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| author | qmuntal <quimmuntal@gmail.com> | 2023-02-08 09:40:44 +0100 |
|---|---|---|
| committer | Quim Muntal <quimmuntal@gmail.com> | 2023-02-22 21:35:26 +0000 |
| commit | 521d2614df0cf4fa3a92bd01e1c98d77bfeac9ed (patch) | |
| tree | 946da115e94c13f893c7f417e00603197bcc26d8 /src/cmd/internal | |
| parent | 133e0bca0be23980604ee98589ddcacdb1262afd (diff) | |
| download | go-521d2614df0cf4fa3a92bd01e1c98d77bfeac9ed.tar.xz | |
runtime: use explicit NOFRAME on linux/amd64
This CL marks some linux assembly functions as NOFRAME to avoid relying
on the implicit amd64 NOFRAME heuristic, where NOSPLIT functions
without stack were also marked as NOFRAME.
Updates #58378
Change-Id: I7792cff4f6e539bfa56c02868f2965088ca1975a
Reviewed-on: https://go-review.googlesource.com/c/go/+/466316
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Diffstat (limited to 'src/cmd/internal')
| -rw-r--r-- | src/cmd/internal/obj/x86/obj6.go | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/cmd/internal/obj/x86/obj6.go b/src/cmd/internal/obj/x86/obj6.go index 8b62120d19..c6fe3279c4 100644 --- a/src/cmd/internal/obj/x86/obj6.go +++ b/src/cmd/internal/obj/x86/obj6.go @@ -611,17 +611,23 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { } } + var usefpheuristic bool + switch ctxt.Headtype { + case objabi.Hwindows, objabi.Hdarwin, objabi.Hlinux: + default: + usefpheuristic = true + } + var bpsize int if ctxt.Arch.Family == sys.AMD64 && !p.From.Sym.NoFrame() && // (1) below - !(autoffset == 0 && p.From.Sym.NoSplit() && ctxt.Headtype != objabi.Hwindows && ctxt.Headtype != objabi.Hdarwin) && // (2) below + !(autoffset == 0 && p.From.Sym.NoSplit() && usefpheuristic) && // (2) below !(autoffset == 0 && !hasCall) { // (3) below // Make room to save a base pointer. // There are 2 cases we must avoid: // 1) If noframe is set (which we do for functions which tail call). // 2) Scary runtime internals which would be all messed up by frame pointers. // We detect these using a heuristic: frameless nosplit functions. - // Windows and Darwin do not use this heuristic anymore. // TODO: Maybe someday we label them all with NOFRAME and get rid of this heuristic. // For performance, we also want to avoid: // 3) Frameless leaf functions |