diff options
Diffstat (limited to 'arch/powerpc/lib/code-patching.c')
| -rw-r--r-- | arch/powerpc/lib/code-patching.c | 497 |
1 files changed, 49 insertions, 448 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index c5ed98823835..906d43463366 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -3,22 +3,18 @@ * 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(u32 *exec_addr, struct ppc_inst instr, u32 *patch_addr) +static int __patch_instruction(u32 *exec_addr, ppc_inst_t instr, u32 *patch_addr) { if (!ppc_inst_prefixed(instr)) { u32 val = ppc_inst_val(instr); @@ -39,7 +35,7 @@ failed: return -EFAULT; } -int raw_patch_instruction(u32 *addr, struct ppc_inst instr) +int raw_patch_instruction(u32 *addr, ppc_inst_t instr) { return __patch_instruction(addr, instr, addr); } @@ -86,23 +82,16 @@ void __init poking_init(void) 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; + return map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL); } -static inline int unmap_patch_area(unsigned long addr) +static void unmap_patch_area(unsigned long addr) { pte_t *ptep; pmd_t *pmdp; @@ -111,43 +100,56 @@ static inline int unmap_patch_area(unsigned long addr) pgd_t *pgdp; pgdp = pgd_offset_k(addr); - if (unlikely(!pgdp)) - return -EINVAL; + if (WARN_ON(pgd_none(*pgdp))) + return; p4dp = p4d_offset(pgdp, addr); - if (unlikely(!p4dp)) - return -EINVAL; + if (WARN_ON(p4d_none(*p4dp))) + return; pudp = pud_offset(p4dp, addr); - if (unlikely(!pudp)) - return -EINVAL; + if (WARN_ON(pud_none(*pudp))) + return; pmdp = pmd_offset(pudp, addr); - if (unlikely(!pmdp)) - return -EINVAL; + if (WARN_ON(pmd_none(*pmdp))) + return; 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); + if (WARN_ON(pte_none(*ptep))) + return; /* * 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(u32 *addr, ppc_inst_t instr) +{ + int err; + u32 *patch_addr; + unsigned long text_poke_addr; + + text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr; + patch_addr = (u32 *)(text_poke_addr + offset_in_page(addr)); + + err = map_patch_area(addr, text_poke_addr); + if (err) + return err; + + err = __patch_instruction(addr, instr, patch_addr); + + unmap_patch_area(text_poke_addr); + + return err; } -static int do_patch_instruction(u32 *addr, struct ppc_inst instr) +static int do_patch_instruction(u32 *addr, ppc_inst_t instr) { int err; - u32 *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 @@ -158,51 +160,37 @@ static int do_patch_instruction(u32 *addr, struct ppc_inst instr) 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 = (u32 *)(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: + err = __do_patch_instruction(addr, instr); local_irq_restore(flags); return err; } #else /* !CONFIG_STRICT_KERNEL_RWX */ -static int do_patch_instruction(u32 *addr, struct ppc_inst instr) +static int do_patch_instruction(u32 *addr, ppc_inst_t instr) { return raw_patch_instruction(addr, instr); } #endif /* CONFIG_STRICT_KERNEL_RWX */ -int patch_instruction(u32 *addr, struct ppc_inst instr) +int patch_instruction(u32 *addr, ppc_inst_t 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); + if (system_state >= SYSTEM_FREEING_INITMEM && init_section_contains(addr, 4)) return 0; - } + return do_patch_instruction(addr, instr); } NOKPROBE_SYMBOL(patch_instruction); int patch_branch(u32 *addr, unsigned long target, int flags) { - struct ppc_inst instr; + ppc_inst_t instr; + + if (create_branch(&instr, addr, target, flags)) + return -ERANGE; - create_branch(&instr, addr, target, flags); return patch_instruction(addr, instr); } @@ -237,7 +225,7 @@ bool is_offset_in_cond_branch_range(long offset) * 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) +bool is_conditional_branch(ppc_inst_t instr) { unsigned int opcode = ppc_inst_primary_opcode(instr); @@ -255,7 +243,7 @@ bool is_conditional_branch(struct ppc_inst instr) } NOKPROBE_SYMBOL(is_conditional_branch); -int create_branch(struct ppc_inst *instr, const u32 *addr, +int create_branch(ppc_inst_t *instr, const u32 *addr, unsigned long target, int flags) { long offset; @@ -275,7 +263,7 @@ int create_branch(struct ppc_inst *instr, const u32 *addr, return 0; } -int create_cond_branch(struct ppc_inst *instr, const u32 *addr, +int create_cond_branch(ppc_inst_t *instr, const u32 *addr, unsigned long target, int flags) { long offset; @@ -294,22 +282,7 @@ int create_cond_branch(struct ppc_inst *instr, const u32 *addr, 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) +int instr_is_relative_branch(ppc_inst_t instr) { if (ppc_inst_val(instr) & BRANCH_ABSOLUTE) return 0; @@ -317,7 +290,7 @@ int instr_is_relative_branch(struct ppc_inst instr) return instr_is_branch_iform(instr) || instr_is_branch_bform(instr); } -int instr_is_relative_link_branch(struct ppc_inst instr) +int instr_is_relative_link_branch(ppc_inst_t instr) { return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK); } @@ -364,7 +337,7 @@ unsigned long branch_target(const u32 *instr) return 0; } -int translate_branch(struct ppc_inst *instr, const u32 *dest, const u32 *src) +int translate_branch(ppc_inst_t *instr, const u32 *dest, const u32 *src) { unsigned long target; target = branch_target(src); @@ -378,375 +351,3 @@ int translate_branch(struct ppc_inst *instr, const u32 *dest, const u32 *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(ibase + (exc / 4) + 1, addr, 0); -} -#endif - -#ifdef CONFIG_CODE_PATCHING_SELFTEST - -static int 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;\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; - 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 */ - patch_instruction(iptr, ppc_inst(0x48000103)); - check(instr_is_branch_to_addr(iptr, 0x100)); - /* Absolute branch to 0x420fc */ - patch_instruction(iptr, ppc_inst(0x480420ff)); - check(instr_is_branch_to_addr(iptr, 0x420fc)); - /* Maximum positive relative branch, + 20MB - 4B */ - patch_instruction(iptr, ppc_inst(0x49fffffc)); - check(instr_is_branch_to_addr(iptr, addr + 0x1FFFFFC)); - /* Smallest negative relative branch, - 4B */ - patch_instruction(iptr, ppc_inst(0x4bfffffc)); - check(instr_is_branch_to_addr(iptr, addr - 4)); - /* Largest negative relative branch, - 32 MB */ - patch_instruction(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); - patch_instruction(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); - patch_instruction(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); - patch_instruction(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); - patch_instruction(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); - patch_instruction(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; - struct ppc_inst 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; - struct ppc_inst 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 */ - patch_instruction(iptr, ppc_inst(0x43ff0103)); - check(instr_is_branch_to_addr(iptr, 0x100)); - /* Absolute conditional branch to 0x20fc */ - patch_instruction(iptr, ppc_inst(0x43ff20ff)); - check(instr_is_branch_to_addr(iptr, 0x20fc)); - /* Maximum positive relative conditional branch, + 32 KB - 4B */ - patch_instruction(iptr, ppc_inst(0x43ff7ffc)); - check(instr_is_branch_to_addr(iptr, addr + 0x7FFC)); - /* Smallest negative relative conditional branch, - 4B */ - patch_instruction(iptr, ppc_inst(0x43fffffc)); - check(instr_is_branch_to_addr(iptr, addr - 4)); - /* Largest negative relative conditional branch, - 32 KB */ - patch_instruction(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); - patch_instruction(iptr, instr); - check(instr_is_branch_to_addr(iptr, addr)); - - /* Branch to self - 0x100 */ - err = create_cond_branch(&instr, iptr, addr - 0x100, flags); - patch_instruction(iptr, instr); - check(instr_is_branch_to_addr(iptr, addr - 0x100)); - - /* Branch to self + 0x100 */ - err = create_cond_branch(&instr, iptr, addr + 0x100, flags); - patch_instruction(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); - patch_instruction(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); - patch_instruction(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; - 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(code_patching_test1, - ppc_inst_prefix(OP_PREFIX << 26, 0x00000000), - 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 */ |