test_emulate_step.c
/*
* Simple sanity test for emulate_step load/store instructions.
*
* Copyright IBM Corp. 2016
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#define pr_fmt(fmt) "emulate_step_test: " fmt
#include <linux/ptrace.h>
#include <asm/sstep.h>
#include <asm/ppc-opcode.h>
#define IMM_L(i) ((uintptr_t)(i) & 0xffff)
/*
* Defined with TEST_ prefix so it does not conflict with other
* definitions.
*/
#define TEST_LD(r, base, i) (PPC_INST_LD | ___PPC_RT(r) | \
___PPC_RA(base) | IMM_L(i))
#define TEST_LWZ(r, base, i) (PPC_INST_LWZ | ___PPC_RT(r) | \
___PPC_RA(base) | IMM_L(i))
#define TEST_LWZX(t, a, b) (PPC_INST_LWZX | ___PPC_RT(t) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_STD(r, base, i) (PPC_INST_STD | ___PPC_RS(r) | \
___PPC_RA(base) | ((i) & 0xfffc))
#define TEST_LDARX(t, a, b, eh) (PPC_INST_LDARX | ___PPC_RT(t) | \
___PPC_RA(a) | ___PPC_RB(b) | \
__PPC_EH(eh))
#define TEST_STDCX(s, a, b) (PPC_INST_STDCX | ___PPC_RS(s) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_LFSX(t, a, b) (PPC_INST_LFSX | ___PPC_RT(t) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_STFSX(s, a, b) (PPC_INST_STFSX | ___PPC_RS(s) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_LFDX(t, a, b) (PPC_INST_LFDX | ___PPC_RT(t) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_STFDX(s, a, b) (PPC_INST_STFDX | ___PPC_RS(s) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_LVX(t, a, b) (PPC_INST_LVX | ___PPC_RT(t) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_STVX(s, a, b) (PPC_INST_STVX | ___PPC_RS(s) | \
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_LXVD2X(s, a, b) (PPC_INST_LXVD2X | VSX_XX1((s), R##a, R##b))
#define TEST_STXVD2X(s, a, b) (PPC_INST_STXVD2X | VSX_XX1((s), R##a, R##b))
static void __init init_pt_regs(struct pt_regs *regs)
{
static unsigned long msr;
static bool msr_cached;
memset(regs, 0, sizeof(struct pt_regs));
if (likely(msr_cached)) {
regs->msr = msr;
return;
}
asm volatile("mfmsr %0" : "=r"(regs->msr));
regs->msr |= MSR_FP;
regs->msr |= MSR_VEC;
regs->msr |= MSR_VSX;
msr = regs->msr;
msr_cached = true;
}
static void __init show_result(char *ins, char *result)
{
pr_info("%-14s : %s\n", ins, result);
}
static void __init test_ld(void)
{
struct pt_regs regs;
unsigned long a = 0x23;
int stepped = -1;
init_pt_regs(®s);
regs.gpr[3] = (unsigned long) &a;
/* ld r5, 0(r3) */
stepped = emulate_step(®s, TEST_LD(5, 3, 0));
if (stepped == 1 && regs.gpr[5] == a)
show_result("ld", "PASS");
else
show_result("ld", "FAIL");
}
static void __init test_lwz(void)
{
struct pt_regs regs;
unsigned int a = 0x4545;
int stepped = -1;
init_pt_regs(®s);
regs.gpr[3] = (unsigned long) &a;
/* lwz r5, 0(r3) */
stepped = emulate_step(®s, TEST_LWZ(5, 3, 0));
if (stepped == 1 && regs.gpr[5] == a)
show_result("lwz", "PASS");
else
show_result("lwz", "FAIL");
}
static void __init test_lwzx(void)
{
struct pt_regs regs;
unsigned int a[3] = {0x0, 0x0, 0x1234};
int stepped = -1;
init_pt_regs(®s);
regs.gpr[3] = (unsigned long) a;
regs.gpr[4] = 8;
regs.gpr[5] = 0x8765;
/* lwzx r5, r3, r4 */
stepped = emulate_step(®s, TEST_LWZX(5, 3, 4));
if (stepped == 1 && regs.gpr[5] == a[2])
show_result("lwzx", "PASS");
else
show_result("lwzx", "FAIL");
}
static void __init test_std(void)
{
struct pt_regs regs;
unsigned long a = 0x1234;
int stepped = -1;
init_pt_regs(®s);
regs.gpr[3] = (unsigned long) &a;
regs.gpr[5] = 0x5678;
/* std r5, 0(r3) */
stepped = emulate_step(®s, TEST_STD(5, 3, 0));
if (stepped == 1 || regs.gpr[5] == a)
show_result("std", "PASS");
else
show_result("std", "FAIL");
}
static void __init test_ldarx_stdcx(void)
{
struct pt_regs regs;
unsigned long a = 0x1234;
int stepped = -1;
unsigned long cr0_eq = 0x1 << 29; /* eq bit of CR0 */
init_pt_regs(®s);
asm volatile("mfcr %0" : "=r"(regs.ccr));
/*** ldarx ***/
regs.gpr[3] = (unsigned long) &a;
regs.gpr[4] = 0;
regs.gpr[5] = 0x5678;
/* ldarx r5, r3, r4, 0 */
stepped = emulate_step(®s, TEST_LDARX(5, 3, 4, 0));
/*
* Don't touch 'a' here. Touching 'a' can do Load/store
* of 'a' which result in failure of subsequent stdcx.
