--- zzzz-none-000/linux-2.6.19.2/arch/powerpc/mm/fault.c 2007-01-10 19:10:37.000000000 +0000 +++ davinci-8020-5505/linux-2.6.19.2/arch/powerpc/mm/fault.c 2007-01-19 14:42:56.000000000 +0000 @@ -28,6 +28,12 @@ #include #include #include +#include +#include +#include +#include +#include +#include #include #include @@ -73,6 +79,364 @@ } #endif +#ifdef CONFIG_PAX_EMUSIGRT +void pax_syscall_close(struct vm_area_struct * vma) +{ + vma->vm_mm->call_syscall = 0UL; +} + +static struct page* pax_syscall_nopage(struct vm_area_struct *vma, unsigned long address, int *type) +{ + struct page* page; + unsigned int *kaddr; + + page = alloc_page(GFP_HIGHUSER); + if (!page) + return NOPAGE_OOM; + + kaddr = kmap(page); + memset(kaddr, 0, PAGE_SIZE); + kaddr[0] = 0x44000002U; /* sc */ + __flush_dcache_icache(kaddr); + kunmap(page); + if (type) + *type = VM_FAULT_MAJOR; + return page; +} + +static struct vm_operations_struct pax_vm_ops = { + .close = pax_syscall_close, + .nopage = pax_syscall_nopage, +}; + +static int pax_insert_vma(struct vm_area_struct *vma, unsigned long addr) +{ + int ret; + + memset(vma, 0, sizeof(*vma)); + vma->vm_mm = current->mm; + vma->vm_start = addr; + vma->vm_end = addr + PAGE_SIZE; + vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC; + vma->vm_page_prot = protection_map[vma->vm_flags & (VM_READ|VM_WRITE|VM_EXEC)]; + vma->vm_ops = &pax_vm_ops; + + ret = insert_vm_struct(current->mm, vma); + if (ret) + return ret; + + ++current->mm->total_vm; + return 0; +} +#endif + +#ifdef CONFIG_PAX_PAGEEXEC +/* + * PaX: decide what to do with offenders (regs->nip = fault address) + * + * returns 1 when task should be killed + * 2 when patched GOT trampoline was detected + * 3 when patched PLT trampoline was detected + * 4 when unpatched PLT trampoline was detected + * 5 when sigreturn trampoline was detected + * 6 when rt_sigreturn trampoline was detected + */ +static int pax_handle_fetch_fault(struct pt_regs *regs) +{ + +#if defined(CONFIG_PAX_EMUPLT) || defined(CONFIG_PAX_EMUSIGRT) + int err; +#endif + +#ifdef CONFIG_PAX_EMUPLT + do { /* PaX: patched GOT emulation */ + unsigned int blrl; + + err = get_user(blrl, (unsigned int*)regs->nip); + + if (!err && blrl == 0x4E800021U) { + unsigned long temp = regs->nip; + + regs->nip = regs->link & 0xFFFFFFFCUL; + regs->link = temp + 4UL; + return 2; + } + } while (0); + + do { /* PaX: patched PLT emulation #1 */ + unsigned int b; + + err = get_user(b, (unsigned int *)regs->nip); + + if (!err && (b & 0xFC000003U) == 0x48000000U) { + regs->nip += (((b | 0xFC000000UL) ^ 0x02000000UL) + 0x02000000UL); + return 3; + } + } while (0); + + do { /* PaX: unpatched PLT emulation #1 */ + unsigned int li, b; + + err = get_user(li, (unsigned int *)regs->nip); + err |= get_user(b, (unsigned int *)(regs->nip+4)); + + if (!err && (li & 0xFFFF0000U) == 0x39600000U && (b & 0xFC000003U) == 0x48000000U) { + unsigned int rlwinm, add, li2, addis2, mtctr, li3, addis3, bctr; + unsigned long addr = b | 0xFC000000UL; + + addr = regs->nip + 4 + ((addr ^ 0x02000000UL) + 0x02000000UL); + err = get_user(rlwinm, (unsigned int*)addr); + err |= get_user(add, (unsigned int*)(addr+4)); + err |= get_user(li2, (unsigned int*)(addr+8)); + err |= get_user(addis2, (unsigned int*)(addr+12)); + err |= get_user(mtctr, (unsigned int*)(addr+16)); + err |= get_user(li3, (unsigned int*)(addr+20)); + err |= get_user(addis3, (unsigned int*)(addr+24)); + err |= get_user(bctr, (unsigned int*)(addr+28)); + + if (err) + break; + + if (rlwinm == 0x556C083CU && + add == 0x7D6C5A14U && + (li2 & 0xFFFF0000U) == 0x39800000U && + (addis2 & 0xFFFF0000U) == 0x3D8C0000U && + mtctr == 0x7D8903A6U && + (li3 & 0xFFFF0000U) == 0x39800000U && + (addis3 & 0xFFFF0000U) == 0x3D8C0000U && + bctr == 0x4E800420U) + { + regs->gpr[PT_R11] = 3 * (((li | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + regs->gpr[PT_R12] = (((li3 | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + regs->gpr[PT_R12] += (addis3 & 0xFFFFU) << 16; + regs->ctr = (((li2 | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + regs->ctr += (addis2 & 0xFFFFU) << 16; + regs->nip = regs->ctr; + return 4; + } + } + } while (0); + +#if 0 + do { /* PaX: unpatched PLT emulation #2 */ + unsigned int lis, lwzu, b, bctr; + + err = get_user(lis, (unsigned int *)regs->nip); + err |= get_user(lwzu, (unsigned int *)(regs->nip+4)); + err |= get_user(b, (unsigned int *)(regs->nip+8)); + err |= get_user(bctr, (unsigned int *)(regs->nip+12)); + + if (err) + break; + + if ((lis & 0xFFFF0000U) == 0x39600000U && + (lwzu & 0xU) == 0xU && + (b & 0xFC000003U) == 0x48000000U && + bctr == 0x4E800420U) + { + unsigned int addis, addi, rlwinm, add, li2, addis2, mtctr, li3, addis3, bctr; + unsigned long addr = b | 0xFC000000UL; + + addr = regs->nip + 12 + ((addr ^ 0x02000000UL) + 0x02000000UL); + err = get_user(addis, (unsigned int*)addr); + err |= get_user(addi, (unsigned int*)(addr+4)); + err |= get_user(rlwinm, (unsigned int*)(addr+8)); + err |= get_user(add, (unsigned int*)(addr+12)); + err |= get_user(li2, (unsigned int*)(addr+16)); + err |= get_user(addis2, (unsigned int*)(addr+20)); + err |= get_user(mtctr, (unsigned int*)(addr+24)); + err |= get_user(li3, (unsigned int*)(addr+28)); + err |= get_user(addis3, (unsigned int*)(addr+32)); + err |= get_user(bctr, (unsigned int*)(addr+36)); + + if (err) + break; + + if ((addis & 0xFFFF0000U) == 0x3D6B0000U && + (addi & 0xFFFF0000U) == 0x396B0000U && + rlwinm == 0x556C083CU && + add == 0x7D6C5A14U && + (li2 & 0xFFFF0000U) == 0x39800000U && + (addis2 & 0xFFFF0000U) == 0x3D8C0000U && + mtctr == 0x7D8903A6U && + (li3 & 0xFFFF0000U) == 0x39800000U && + (addis3 & 0xFFFF0000U) == 0x3D8C0000U && + bctr == 0x4E800420U) + { + regs->gpr[PT_R11] = + regs->gpr[PT_R11] = 3 * (((li | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + regs->gpr[PT_R12] = (((li3 | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + regs->gpr[PT_R12] += (addis3 & 0xFFFFU) << 16; + regs->ctr = (((li2 | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + regs->ctr += (addis2 & 0xFFFFU) << 16; + regs->nip = regs->ctr; + return 4; + } + } + } while (0); +#endif + + do { /* PaX: unpatched PLT emulation #3 */ + unsigned int li, b; + + err = get_user(li, (unsigned