src/runtime/race_ppc64le.s

// Copyright 2018 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.

//go:build race

#include "go_asm.h"
#include "go_tls.h"
#include "funcdata.h"
#include "textflag.h"
#include "asm_ppc64x.h"
#include "cgo/abi_ppc64x.h"

// The following functions allow calling the clang-compiled race runtime directly
// from Go code without going all the way through cgo.
// First, it's much faster (up to 50% speedup for real Go programs).
// Second, it eliminates race-related special cases from cgocall and scheduler.
// Third, in long-term it will allow to remove cyclic runtime/race dependency on cmd/go.

// A brief recap of the ppc64le calling convention.
// Arguments are passed in R3, R4, R5 ...
// SP must be 16-byte aligned.

// Note that for ppc64x, LLVM follows the standard ABI and
// expects arguments in registers, so these functions move
// the arguments from storage to the registers expected
// by the ABI.

// When calling from Go to Clang tsan code:
// R3 is the 1st argument and is usually the ThreadState*
// R4-? are the 2nd, 3rd, 4th, etc. arguments

// When calling racecalladdr:
// R8 is the call target address

// The race ctx is passed in R3 and loaded in
// racecalladdr.
//
// The sequence used to get the race ctx:
//    MOVD    runtime·tls_g(SB), R10 // Address of TLS variable
//    MOVD    0(R10), g              // g = R30
//    MOVD    g_racectx(g), R3       // racectx == ThreadState

// func runtime·RaceRead(addr uintptr)
// Called from instrumented Go code
TEXT	runtime·raceread<ABIInternal>(SB), NOSPLIT, $0-8
	MOVD	R3, R4 // addr
	MOVD	LR, R5 // caller of this?
	// void __tsan_read(ThreadState *thr, void *addr, void *pc);
	MOVD	$__tsan_read(SB), R8
	BR	racecalladdr<>(SB)

TEXT    runtime·RaceRead(SB), NOSPLIT, $0-8
	BR	runtime·raceread(SB)

// void runtime·racereadpc(void *addr, void *callpc, void *pc)
TEXT	runtime·racereadpc(SB), NOSPLIT, $0-24
	MOVD	addr+0(FP), R4
	MOVD	callpc+8(FP), R5
	MOVD	pc+16(FP), R6
	// void __tsan_read_pc(ThreadState *thr, void *addr, void *callpc, void *pc);
	MOVD	$__tsan_read_pc(SB), R8
	BR	racecalladdr<>(SB)

// func runtime·RaceWrite(addr uintptr)
// Called from instrumented Go code
TEXT	runtime·racewrite<ABIInternal>(SB), NOSPLIT, $0-8
	MOVD	R3, R4 // addr
	MOVD	LR, R5 // caller has set LR via BL inst
	// void __tsan_write(ThreadState *thr, void *addr, void *pc);
	MOVD	$__tsan_write(SB), R8
	BR	racecalladdr<>(SB)

TEXT    runtime·RaceWrite(SB), NOSPLIT, $0-8
	JMP	runtime·racewrite(SB)

// void runtime·racewritepc(void *addr, void *callpc, void *pc)
TEXT	runtime·racewritepc(SB), NOSPLIT, $0-24
	MOVD	addr+0(FP), R4
	MOVD	callpc+8(FP), R5
	MOVD	pc+16(FP), R6
	// void __tsan_write_pc(ThreadState *thr, void *addr, void *callpc, void *pc);
	MOVD	$__tsan_write_pc(SB), R8
	BR	racecalladdr<>(SB)

// func runtime·RaceReadRange(addr, size uintptr)
// Called from instrumented Go code.
TEXT	runtime·racereadrange<ABIInternal>(SB), NOSPLIT, $0-16
	MOVD	R4, R5 // size
	MOVD	R3, R4 // addr
	MOVD	LR, R6
	// void __tsan_read_range(ThreadState *thr, void *addr, uintptr size, void *pc);
	MOVD	$__tsan_read_range(SB), R8
	BR	racecalladdr<>(SB)

