| // SPDX-License-Identifier: GPL-2.0-or-later | |
| /* | |
| * Copyright 2008 Michael Ellerman, IBM Corporation. | |
| */ | |
| #include <linux/kernel.h> | |
| #include <linux/kprobes.h> | |
| #include <linux/vmalloc.h> | |
| #include <linux/init.h> | |
| #include <linux/mm.h> | |
| #include <linux/cpuhotplug.h> | |
| #include <linux/slab.h> | |
| #include <linux/uaccess.h> | |
| #include <asm/tlbflush.h> | |
| #include <asm/page.h> | |
| #include <asm/code-patching.h> | |
| #include <asm/setup.h> | |
| #include <asm/inst.h> | |
| static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr, | |
| struct ppc_inst *patch_addr) | |
| { | |
| if (!ppc_inst_prefixed(instr)) | |
| __put_user_asm_goto(ppc_inst_val(instr), patch_addr, failed, "stw"); | |
| else | |
| __put_user_asm_goto(ppc_inst_as_u64(instr), patch_addr, failed, "std"); | |
| asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr), | |
| "r" (exec_addr)); | |
| return 0; | |
| failed: | |
| return -EFAULT; | |
| } | |
| int raw_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) | |
| { | |
| return __patch_instruction(addr, instr, addr); | |
| } | |
| #ifdef CONFIG_STRICT_KERNEL_RWX | |
| static DEFINE_PER_CPU(struct vm_struct *, text_poke_area); | |
| static int text_area_cpu_up(unsigned int cpu) | |
| { | |
| struct vm_struct *area; | |
| area = get_vm_area(PAGE_SIZE, VM_ALLOC); | |
| if (!area) { | |
| WARN_ONCE(1, "Failed to create text area for cpu %d\n", | |
| cpu); | |
| return -1; | |
| } | |
| this_cpu_write(text_poke_area, area); | |
| return 0; | |
| } | |
| static int text_area_cpu_down(unsigned int cpu) | |
| { | |
| free_vm_area(this_cpu_read(text_poke_area)); | |
| return 0; | |
| } | |
| /* | |
| * Run as a late init call. This allows all the boot time patching to be done | |
| * simply by patching the code, and then we're called here prior to | |
| * mark_rodata_ro(), which happens after all init calls are run. Although | |
| * BUG_ON() is rude, in this case it should only happen if ENOMEM, and we judge | |
| * it as being preferable to a kernel that will crash later when someone tries | |
| * to use patch_instruction(). | |
| */ | |
| static int __init setup_text_poke_area(void) | |
| { | |
| BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, | |
| "powerpc/text_poke:online", text_area_cpu_up, | |
| text_area_cpu_down)); | |
| return 0; | |
| } | |
| late_initcall(setup_text_poke_area); | |
| /* | |
| * This can be called for kernel text or a module. | |
| */ | |
| static int map_patch_area(void *addr, unsigned long text_poke_addr) | |
| { | |
| unsigned long pfn; | |
| int err; | |
| if (is_vmalloc_or_module_addr(addr)) | |
| pfn = vmalloc_to_pfn(addr); | |
| else | |
| pfn = __pa_symbol(addr) >> PAGE_SHIFT; | |
| err = map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL); | |
| pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err); | |
| if (err) | |
| return -1; | |
| return 0; | |
| } | |
| static inline int unmap_patch_area(unsigned long addr) | |
| { | |
| pte_t *ptep; | |
| pmd_t *pmdp; | |
| pud_t *pudp; | |
| p4d_t *p4dp; | |
| pgd_t *pgdp; | |
| pgdp = pgd_offset_k(addr); | |
| if (unlikely(!pgdp)) | |
| return -EINVAL; | |
| p4dp = p4d_offset(pgdp, addr); | |
| if (unlikely(!p4dp)) | |
| return -EINVAL; | |
| pudp = pud_offset(p4dp, addr); | |
| if (unlikely(!pudp)) | |
| return -EINVAL; | |
| pmdp = pmd_offset(pudp, addr); | |
| if (unlikely(!pmdp)) | |
| return -EINVAL; | |
| ptep = pte_offset_kernel(pmdp, addr); | |
| if (unlikely(!ptep)) | |
| return -EINVAL; | |
| pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr); | |
| /* | |
| * In hash, pte_clear flushes the tlb, in radix, we have to | |
| */ | |
