From 1e3c19f3fee12e5e2b7802a54908a4d4d03960da Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Fri, 27 May 2022 18:55:35 +0200 Subject: runtime: support riscv64 SV57 mode riscv64 has SV57 mode when user-space VA is 56 bits. Linux kernel recently got support for this mode and Go binaries started crashing as: runtime: lfstack.push invalid packing: node=0xffffff5908a940 cnt=0x1 packed=0xffff5908a9400001 -> node=0xffff5908a940 Adjust lfstack code to use only 8 top bits of pointers on riscv64. For context see: https://groups.google.com/g/syzkaller-bugs/c/lU0GQTZoNQQ/m/O_c3vmE3AAAJ Update #54104 Change-Id: Ib5d3d6a79c0c6eddf11618d73fcc8bc1832a9c25 Reviewed-on: https://go-review.googlesource.com/c/go/+/409055 Reviewed-by: Joel Sing Reviewed-by: Meng Zhuo Reviewed-by: Michael Knyszek Reviewed-by: Cherry Mui --- src/runtime/lfstack_64bit.go | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/runtime/lfstack_64bit.go b/src/runtime/lfstack_64bit.go index 154130cf63..88cbd3bcc7 100644 --- a/src/runtime/lfstack_64bit.go +++ b/src/runtime/lfstack_64bit.go @@ -36,12 +36,21 @@ const ( // We use one bit to distinguish between the two ranges. aixAddrBits = 57 aixCntBits = 64 - aixAddrBits + 3 + + // riscv64 SV57 mode gives 56 bits of userspace VA. + // lfstack code supports it, but broader support for SV57 mode is incomplete, + // and there may be other issues (see #54104). + riscv64AddrBits = 56 + riscv64CntBits = 64 - riscv64AddrBits + 3 ) func lfstackPack(node *lfnode, cnt uintptr) uint64 { if GOARCH == "ppc64" && GOOS == "aix" { return uint64(uintptr(unsafe.Pointer(node)))<<(64-aixAddrBits) | uint64(cnt&(1<> aixCntBits << 3) | 0xa<<56))) } + if GOARCH == "riscv64" { + return (*lfnode)(unsafe.Pointer(uintptr(val >> riscv64CntBits << 3))) + } return (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3))) } -- cgit v1.2.1