// void runtime·racereadrangepc1(void *addr, uintptr sz, void *pc)
TEXT	runtime·racereadrangepc1(SB), NOSPLIT, $0-24
	MOVD    addr+0(FP), R4
	MOVD    size+8(FP), R5
	MOVD    pc+16(FP), R6
	ADD	$4, R6		// tsan wants return addr
	// void __tsan_read_range(ThreadState *thr, void *addr, uintptr size, void *pc);
	MOVD    $__tsan_read_range(SB), R8
	BR	racecalladdr<>(SB)

TEXT    runtime·RaceReadRange(SB), NOSPLIT, $0-16
	BR	runtime·racereadrange(SB)

// func runtime·RaceWriteRange(addr, size uintptr)
// Called from instrumented Go code.
TEXT	runtime·racewriterange<ABIInternal>(SB), NOSPLIT, $0-16
	MOVD	R4, R5 // size
	MOVD	R3, R4 // addr
	MOVD	LR, R6
	// void __tsan_write_range(ThreadState *thr, void *addr, uintptr size, void *pc);
	MOVD	$__tsan_write_range(SB), R8
	BR	racecalladdr<>(SB)

TEXT    runtime·RaceWriteRange(SB), NOSPLIT, $0-16
	BR	runtime·racewriterange(SB)

// void runtime·racewriterangepc1(void *addr, uintptr sz, void *pc)
// Called from instrumented Go code
TEXT	runtime·racewriterangepc1(SB), NOSPLIT, $0-24
	MOVD	addr+0(FP), R4
	MOVD	size+8(FP), R5
	MOVD	pc+16(FP), R6
	ADD	$4, R6			// add 4 to inst offset?
	// void __tsan_write_range(ThreadState *thr, void *addr, uintptr size, void *pc);
	MOVD	$__tsan_write_range(SB), R8
	BR	racecalladdr<>(SB)

// Call a __tsan function from Go code.
// R8 = tsan function address
// R3 = *ThreadState a.k.a. g_racectx from g
// R4 = addr passed to __tsan function
//
// Otherwise, setup goroutine context and invoke racecall. Other arguments already set.
TEXT	racecalladdr<>(SB), NOSPLIT, $0-0
	MOVD    runtime·tls_g(SB), R10
	MOVD	0(R10), g
	MOVD	g_racectx(g), R3	// goroutine context
	// Check that addr is within [arenastart, arenaend) or within [racedatastart, racedataend).
	MOVD	runtime·racearenastart(SB), R9
	CMP	R4, R9
	BLT	data
	MOVD	runtime·racearenaend(SB), R9
	CMP	R4, R9
	BLT	call
data:
	MOVD	runtime·racedatastart(SB), R9
	CMP	R4, R9
	BLT	ret
	MOVD	runtime·racedataend(SB), R9
	CMP	R4, R9
	BGE	ret
call:
	// Careful!! racecall will save LR on its
	// stack, which is OK as long as racecalladdr
	// doesn't change in a way that generates a stack.
	// racecall should return to the caller of
	// recalladdr.
	BR	racecall<>(SB)
ret:
	RET

// func runtime·racefuncenter(pc uintptr)
// Called from instrumented Go code.
TEXT	runtime·racefuncenter(SB), NOSPLIT, $0-8
	MOVD	callpc+0(FP), R8
	BR	racefuncenter<>(SB)

// Common code for racefuncenter
// R11 = caller's return address
TEXT	racefuncenter<>(SB), NOSPLIT, $0-0
	MOVD    runtime·tls_g(SB), R10
	MOVD    0(R10), g
	MOVD    g_racectx(g), R3        // goroutine racectx aka *ThreadState
	MOVD	R8, R4			// caller pc set by caller in R8
	// void __tsan_func_enter(ThreadState *thr, void *pc);
	MOVD	$__tsan_func_enter(SB), R8
	BR	racecall<>(SB)
	RET