| pte_clear(&init_mm, addr, ptep); | |
| flush_tlb_kernel_range(addr, addr + PAGE_SIZE); | |
| return 0; | |
| } | |
| static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) | |
| { | |
| int err; | |
| struct ppc_inst *patch_addr = NULL; | |
| unsigned long flags; | |
| unsigned long text_poke_addr; | |
| unsigned long kaddr = (unsigned long)addr; | |
| /* | |
| * During early early boot patch_instruction is called | |
| * when text_poke_area is not ready, but we still need | |
| * to allow patching. We just do the plain old patching | |
| */ | |
| if (!this_cpu_read(text_poke_area)) | |
| return raw_patch_instruction(addr, instr); | |
| local_irq_save(flags); | |
| text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr; | |
| if (map_patch_area(addr, text_poke_addr)) { | |
| err = -1; | |
| goto out; | |
| } | |
| patch_addr = (struct ppc_inst *)(text_poke_addr + (kaddr & ~PAGE_MASK)); | |
| __patch_instruction(addr, instr, patch_addr); | |
| err = unmap_patch_area(text_poke_addr); | |
| if (err) | |
| pr_warn("failed to unmap %lx\n", text_poke_addr); | |
| out: | |
| local_irq_restore(flags); | |
| return err; | |
| } | |
| #else /* !CONFIG_STRICT_KERNEL_RWX */ | |
| static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) | |
| { | |
| return raw_patch_instruction(addr, instr); | |
| } | |
| #endif /* CONFIG_STRICT_KERNEL_RWX */ | |
| int patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) | |
| { | |
| /* Make sure we aren't patching a freed init section */ | |
| if (init_mem_is_free && init_section_contains(addr, 4)) { | |
| pr_debug("Skipping init section patching addr: 0x%px\n", addr); | |
| return 0; | |
| } | |
| return do_patch_instruction(addr, instr); | |
| } | |
| NOKPROBE_SYMBOL(patch_instruction); | |
| int patch_branch(struct ppc_inst *addr, unsigned long target, int flags) | |
| { | |
| struct ppc_inst instr; | |
| create_branch(&instr, addr, target, flags); | |
| return patch_instruction(addr, instr); | |
| } | |
| bool is_offset_in_branch_range(long offset) | |
| { | |
| /* | |
| * Powerpc branch instruction is : | |
| * | |
| * 0 6 30 31 | |
| * +---------+----------------+---+---+ | |
| * | opcode | LI |AA |LK | | |
| * +---------+----------------+---+---+ | |
| * Where AA = 0 and LK = 0 | |
| * | |
| * LI is a signed 24 bits integer. The real branch offset is computed | |
| * by: imm32 = SignExtend(LI:'0b00', 32); | |
| * | |
| * So the maximum forward branch should be: | |
| * (0x007fffff << 2) = 0x01fffffc = 0x1fffffc | |
| * The maximum backward branch should be: | |
| * (0xff800000 << 2) = 0xfe000000 = -0x2000000 | |
| */ | |
| return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3)); | |
| } | |
| /* | |
| * Helper to check if a given instruction is a conditional branch | |
| * Derived from the conditional checks in analyse_instr() | |
| */ | |
| bool is_conditional_branch(struct ppc_inst instr) | |
| { | |
| unsigned int opcode = ppc_inst_primary_opcode(instr); | |
| if (opcode == 16) /* bc, bca, bcl, bcla */ | |
| return true; | |
| if (opcode == 19) { | |
| switch ((ppc_inst_val(instr) >> 1) & 0x3ff) { | |
| case 16: /* bclr, bclrl */ | |
| case 528: /* bcctr, bcctrl */ | |
| case 560: /* bctar, bctarl */ | |
| return true; | |
| } | |
| } | |
| return false; | |
| } | |
| NOKPROBE_SYMBOL(is_conditional_branch); | |
| int create_branch(struct ppc_inst *instr, | |
| const struct ppc_inst *addr, | |
| unsigned long target, int flags) | |
| { | |
| long offset; | |
| *instr = ppc_inst(0); | |
| offset = target; | |
| if (! (flags & BRANCH_ABSOLUTE)) | |
| offset = offset - (unsigned long)addr; | |
| /* Check we can represent the target in the instruction format */ | |
