path: root/tools/testing/selftests/rseq/rseq-x86-bits.h

/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
 * rseq-x86-bits.h
 *
 * (C) Copyright 2016-2022 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#include "rseq-bits-template.h"

#ifdef __x86_64__

#if defined(RSEQ_TEMPLATE_MO_RELAXED) && \
	(defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID))

static inline __attribute__((always_inline))
int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_storev)(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
{
	RSEQ_INJECT_C(9)

	__asm__ __volatile__ goto (
		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
#endif
		/* Start rseq by storing table entry pointer into rseq_cs. */
		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_TEMPLATE_CPU_ID_OFFSET(%[rseq_offset]), 4f)
		RSEQ_INJECT_ASM(3)
		"cmpq %[v], %[expect]\n\t"
		"jnz %l[cmpfail]\n\t"
		RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_TEMPLATE_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
		"cmpq %[v], %[expect]\n\t"
		"jnz %l[error2]\n\t"
#endif
		/* final store */
		"movq %[newv], %[v]\n\t"
		"2:\n\t"
		RSEQ_INJECT_ASM(5)
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
		: /* gcc asm goto does not allow outputs */
		: [cpu_id]		"r" (cpu),
		  [rseq_offset]		"r" (rseq_offset),
		  [v]			"m" (*v),
		  [expect]		"r" (expect),
		  [newv]		"r" (newv)
		: "memory", "cc", "rax"
		  RSEQ_INJECT_CLOBBER
		: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
		  , error1, error2
#endif
	);
	rseq_after_asm_goto();
	return 0;
abort:
	rseq_after_asm_goto();
	RSEQ_INJECT_FAILED
	return -1;
cmpfail:
	rseq_after_asm_goto();
	return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
	rseq_after_asm_goto();
	rseq_bug("cpu_id comparison failed");
error2:
	rseq_after_asm_goto();
	rseq_bug("expected value comparison failed");
#endif
}

/*
 * Compare @v against @expectnot. When it does _not_ match, load @v
 * into @load, and store the content of *@v + voffp into @v.
 */
static inline __attribute__((always_inline))
int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpnev_storeoffp_load)(intptr_t *v, intptr_t expectnot,
			       long voffp, intptr_t *load, int cpu)
{
	RSEQ_INJECT_C(9)

	__asm__ __volatile__ goto (
		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
#endif
		/* Start rseq by storing table entry pointer into rseq_cs. */
		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_TEMPLATE_CPU_ID_OFFSET(%[rseq_offset]), 4f)
		RSEQ_INJECT_ASM(3)
		"movq %[v], %%rbx\n\t"
		"cmpq %%rbx, %[expectnot]\n\t"
		"je %l[cmpfail]\n\t"
		RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_TEMPLATE_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
		"movq %[v], %%rbx\n\t"
		"cmpq %%rbx, %[expectnot]\n\t"
		"je %l[error2]\n\t"
#endif
		"movq %%rbx, %[load]\n\t"
		"addq %[voffp], %%rbx\n\t"
		"movq (%%rbx), %%rbx\n\t"
		/* final store */
		"movq %%rbx, %[v]\n\t"
		"2:\n\t"
		RSEQ_INJECT_ASM(5)
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
		: /* gcc asm goto does not allow outputs */
		: [cpu_id]		"r" (cpu),
		  [rseq_offset]		"r" (rseq_offset),
		  /* final store input */
		  [v]			"m" (*v),
		  [expectnot]		"r" (expectnot),
		  [voffp]		"er" (voffp),
		  [load]		"m" (*load)
		: "memory", "cc", "rax", "rbx"
		  RSEQ_INJECT_CLOBBER
		: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
		  , error1, error2
#endif
	);
	rseq_after_asm_goto();
	return 0;
abort:
	rseq_after_asm_goto();
	RSEQ_INJECT_FAILED
	return -1;
cmpfail:
	rseq_after_asm_goto();
	return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
	rseq_after_asm_goto();
	rseq_bug("cpu_id comparison failed");
error2:
	rseq_after_asm_goto();
	rseq_bug("expected value comparison failed");
#endif
}

static inline __attribute__((always_inline))