), the glibc.malloc.check requires preloading the debug library to enable it. It means that suid-debug support has not been working since 2.34. To restore its support, it would require to add additional information and parsing to where to find libc_malloc_debug.so. It is one thing less that might change AT_SECURE binaries' behavior due to environment configurations. Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Remove unused l_text_end field from struct link_mapFlorian Weimer2023-09-081-6/+0
| | | | | | | | | | | | | It is a left-over from commit 52a01100ad011293197637e42b5be1a479a2 ("elf: Remove ad-hoc restrictions on dlopen callers [BZ #22787]"). When backporting commmit 6985865bc3ad5b23147ee73466583dd7fdf65892 ("elf: Always call destructors in reverse constructor order (bug 30785)"), we can move the l_init_called_next field to this place, so that the internal GLIBC_PRIVATE ABI does not change. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* elf: Remove spurios SHARED conditional from elf/rtld.cFlorian Weimer2023-05-311-2/+0
| | | | elf/rtld.c is only ever built in SHARED mode.
* Fix misspellings in elf/ -- BZ 25337Paul Pluzhnikov2023-05-291-3/+3
| | | | | | | 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>
* Remove --enable-tunables configure optionAdhemerval Zanella Netto2023-03-291-22/+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>
* Replace rawmemchr (s, '\0') with strchrWilco Dijkstra2023-02-061-3/+2
| | | | | | | | | Almost all uses of rawmemchr find the end of a string. Since most targets use a generic implementation, replacing it with strchr is better since that is optimized by compilers into strlen (s) + s. Also fix the generic rawmemchr implementation to use a cast to unsigned char in the if statement. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Update copyright dates with scripts/update-copyrightsJoseph Myers2023-01-061-1/+1
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* elf: Introduce <dl-call_tls_init_tp.h> and call_tls_init_tp (bug 29249)Florian Weimer2022-11-031-11/+3
| | | | | | | | This makes it more likely that the compiler can compute the strlen argument in _startup_fatal at compile time, which is required to avoid a dependency on strlen this early during process startup. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* elf: Rework exception handling in the dynamic loader [BZ #25486]Florian Weimer2022-11-031-1/+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>
* ld.so: Export tls_init_tp_called as __rtld_tls_init_tp_calledFlorian Weimer2022-10-271-5/+5
| | | | | | | This allows the rest of dynamic loader to check whether the TCB has been set up (and THREAD_GETMEM and THREAD_SETMEM will work). Reviewed-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
* Use '%z' instead of '%Z' on printf functionsAdhemerval Zanella Netto2022-09-221-3/+3
| | | | | | | | The Z modifier is a nonstandard synonymn for z (that predates z itself) and compiler might issue an warning for in invalid conversion specifier. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Restore how vDSO dependency is printed with LD_TRACE_LOADED_OBJECTS (BZ ↵Adhemerval Zanella2022-08-311-0/+6
| | | | | | | | | | | | | | | | | | | | | | | #29539) The d7703d3176d225d5743b21811d888619eba39e82 changed how vDSO like dependencies are printed, instead of just the name and address it follows other libraries mode and prints 'name => path'. Unfortunately, this broke some ldd consumer that uses the output to filter out the program's dependencies. For instance CMake bundleutilities module [1], where GetPrequirite uses the regex to filter out 'name => path' [2]. This patch restore the previous way to print just the name and the mapping address. Checked on x86_64-linux-gnu. [1] https://github.com/Kitware/CMake/tree/master/Tests/BundleUtilities [2] https://github.com/Kitware/CMake/blob/master/Modules/GetPrerequisites.cmake#L733 Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Revert "Detect ld.so and libc.so version inconsistency during startup"Florian Weimer2022-08-251-2/+10
| | | | | | | | | | | | | | | | 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 Weimer2022-08-241-10/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* elf: Fix -DNDEBUG warning in _dl_start_args_adjustFlorian Weimer2022-06-281-1/+1
| | | | | This is another blocker for building glibc with the default -Werror setting and -DNDEBUG.
