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* stdio: Remove the usage of $(fno-unit-at-a-time) for siglist.cAdhemerval Zanella2022-05-132-13/+15
| | | | | | | | | | | | | | | | | | The siglist.c is built with -fno-toplevel-reorder to avoid compiler to reorder the compat assembly directives due an assembler issue [1] (fixed on 2.39). This patch removes the compiler flags by split the compat symbol generation in two phases. First the __sys_siglist and __sys_sigabbrev without any compat symbol directive is preprocessed to generate an assembly source code. This generate assembly is then used as input on a platform agnostic siglist.S which then creates the compat definitions. This prevents compiler to move any compat directive prior the _sys_errlist definition itself. Checked on a make check run-built-tests=no on all affected ABIs. Reviewed-by: Fangrui Song <maskray@google.com>
* sysdeps: Add 'get_fast_jitter' interace in fast-jitter.hNoah Goldstein2022-04-271-0/+42
| | | | | | | | | | | | | | 'get_fast_jitter' is meant to be used purely for performance purposes. In all cases it's used it should be acceptable to get no randomness (see default case). An example use case is in setting jitter for retries between threads at a lock. There is a performance benefit to having jitter, but only if the jitter can be generated very quickly and ultimately there is no serious issue if no jitter is generated. The implementation generally uses 'HP_TIMING_NOW' iff it is inlined (avoid any potential syscall paths). Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* elf: Remove unused enum allowmaskFangrui Song2022-04-251-11/+0
| | | | | | | Unused since 52a01100ad011293197637e42b5be1a479a2f4ae ("elf: Remove ad-hoc restrictions on dlopen callers [BZ #22787]"). Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Remove __libc_init_secureFangrui Song2022-04-191-24/+0
| | | | | | | | | | | | | | After 73fc4e28b9464f0e13edc719a5372839970e7ddb, __libc_enable_secure_decided is always 0 and a statically linked executable may overwrite __libc_enable_secure without considering AT_SECURE. The __libc_enable_secure has been correctly initialized in _dl_aux_init, so just remove __libc_enable_secure_decided and __libc_init_secure. This allows us to remove some startup_get*id functions from 22b79ed7f413cd980a7af0cf258da5bf82b6d5e5. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Remove _dl_skip_args_internal declarationSzabolcs Nagy2022-04-121-5/+0
| | | | | | It does not seem to be used. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Remove inline _dl_dprintfAdhemerval Zanella2022-03-231-11/+0
| | | | | | It is not used on rtld and ldsodef interfaces are meant to be used solely on loader. It also removes the only usage of gcc extension __builtin_va_arg_pack.
* elf: Remove LD_USE_LOAD_BIASAdhemerval Zanella2022-02-102-6/+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>
* elf: Remove prelink supportAdhemerval Zanella2022-02-101-11/+0
| | | | | | | | | | | | | 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>
* SET_RELHOOK: merge i386 and x86_64, and move to sysdeps/mach/hurd/x86Samuel Thibault2022-02-011-1/+1
| | | | | | | It is not Hurd-specific, but H.J. Lu wants it there. Also, dc.a can be used to avoid hardcoding .long vs .quad and thus use the same implementation for i386 and x86_64.
