diff options
| author | Cherry Zhang <cherryyz@google.com> | 2020-10-24 13:14:36 -0400 |
|---|---|---|
| committer | Cherry Zhang <cherryyz@google.com> | 2020-10-28 13:25:44 +0000 |
| commit | 72dec90bfdb60a0ca2ac1b743db472d2e689414e (patch) | |
| tree | 9c3e315b322275e8b55f01c40757bb0ed2f47b25 /src/runtime/asm_arm64.s | |
| parent | cf6cfba4d5358404dd890f6025e573a4b2156543 (diff) | |
| download | go-72dec90bfdb60a0ca2ac1b743db472d2e689414e.tar.xz | |
runtime: set up TLS without cgo on darwin/arm64
Currently, on darwin/arm64 we set up TLS using cgo. TLS is not
set for pure Go programs. As we use libc for syscalls on darwin,
we need to save the G register before the libc call. Otherwise it
is not signal-safe, as a signal may land during the execution of
a libc function, where the G register may be clobbered.
This CL initializes TLS in Go, by calling the pthread functions
directly without cgo. This makes it possible to save the G
register to TLS in pure Go programs (done in a later CL).
Inspired by Elias's CL 209197. Write the logic in Go instead of
assembly.
Updates #38485, #35853.
Change-Id: I257ba2a411ad387b2f4d50d10129d37fec7a226e
Reviewed-on: https://go-review.googlesource.com/c/go/+/265118
Trust: Cherry Zhang <cherryyz@google.com>
Trust: Elias Naur <mail@eliasnaur.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/runtime/asm_arm64.s')
| -rw-r--r-- | src/runtime/asm_arm64.s | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/src/runtime/asm_arm64.s b/src/runtime/asm_arm64.s index a45e342478..6257c1a183 100644 --- a/src/runtime/asm_arm64.s +++ b/src/runtime/asm_arm64.s @@ -15,6 +15,19 @@ TEXT runtime·rt0_go(SB),NOSPLIT,$0 MOVW R0, 8(RSP) // argc MOVD R1, 16(RSP) // argv +#ifdef TLS_darwin + // Initialize TLS. + MOVD ZR, g // clear g, make sure it's not junk. + SUB $32, RSP + MRS_TPIDR_R0 + AND $~7, R0 + MOVD R0, 16(RSP) // arg2: TLS base + MOVD $runtime·tls_g(SB), R2 + MOVD R2, 8(RSP) // arg1: &tlsg + BL ·tlsinit(SB) + ADD $32, RSP +#endif + // create istack out of the given (operating system) stack. // _cgo_init may update stackguard. MOVD $runtime·g0(SB), g @@ -29,9 +42,9 @@ TEXT runtime·rt0_go(SB),NOSPLIT,$0 MOVD _cgo_init(SB), R12 CBZ R12, nocgo +#ifdef GOOS_android MRS_TPIDR_R0 // load TLS base pointer MOVD R0, R3 // arg 3: TLS base pointer -#ifdef TLSG_IS_VARIABLE MOVD $runtime·tls_g(SB), R2 // arg 2: &tls_g #else MOVD $0, R2 // arg 2: not used when using platform's TLS |