3f1642e4bc
ring0.Save/LoadFloatingPoint() are only usable if the caller can ensure that Go will not clobber floating point registers before/after calling them respectively. Due to regabig in Go 1.17, this is no longer the case; regabig (among other things) maintains a zeroed XMM15 during ABIInternal execution, including by zeroing it after ABI0-to-ABIInternal transitions. In ring0.sysenter/exception, this happens in ring0.kernelSyscall/kernelException.abi0 respectively; in ring0.CPU.SwitchToUser, this happens after returning from ring0.sysret/iret.abi0. Delete these functions and do floating point save/load in assembly. While arm64 doesn't appear to be immediately affected (so this CL permits us to resume usage of Go 1.17), its use of Save/LoadFloatingPoint() still seems to be incorrect for the same fundamental reason (Go code can't sanely assume what registers the Go compiler will or won't use) and should be fixed eventually. PiperOrigin-RevId: 401895658 |
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| .. | ||
| gen_offsets | ||
| pagetables | ||
| BUILD | ||
| aarch64.go | ||
| defs.go | ||
| defs_amd64.go | ||
| defs_arm64.go | ||
| entry_amd64.go | ||
| entry_amd64.s | ||
| entry_arm64.go | ||
| entry_arm64.s | ||
| kernel.go | ||
| kernel_amd64.go | ||
| kernel_arm64.go | ||
| kernel_unsafe.go | ||
| lib_amd64.go | ||
| lib_amd64.s | ||
| lib_arm64.go | ||
| lib_arm64.s | ||
| offsets_amd64.go | ||
| offsets_arm64.go | ||
| ring0.go | ||
| x86.go | ||