| if (!is_offset_in_branch_range(offset)) | |
| return 1; | |
| /* Mask out the flags and target, so they don't step on each other. */ | |
| *instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC)); | |
| return 0; | |
| } | |
| int create_cond_branch(struct ppc_inst *instr, const struct ppc_inst *addr, | |
| unsigned long target, int flags) | |
| { | |
| long offset; | |
| offset = target; | |
| if (! (flags & BRANCH_ABSOLUTE)) | |
| offset = offset - (unsigned long)addr; | |
| /* Check we can represent the target in the instruction format */ | |
| if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) | |
| return 1; | |
| /* Mask out the flags and target, so they don't step on each other. */ | |
| *instr = ppc_inst(0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC)); | |
| return 0; | |
| } | |
| static unsigned int branch_opcode(struct ppc_inst instr) | |
| { | |
| return ppc_inst_primary_opcode(instr) & 0x3F; | |
| } | |
| static int instr_is_branch_iform(struct ppc_inst instr) | |
| { | |
| return branch_opcode(instr) == 18; | |
| } | |
| static int instr_is_branch_bform(struct ppc_inst instr) | |
| { | |
| return branch_opcode(instr) == 16; | |
| } | |
| int instr_is_relative_branch(struct ppc_inst instr) | |
| { | |
| if (ppc_inst_val(instr) & BRANCH_ABSOLUTE) | |
| return 0; | |
| return instr_is_branch_iform(instr) || instr_is_branch_bform(instr); | |
| } | |
| int instr_is_relative_link_branch(struct ppc_inst instr) | |
| { | |
| return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK); | |
| } | |
| static unsigned long branch_iform_target(const struct ppc_inst *instr) | |
| { | |
| signed long imm; | |
| imm = ppc_inst_val(*instr) & 0x3FFFFFC; | |
| /* If the top bit of the immediate value is set this is negative */ | |
| if (imm & 0x2000000) | |
| imm -= 0x4000000; | |
| if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0) | |
| imm += (unsigned long)instr; | |
| return (unsigned long)imm; | |
| } | |
| static unsigned long branch_bform_target(const struct ppc_inst *instr) | |
| { | |
| signed long imm; | |
| imm = ppc_inst_val(*instr) & 0xFFFC; | |
| /* If the top bit of the immediate value is set this is negative */ | |
| if (imm & 0x8000) | |
| imm -= 0x10000; | |
| if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0) | |
| imm += (unsigned long)instr; | |
| return (unsigned long)imm; | |
| } | |
| unsigned long branch_target(const struct ppc_inst *instr) | |
| { | |
| if (instr_is_branch_iform(ppc_inst_read(instr))) | |
| return branch_iform_target(instr); | |
| else if (instr_is_branch_bform(ppc_inst_read(instr))) | |
| return branch_bform_target(instr); | |
| return 0; | |
| } | |
| int instr_is_branch_to_addr(const struct ppc_inst *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; | |
| } | |
| int translate_branch(struct ppc_inst *instr, const struct ppc_inst *dest, | |
| const struct ppc_inst *src) | |
| { | |
| unsigned long target; | |
| target = branch_target(src); | |
| if (instr_is_branch_iform(ppc_inst_read(src))) | |
| return create_branch(instr, dest, target, | |
| ppc_inst_val(ppc_inst_read(src))); | |
| else if (instr_is_branch_bform(ppc_inst_read(src))) | |
| return create_cond_branch(instr, dest, target, | |
| ppc_inst_val(ppc_inst_read(src))); | |
| return 1; | |
| } | |
| #ifdef CONFIG_PPC_BOOK3E_64 | |
| void __patch_exception(int exc, unsigned long addr) | |
| { | |
| extern unsigned int interrupt_base_book3e; | |
| unsigned int *ibase = &interrupt_base_book3e; | |
| /* Our exceptions vectors start with a NOP and -then- a branch | |
| * to deal with single stepping from userspace which stops on | |
| * the second instruction. Thus we need to patch the second | |