* elf: Remove _dl_skip_argsAdhemerval Zanella2022-05-301-2/+0
| | | | | | Now that no architecture uses it anymore. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* rtld: Remove DL_ARGV_NOT_RELRO and make _dl_skip_args constSzabolcs Nagy2022-05-171-8/+2
| | | | | | | | | | | _dl_skip_args is always 0, so the target specific code that modifies argv after relro protection is applied is no longer used. After the patch relro protection is applied to _dl_argv consistently on all targets. Reviewed-by: Florian Weimer <fweimer@redhat.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* rtld: Use generic argv adjustment in ld.so [BZ #23293]Szabolcs Nagy2022-05-171-13/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an executable is invoked as ./ld.so [ld.so-args] ./exe [exe-args] then the argv is adujusted in ld.so before calling the entry point of the executable so ld.so args are not visible to it. On most targets this requires moving argv, env and auxv on the stack to ensure correct stack alignment at the entry point. This had several issues: - The code for this adjustment on the stack is written in asm as part of the target specific ld.so _start code which is hard to maintain. - The adjustment is done after _dl_start returns, where it's too late to update GLRO(dl_auxv), as it is already readonly, so it points to memory that was clobbered by the adjustment. This is bug 23293. - _environ is also wrong in ld.so after the adjustment, but it is likely not used after _dl_start returns so this is not user visible. - _dl_argv was updated, but for this it was moved out of relro, which changes security properties across targets unnecessarily. This patch introduces a generic _dl_start_args_adjust function that handles the argument adjustments after ld.so processed its own args and before relro protection is applied. The same algorithm is used on all targets, _dl_skip_args is now 0, so existing target specific adjustment code is no longer used. The bug affects aarch64, alpha, arc, arm, csky, ia64, nios2, s390-32 and sparc, other targets don't need the change in principle, only for consistency. The GNU Hurd start code relied on _dl_skip_args after dl_main returned, now it checks directly if args were adjusted and fixes the Hurd startup data accordingly. Follow up patches can remove _dl_skip_args and DL_ARGV_NOT_RELRO. Tested on aarch64-linux-gnu and cross tested on i686-gnu. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Remove dl-librecon.h header.Adhemerval Zanella2022-05-161-23/+2
| | | | | | | | | | | | | | | | | | | | | | | The Linux version used by i686 and m68k provide three overrrides for generic code: 1. DISTINGUISH_LIB_VERSIONS to print additional information when libc5 is used by a dependency. 2. EXTRA_LD_ENVVARS to that enabled LD_LIBRARY_VERSION environment variable. 3. EXTRA_UNSECURE_ENVVARS to add two environment variables related to aout support. None are really requires, it has some decades since libc5 or aout suppported was removed and Linux even remove support for aout files. The LD_LIBRARY_VERSION is also dead code, dl_correct_cache_id is not used anywhere. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Remove kernel version checkAdhemerval Zanella2022-05-161-15/+0
| | | | | | | | | | | | | | | | | | | | The kernel version check is used to avoid glibc to run on older kernels where some syscall are not available and fallback code are not enabled to handle graciously fail. However, it does not prevent if the kernel does not correctly advertise its version through vDSO note, uname or procfs. Also kernel version checks are sometime not desirable by users, where they want to deploy on different system with different kernel version knowing the minimum set of syscall is always presented on such systems. The kernel version check has been removed along with the LD_ASSUME_KERNEL environment variable. The minimum kernel used to built glibc is still provided through NT_GNU_ABI_TAG ELF note and also printed when libc.so is issued. Checked on x86_64-linux-gnu.
* Use __ehdr_start rather than _begin in _dl_start_finalAlan Modra2022-04-281-4/+3
| | | | | | | | | | __ehdr_start is already used in rltld.c:dl_main, and can serve the same purpose as _begin. Besides tidying the code, using linker defined section relative symbols rather than "-defsym _begin=0" better reflects the intent of _dl_start_final use of _begin, which is to refer to the load address of ld.so rather than absolute address zero. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Replace PI_STATIC_AND_HIDDEN with opposite HIDDEN_VAR_NEEDS_DYNAMIC_RELOCFangrui Song2022-04-261-1/+1
| | | | | | | | | | | | | | | | | | PI_STATIC_AND_HIDDEN indicates whether accesses to internal linkage variables and hidden visibility variables in a shared object (ld.so) need dynamic relocations (usually R_*_RELATIVE). PI (position independent) in the macro name is a misnomer: a code sequence using GOT is typically position-independent as well, but using dynamic relocations does not meet the requirement. Not defining PI_STATIC_AND_HIDDEN is legacy and we expect that all new ports will define PI_STATIC_AND_HIDDEN. Current ports defining PI_STATIC_AND_HIDDEN are more than the opposite. Change the configure default. No functional change. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Move post-relocation code of _dl_start into _dl_start_finalFangrui Song2022-04-251-15/+10
| | | | | | | | | | | | | | | | On non-PI_STATIC_AND_HIDDEN architectures, getting the address of _rtld_local_ro (for GLRO (dl_final_object)) goes through a GOT entry. The GOT load may be reordered before self relocation, leading to an unrelocated/incorrect _rtld_local_ro address. 84e02af1ebc9988126eebe60bf19226cea835623 tickled GCC powerpc32 to reorder the GOT load before relative relocations, leading to ld.so crash. This is similar to the m68k jump table reordering issue fixed by a8e9b5b8079d18116ca69c9797e77804ecf2ee7e. Move code after self relocation into _dl_start_final to avoid the reordering. This fixes powerpc32 and may help other architectures when ELF_DYNAMIC_RELOCATE is simplified in the future.
