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Revert "Revert "Revert "runtime: consolidate function descriptor definitions on PPC64"""

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This reverts CL 481075 (a re-apply of previously reverted CL 478917).

Reason for revert: CL 481061 causes C TSAN failures and must be
reverted. See CL 485275. This CL depends on CL 481061.

For #59678.

Change-Id: I4bf7f43d9df1ae28e04cd4065552bcbee82ef13f
Reviewed-on: https://go-review.googlesource.com/c/go/+/485316
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
This commit is contained in:
Michael Pratt 2023-04-17 14:09:39 -04:00 committed by Gopher Robot
parent 0e9b2bc39a
commit 2068d5658e
6 changed files with 73 additions and 46 deletions
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20
src/runtime/asm_ppc64x.h
View File

@ -24,32 +24,16 @@
#define FIXED_FRAME 32
// aix/ppc64 uses XCOFF which uses function descriptors.
// AIX cannot perform the TOC relocation in a text section.
// Therefore, these descriptors must live in a data section.
// aix/ppc64 uses XCOFF which has function descriptors.
#ifdef GOOS_aix
#ifdef GOARCH_ppc64
#define GO_PPC64X_HAS_FUNCDESC
#define DEFINE_PPC64X_FUNCDESC(funcname, localfuncname) \
DATA funcname+0(SB)/8, $localfuncname(SB) \
DATA funcname+8(SB)/8, $TOC(SB) \
DATA funcname+16(SB)/8, $0 \
GLOBL funcname(SB), NOPTR, $24
#endif
#endif
// linux/ppc64 uses ELFv1 which uses function descriptors.
// These must also look like ABI0 functions on linux/ppc64
// to work with abi.FuncPCABI0(sigtramp) in os_linux.go.
// Only static codegen is supported on linux/ppc64, so TOC
// is not needed.
// linux/ppc64 uses ELFv1 which has function descriptors.
#ifdef GOOS_linux
#ifdef GOARCH_ppc64
#define GO_PPC64X_HAS_FUNCDESC
#define DEFINE_PPC64X_FUNCDESC(funcname, localfuncname) \
TEXT funcname(SB),NOSPLIT|NOFRAME,$0 \
DWORD $localfuncname(SB) \
DWORD $0 \
DWORD $0
#endif
#endif

21
src/runtime/asm_ppc64x.s
View File

@ -771,11 +771,26 @@ TEXT runtime·setg(SB), NOSPLIT, $0-8
BL runtime·save_g(SB)
RET
#ifdef GO_PPC64X_HAS_FUNCDESC
DEFINE_PPC64X_FUNCDESC(setg_gcc<>, _setg_gcc<>)
TEXT _setg_gcc<>(SB),NOSPLIT|NOFRAME,$0-0
#ifdef GOARCH_ppc64
#ifdef GOOS_aix
DATA setg_gcc<>+0(SB)/8, $_setg_gcc<>(SB)
DATA setg_gcc<>+8(SB)/8, $TOC(SB)
DATA setg_gcc<>+16(SB)/8, $0
GLOBL setg_gcc<>(SB), NOPTR, $24
#else
TEXT setg_gcc<>(SB),NOSPLIT|NOFRAME,$0-0
DWORD $_setg_gcc<>(SB)
DWORD $0
DWORD $0
#endif
#endif
// void setg_gcc(G*); set g in C TLS.
// Must obey the gcc calling convention.
#ifdef GOARCH_ppc64le
TEXT setg_gcc<>(SB),NOSPLIT|NOFRAME,$0-0
#else
TEXT _setg_gcc<>(SB),NOSPLIT|NOFRAME,$0-0
#endif
// The standard prologue clobbers R31, which is callee-save in
// the C ABI, so we have to use $-8-0 and save LR ourselves.

25
src/runtime/cgo/asm_ppc64x.s
View File

@ -7,25 +7,26 @@
#include "textflag.h"
#include "asm_ppc64x.h"
#ifdef GO_PPC64X_HAS_FUNCDESC
// crosscall2 is marked with go:cgo_export_static. On AIX, this creates and exports
// the symbol name and descriptor as the AIX linker expects, but does not work if
// referenced from within Go. Create and use an aliased descriptor of crosscall2
// to workaround this.
DEFINE_PPC64X_FUNCDESC(_crosscall2<>, crosscall2)
#define CROSSCALL2_FPTR $_crosscall2<>(SB)
#else
#define CROSSCALL2_FPTR $crosscall2(SB)
#endif
// Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2
TEXT ·set_crosscall2(SB),NOSPLIT,$0-0
MOVD _crosscall2_ptr(SB), R5
MOVD CROSSCALL2_FPTR, R6
#ifdef GOARCH_ppc64
MOVD $_crosscall2<>(SB), R6
#else
MOVD $crosscall2(SB), R6
#endif
MOVD R6, (R5)
RET
#ifdef GO_PPC64X_HAS_FUNCDESC
// _crosscall2<> is a function descriptor to the real crosscall2.
DATA _crosscall2<>+0(SB)/8, $crosscall2(SB)
DATA _crosscall2<>+8(SB)/8, $TOC(SB)
DATA _crosscall2<>+16(SB)/8, $0
GLOBL _crosscall2<>(SB), NOPTR, $24
#endif
// Called by C code generated by cmd/cgo.
// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
// Saves C callee-saved registers and calls cgocallback with three arguments.

