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| author | Florian Weimer <fweimer@redhat.com> | 2024-07-08 21:14:00 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2024-07-16 17:24:53 +0200 |
| commit | 7f769dd0084cb1c857fd6fa90f60e92711b9ce7c (patch) | |
| tree | 8b7836dda7df64c1469d15bbb9bd83e4f53e41b8 /manual | |
| parent | 643709c6eeaa04cd48916c3bdb017f149d8ae6ac (diff) | |
| download | glibc-7f769dd0084cb1c857fd6fa90f60e92711b9ce7c.zip glibc-7f769dd0084cb1c857fd6fa90f60e92711b9ce7c.tar.gz glibc-7f769dd0084cb1c857fd6fa90f60e92711b9ce7c.tar.bz2 | |
Linux: Make __rseq_size useful for feature detection (bug 31965)
The __rseq_size value is now the active area of struct rseq
(so 20 initially), not the full struct size including padding
at the end (32 initially).
Update misc/tst-rseq to print some additional diagnostics.
Reviewed-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
(cherry picked from commit 2e456ccf0c34a056e3ccafac4a0c7effef14d918)
Diffstat (limited to 'manual')
| -rw-r--r-- | manual/threads.texi | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/manual/threads.texi b/manual/threads.texi index 48fd562..fcf9e2b 100644 --- a/manual/threads.texi +++ b/manual/threads.texi @@ -1020,8 +1020,12 @@ This variable is either zero (if restartable sequence registration failed or has been disabled) or the size of the restartable sequence registration. This can be different from the size of @code{struct rseq} if the kernel has extended the size of the registration. If -registration is successful, @code{__rseq_size} is at least 32 (the -initial size of @code{struct rseq}). +registration is successful, @code{__rseq_size} is at least 20 (the +initially active size of @code{struct rseq}). + +Previous versions of @theglibc{} set this to 32 even if the kernel only +supported the initial area of 20 bytes because the value included unused +padding at the end of the restartable sequence area. @end deftypevar @deftypevar {unsigned int} __rseq_flags |