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author | Keith Randall <khr@golang.org> | 2022-12-05 16:26:26 -0800 |
---|---|---|
committer | Keith Randall <khr@google.com> | 2022-12-06 05:12:12 +0000 |
commit | 1eb0465fa596a2d6e9c1a632499989544f0d7e68 (patch) | |
tree | 6449c26d4caa4841f0f28fc8da3f1deaa79482d8 | |
parent | 9dde2de454b78e681dd7318dbf3ef68d6a3df2d1 (diff) | |
download | go-1eb0465fa596a2d6e9c1a632499989544f0d7e68.tar.gz go-1eb0465fa596a2d6e9c1a632499989544f0d7e68.zip |
cmd/compile: turn off jump tables when spectre retpolines are on
Fixes #57097
Change-Id: I6ab659abbca1ae0ac8710674d39aec116fab0baa
Reviewed-on: https://go-review.googlesource.com/c/go/+/455336
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
-rw-r--r-- | src/cmd/compile/internal/walk/switch.go | 2 | ||||
-rw-r--r-- | test/codegen/retpoline.go | 28 |
2 files changed, 29 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/walk/switch.go b/src/cmd/compile/internal/walk/switch.go index d38ba500f2..8ca8fa82e1 100644 --- a/src/cmd/compile/internal/walk/switch.go +++ b/src/cmd/compile/internal/walk/switch.go @@ -290,7 +290,7 @@ func (s *exprSwitch) tryJumpTable(cc []exprClause, out *ir.Nodes) bool { const minCases = 8 // have at least minCases cases in the switch const minDensity = 4 // use at least 1 out of every minDensity entries - if !go119UseJumpTables || base.Flag.N != 0 || !ssagen.Arch.LinkArch.CanJumpTable { + if !go119UseJumpTables || base.Flag.N != 0 || !ssagen.Arch.LinkArch.CanJumpTable || base.Ctxt.Retpoline { return false } if len(cc) < minCases { diff --git a/test/codegen/retpoline.go b/test/codegen/retpoline.go index 15d6a26615..a04a005e2e 100644 --- a/test/codegen/retpoline.go +++ b/test/codegen/retpoline.go @@ -12,3 +12,31 @@ func CallInterface(x interface{ M() }) { // amd64:`CALL\truntime.retpoline` x.M() } + +// Check to make sure that jump tables are disabled +// when retpoline is on. See issue 57097. +func noJumpTables(x int) int { + switch x { + case 0: + return 0 + case 1: + return 1 + case 2: + return 2 + case 3: + return 3 + case 4: + return 4 + case 5: + return 5 + case 6: + return 6 + case 7: + return 7 + case 8: + return 8 + case 9: + return 9 + } + return 10 +} |