17
src/runtime/rt0_aix_ppc64.s
View File

@ -3,11 +3,13 @@
// license that can be found in the LICENSE file.
#include "textflag.h"
#include "asm_ppc64x.h"
// _rt0_ppc64_aix is a function descriptor of the entrypoint function
// __start. This name is needed by cmd/link.
DEFINE_PPC64X_FUNCDESC(_rt0_ppc64_aix, __start<>)
DATA _rt0_ppc64_aix+0(SB)/8, $__start<>(SB)
DATA _rt0_ppc64_aix+8(SB)/8, $TOC(SB)
GLOBL _rt0_ppc64_aix(SB), NOPTR, $16
// The starting function must return in the loader to
// initialise some libraries, especially libthread which
@ -35,7 +37,11 @@ TEXT __start<>(SB),NOSPLIT,$-8
BL _main(SB)
DEFINE_PPC64X_FUNCDESC(main, _main)
DATA main+0(SB)/8, $_main(SB)
DATA main+8(SB)/8, $TOC(SB)
DATA main+16(SB)/8, $0
GLOBL main(SB), NOPTR, $24
TEXT _main(SB),NOSPLIT,$-8
MOVD $runtime·rt0_go(SB), R12
MOVD R12, CTR
@ -175,7 +181,10 @@ done:
MOVD R0, LR
RET
DEFINE_PPC64X_FUNCDESC(_rt0_ppc64_aix_lib_go, __rt0_ppc64_aix_lib_go)
DATA _rt0_ppc64_aix_lib_go+0(SB)/8, $__rt0_ppc64_aix_lib_go(SB)
DATA _rt0_ppc64_aix_lib_go+8(SB)/8, $TOC(SB)
DATA _rt0_ppc64_aix_lib_go+16(SB)/8, $0
GLOBL _rt0_ppc64_aix_lib_go(SB), NOPTR, $24
TEXT __rt0_ppc64_aix_lib_go(SB),NOSPLIT,$0
MOVD _rt0_ppc64_aix_lib_argc<>(SB), R3

13
src/runtime/rt0_linux_ppc64.s
View File

@ -3,10 +3,17 @@
// license that can be found in the LICENSE file.
#include "textflag.h"
#include "asm_ppc64x.h"
DEFINE_PPC64X_FUNCDESC(_rt0_ppc64_linux, _main<>)
DEFINE_PPC64X_FUNCDESC(main, _main<>)
// actually a function descriptor for _main<>(SB)
TEXT _rt0_ppc64_linux(SB),NOSPLIT,$0
DWORD $_main<>(SB)
DWORD $0
DWORD $0
TEXT main(SB),NOSPLIT,$0
DWORD $_main<>(SB)
DWORD $0
DWORD $0
TEXT _main<>(SB),NOSPLIT,$-8
// In a statically linked binary, the stack contains argc,

23
src/runtime/sys_linux_ppc64x.s
View File

@ -447,12 +447,7 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
MOVD 24(R1), R2
RET
#ifdef GO_PPC64X_HAS_FUNCDESC
DEFINE_PPC64X_FUNCDESC(runtime·sigtramp, sigtramp<>)
// cgo isn't supported on ppc64, but we need to supply a cgoSigTramp function.
DEFINE_PPC64X_FUNCDESC(runtime·cgoSigtramp, sigtramp<>)
TEXT sigtramp<>(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
#else
#ifdef GOARCH_ppc64le
// ppc64le doesn't need function descriptors
// Save callee-save registers in the case of signal forwarding.
// Same as on ARM64 https://golang.org/issue/31827 .
@ -461,6 +456,13 @@ TEXT sigtramp<>(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
// a function pointer) as R2 may not be preserved when calling this
// function. In those cases, the caller preserves their R2.
TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0
#else
// function descriptor for the real sigtramp
TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0
DWORD $sigtramp<>(SB)
DWORD $0
DWORD $0
TEXT sigtramp<>(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
#endif
// This is called with ELF calling conventions. Convert to Go.
// Allocate space for argument storage to call runtime.sigtrampgo.
@ -489,6 +491,7 @@ TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0
RET
#ifdef GOARCH_ppc64le
// ppc64le doesn't need function descriptors
TEXT runtime·cgoSigtramp(SB),NOSPLIT|NOFRAME,$0
// The stack unwinder, presumably written in C, may not be able to
// handle Go frame correctly. So, this function is NOFRAME, and we
@ -583,6 +586,14 @@ sigtrampnog:
MOVD R12, CTR
MOVD R10, LR // restore LR
JMP (CTR)
#else
// function descriptor for the real sigtramp
TEXT runtime·cgoSigtramp(SB),NOSPLIT|NOFRAME,$0
DWORD $cgoSigtramp<>(SB)
DWORD $0
DWORD $0
TEXT cgoSigtramp<>(SB),NOSPLIT,$0
JMP sigtramp<>(SB)
#endif
// Used by cgoSigtramp to inspect without clobbering R30/R31 via runtime.load_g.