// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 2008 Michael Ellerman, IBM Corporation. */ #include #include #include static int __init instr_is_branch_to_addr(const u32 *instr, unsigned long addr) { if (instr_is_branch_iform(ppc_inst_read(instr)) || instr_is_branch_bform(ppc_inst_read(instr))) return branch_target(instr) == addr; return 0; } static void __init test_trampoline(void) { asm ("nop;nop;\n"); } #define check(x) do { \ if (!(x)) \ pr_err("code-patching: test failed at line %d\n", __LINE__); \ } while (0) static void __init test_branch_iform(void) { int err; ppc_inst_t instr; u32 tmp[2]; u32 *iptr = tmp; unsigned long addr = (unsigned long)tmp; /* The simplest case, branch to self, no flags */ check(instr_is_branch_iform(ppc_inst(0x48000000))); /* All bits of target set, and flags */ check(instr_is_branch_iform(ppc_inst(0x4bffffff))); /* High bit of opcode set, which is wrong */ check(!instr_is_branch_iform(ppc_inst(0xcbffffff))); /* Middle bits of opcode set, which is wrong */ check(!instr_is_branch_iform(ppc_inst(0x7bffffff))); /* Simplest case, branch to self with link */ check(instr_is_branch_iform(ppc_inst(0x48000001))); /* All bits of targets set */ check(instr_is_branch_iform(ppc_inst(0x4bfffffd))); /* Some bits of targets set */ check(instr_is_branch_iform(ppc_inst(0x4bff00fd))); /* Must be a valid branch to start with */ check(!instr_is_branch_iform(ppc_inst(0x7bfffffd))); /* Absolute branch to 0x100 */ ppc_inst_write(iptr, ppc_inst(0x48000103)); check(instr_is_branch_to_addr(iptr, 0x100)); /* Absolute branch to 0x420fc */ ppc_inst_write(iptr, ppc_inst(0x480420ff)); check(instr_is_branch_to_addr(iptr, 0x420fc)); /* Maximum positive relative branch, + 20MB - 4B */ ppc_inst_write(iptr, ppc_inst(0x49fffffc)); check(instr_is_branch_to_addr(iptr, addr + 0x1FFFFFC)); /* Smallest negative relative branch, - 4B */ ppc_inst_write(iptr, ppc_inst(0x4bfffffc)); check(instr_is_branch_to_addr(iptr, addr - 4)); /* Largest negative relative branch, - 32 MB */ ppc_inst_write(iptr, ppc_inst(0x4a000000)); check(instr_is_branch_to_addr(iptr, addr - 0x2000000)); /* Branch to self, with link */ err = create_branch(&instr, iptr, addr, BRANCH_SET_LINK); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr)); /* Branch to self - 0x100, with link */ err = create_branch(&instr, iptr, addr - 0x100, BRANCH_SET_LINK); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr - 0x100)); /* Branch to self + 0x100, no link */ err = create_branch(&instr, iptr, addr + 0x100, 0); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr + 0x100)); /* Maximum relative negative offset, - 32 MB */ err = create_branch(&instr, iptr, addr - 0x2000000, BRANCH_SET_LINK); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr - 0x2000000)); /* Out of range relative negative offset, - 32 MB + 4*/ err = create_branch(&instr, iptr, addr - 0x2000004, BRANCH_SET_LINK); check(err); /* Out of range relative positive offset, + 32 MB */ err = create_branch(&instr, iptr, addr + 0x2000000, BRANCH_SET_LINK); check(err); /* Unaligned target */ err = create_branch(&instr, iptr, addr + 3, BRANCH_SET_LINK); check(err); /* Check flags are masked correctly */ err = create_branch(&instr, iptr, addr, 0xFFFFFFFC); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr)); check(ppc_inst_equal(instr, ppc_inst(0x48000000))); } static void __init test_create_function_call(void) { u32 *iptr; unsigned long dest; ppc_inst_t instr; /* Check we can create a function call */ iptr = (u32 *)ppc_function_entry(test_trampoline); dest = ppc_function_entry(test_create_function_call); create_branch(&instr, iptr, dest, BRANCH_SET_LINK); patch_instruction(iptr, instr); check(instr_is_branch_to_addr(iptr, dest)); } static void __init test_branch_bform(void) { int err; unsigned long addr; ppc_inst_t instr; u32 tmp[2]; u32 *iptr = tmp; unsigned int flags; addr = (unsigned long)iptr; /* The simplest case, branch to self, no flags */ check(instr_is_branch_bform(ppc_inst(0x40000000))); /* All bits of target set, and flags */ check(instr_is_branch_bform(ppc_inst(0x43ffffff))); /* High bit of opcode set, which is wrong */ check(!instr_is_branch_bform(ppc_inst(0xc3ffffff))); /* Middle bits of opcode set, which is wrong */ check(!instr_is_branch_bform(ppc_inst(0x7bffffff))); /* Absolute conditional branch to 0x100 */ ppc_inst_write(iptr, ppc_inst(0x43ff0103)); check(instr_is_branch_to_addr(iptr, 0x100)); /* Absolute conditional branch to 0x20fc */ ppc_inst_write(iptr, ppc_inst(0x43ff20ff)); check(instr_is_branch_to_addr(iptr, 0x20fc)); /* Maximum positive relative conditional branch, + 32 KB - 4B */ ppc_inst_write(iptr, ppc_inst(0x43ff7ffc)); check(instr_is_branch_to_addr(iptr, addr + 0x7FFC)); /* Smallest negative relative conditional branch, - 4B */ ppc_inst_write(iptr, ppc_inst(0x43fffffc)); check(instr_is_branch_to_addr(iptr, addr - 4)); /* Largest negative relative conditional branch, - 32 KB */ ppc_inst_write(iptr, ppc_inst(0x43ff8000)); check(instr_is_branch_to_addr(iptr, addr - 0x8000)); /* All condition code bits set & link */ flags = 0x3ff000 | BRANCH_SET_LINK; /* Branch to self */ err = create_cond_branch(&instr, iptr, addr, flags); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr)); /* Branch to self - 0x100 */ err = create_cond_branch(&instr, iptr, addr - 0x100, flags); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr - 0x100)); /* Branch to self + 0x100 */ err = create_cond_branch(&instr, iptr, addr + 0x100, flags); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr + 0x100)); /* Maximum relative negative offset, - 32 KB */ err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr - 0x8000)); /* Out of range relative negative offset, - 32 KB + 4*/ err = create_cond_branch(&instr, iptr, addr - 0x8004, flags); check(err); /* Out of range relative positive offset, + 32 KB */ err = create_cond_branch(&instr, iptr, addr + 0x8000, flags); check(err); /* Unaligned target */ err = create_cond_branch(&instr, iptr, addr + 3, flags); check(err); /* Check flags are masked correctly */ err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC); ppc_inst_write(iptr, instr); check(instr_is_branch_to_addr(iptr, addr)); check(ppc_inst_equal(instr, ppc_inst(0x43FF0000))); } static void __init test_translate_branch(void) { unsigned long addr; void *p, *q; ppc_inst_t instr; void *buf; buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); check(buf); if (!buf) return; /* Simple case, branch to self moved a little */ p = buf; addr = (unsigned long)p; create_branch(&instr, p, addr, 0); ppc_inst_write(p, instr); check(instr_is_branch_to_addr(p, addr)); q = p + 4; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(q, addr)); /* Maximum negative case, move b . to addr + 32 MB */ p = buf; addr = (unsigned long)p; create_branch(&instr, p, addr, 0); ppc_inst_write(p, instr); q = buf + 0x2000000; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000))); /* Maximum positive case, move x to x - 32 MB + 4 */ p = buf + 0x2000000; addr = (unsigned long)p; create_branch(&instr, p, addr, 0); ppc_inst_write(p, instr); q = buf + 4; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x49fffffc))); /* Jump to x + 16 MB moved to x + 20 MB */ p = buf; addr = 0x1000000 + (unsigned long)buf; create_branch(&instr, p, addr, BRANCH_SET_LINK); ppc_inst_write(p, instr); q = buf + 0x1400000; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Jump to x + 16 MB moved to x - 16 MB + 4 */ p = buf + 0x1000000; addr = 0x2000000 + (unsigned long)buf; create_branch(&instr, p, addr, 0); ppc_inst_write(p, instr); q = buf + 4; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Conditional branch tests */ /* Simple case, branch to self moved a little */ p = buf; addr = (unsigned long)p; create_cond_branch(&instr, p, addr, 0); ppc_inst_write(p, instr); check(instr_is_branch_to_addr(p, addr)); q = buf + 4; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(q, addr)); /* Maximum negative case, move b . to addr + 32 KB */ p = buf; addr = (unsigned long)p; create_cond_branch(&instr, p, addr, 0xFFFFFFFC); ppc_inst_write(p, instr); q = buf + 0x8000; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000))); /* Maximum positive case, move x to x - 32 KB + 4 */ p = buf + 0x8000; addr = (unsigned long)p; create_cond_branch(&instr, p, addr, 0xFFFFFFFC); ppc_inst_write(p, instr); q = buf + 4; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff7ffc))); /* Jump to x + 12 KB moved to x + 20 KB */ p = buf; addr = 0x3000 + (unsigned long)buf; create_cond_branch(&instr, p, addr, BRANCH_SET_LINK); ppc_inst_write(p, instr); q = buf + 0x5000; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Jump to x + 8 KB moved to x - 8 KB + 4 */ p = buf + 0x2000; addr = 0x4000 + (unsigned long)buf; create_cond_branch(&instr, p, addr, 0); ppc_inst_write(p, instr); q = buf + 4; translate_branch(&instr, q, p); ppc_inst_write(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Free the buffer we were using */ vfree(buf); } static void __init test_prefixed_patching(void) { u32 *iptr = (u32 *)ppc_function_entry(test_trampoline); u32 expected[2] = {OP_PREFIX << 26, 0}; ppc_inst_t inst = ppc_inst_prefix(OP_PREFIX << 26, 0); if (!IS_ENABLED(CONFIG_PPC64)) return; patch_instruction(iptr, inst); check(!memcmp(iptr, expected, sizeof(expected))); } static int __init test_code_patching(void) { pr_info("Running code patching self-tests ...\n"); test_branch_iform(); test_branch_bform(); test_create_function_call(); test_translate_branch(); test_prefixed_patching(); return 0; } late_initcall(test_code_patching);