glibc/csu/libc-tls.c, branch vdso

Update copyright dates with scripts/update-copyrights

2024-01-01T18:53:40Z

elf: Fix GL(dl_phdr) and GL(dl_phnum) for static builds [BZ #29864]

2023-01-12T16:54:34Z

The 73fc4e28b9464f0e refactor did not add the GL(dl_phdr) and GL(dl_phnum) for static build, relying on the __ehdr_start symbol, which is always added by the static linker, to get the correct values. This is problematic in some ways: - The segment may see its in-memory size differ from its in-file size (or the binary may have holes). The Linux has fixed is to provide concise values for both AT_PHDR and AT_PHNUM (commit 0da1d5002745c - "fs/binfmt_elf: Fix AT_PHDR for unusual ELF files") - Some archs (alpha for instance) the hidden weak reference is not correctly pulled by the static linker and __ehdr_start address end up being 0, which makes GL(dl_phdr) and GL(dl_phnum) have both invalid values (and triggering a segfault later on libc.so while accessing TLS variables). The safer fix is to just restore the previous behavior to setup GL(dl_phdr) and GL(dl_phnum) for static based on kernel auxv. The __ehdr_start fallback can also be simplified by not assuming weak linkage (as for PIE). The libc-static.c auxv init logic is moved to dl-support.c, since the later is build without SHARED and then GLRO macro is defined to access the variables directly. The _dl_phdr is also assumed to be always non NULL, since an invalid NULL values does not trigger TLS initialization (which is used in various libc systems). Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. Reviewed-by: Florian Weimer

Update copyright dates with scripts/update-copyrights

2023-01-06T21:14:39Z

elf: Introduce and call_tls_init_tp (bug 29249)

2022-11-03T16:28:03Z

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

csu: Implement and use _dl_early_allocate during static startup

2022-05-16T16:42:03Z

This implements mmap fallback for a brk failure during TLS allocation. scripts/tls-elf-edit.py is updated to support the new patching method. The script no longer requires that in the input object is of ET_DYN type. Reviewed-by: Adhemerval Zanella

Update copyright dates with scripts/update-copyrights

2022-01-01T19:40:24Z

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

Remove TLS_TCB_ALIGN and TLS_INIT_TCB_ALIGN

2021-12-09T22:47:49Z

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

elf: Introduce __tls_pre_init_tp

2021-05-10T08:31:41Z

This is an early variant of __tls_init_tp, primarily for initializing thread-related elements of _rtld_global/GL. Some existing initialization code not needed for NPTL is moved into the generic version of this function. Tested-by: Carlos O'Donell Reviewed-by: Carlos O'Donell

elf: Introduce __tls_init_tp for second-phase TCB initialization

2021-04-21T17:49:51Z

TLS_INIT_TP is processor-specific, so it is not a good place to put thread library initialization code (it would have to be repeated for all CPUs). Introduce __tls_init_tp as a separate function, to be called immediately after TLS_INIT_TP. Move the existing stack list setup code for NPTL to this function. Reviewed-by: Adhemerval Zanella

Update copyright dates with scripts/update-copyrights

2021-01-02T20:17:34Z

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 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master