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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/tst-cpu-features-cpuinfo.c | |
| 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/tst-cpu-features-cpuinfo.c')
| -rw-r--r-- | sysdeps/x86/tst-cpu-features-cpuinfo.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/sysdeps/x86/tst-cpu-features-cpuinfo.c b/sysdeps/x86/tst-cpu-features-cpuinfo.c index e963592c4b..18d64375ca 100644 --- a/sysdeps/x86/tst-cpu-features-cpuinfo.c +++ b/sysdeps/x86/tst-cpu-features-cpuinfo.c @@ -96,6 +96,11 @@ check_proc (const char *proc_name, const char *search_name, int flag, CPU_FEATURE_USABLE (name), \ "HAS_CPU_FEATURE (" #name ")") +#define CHECK_PROC_ACTIVE(str, name) \ + check_proc (#str, " "#str" ", CPU_FEATURE_USABLE (name), \ + CPU_FEATURE_USABLE (name), \ + "CPU_FEATURE_USABLE (" #name ")") + static int do_test (int argc, char **argv) { @@ -298,6 +303,8 @@ do_test (int argc, char **argv) fails += CHECK_PROC (xsaves, XSAVES); fails += CHECK_PROC (xtpr, XTPRUPDCTRL); + fails += CHECK_PROC_ACTIVE (fsgsbase, FSGSBASE); + printf ("%d differences between /proc/cpuinfo and glibc code.\n", fails); return (fails != 0); |