* elf: Fix runtime linker auditing on aarch64 (BZ #26643)Ben Woodard2022-02-011-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Issue la_symbind for bind-now (BZ #23734)Adhemerval Zanella2022-02-012-1/+7
| | | | | | | | | | | | | | | | | | | | | | | The audit symbind callback is not called for binaries built with -Wl,-z,now or when LD_BIND_NOW=1 is used, nor the PLT tracking callbacks (plt_enter and plt_exit) since this would change the expected program semantics (where no PLT is expected) and would have performance implications (such as for BZ#15533). LAV_CURRENT is also bumped to indicate the audit ABI change (where la_symbind flags are set by the loader to indicate no possible PLT trace). To handle powerpc64 ELFv1 function descriptor, _dl_audit_symbind requires to know whether bind-now is used so the symbol value is updated to function text segment instead of the OPD (for lazy binding this is done by PPC64_LOAD_FUNCPTR on _dl_runtime_resolve). Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, powerpc64-linux-gnu. 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: Add <dl-r_debug.h>H.J. Lu2022-01-311-0/+36
| | | | | | | | Add <dl-r_debug.h> to get the adddress of the r_debug structure after relocation and its offset before relocation from the PT_DYNAMIC segment to support DT_DEBUG, DT_MIPS_RLD_MAP_REL and DT_MIPS_RLD_MAP. Co-developed-by: Xi Ruoyao <xry111@mengyan1223.wang>
* elf: Fix 64 time_t support for installed statically binariesAdhemerval Zanella2022-01-171-3/+3
| | | | | | | | | | | | | | The usage of internal static symbol for statically linked binaries does not work correctly for objects built with -D_TIME_BITS=64, since the internal definition does not provide the expected aliases. This patch makes it to use the default stat functions instead (which uses the default 64 time_t alias and types). Checked on i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* Revert "elf: Fix 64 time_t support for installed statically binaries"Adhemerval Zanella2022-01-171-3/+3
| | | | This reverts commit 0b8e83eb1455f3c0332eeb1f96fbc262fbd054e0.
* elf: Fix 64 time_t support for installed statically binariesAdhemerval Zanella2022-01-121-3/+3
| | | | | | | | | | | The usage of internal static symbol for statically linked binaries does not work correctly for objects built with -D_TIME_BITS=64, since the internal definition does not provide the expected aliases. This patch makes it to use the default stat functions instead (which uses the default 64 time_t alias and types). Checked on i686-linux-gnu.
* math: Fix float conversion regressions with gcc-12 [BZ #28713]Szabolcs Nagy2022-01-101-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Converting double precision constants to float is now affected by the runtime dynamic rounding mode instead of being evaluated at compile time with default rounding mode (except static object initializers). This can change the computed result and cause performance regression. The known correctness issues (increased ulp errors) are already fixed, this patch fixes remaining cases of unnecessary runtime conversions. Add float M_* macros to math.h as new GNU extension API. To avoid conversions the new M_* macros are used and instead of casting double literals to float, use float literals (only required if the conversion is inexact). The patch was tested on aarch64 where the following symbols had new spurious conversion instructions that got fixed: __clog10f __gammaf_r_finite@GLIBC_2.17 __j0f_finite@GLIBC_2.17 __j1f_finite@GLIBC_2.17 __jnf_finite@GLIBC_2.17 __kernel_casinhf __lgamma_negf __log1pf __y0f_finite@GLIBC_2.17 __y1f_finite@GLIBC_2.17 cacosf cacoshf casinhf catanf catanhf clogf gammaf_positive Fixes bug 28713. Reviewed-by: Paul Zimmermann <Paul.Zimmermann@inria.fr>
* ttydefaults.h: Fix CSTATUS to control-tSamuel Thibault2022-01-071-5/+1
| | | | | 4.4BSD actually defaults CSTATUS to control-t, so our generic header should as well.
* debug: Remove catchsegv and libSegfault (BZ #14913)Adhemerval Zanella2022-01-061-19/+0
| | | | | | | | | | | | Trapping SIGSEGV within the process is error-prone, adds security issues, and modern analysis design tends to happen out of the process (either by attaching a debugger or by post-mortem analysis). The libSegfault also has some design problems, it uses non async-signal-safe function (backtrace) on signal handler. There are multiple alternatives if users do want to use similar functionality, such as sigsegv gnulib module or libsegfault.
* elf: Add <dl-debug.h>H.J. Lu2022-01-031-0/+33
| | | | | | | 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 Eggert2022-01-01162-162/+162
| | | | | | | | | | | | | | | | | | | | | | | 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/+5
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* malloc: Remove memusage.hAdhemerval Zanella2021-12-281-25/+0
| | | | | | And use machine-sp.h instead. The Linux implementation is based on already provided CURRENT_STACK_FRAME (used on nptl code) and STACK_GROWS_UPWARD is replaced with _STACK_GROWS_UP.
* malloc: Use hp-timing on libmemusageAdhemerval Zanella2021-12-281-12/+0
| | | | Instead of reimplemeting on GETTIME macro.
