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author | Dmitry Vyukov <dvyukov@google.com> | 2022-05-27 18:55:35 +0200 |
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committer | Dmitry Vyukov <dvyukov@google.com> | 2022-08-04 05:33:40 +0000 |
commit | 1e3c19f3fee12e5e2b7802a54908a4d4d03960da (patch) | |
tree | 80e1bb7caf14223b64a21f270f0275dd02cad792 | |
parent | f28fa952b5f81a63afd96c9c58dceb99cc7d1dbf (diff) | |
download | go-1e3c19f3fee12e5e2b7802a54908a4d4d03960da.tar.gz go-1e3c19f3fee12e5e2b7802a54908a4d4d03960da.zip |
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 <joel@sing.id.au>
Reviewed-by: Meng Zhuo <mzh@golangcn.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
-rw-r--r-- | src/runtime/lfstack_64bit.go | 12 |
1 files changed, 12 insertions, 0 deletions
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-1)) } + if GOARCH == "riscv64" { + return uint64(uintptr(unsafe.Pointer(node)))<<(64-riscv64AddrBits) | uint64(cnt&(1<<riscv64CntBits-1)) + } return uint64(uintptr(unsafe.Pointer(node)))<<(64-addrBits) | uint64(cnt&(1<<cntBits-1)) } @@ -54,5 +63,8 @@ func lfstackUnpack(val uint64) *lfnode { if GOARCH == "ppc64" && GOOS == "aix" { return (*lfnode)(unsafe.Pointer(uintptr((val >> aixCntBits << 3) | 0xa<<56))) } + if GOARCH == "riscv64" { + return (*lfnode)(unsafe.Pointer(uintptr(val >> riscv64CntBits << 3))) + } return (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3))) } |