| * instruction of the exception, not the first one | |
| */ | |
| patch_branch((struct ppc_inst *)(ibase + (exc / 4) + 1), addr, 0); | |
| } | |
| #endif | |
| #ifdef CONFIG_CODE_PATCHING_SELFTEST | |
| static void __init test_trampoline(void) | |
| { | |
| asm ("nop;\n"); | |
| } | |
| #define check(x) \ | |
| if (!(x)) printk("code-patching: test failed at line %d\n", __LINE__); | |
| static void __init test_branch_iform(void) | |
| { | |
| int err; | |
| struct ppc_inst instr; | |
| unsigned long addr; | |
| addr = (unsigned long)&instr; | |
| /* 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 */ | |
| instr = ppc_inst(0x48000103); | |
| check(instr_is_branch_to_addr(&instr, 0x100)); | |
| /* Absolute branch to 0x420fc */ | |
| instr = ppc_inst(0x480420ff); | |
| check(instr_is_branch_to_addr(&instr, 0x420fc)); | |
| /* Maximum positive relative branch, + 20MB - 4B */ | |
| instr = ppc_inst(0x49fffffc); | |
| check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC)); | |
| /* Smallest negative relative branch, - 4B */ | |
| instr = ppc_inst(0x4bfffffc); | |
| check(instr_is_branch_to_addr(&instr, addr - 4)); | |
| /* Largest negative relative branch, - 32 MB */ | |
| instr = ppc_inst(0x4a000000); | |
| check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); | |
| /* Branch to self, with link */ | |
| err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK); | |
| check(instr_is_branch_to_addr(&instr, addr)); | |
| /* Branch to self - 0x100, with link */ | |
| err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK); | |
| check(instr_is_branch_to_addr(&instr, addr - 0x100)); | |
| /* Branch to self + 0x100, no link */ | |
| err = create_branch(&instr, &instr, addr + 0x100, 0); | |
| check(instr_is_branch_to_addr(&instr, addr + 0x100)); | |
| /* Maximum relative negative offset, - 32 MB */ | |
| err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK); | |
| check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); | |
| /* Out of range relative negative offset, - 32 MB + 4*/ | |
| err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK); | |
| check(err); | |
| /* Out of range relative positive offset, + 32 MB */ | |
| err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK); | |
| check(err); | |
| /* Unaligned target */ | |
| err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK); | |
| check(err); | |
| /* Check flags are masked correctly */ | |
| err = create_branch(&instr, &instr, addr, 0xFFFFFFFC); | |
| check(instr_is_branch_to_addr(&instr, addr)); | |
| check(ppc_inst_equal(instr, ppc_inst(0x48000000))); | |
| } | |
| static void __init test_create_function_call(void) | |
| { | |
| struct ppc_inst *iptr; | |
| unsigned long dest; | |
| struct ppc_inst instr; | |
| /* Check we can create a function call */ | |
| iptr = (struct ppc_inst *)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; | |
| struct ppc_inst *iptr, instr; | |
| unsigned int flags; | |
| iptr = &instr; | |
| 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 */ | |
| instr = ppc_inst(0x43ff0103); | |
| check(instr_is_branch_to_addr(&instr, 0x100)); | |
| /* Absolute conditional branch to 0x20fc */ | |
| instr = ppc_inst(0x43ff20ff); | |
| check(instr_is_branch_to_addr(&instr, 0x20fc)); | |
| /* Maximum positive relative conditional branch, + 32 KB - 4B */ | |
| instr = ppc_inst(0x43ff7ffc); | |
| check(instr_is_branch_to_addr(&instr, addr + 0x7FFC)); | |
| /* Smallest negative relative conditional branch, - 4B */ | |
| instr = ppc_inst(0x43fffffc); | |
| check(instr_is_branch_to_addr(&instr, addr - 4)); | |
| /* Largest negative relative conditional branch, - 32 KB */ | |
| instr = ppc_inst(0x43ff8000); | |
| check(instr_is_branch_to_addr(&instr, addr - 0x8000)); | |
