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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>
This commit is contained in:
qmuntal 2023-02-08 09:40:44 +01:00 committed by Quim Muntal
parent 133e0bca0b
commit 521d2614df
3 changed files with 17 additions and 12 deletions
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10
src/cmd/internal/obj/x86/obj6.go
View File

@ -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

5
src/cmd/link/internal/ld/testdata/stackcheck/main.s vendored
View File

@ -3,6 +3,7 @@
// license that can be found in the LICENSE file.
#define NOSPLIT 7
#define NOFRAME 512
TEXT ·asmMain(SB),0,$0-0
CALL ·startSelf(SB)
@ -32,9 +33,9 @@ TEXT ·chainEnd(SB),NOSPLIT,$1000-0 // Should be reported twice
RET
// Test reporting of rootless recursion
TEXT ·startRec(SB),NOSPLIT,$0-0
TEXT ·startRec(SB),NOSPLIT|NOFRAME,$0-0
CALL ·startRec0(SB)
RET
TEXT ·startRec0(SB),NOSPLIT,$0-0
TEXT ·startRec0(SB),NOSPLIT|NOFRAME,$0-0
CALL ·startRec(SB)
RET

14
src/runtime/sys_linux_amd64.s
View File

@ -325,16 +325,14 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
MOVL sig+8(FP), DI
MOVQ info+16(FP), SI
MOVQ ctx+24(FP), DX
PUSHQ BP
MOVQ SP, BP
MOVQ SP, BX // callee-saved
ANDQ $~15, SP // alignment for x86_64 ABI
CALL AX
MOVQ BP, SP
POPQ BP
MOVQ BX, SP
RET
// Called using C ABI.
TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$0
TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME|NOFRAME,$0
// Transition from C ABI to Go ABI.
PUSH_REGS_HOST_TO_ABI0()
@ -359,7 +357,7 @@ TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$0
RET
// Called using C ABI.
TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT,$0
TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT|NOFRAME,$0
// Transition from C ABI to Go ABI.
PUSH_REGS_HOST_TO_ABI0()
@ -556,7 +554,7 @@ TEXT runtime·futex(SB),NOSPLIT,$0
RET
// int32 clone(int32 flags, void *stk, M *mp, G *gp, void (*fn)(void));
TEXT runtime·clone(SB),NOSPLIT,$0
TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0
MOVL flags+0(FP), DI
MOVQ stk+8(FP), SI
MOVQ $0, DX
@ -620,7 +618,7 @@ nog2:
SYSCALL
JMP -3(PC) // keep exiting
TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
TEXT runtime·sigaltstack(SB),NOSPLIT,$0
MOVQ new+0(FP), DI
MOVQ old+8(FP), SI
MOVQ $SYS_sigaltstack, AX