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| author | Michael Jeanson <mjeanson@efficios.com> | 2024-07-10 15:37:28 -0400 |
|---|---|---|
| committer | Michael Jeanson <mjeanson@efficios.com> | 2025-01-10 20:19:07 +0000 |
| commit | c813c1490d5d8640a94fced10fc7674a48737b96 (patch) | |
| tree | 36b9f24bfee314322a72de8b0077b324dbb64055 /sysdeps/unix/sysv/linux/dl-parse_auxv.h | |
| parent | 4a9a8a50981e2a3e0a04ef4c7ad7c26807c18161 (diff) | |
| download | glibc-c813c1490d5d8640a94fced10fc7674a48737b96.zip glibc-c813c1490d5d8640a94fced10fc7674a48737b96.tar.gz glibc-c813c1490d5d8640a94fced10fc7674a48737b96.tar.bz2 | |
nptl: Add rseq auxvals
Get the rseq feature size and alignment requirement from the auxiliary
vector for use inside the dynamic loader. Use '__rseq_size' directly to
store the feature size. If the main thread registration fails or is
disabled by tunable, reset the value to 0.
This will be used in the TLS block allocator to compute the size and
alignment of the rseq area block for the extended ABI support.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Diffstat (limited to 'sysdeps/unix/sysv/linux/dl-parse_auxv.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/dl-parse_auxv.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/dl-parse_auxv.h b/sysdeps/unix/sysv/linux/dl-parse_auxv.h index 7b4427d..2d42437 100644 --- a/sysdeps/unix/sysv/linux/dl-parse_auxv.h +++ b/sysdeps/unix/sysv/linux/dl-parse_auxv.h @@ -21,6 +21,7 @@ #include <fpu_control.h> #include <ldsodefs.h> #include <link.h> +#include <rseq-internal.h> typedef ElfW(Addr) dl_parse_auxv_t[AT_MINSIGSTKSZ + 1]; @@ -59,5 +60,17 @@ void _dl_parse_auxv (ElfW(auxv_t) *av, dl_parse_auxv_t auxv_values) GLRO(dl_sysinfo) = auxv_values[AT_SYSINFO]; #endif + /* Get the rseq feature size, with a minimum of RSEQ_AREA_SIZE_INITIAL_USED + (20) for kernels that don't have AT_RSEQ_FEATURE_SIZE. Limit the feature + size to RSEQ_AREA_SIZE_MAX_USED (28) which fits the rseq area in 'struct + pthread' and represents the maximum feature size of currently released + kernels. Since no kernels currently cross the 32 bytes of the original + ABI, the semantics of a feature size of 32 or more are still undetermined. + */ + _rseq_size = MIN (MAX (auxv_values[AT_RSEQ_FEATURE_SIZE], + RSEQ_AREA_SIZE_INITIAL_USED), + RSEQ_AREA_SIZE_MAX_USED); + _rseq_align = MAX (auxv_values[AT_RSEQ_ALIGN], RSEQ_MIN_ALIGN); + DL_PLATFORM_AUXV } |