// func runtime·racefuncexit()
// Called from Go instrumented code.
TEXT	runtime·racefuncexit(SB), NOSPLIT, $0-0
	MOVD    runtime·tls_g(SB), R10
	MOVD    0(R10), g
	MOVD    g_racectx(g), R3        // goroutine racectx aka *ThreadState
	// void __tsan_func_exit(ThreadState *thr);
	MOVD	$__tsan_func_exit(SB), R8
	BR	racecall<>(SB)

// Atomic operations for sync/atomic package.
// Some use the __tsan versions instead
// R6 = addr of arguments passed to this function
// R3, R4, R5 set in racecallatomic

// Load atomic in tsan
TEXT	sync∕atomic·LoadInt32(SB), NOSPLIT, $0-12
	GO_ARGS
	// void __tsan_go_atomic32_load(ThreadState *thr, uptr cpc, uptr pc, u8 *a);
	MOVD	$__tsan_go_atomic32_load(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)
	RET

TEXT	sync∕atomic·LoadInt64(SB), NOSPLIT, $0-16
	GO_ARGS
	// void __tsan_go_atomic64_load(ThreadState *thr, uptr cpc, uptr pc, u8 *a);
	MOVD	$__tsan_go_atomic64_load(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)
	RET

TEXT	sync∕atomic·LoadUint32(SB), NOSPLIT, $0-12
	GO_ARGS
	BR	sync∕atomic·LoadInt32(SB)

TEXT	sync∕atomic·LoadUint64(SB), NOSPLIT, $0-16
	GO_ARGS
	BR	sync∕atomic·LoadInt64(SB)

TEXT	sync∕atomic·LoadUintptr(SB), NOSPLIT, $0-16
	GO_ARGS
	BR	sync∕atomic·LoadInt64(SB)

TEXT	sync∕atomic·LoadPointer(SB), NOSPLIT, $0-16
	GO_ARGS
	BR	sync∕atomic·LoadInt64(SB)

// Store atomic in tsan
TEXT	sync∕atomic·StoreInt32(SB), NOSPLIT, $0-12
	GO_ARGS
	// void __tsan_go_atomic32_store(ThreadState *thr, uptr cpc, uptr pc, u8 *a);
	MOVD	$__tsan_go_atomic32_store(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·StoreInt64(SB), NOSPLIT, $0-16
	GO_ARGS
	// void __tsan_go_atomic64_store(ThreadState *thr, uptr cpc, uptr pc, u8 *a);
	MOVD	$__tsan_go_atomic64_store(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·StoreUint32(SB), NOSPLIT, $0-12
	GO_ARGS
	BR	sync∕atomic·StoreInt32(SB)

TEXT	sync∕atomic·StoreUint64(SB), NOSPLIT, $0-16
	GO_ARGS
	BR	sync∕atomic·StoreInt64(SB)

TEXT	sync∕atomic·StoreUintptr(SB), NOSPLIT, $0-16
	GO_ARGS
	BR	sync∕atomic·StoreInt64(SB)

// Swap in tsan
TEXT	sync∕atomic·SwapInt32(SB), NOSPLIT, $0-20
	GO_ARGS
	// void __tsan_go_atomic32_exchange(ThreadState *thr, uptr cpc, uptr pc, u8 *a);
	MOVD	$__tsan_go_atomic32_exchange(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·SwapInt64(SB), NOSPLIT, $0-24
	GO_ARGS
	// void __tsan_go_atomic64_exchange(ThreadState *thr, uptr cpc, uptr pc, u8 *a)
	MOVD	$__tsan_go_atomic64_exchange(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·SwapUint32(SB), NOSPLIT, $0-20
	GO_ARGS
	BR	sync∕atomic·SwapInt32(SB)

TEXT	sync∕atomic·SwapUint64(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·SwapInt64(SB)

