From e148bd17f48bd17fca2f4f089ec879fa6e47e34c Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Tue, 14 Feb 2017 14:46:42 +0530 Subject: powerpc: Emulation support for load/store instructions on LE emulate_step() uses a number of underlying kernel functions that were initially not enabled for LE. This has been rectified since. So, fix emulate_step() for LE for the corresponding instructions. Cc: stable@vger.kernel.org # v3.18+ Reported-by: Anton Blanchard Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman --- arch/powerpc/lib/sstep.c | 20 -------------------- 1 file changed, 20 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 846dba2c6360..9c542ec70c5b 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -1799,8 +1799,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) goto instr_done; case LARX: - if (regs->msr & MSR_LE) - return 0; if (op.ea & (size - 1)) break; /* can't handle misaligned */ if (!address_ok(regs, op.ea, size)) @@ -1823,8 +1821,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) goto ldst_done; case STCX: - if (regs->msr & MSR_LE) - return 0; if (op.ea & (size - 1)) break; /* can't handle misaligned */ if (!address_ok(regs, op.ea, size)) @@ -1849,8 +1845,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) goto ldst_done; case LOAD: - if (regs->msr & MSR_LE) - return 0; err = read_mem(®s->gpr[op.reg], op.ea, size, regs); if (!err) { if (op.type & SIGNEXT) @@ -1862,8 +1856,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) #ifdef CONFIG_PPC_FPU case LOAD_FP: - if (regs->msr & MSR_LE) - return 0; if (size == 4) err = do_fp_load(op.reg, do_lfs, op.ea, size, regs); else @@ -1872,15 +1864,11 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) #endif #ifdef CONFIG_ALTIVEC case LOAD_VMX: - if (regs->msr & MSR_LE) - return 0; err = do_vec_load(op.reg, do_lvx, op.ea & ~0xfUL, regs); goto ldst_done; #endif #ifdef CONFIG_VSX case LOAD_VSX: - if (regs->msr & MSR_LE) - return 0; err = do_vsx_load(op.reg, do_lxvd2x, op.ea, regs); goto ldst_done; #endif @@ -1903,8 +1891,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) goto instr_done; case STORE: - if (regs->msr & MSR_LE) - return 0; if ((op.type & UPDATE) && size == sizeof(long) && op.reg == 1 && op.update_reg == 1 && !(regs->msr & MSR_PR) && @@ -1917,8 +1903,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) #ifdef CONFIG_PPC_FPU case STORE_FP: - if (regs->msr & MSR_LE) - return 0; if (size == 4) err = do_fp_store(op.reg, do_stfs, op.ea, size, regs); else @@ -1927,15 +1911,11 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) #endif #ifdef CONFIG_ALTIVEC case STORE_VMX: - if (regs->msr & MSR_LE) - return 0; err = do_vec_store(op.reg, do_stvx, op.ea & ~0xfUL, regs); goto ldst_done; #endif #ifdef CONFIG_VSX case STORE_VSX: - if (regs->msr & MSR_LE) - return 0; err = do_vsx_store(op.reg, do_stxvd2x, op.ea, regs); goto ldst_done; #endif -- cgit From 4ceae137bdab2232e57b2e6fd5631a22a0160938 Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Tue, 14 Feb 2017 14:46:43 +0530 Subject: powerpc: emulate_step() tests for load/store instructions Add new selftest that test emulate_step for Normal, Floating Point, Vector and Vector Scalar - load/store instructions. Test should run at boot time if CONFIG_KPROBES_SANITY_TEST and CONFIG_PPC64 is set. Sample log: emulate_step_test: ld : PASS emulate_step_test: lwz : PASS emulate_step_test: lwzx : PASS emulate_step_test: std : PASS emulate_step_test: ldarx / stdcx. : PASS emulate_step_test: lfsx : PASS emulate_step_test: stfsx : PASS emulate_step_test: lfdx : PASS emulate_step_test: stfdx : PASS emulate_step_test: lvx : PASS emulate_step_test: stvx : PASS emulate_step_test: lxvd2x : PASS emulate_step_test: stxvd2x : PASS Signed-off-by: Ravi Bangoria [mpe: Drop start/complete lines, make it all __init] Signed-off-by: Michael Ellerman --- arch/powerpc/lib/Makefile | 1 + arch/powerpc/lib/test_emulate_step.c | 434 +++++++++++++++++++++++++++++++++++ 2 files changed, 435 insertions(+) create mode 100644 arch/powerpc/lib/test_emulate_step.c (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index 0e649d72fe8d..2b5e09020cfe 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -20,6 +20,7 @@ obj64-y += copypage_64.o copyuser_64.o usercopy_64.o mem_64.o hweight_64.o \ obj64-$(CONFIG_SMP) += locks.o obj64-$(CONFIG_ALTIVEC) += vmx-helper.o +obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o obj-y += checksum_$(BITS).o checksum_wrappers.o diff --git a/arch/powerpc/lib/test_emulate_step.c b/arch/powerpc/lib/test_emulate_step.c new file mode 100644 index 000000000000..2534c1447554 --- /dev/null +++ b/arch/powerpc/lib/test_emulate_step.c @@ -0,0 +1,434 @@ +/* + * 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 +#include +#include + +#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) + show_result("lxvd2x", "PASS"); + 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]) + show_result("stxvd2x", "PASS"); + 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); -- cgit