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| author | 3541 <alex@emobrien.com> | 2020-06-27 15:15:54 +1000 |
|---|---|---|
| committer | Andreas Kling <kling@serenityos.org> | 2020-06-27 12:57:03 +0200 |
| commit | 4fa6301523bc9d4fad1f6c2f6b6a7b9a8e40d758 (patch) | |
| tree | 461421079bd29312e32f9268ab9c49c53473d2ce /Kernel/Arch/i386 | |
| parent | ebbcef926a02e211ebb44bcf029efd839059616a (diff) | |
| download | serenity-4fa6301523bc9d4fad1f6c2f6b6a7b9a8e40d758.zip | |
Kernel: Add g_cpu_supports_rdseed
CPUs which support RDRAND do not necessarily support RDSEED. This
introduces a flag g_cpu_supports_rdseed which is set appropriately
by CPUID. This causes Haswell CPUs in particular (and probably a lot
of AMD chips) to now fail to boot with #2634, rather than an illegal
instruction.
It seems like the KernelRng needs either an initial reseed call or
more random events added before the first call to get_good_random,
but I don't feel qualified to make that kind of change.
Diffstat (limited to 'Kernel/Arch/i386')
| -rw-r--r-- | Kernel/Arch/i386/CPU.cpp | 2 | ||||
| -rw-r--r-- | Kernel/Arch/i386/CPU.h | 1 |
2 files changed, 3 insertions, 0 deletions
diff --git a/Kernel/Arch/i386/CPU.cpp b/Kernel/Arch/i386/CPU.cpp index 9ad0b6ff43..354447d5c5 100644 --- a/Kernel/Arch/i386/CPU.cpp +++ b/Kernel/Arch/i386/CPU.cpp @@ -714,6 +714,7 @@ bool g_cpu_supports_nx; bool g_cpu_supports_pae; bool g_cpu_supports_pge; bool g_cpu_supports_rdrand; +bool g_cpu_supports_rdseed; bool g_cpu_supports_smap; bool g_cpu_supports_smep; bool g_cpu_supports_sse; @@ -736,6 +737,7 @@ void cpu_detect() g_cpu_supports_smap = (extended_features.ebx() & (1 << 20)); g_cpu_supports_smep = (extended_features.ebx() & (1 << 7)); g_cpu_supports_umip = (extended_features.ecx() & (1 << 2)); + g_cpu_supports_rdseed = (extended_features.ebx() & (1 << 18)); } void cpu_setup() diff --git a/Kernel/Arch/i386/CPU.h b/Kernel/Arch/i386/CPU.h index b59819bc3f..398bbcd69d 100644 --- a/Kernel/Arch/i386/CPU.h +++ b/Kernel/Arch/i386/CPU.h @@ -588,6 +588,7 @@ extern bool g_cpu_supports_nx; extern bool g_cpu_supports_pae; extern bool g_cpu_supports_pge; extern bool g_cpu_supports_rdrand; +extern bool g_cpu_supports_rdseed; extern bool g_cpu_supports_smap; extern bool g_cpu_supports_smep; extern bool g_cpu_supports_sse; |