TEXT	sync∕atomic·SwapUintptr(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·SwapInt64(SB)

// Add atomic in tsan
TEXT	sync∕atomic·AddInt32(SB), NOSPLIT, $0-20
	GO_ARGS
	// void __tsan_go_atomic32_fetch_add(ThreadState *thr, uptr cpc, uptr pc, u8 *a);
	MOVD	$__tsan_go_atomic32_fetch_add(SB), R8
	ADD	$64, R1, R6	// addr of caller's 1st arg
	BL	racecallatomic<>(SB)
	// The tsan fetch_add result is not as expected by Go,
	// so the 'add' must be added to the result.
	MOVW	add+8(FP), R3	// The tsa fetch_add does not return the
	MOVW	ret+16(FP), R4	// result as expected by go, so fix it.
	ADD	R3, R4, R3
	MOVW	R3, ret+16(FP)
	RET

TEXT	sync∕atomic·AddInt64(SB), NOSPLIT, $0-24
	GO_ARGS
	// void __tsan_go_atomic64_fetch_add(ThreadState *thr, uptr cpc, uptr pc, u8 *a);
	MOVD	$__tsan_go_atomic64_fetch_add(SB), R8
	ADD	$64, R1, R6	// addr of caller's 1st arg
	BL	racecallatomic<>(SB)
	// The tsan fetch_add result is not as expected by Go,
	// so the 'add' must be added to the result.
	MOVD	add+8(FP), R3
	MOVD	ret+16(FP), R4
	ADD	R3, R4, R3
	MOVD	R3, ret+16(FP)
	RET

TEXT	sync∕atomic·AddUint32(SB), NOSPLIT, $0-20
	GO_ARGS
	BR	sync∕atomic·AddInt32(SB)

TEXT	sync∕atomic·AddUint64(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·AddInt64(SB)

TEXT	sync∕atomic·AddUintptr(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·AddInt64(SB)

// And
TEXT	sync∕atomic·AndInt32(SB), NOSPLIT, $0-20
	GO_ARGS
	MOVD	$__tsan_go_atomic32_fetch_and(SB), R8
	ADD     $32, R1, R6
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·AndInt64(SB), NOSPLIT, $0-24
	GO_ARGS
	MOVD	$__tsan_go_atomic64_fetch_and(SB), R8
	ADD     $32, R1, R6
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·AndUint32(SB), NOSPLIT, $0-20
	GO_ARGS
	BR	sync∕atomic·AndInt32(SB)

TEXT	sync∕atomic·AndUint64(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·AndInt64(SB)

TEXT	sync∕atomic·AndUintptr(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·AndInt64(SB)

// Or
TEXT	sync∕atomic·OrInt32(SB), NOSPLIT, $0-20
	GO_ARGS
	MOVD	$__tsan_go_atomic32_fetch_or(SB), R8
	ADD     $32, R1, R6
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·OrInt64(SB), NOSPLIT, $0-24
	GO_ARGS
	MOVD	$__tsan_go_atomic64_fetch_or(SB), R8
	ADD     $32, R1, R6
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·OrUint32(SB), NOSPLIT, $0-20
	GO_ARGS
	BR	sync∕atomic·OrInt32(SB)

TEXT	sync∕atomic·OrUint64(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·OrInt64(SB)

TEXT	sync∕atomic·OrUintptr(SB), NOSPLIT, $0-24
	GO_ARGS
	BR	sync∕atomic·OrInt64(SB)

// CompareAndSwap in tsan
TEXT	sync∕atomic·CompareAndSwapInt32(SB), NOSPLIT, $0-17
	GO_ARGS
	// void __tsan_go_atomic32_compare_exchange(
	//   ThreadState *thr, uptr cpc, uptr pc, u8 *a)
	MOVD	$__tsan_go_atomic32_compare_exchange(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·CompareAndSwapInt64(SB), NOSPLIT, $0-25
	GO_ARGS
	// void __tsan_go_atomic32_compare_exchange(
	//   ThreadState *thr, uptr cpc, uptr pc, u8 *a)
	MOVD	$__tsan_go_atomic64_compare_exchange(SB), R8
	ADD	$32, R1, R6	// addr of caller's 1st arg
	BR	racecallatomic<>(SB)

