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| author | H.J. Lu <hjl.tools@gmail.com> | 2023-03-15 17:42:54 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2023-04-03 11:36:48 -0700 |
| commit | 743113d42e6cad77477769a3de5542d33443ae76 (patch) | |
| tree | 02f5ac20ff2715acfd54dd50fb670eb49ee43c94 /sysdeps/x86_64/multiarch/varshift.h | |
| parent | 5d1ccdda7b0c625751661d50977f3dfbc73f8eae (diff) | |
| download | glibc-743113d42e6cad77477769a3de5542d33443ae76.tar.gz glibc-743113d42e6cad77477769a3de5542d33443ae76.tar.xz glibc-743113d42e6cad77477769a3de5542d33443ae76.zip | |
x86: Set FSGSBASE to active if enabled by kernel
Linux kernel uses AT_HWCAP2 to indicate if FSGSBASE instructions are enabled. If the HWCAP2_FSGSBASE bit in AT_HWCAP2 is set, FSGSBASE instructions can be used in user space. Define dl_check_hwcap2 to set the FSGSBASE feature to active on Linux when the HWCAP2_FSGSBASE bit is set. Add a test to verify that FSGSBASE is active on current kernels. NB: This test will fail if the kernel doesn't set the HWCAP2_FSGSBASE bit in AT_HWCAP2 while fsgsbase shows up in /proc/cpuinfo. Reviewed-by: Florian Weimer <fweimer@redhat.com>
Diffstat (limited to 'sysdeps/x86_64/multiarch/varshift.h')
0 files changed, 0 insertions, 0 deletions