* elf: Remove LD_USE_LOAD_BIASAdhemerval Zanella2022-02-101-13/+0
| | | | | | | | It is solely for prelink with PIE executables [1]. [1] https://sourceware.org/legacy-ml/libc-hacker/2003-11/msg00127.html Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* malloc: Remove LD_TRACE_PRELINKING usage from mtraceAdhemerval Zanella2022-02-101-9/+13
| | | | | | | | | | | | | | | | | | | | | | The fix for BZ#22716 replacde LD_TRACE_LOADED_OBJECTS with LD_TRACE_PRELINKING so mtrace could record executable address position. To provide the same information, LD_TRACE_LOADED_OBJECTS is extended where a value or '2' also prints the executable address as well. It avoid adding another loader environment variable to be used solely for mtrace. The vDSO will be printed as a default library (with '=>' pointing the same name), which is ok since both mtrace and ldd already handles it. The mtrace script is changed to also parse the new format. To correctly support PIE and non-PIE executables, both the default mtrace address and the one calculated as used (it fixes mtrace for non-PIE exectuable as for BZ#22716 for PIE). Checked on x86_64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Remove prelink supportAdhemerval Zanella2022-02-101-200/+50
| | | | | | | | | | | | | Prelinked binaries and libraries still work, the dynamic tags DT_GNU_PRELINKED, DT_GNU_LIBLIST, DT_GNU_CONFLICT just ignored (meaning the process is reallocated as default). The loader environment variable TRACE_PRELINKING is also removed, since it used solely on prelink. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* elf: Fix runtime linker auditing on aarch64 (BZ #26643)Ben Woodard2022-02-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rtld audit support show two problems on aarch64: 1. _dl_runtime_resolve does not preserve x8, the indirect result location register, which might generate wrong result calls depending of the function signature. 2. The NEON Q registers pushed onto the stack by _dl_runtime_resolve were twice the size of D registers extracted from the stack frame by _dl_runtime_profile. While 2. might result in wrong information passed on the PLT tracing, 1. generates wrong runtime behaviour. The aarch64 rtld audit support is changed to: * Both La_aarch64_regs and La_aarch64_retval are expanded to include both x8 and the full sized NEON V registers, as defined by the ABI. * dl_runtime_profile needed to extract registers saved by _dl_runtime_resolve and put them into the new correctly sized La_aarch64_regs structure. * The LAV_CURRENT check is change to only accept new audit modules to avoid the undefined behavior of not save/restore x8. * Different than other architectures, audit modules older than LAV_CURRENT are rejected (both La_aarch64_regs and La_aarch64_retval changed their layout and there are no requirements to support multiple audit interface with the inherent aarch64 issues). * A new field is also reserved on both La_aarch64_regs and La_aarch64_retval to support variant pcs symbols. Similar to x86, a new La_aarch64_vector type to represent the NEON register is added on the La_aarch64_regs (so each type can be accessed directly). Since LAV_CURRENT was already bumped to support bind-now, there is no need to increase it again. Checked on aarch64-linux-gnu. Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* elf: Fix initial-exec TLS access on audit modules (BZ #28096)Adhemerval Zanella2022-02-011-1/+1
| | | | | | | | | | | | | | | | | For audit modules and dependencies with initial-exec TLS, we can not set the initial TLS image on default loader initialization because it would already be set by the audit setup. However, subsequent thread creation would need to follow the default behaviour. This patch fixes it by setting l_auditing link_map field not only for the audit modules, but also for all its dependencies. This is used on _dl_allocate_tls_init to avoid the static TLS initialization at load time. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* elf: Set l_contiguous to 1 for the main map in more casesFlorian Weimer2022-01-171-0/+25
| | | | | | | | | | | | | | | | | l_contiguous was not initialized at all for the main map and always 0. This commit adds code to check if the LOAD segments are adjacent to each other, and sets l_contiguous accordingly. This helps _dl_find_object because it is more efficient if the main mapping is contiguous. Note that not all (PIE or non-PIE) binaries are contiguous in this way because BFD ld creates executables with LOAD holes: ELF LOAD segments creating holes in the process image on GNU/Linux https://sourceware.org/pipermail/binutils/2022-January/119082.html https://sourceware.org/bugzilla/show_bug.cgi?id=28743 Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* elf: Introduce rtld_setup_main_mapFlorian Weimer2022-01-171-144/+159
| | | | | | | This function collects most of the processing needed to initialize the link map for the main executable. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* elf: Add <dl-debug.h>H.J. Lu2022-01-031-9/+4
| | | | | | | Add <dl-debug.h> to setup debugging entry in PT_DYNAMIC segment to support DT_DEBUG, DT_MIPS_RLD_MAP_REL and DT_MIPS_RLD_MAP. Tested on x86-64, x32 and i686 as well as with build-many-glibcs.py.
