| // 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 */ |