| /* All condition code bits set & link */ | |
| flags = 0x3ff000 | BRANCH_SET_LINK; | |
| /* Branch to self */ | |
| err = create_cond_branch(&instr, iptr, addr, flags); | |
| check(instr_is_branch_to_addr(&instr, addr)); | |
| /* Branch to self - 0x100 */ | |
| err = create_cond_branch(&instr, iptr, addr - 0x100, flags); | |
| check(instr_is_branch_to_addr(&instr, addr - 0x100)); | |
| /* Branch to self + 0x100 */ | |
| err = create_cond_branch(&instr, iptr, addr + 0x100, flags); | |
| check(instr_is_branch_to_addr(&instr, addr + 0x100)); | |
| /* Maximum relative negative offset, - 32 KB */ | |
| err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); | |
| check(instr_is_branch_to_addr(&instr, 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); | |
| check(instr_is_branch_to_addr(&instr, addr)); | |
| check(ppc_inst_equal(instr, ppc_inst(0x43FF0000))); | |
| } | |
| static void __init test_translate_branch(void) | |
| { | |
| unsigned long addr; | |
| void *p, *q; | |
| struct ppc_inst 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; | |
| patch_branch(p, addr, 0); | |
| check(instr_is_branch_to_addr(p, addr)); | |
| q = p + 4; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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; | |
| patch_branch(p, addr, 0); | |
| q = buf + 0x2000000; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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; | |
| patch_branch(p, addr, 0); | |
| q = buf + 4; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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; | |
| patch_branch(p, addr, BRANCH_SET_LINK); | |
| q = buf + 0x1400000; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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; | |
| patch_branch(p, addr, 0); | |
| q = buf + 4; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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); | |
| patch_instruction(p, instr); | |
| check(instr_is_branch_to_addr(p, addr)); | |
| q = buf + 4; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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); | |
| patch_instruction(p, instr); | |
| q = buf + 0x8000; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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); | |
| patch_instruction(p, instr); | |
| q = buf + 4; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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); | |
| patch_instruction(p, instr); | |
| q = buf + 0x5000; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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); | |
| patch_instruction(p, instr); | |
| q = buf + 4; | |
| translate_branch(&instr, q, p); | |
| patch_instruction(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); | |
| } | |
| #ifdef CONFIG_PPC64 | |
| static void __init test_prefixed_patching(void) | |
| { | |
| extern unsigned int code_patching_test1[]; | |
| extern unsigned int code_patching_test1_expected[]; | |
| extern unsigned int end_code_patching_test1[]; | |
| __patch_instruction((struct ppc_inst *)code_patching_test1, | |
| ppc_inst_prefix(OP_PREFIX << 26, 0x00000000), | |
| (struct ppc_inst *)code_patching_test1); | |
| check(!memcmp(code_patching_test1, | |
| code_patching_test1_expected, | |
| sizeof(unsigned int) * | |
| (end_code_patching_test1 - code_patching_test1))); | |
| } | |
| #else | |
| static inline void test_prefixed_patching(void) {} | |
| #endif | |
| static int __init test_code_patching(void) | |
| { | |
| printk(KERN_DEBUG "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); | |
| #endif /* CONFIG_CODE_PATCHING_SELFTEST */ |