* Update copyright dates with scripts/update-copyrightsPaul Eggert2022-01-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
* elf: Add _dl_find_object functionFlorian Weimer2021-12-281-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | It can be used to speed up the libgcc unwinder, and the internal _dl_find_dso_for_object function (which is used for caller identification in dlopen and related functions, and in dladdr). _dl_find_object is in the internal namespace due to bug 28503. If libgcc switches to _dl_find_object, this namespace issue will be fixed. It is located in libc for two reasons: it is necessary to forward the call to the static libc after static dlopen, and there is a link ordering issue with -static-libgcc and libgcc_eh.a because libc.so is not a linker script that includes ld.so in the glibc build tree (so that GCC's internal -lc after libgcc_eh.a does not pick up ld.so). It is necessary to do the i386 customization in the sysdeps/x86/bits/dl_find_object.h header shared with x86-64 because otherwise, multilib installations are broken. The implementation uses software transactional memory, as suggested by Torvald Riegel. Two copies of the supporting data structures are used, also achieving full async-signal-safety. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Issue audit la_objopen for vDSOAdhemerval Zanella2021-12-281-0/+6
| | | | | | | | | | | | | | | The vDSO is is listed in the link_map chain, but is never the subject of an la_objopen call. A new internal flag __RTLD_VDSO is added that acts as __RTLD_OPENEXEC to allocate the required 'struct auditstate' extra space for the 'struct link_map'. The return value from the callback is currently ignored, since there is no PLT call involved by glibc when using the vDSO, neither the vDSO are exported directly. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Avoid unnecessary slowdown from profiling with audit (BZ#15533)Adhemerval Zanella2021-12-281-7/+1
| | | | | | | | | | | | | | | | | | | The rtld-audit interfaces introduces a slowdown due to enabling profiling instrumentation (as if LD_AUDIT implied LD_PROFILE). However, instrumenting is only necessary if one of audit libraries provides PLT callbacks (la_pltenter or la_pltexit symbols). Otherwise, the slowdown can be avoided. The following patch adjusts the logic that enables profiling to iterate over all audit modules and check if any of those provides a PLT hook. To keep la_symbind to work even without PLT callbacks, _dl_fixup now calls the audit callback if the modules implements it. Co-authored-by: Alexander Monakov <amonakov@ispras.ru> Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add _dl_audit_activity_map and _dl_audit_activity_nsidAdhemerval Zanella2021-12-281-29/+2
| | | | | | | | | | | | | It consolidates the code required to call la_activity audit callback. Also for a new Lmid_t the namespace link_map list are empty, so it requires to check if before using it. This can happen for when audit module is used along with dlmopen. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add _dl_audit_objopenAdhemerval Zanella2021-12-281-21/+2
| | | | | | | | It consolidates the code required to call la_objopen audit callback. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Use errcode instead of (unset) errno in rtld_chain_loadFlorian Weimer2021-12-101-1/+1
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* elf: execve statically linked programs instead of crashing [BZ #28648]Florian Weimer2021-12-051-8/+42
| | | | | | | | | | | | | | | 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>
* elf: Introduce GLRO (dl_libc_freeres), called from __libc_freeresFlorian Weimer2021-11-171-0/+1
| | | | | | | This will be used to deallocate memory allocated using the non-minimal malloc. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-01 18:04:53 +0000