TEXT	sync∕atomic·CompareAndSwapUint32(SB), NOSPLIT, $0-17
	GO_ARGS
	BR	sync∕atomic·CompareAndSwapInt32(SB)

TEXT	sync∕atomic·CompareAndSwapUint64(SB), NOSPLIT, $0-25
	GO_ARGS
	BR	sync∕atomic·CompareAndSwapInt64(SB)

TEXT	sync∕atomic·CompareAndSwapUintptr(SB), NOSPLIT, $0-25
	GO_ARGS
	BR	sync∕atomic·CompareAndSwapInt64(SB)

// Common function used to call tsan's atomic functions
// R3 = *ThreadState
// R4 = TODO: What's this supposed to be?
// R5 = caller pc
// R6 = addr of incoming arg list
// R8 contains addr of target function.
TEXT	racecallatomic<>(SB), NOSPLIT, $0-0
	// Trigger SIGSEGV early if address passed to atomic function is bad.
	MOVD	(R6), R7	// 1st arg is addr
	MOVB	(R7), R9	// segv here if addr is bad
	// Check that addr is within [arenastart, arenaend) or within [racedatastart, racedataend).
	MOVD	runtime·racearenastart(SB), R9
	CMP	R7, R9
	BLT	racecallatomic_data
	MOVD	runtime·racearenaend(SB), R9
	CMP	R7, R9
	BLT	racecallatomic_ok
racecallatomic_data:
	MOVD	runtime·racedatastart(SB), R9
	CMP	R7, R9
	BLT	racecallatomic_ignore
	MOVD	runtime·racedataend(SB), R9
	CMP	R7, R9
	BGE	racecallatomic_ignore
racecallatomic_ok:
	// Addr is within the good range, call the atomic function.
	MOVD    runtime·tls_g(SB), R10
	MOVD    0(R10), g
	MOVD    g_racectx(g), R3        // goroutine racectx aka *ThreadState
	MOVD	R8, R5			// pc is the function called
	MOVD	(R1), R4		// caller pc from stack
	BL	racecall<>(SB)		// BL needed to maintain stack consistency
	RET				//
racecallatomic_ignore:
	// Addr is outside the good range.
	// Call __tsan_go_ignore_sync_begin to ignore synchronization during the atomic op.
	// An attempt to synchronize on the address would cause crash.
	MOVD	R8, R15	// save the original function
	MOVD	R6, R17 // save the original arg list addr
	MOVD	$__tsan_go_ignore_sync_begin(SB), R8 // func addr to call
	MOVD    runtime·tls_g(SB), R10
	MOVD    0(R10), g
	MOVD    g_racectx(g), R3        // goroutine context
	BL	racecall<>(SB)
	MOVD	R15, R8	// restore the original function
	MOVD	R17, R6 // restore arg list addr
	// Call the atomic function.
	// racecall will call LLVM race code which might clobber r30 (g)
	MOVD	runtime·tls_g(SB), R10
	MOVD	0(R10), g

	MOVD	g_racectx(g), R3
	MOVD	R8, R4		// pc being called same TODO as above
	MOVD	(R1), R5	// caller pc from latest LR
	BL	racecall<>(SB)
	// Call __tsan_go_ignore_sync_end.
	MOVD	$__tsan_go_ignore_sync_end(SB), R8
	MOVD	g_racectx(g), R3	// goroutine context g should still be good?
	BL	racecall<>(SB)
	RET

