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runtime,runtime/cgo: fix tsan/pprof/cgo issues

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The tsan13 test highlighted a few bugs.

The first being runtime.sigprofNonGoWrapper was being
called from C code and violating the C ABI.

The second was a missed tsan acquire/release after
thread creation.

The third was runtime.cgoSigtramp violating ELFv2
ABI constraints when loading g. It is reworked to
avoid clobbering R30 and R31 via runtime.load_g.

Change-Id: Ib2d98047fa1b4e72b8045767e86457a8ddfe492e
Reviewed-on: https://go-review.googlesource.com/c/go/+/475935
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Archana Ravindar <aravind5@in.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This commit is contained in:
Paul E. Murphy 2023-03-10 16:05:47 -06:00 committed by Paul Murphy
parent 035db07d7c
commit 46bc9a6e1e
3 changed files with 206 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

161
src/runtime/cgo/abi_ppc64x.h Normal file
View File

@ -0,0 +1,161 @@
// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Macros for transitioning from the host ABI to Go ABI
//
// On PPC64/ELFv2 targets, the following registers are callee
// saved when called from C. They must be preserved before
// calling into Go which does not preserve any of them.
//
// R14-R31
// CR2-4
// VR20-31
// F14-F31
//
// xcoff(aix) and ELFv1 are similar, but may only require a
// subset of these.
//
// These macros assume a 16 byte aligned stack pointer. This
// is required by ELFv1, ELFv2, and AIX PPC64.
#define SAVE_GPR_SIZE (18*8)
#define SAVE_GPR(offset) \
MOVD R14, (offset+8*0)(R1) \
MOVD R15, (offset+8*1)(R1) \
MOVD R16, (offset+8*2)(R1) \
MOVD R17, (offset+8*3)(R1) \
MOVD R18, (offset+8*4)(R1) \
MOVD R19, (offset+8*5)(R1) \
MOVD R20, (offset+8*6)(R1) \
MOVD R21, (offset+8*7)(R1) \
MOVD R22, (offset+8*8)(R1) \
MOVD R23, (offset+8*9)(R1) \
MOVD R24, (offset+8*10)(R1) \
MOVD R25, (offset+8*11)(R1) \
MOVD R26, (offset+8*12)(R1) \
MOVD R27, (offset+8*13)(R1) \
MOVD R28, (offset+8*14)(R1) \
MOVD R29, (offset+8*15)(R1) \
MOVD g, (offset+8*16)(R1) \
MOVD R31, (offset+8*17)(R1)
#define RESTORE_GPR(offset) \
MOVD (offset+8*0)(R1), R14 \
MOVD (offset+8*1)(R1), R15 \
MOVD (offset+8*2)(R1), R16 \
MOVD (offset+8*3)(R1), R17 \
MOVD (offset+8*4)(R1), R18 \
MOVD (offset+8*5)(R1), R19 \
MOVD (offset+8*6)(R1), R20 \
MOVD (offset+8*7)(R1), R21 \
MOVD (offset+8*8)(R1), R22 \
MOVD (offset+8*9)(R1), R23 \
MOVD (offset+8*10)(R1), R24 \
MOVD (offset+8*11)(R1), R25 \
MOVD (offset+8*12)(R1), R26 \
MOVD (offset+8*13)(R1), R27 \
MOVD (offset+8*14)(R1), R28 \
MOVD (offset+8*15)(R1), R29 \
MOVD (offset+8*16)(R1), g \
MOVD (offset+8*17)(R1), R31
#define SAVE_FPR_SIZE (18*8)
#define SAVE_FPR(offset) \
FMOVD F14, (offset+8*0)(R1) \
FMOVD F15, (offset+8*1)(R1) \
FMOVD F16, (offset+8*2)(R1) \
FMOVD F17, (offset+8*3)(R1) \
FMOVD F18, (offset+8*4)(R1) \
FMOVD F19, (offset+8*5)(R1) \
FMOVD F20, (offset+8*6)(R1) \
FMOVD F21, (offset+8*7)(R1) \
FMOVD F22, (offset+8*8)(R1) \
FMOVD F23, (offset+8*9)(R1) \
FMOVD F24, (offset+8*10)(R1) \
FMOVD F25, (offset+8*11)(R1) \
FMOVD F26, (offset+8*12)(R1) \
FMOVD F27, (offset+8*13)(R1) \
FMOVD F28, (offset+8*14)(R1) \
FMOVD F29, (offset+8*15)(R1) \
FMOVD F30, (offset+8*16)(R1) \
FMOVD F31, (offset+8*17)(R1)
#define RESTORE_FPR(offset) \
FMOVD (offset+8*0)(R1), F14 \
FMOVD (offset+8*1)(R1), F15 \
FMOVD (offset+8*2)(R1), F16 \
FMOVD (offset+8*3)(R1), F17 \
FMOVD (offset+8*4)(R1), F18 \
FMOVD (offset+8*5)(R1), F19 \
FMOVD (offset+8*6)(R1), F20 \
FMOVD (offset+8*7)(R1), F21 \
FMOVD (offset+8*8)(R1), F22 \
FMOVD (offset+8*9)(R1), F23 \
FMOVD (offset+8*10)(R1), F24 \
FMOVD (offset+8*11)(R1), F25 \
FMOVD (offset+8*12)(R1), F26 \
FMOVD (offset+8*13)(R1), F27 \
FMOVD (offset+8*14)(R1), F28 \
FMOVD (offset+8*15)(R1), F29 \
FMOVD (offset+8*16)(R1), F30 \
FMOVD (offset+8*17)(R1), F31
// Save and restore VR20-31 (aka VSR56-63). These
// macros must point to a 16B aligned offset.
#define SAVE_VR_SIZE (12*16)
#define SAVE_VR(offset, rtmp) \
MOVD $(offset), rtmp \
STVX V20, (rtmp)(R1) \
ADD $16, rtmp \
STVX V21, (rtmp)(R1) \
ADD $16, rtmp \
STVX V22, (rtmp)(R1) \
ADD $16, rtmp \
STVX V23, (rtmp)(R1) \
ADD $16, rtmp \
STVX V24, (rtmp)(R1) \
ADD $16, rtmp \
STVX V25, (rtmp)(R1) \
ADD $16, rtmp \
STVX V26, (rtmp)(R1) \
ADD $16, rtmp \
STVX V27, (rtmp)(R1) \
ADD $16, rtmp \
STVX V28, (rtmp)(R1) \
ADD $16, rtmp \
STVX V29, (rtmp)(R1) \
ADD $16, rtmp \
STVX V30, (rtmp)(R1) \
ADD $16, rtmp \
STVX V31, (rtmp)(R1)
#define RESTORE_VR(offset, rtmp) \
MOVD $(offset), rtmp \
LVX (rtmp)(R1), V20 \
ADD $16, rtmp \
LVX (rtmp)(R1), V21 \
ADD $16, rtmp \
LVX (rtmp)(R1), V22 \
ADD $16, rtmp \
LVX (rtmp)(R1), V23 \
ADD $16, rtmp \
LVX (rtmp)(R1), V24 \
ADD $16, rtmp \
LVX (rtmp)(R1), V25 \
ADD $16, rtmp \
LVX (rtmp)(R1), V26 \
ADD $16, rtmp \
LVX (rtmp)(R1), V27 \
ADD $16, rtmp \
LVX (rtmp)(R1), V28 \
ADD $16, rtmp \
LVX (rtmp)(R1), V29 \
ADD $16, rtmp \
LVX (rtmp)(R1), V30 \
ADD $16, rtmp \
LVX (rtmp)(R1), V31
// LR and CR are saved in the caller's frame. The callee must
// make space for all other callee-save registers.
#define SAVE_ALL_REG_SIZE (SAVE_GPR_SIZE+SAVE_FPR_SIZE+SAVE_VR_SIZE)

2
src/runtime/cgo/gcc_ppc64x.c
View File

@ -61,7 +61,9 @@ threadentry(void *v)
ThreadStart ts;
ts = *(ThreadStart*)v;
_cgo_tsan_acquire();
free(v);
_cgo_tsan_release();
// Save g for this thread in C TLS
setg_gcc((void*)ts.g);

57
src/runtime/sys_linux_ppc64x.s
View File

@ -12,6 +12,7 @@
#include "go_tls.h"
#include "textflag.h"
#include "asm_ppc64x.h"
#include "cgo/abi_ppc64x.h"
#define SYS_exit 1
#define SYS_read 3
@ -633,11 +634,11 @@ TEXT sigtramp<>(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
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
// save/restore LR manually.
// save/restore LR manually, and obey ELFv2 calling conventions.
MOVD LR, R10
// We're coming from C code, initialize essential registers.
CALL runtime·reginit(SB)
// We're coming from C code, initialize R0
MOVD $0, R0
// If no traceback function, do usual sigtramp.
MOVD runtime·cgoTraceback(SB), R6
@ -650,15 +651,18 @@ TEXT runtime·cgoSigtramp(SB),NOSPLIT|NOFRAME,$0
CMP $0, R6
BEQ sigtramp
// Set up g register.
CALL runtime·load_g(SB)
// Inspect the g in TLS without clobbering R30/R31 via runtime.load_g.
MOVD runtime·tls_g(SB), R9
MOVD 0(R9), R9
// Figure out if we are currently in a cgo call.
// If not, just do usual sigtramp.
// compared to ARM64 and others.
CMP $0, g
CMP $0, R9
BEQ sigtrampnog // g == nil
MOVD g_m(g), R6
// g is not nil. Check further.
MOVD g_m(R9), R6
CMP $0, R6
BEQ sigtramp // g.m == nil
MOVW m_ncgo(R6), R7
@ -731,13 +735,38 @@ TEXT cgoSigtramp<>(SB),NOSPLIT,$0
JMP sigtramp<>(SB)
#endif
TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT,$0
// We're coming from C code, set up essential register, then call sigprofNonGo.
CALL runtime·reginit(SB)
MOVW R3, FIXED_FRAME+0(R1) // sig
MOVD R4, FIXED_FRAME+8(R1) // info
MOVD R5, FIXED_FRAME+16(R1) // ctx
CALL runtime·sigprofNonGo(SB)
// Used by cgoSigtramp to inspect without clobbering R30/R31 via runtime.load_g.
GLOBL runtime·tls_g+0(SB), TLSBSS+DUPOK, $8
TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT|NOFRAME,$0
// This is called from C code. Callee save registers must be saved.
// R3,R4,R5 hold arguments.
// Save LR into R0 and stack a big frame.
MOVD LR, R0
MOVD R0, 16(R1)
MOVW CR, R0
MOVD R0, 8(R1)
// Don't save a back chain pointer when calling into Go. It will be overwritten.
// Go stores LR where ELF stores a back chain pointer.
ADD $-(32+SAVE_ALL_REG_SIZE), R1
SAVE_GPR(32)
SAVE_FPR(32+SAVE_GPR_SIZE)
SAVE_VR(32+SAVE_GPR_SIZE+SAVE_FPR_SIZE, R6)
MOVD $0, R0
CALL runtime·sigprofNonGo<ABIInternal>(SB)
RESTORE_GPR(32)
RESTORE_FPR(32+SAVE_GPR_SIZE)
RESTORE_VR(32+SAVE_GPR_SIZE+SAVE_FPR_SIZE, R6)
// Clear frame, restore LR, return
ADD $(32+SAVE_ALL_REG_SIZE), R1
MOVD 16(R1), R0
MOVD R0, LR
MOVD 8(R1), R0
MOVW R0, CR
RET
TEXT runtime·mmap(SB),NOSPLIT|NOFRAME,$0