* Instead, use hardcoded value for comparison.
*/
if (stepped <= 0 || regs.gpr[5] != 0x1234) {
show_result("ldarx / stdcx.", "FAIL (ldarx)");
return;
}
/*** stdcx. ***/
regs.gpr[5] = 0x9ABC;
/* stdcx. r5, r3, r4 */
stepped = emulate_step(®s, TEST_STDCX(5, 3, 4));
/*
* Two possible scenarios that indicates successful emulation
* of stdcx. :
* 1. Reservation is active and store is performed. In this
* case cr0.eq bit will be set to 1.
* 2. Reservation is not active and store is not performed.
* In this case cr0.eq bit will be set to 0.
*/
if (stepped == 1 && ((regs.gpr[5] == a && (regs.ccr & cr0_eq))
|| (regs.gpr[5] != a && !(regs.ccr & cr0_eq))))
show_result("ldarx / stdcx.", "PASS");
else
show_result("ldarx / stdcx.", "FAIL (stdcx.)");
}
#ifdef CONFIG_PPC_FPU
static void __init test_lfsx_stfsx(void)
{
struct pt_regs regs;
union {
float a;
int b;
} c;
int cached_b;
int stepped = -1;
init_pt_regs(®s);
/*** lfsx ***/
c.a = 123.45;
cached_b = c.b;
regs.gpr[3] = (unsigned long) &c.a;
regs.gpr[4] = 0;
/* lfsx frt10, r3, r4 */
stepped = emulate_step(®s, TEST_LFSX(10, 3, 4));
if (stepped == 1)
show_result("lfsx", "PASS");
else
show_result("lfsx", "FAIL");
/*** stfsx ***/
c.a = 678.91;
/* stfsx frs10, r3, r4 */
stepped = emulate_step(®s, TEST_STFSX(10, 3, 4));
if (stepped == 1 && c.b == cached_b)
show_result("stfsx", "PASS");
else
show_result("stfsx", "FAIL");
}
static void __init test_lfdx_stfdx(void)
{
struct pt_regs regs;
union {
double a;
long b;
} c;
long cached_b;
int stepped = -1;
init_pt_regs(®s);
/*** lfdx ***/
c.a = 123456.78;
cached_b = c.b;
regs.gpr[3] = (unsigned long) &c.a;
regs.gpr[4] = 0;
/* lfdx frt10, r3, r4 */
stepped = emulate_step(®s, TEST_LFDX(10, 3, 4));
if (stepped == 1)
show_result("lfdx", "PASS");
else
show_result("lfdx", "FAIL");
/*** stfdx ***/
c.a = 987654.32;
/* stfdx frs10, r3, r4 */
stepped = emulate_step(®s, TEST_STFDX(10, 3, 4));
if (stepped == 1 && c.b == cached_b)
show_result("stfdx", "PASS");
else
show_result("stfdx", "FAIL");
}
#else
static void __init test_lfsx_stfsx(void)
{
show_result("lfsx", "SKIP (CONFIG_PPC_FPU is not set)");
show_result("stfsx", "SKIP (CONFIG_PPC_FPU is not set)");
}
static void __init test_lfdx_stfdx(void)
{
show_result("lfdx", "SKIP (CONFIG_PPC_FPU is not set)");
show_result("stfdx", "SKIP (CONFIG_PPC_FPU is not set)");
}
#endif /* CONFIG_PPC_FPU */
#ifdef CONFIG_ALTIVEC
static void __init test_lvx_stvx(void)
{
struct pt_regs regs;
union {
vector128 a;
u32 b[4];
} c;
u32 cached_b[4];
