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runtime: save/fetch g register during VDSO on linux/loong64

Like arm64, ppc64 and risv64, on loong64, the G register may be temporarily
broken during a VDSO call. If a signal is received during a VDSO call, an
invalid G may be obtained.

See #34391.

Change-Id: Iaffa8cce4f0ef8ef74225c355ec3c20ed238025f
Reviewed-on: https://go-review.googlesource.com/c/go/+/426355
Reviewed-by: WANG Xuerui <git@xen0n.name>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Run-TryBot: WANG Xuerui <git@xen0n.name>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This commit is contained in:
Guoqi Chen 2023-03-29 05:10:45 +08:00 committed by Gopher Robot
parent 1b630b5b00
commit 42023d6f52
2 changed files with 41 additions and 5 deletions

View File

@ -397,7 +397,7 @@ func preemptM(mp *m) {
//go:nosplit
func sigFetchG(c *sigctxt) *g {
switch GOARCH {
case "arm", "arm64", "ppc64", "ppc64le", "riscv64", "s390x":
case "arm", "arm64", "loong64", "ppc64", "ppc64le", "riscv64", "s390x":
if !iscgo && inVDSOPage(c.sigpc()) {
// When using cgo, we save the g on TLS and load it from there
// in sigtramp. Just use that.

View File

@ -11,7 +11,9 @@
#include "textflag.h"
#include "cgo/abi_loong64.h"
#define AT_FDCWD -100
#define AT_FDCWD -100
#define CLOCK_REALTIME 0
#define CLOCK_MONOTONIC 1
#define SYS_exit 93
#define SYS_read 63
@ -233,7 +235,7 @@ TEXT runtime·mincore(SB),NOSPLIT|NOFRAME,$0-28
RET
// func walltime() (sec int64, nsec int32)
TEXT runtime·walltime(SB),NOSPLIT,$16-12
TEXT runtime·walltime(SB),NOSPLIT,$24-12
MOVV R3, R23 // R23 is unchanged by C code
MOVV R3, R25
@ -263,12 +265,29 @@ noswitch:
AND $~15, R25 // Align for C code
MOVV R25, R3
MOVW $0, R4 // CLOCK_REALTIME=0
MOVW $CLOCK_REALTIME, R4
MOVV $0(R3), R5
MOVV runtime·vdsoClockgettimeSym(SB), R20
BEQ R20, fallback
// Store g on gsignal's stack, see sys_linux_arm64.s for detail
MOVBU runtime·iscgo(SB), R25
BNE R25, nosaveg
MOVV m_gsignal(R24), R25 // g.m.gsignal
BEQ R25, nosaveg
BEQ g, R25, nosaveg
MOVV (g_stack+stack_lo)(R25), R25 // g.m.gsignal.stack.lo
MOVV g, (R25)
JAL (R20)
MOVV R0, (R25)
JMP finish
nosaveg:
JAL (R20)
finish:
@ -326,12 +345,29 @@ noswitch:
AND $~15, R25 // Align for C code
MOVV R25, R3
MOVW $1, R4 // CLOCK_MONOTONIC=1
MOVW $CLOCK_MONOTONIC, R4
MOVV $0(R3), R5
MOVV runtime·vdsoClockgettimeSym(SB), R20
BEQ R20, fallback
// Store g on gsignal's stack, see sys_linux_arm64.s for detail
MOVBU runtime·iscgo(SB), R25
BNE R25, nosaveg
MOVV m_gsignal(R24), R25 // g.m.gsignal
BEQ R25, nosaveg
BEQ g, R25, nosaveg
MOVV (g_stack+stack_lo)(R25), R25 // g.m.gsignal.stack.lo
MOVV g, (R25)
JAL (R20)
MOVV R0, (R25)
JMP finish
nosaveg:
JAL (R20)
finish: