diff options
Diffstat (limited to 'arch/powerpc/lib/test-code-patching.c')
-rw-r--r-- | arch/powerpc/lib/test-code-patching.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/arch/powerpc/lib/test-code-patching.c b/arch/powerpc/lib/test-code-patching.c new file mode 100644 index 0000000000..c44823292f --- /dev/null +++ b/arch/powerpc/lib/test-code-patching.c @@ -0,0 +1,362 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2008 Michael Ellerman, IBM Corporation. + */ + +#include <linux/vmalloc.h> +#include <linux/init.h> + +#include <asm/code-patching.h> + +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); |