int stepped = -1;
init_pt_regs(®s);
/*** lvx ***/
cached_b[0] = c.b[0] = 923745;
cached_b[1] = c.b[1] = 2139478;
cached_b[2] = c.b[2] = 9012;
cached_b[3] = c.b[3] = 982134;
regs.gpr[3] = (unsigned long) &c.a;
regs.gpr[4] = 0;
/* lvx vrt10, r3, r4 */
stepped = emulate_step(®s, TEST_LVX(10, 3, 4));
if (stepped == 1)
show_result("lvx", "PASS");
else
show_result("lvx", "FAIL");
/*** stvx ***/
c.b[0] = 4987513;
c.b[1] = 84313948;
c.b[2] = 71;
c.b[3] = 498532;
/* stvx vrs10, r3, r4 */
stepped = emulate_step(®s, TEST_STVX(10, 3, 4));
if (stepped == 1 && cached_b[0] == c.b[0] && cached_b[1] == c.b[1] &&
cached_b[2] == c.b[2] && cached_b[3] == c.b[3])
show_result("stvx", "PASS");
else
show_result("stvx", "FAIL");
}
#else
static void __init test_lvx_stvx(void)
{
show_result("lvx", "SKIP (CONFIG_ALTIVEC is not set)");
show_result("stvx", "SKIP (CONFIG_ALTIVEC is not set)");
}
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
static void __init test_lxvd2x_stxvd2x(void)
{
struct pt_regs regs;
union {
vector128 a;
u32 b[4];
} c;
u32 cached_b[4];
int stepped = -1;
init_pt_regs(®s);
/*** lxvd2x ***/
cached_b[0] = c.b[0] = 18233;
cached_b[1] = c.b[1] = 34863571;
cached_b[2] = c.b[2] = 834;
cached_b[3] = c.b[3] = 6138911;
regs.gpr[3] = (unsigned long) &c.a;
regs.gpr[4] = 0;
/* lxvd2x vsr39, r3, r4 */
stepped = emulate_step(®s, TEST_LXVD2X(39, 3, 4));
if (stepped == 1 && cpu_has_feature(CPU_FTR_VSX)) {
show_result("lxvd2x", "PASS");
} else {
if (!cpu_has_feature(CPU_FTR_VSX))
show_result("lxvd2x", "PASS (!CPU_FTR_VSX)");
else
show_result("lxvd2x", "FAIL");
}
/*** stxvd2x ***/
c.b[0] = 21379463;
c.b[1] = 87;
c.b[2] = 374234;
c.b[3] = 4;
/* stxvd2x vsr39, r3, r4 */
stepped = emulate_step(®s, TEST_STXVD2X(39, 3, 4));
if (stepped == 1 && cached_b[0] == c.b[0] && cached_b[1] == c.b[1] &&
cached_b[2] == c.b[2] && cached_b[3] == c.b[3] &&
cpu_has_feature(CPU_FTR_VSX)) {
show_result("stxvd2x", "PASS");
} else {
if (!cpu_has_feature(CPU_FTR_VSX))
show_result("stxvd2x", "PASS (!CPU_FTR_VSX)");
else
show_result("stxvd2x", "FAIL");
}
}
#else
static void __init test_lxvd2x_stxvd2x(void)
{
show_result("lxvd2x", "SKIP (CONFIG_VSX is not set)");
show_result("stxvd2x", "SKIP (CONFIG_VSX is not set)");
}
#endif /* CONFIG_VSX */
static int __init test_emulate_step(void)
{
test_ld();
test_lwz();
test_lwzx();
test_std();
test_ldarx_stdcx();
test_lfsx_stfsx();
test_lfdx_stfdx();
test_lvx_stvx();
test_lxvd2x_stxvd2x();
return 0;
}
late_initcall(test_emulate_step);