// void runtime·racecall(void(*f)(...), ...)
// Calls C function f from race runtime and passes up to 4 arguments to it.
// The arguments are never heap-object-preserving pointers, so we pretend there are no arguments.
TEXT	runtime·racecall(SB), NOSPLIT, $0-0
	MOVD	fn+0(FP), R8
	MOVD	arg0+8(FP), R3
	MOVD	arg1+16(FP), R4
	MOVD	arg2+24(FP), R5
	MOVD	arg3+32(FP), R6
	JMP	racecall<>(SB)

// Finds g0 and sets its stack
// Arguments were loaded for call from Go to C
TEXT	racecall<>(SB), NOSPLIT, $0-0
	// Set the LR slot for the ppc64 ABI
	MOVD	LR, R10
	MOVD	R10, 0(R1)	// Go expectation
	MOVD	R10, 16(R1)	// C ABI
	// Get info from the current goroutine
	MOVD    runtime·tls_g(SB), R10	// g offset in TLS
	MOVD    0(R10), g
	MOVD	g_m(g), R7		// m for g
	MOVD	R1, R16			// callee-saved, preserved across C call

	// Switch to g0 stack if we aren't already on g0 or gsignal.
	MOVD	m_gsignal(R7), R10
	CMP	R10, g
	BEQ	call

	MOVD	m_g0(R7), R10
	CMP	R10, g
	BEQ	call

	MOVD	(g_sched+gobuf_sp)(R10), R1 // switch R1
call:
	// prepare frame for C ABI
	SUB	$32, R1			// create frame for callee saving LR, CR, R2 etc.
	RLDCR   $0, R1, $~15, R1	// align SP to 16 bytes
	MOVD	R8, CTR			// R8 = caller addr
	MOVD	R8, R12			// expected by PPC64 ABI
	BL	(CTR)
	XOR     R0, R0			// clear R0 on return from Clang
	MOVD	R16, R1			// restore R1; R16 nonvol in Clang
	MOVD    runtime·tls_g(SB), R10	// find correct g
	MOVD    0(R10), g
	MOVD	16(R1), R10		// LR was saved away, restore for return
	MOVD	R10, LR
	RET

// C->Go callback thunk that allows to call runtime·racesymbolize from C code.
// Direct Go->C race call has only switched SP, finish g->g0 switch by setting correct g.
// The overall effect of Go->C->Go call chain is similar to that of mcall.
// RARG0 contains command code. RARG1 contains command-specific context.
// See racecallback for command codes.
TEXT	runtime·racecallbackthunk(SB), NOSPLIT|NOFRAME, $0
	// Handle command raceGetProcCmd (0) here.
	// First, code below assumes that we are on curg, while raceGetProcCmd
	// can be executed on g0. Second, it is called frequently, so will
	// benefit from this fast path.
	MOVD	$0, R0		// clear R0 since we came from C code
	CMP	R3, $0
	BNE	rest
	// Inline raceGetProdCmd without clobbering callee-save registers.
	MOVD	runtime·tls_g(SB), R10
	MOVD	0(R10), R11
	MOVD	g_m(R11), R3
	MOVD	m_p(R3), R3
	MOVD	p_raceprocctx(R3), R3
	MOVD	R3, (R4)
	RET

rest:
	// Save registers according to the host PPC64 ABI
	// and reserve 16B for argument storage.
	STACK_AND_SAVE_HOST_TO_GO_ABI(16)

	// Load g, and switch to g0 if not already on it.
	MOVD	runtime·tls_g(SB), R10
	MOVD	0(R10), g

	MOVD	g_m(g), R7
	MOVD	m_g0(R7), R8
	CMP	g, R8
	BEQ	noswitch

	MOVD	R8, g // set g = m->g0

noswitch:
	BL	runtime·racecallback<ABIInternal>(SB)

	UNSTACK_AND_RESTORE_GO_TO_HOST_ABI(16)
	RET

// tls_g, g value for each thread in TLS
GLOBL runtime·tls_g+0(SB), TLSBSS+DUPOK, $8