* malloc: Remove atomic_* usageAdhemerval Zanella2021-12-281-14/+0
| | | | | These typedef are used solely on memusage and can be replaced with generic types.
* elf: Add _dl_audit_pltexitAdhemerval Zanella2021-12-283-0/+32
| | | | | | | | | It consolidates the code required to call la_pltexit audit callback. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add _dl_audit_pltenterAdhemerval Zanella2021-12-281-0/+4
| | | | | | | | | It consolidates the code required to call la_pltenter audit callback. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add _dl_audit_preinitAdhemerval Zanella2021-12-281-0/+3
| | | | | | | | | It consolidates the code required to call la_preinit audit callback. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add _dl_audit_symbind_alt and _dl_audit_symbindAdhemerval Zanella2021-12-281-0/+10
| | | | | | | | | It consolidates the code required to call la_symbind{32,64} audit callback. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add _dl_audit_objcloseAdhemerval Zanella2021-12-281-0/+4
| | | | | | | | | It consolidates the code required to call la_objclose audit callback. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* elf: Add _dl_audit_objsearchAdhemerval Zanella2021-12-281-0/+7
| | | | | | | | | It consolidates the code required to call la_objsearch audit callback. 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 Zanella2021-12-281-0/+10
| | | | | | | | | | | | | 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 Zanella2021-12-281-0/+5
| | | | | | | | 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>
* hurd: Fix static-PIE startupSamuel Thibault2021-12-281-0/+31
| | | | | | | | hurd initialization stages use RUN_HOOK to run various initialization functions. That is however using absolute addresses which need to be relocated, which is done later by csu. We can however easily make the linker compute relative addresses which thus don't need a relocation. The new SET_RELHOOK and RUN_RELHOOK macros implement this.
* malloc: Add Huge Page support for mmapAdhemerval Zanella2021-12-152-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* malloc: Add madvise support for Transparent Huge PagesAdhemerval Zanella2021-12-153-0/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Support target specific ALIGN for variable alignment test [BZ #28676]H.J. Lu2021-12-141-0/+20
| | | | | | | | | | | 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>
* math: Add math-use-builtinds-fmin.hAdhemerval Zanella2021-12-132-0/+5
| | | | | It allows the architecture to use the builtin instead of generic implementation.
* math: Add math-use-builtinds-fmax.hAdhemerval Zanella2021-12-136-0/+9
| | | | | It allows the architecture to use the builtin instead of generic implementation.
* Remove TLS_TCB_ALIGN and TLS_INIT_TCB_ALIGNFlorian Weimer2021-12-091-9/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* elf: execve statically linked programs instead of crashing [BZ #28648]Florian Weimer2021-12-051-0/+25
| | | | | | | | | | | | | | | 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/+7
| | | | | | | This will be used to deallocate memory allocated using the non-minimal malloc. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Use the minimal malloc on tunables_strdupAdhemerval Zanella2021-11-091-0/+28
| | | | | | | | | | | | | | | | | | | | 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>
* x86_64: Add support for __memcmpeq using sse2, avx2, and evexNoah Goldstein2021-10-271-1/+4
| | | | | | No bug. This commit adds support for __memcmpeq to be implemented seperately from memcmp. Support is added for versions optimized with sse2, avx2, and evex.
* elf: Fix e6fd79f379 build with --enable-tunables=noAdhemerval Zanella2021-10-211-0/+9
| | | | | | The _dl_sort_maps_init() is not defined when tunables is not enabled. Checked on x86_64-linux-gnu.
* elf: Fix slow DSO sorting behavior in dynamic loader (BZ #17645)Chung-Lin Tang2021-10-211-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340]H.J. Lu2021-10-192-9/+12
| | | | | | | | | | | | | | | 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.
* elf: Fix dynamic-link.h usage on rtld.cAdhemerval Zanella2021-10-142-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Add run-time check for indirect external accessH.J. Lu2021-10-071-0/+54
| | | | | | | | | | | | | 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>
* Initial support for GNU_PROPERTY_1_NEEDEDH.J. Lu2021-10-072-2/+10
| | | | | | | | | | | | | | | | | 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>