int *)regs->nip); + err |= get_user(b, (unsigned int *)(regs->nip+4)); + + if (!err && (li & 0xFFFF0000U) == 0x39600000U && (b & 0xFC000003U) == 0x48000000U) { + unsigned int addis, lwz, mtctr, bctr; + unsigned long addr = b | 0xFC000000UL; + + addr = regs->nip + 4 + ((addr ^ 0x02000000UL) + 0x02000000UL); + err = get_user(addis, (unsigned int*)addr); + err |= get_user(lwz, (unsigned int*)(addr+4)); + err |= get_user(mtctr, (unsigned int*)(addr+8)); + err |= get_user(bctr, (unsigned int*)(addr+12)); + + if (err) + break; + + if ((addis & 0xFFFF0000U) == 0x3D6B0000U && + (lwz & 0xFFFF0000U) == 0x816B0000U && + mtctr == 0x7D6903A6U && + bctr == 0x4E800420U) + { + unsigned int r11; + + addr = (addis << 16) + (((li | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + addr += (((lwz | 0xFFFF0000UL) ^ 0x00008000UL) + 0x00008000UL); + + err = get_user(r11, (unsigned int*)addr); + if (err) + break; + + regs->gpr[PT_R11] = r11; + regs->ctr = r11; + regs->nip = r11; + return 4; + } + } + } while (0); +#endif + +#ifdef CONFIG_PAX_EMUSIGRT + do { /* PaX: sigreturn emulation */ + unsigned int li, sc; + + err = get_user(li, (unsigned int *)regs->nip); + err |= get_user(sc, (unsigned int *)(regs->nip+4)); + + if (!err && li == 0x38000000U + __NR_sigreturn && sc == 0x44000002U) { + struct vm_area_struct *vma; + unsigned long call_syscall; + + down_read(¤t->mm->mmap_sem); + call_syscall = current->mm->call_syscall; + up_read(¤t->mm->mmap_sem); + if (likely(call_syscall)) + goto emulate; + + vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); + + down_write(¤t->mm->mmap_sem); + if (current->mm->call_syscall) { + call_syscall = current->mm->call_syscall; + up_write(¤t->mm->mmap_sem); + if (vma) kmem_cache_free(vm_area_cachep, vma); + goto emulate; + } + + call_syscall = get_unmapped_area(NULL, 0UL, PAGE_SIZE, 0UL, MAP_PRIVATE); + if (!vma || (call_syscall & ~PAGE_MASK)) { + up_write(¤t->mm->mmap_sem); + if (vma) kmem_cache_free(vm_area_cachep, vma); + return 1; + } + + if (pax_insert_vma(vma, call_syscall)) { + up_write(¤t->mm->mmap_sem); + kmem_cache_free(vm_area_cachep, vma); + return 1; + } + + current->mm->call_syscall = call_syscall; + up_write(¤t->mm->mmap_sem); + +emulate: + regs->gpr[PT_R0] = __NR_sigreturn; + regs->nip = call_syscall; + return 5; + } + } while (0); + + do { /* PaX: rt_sigreturn emulation */ + unsigned int li, sc; + + err = get_user(li, (unsigned int *)regs->nip); + err |= get_user(sc, (unsigned int *)(regs->nip+4)); + + if (!err && li == 0x38000000U + __NR_rt_sigreturn && sc == 0x44000002U) { + struct vm_area_struct *vma; + unsigned int call_syscall; + + down_read(¤t->mm->mmap_sem); + call_syscall = current->mm->call_syscall; + up_read(¤t->mm->mmap_sem); + if (likely(call_syscall)) + goto rt_emulate; + + vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); + + down_write(¤t->mm->mmap_sem); + if (current->mm->call_syscall) { + call_syscall = current->mm->call_syscall; + up_write(¤t->mm->mmap_sem); + if (vma) kmem_cache_free(vm_area_cachep, vma); + goto rt_emulate; + } + + call_syscall = get_unmapped_area(NULL, 0UL, PAGE_SIZE, 0UL, MAP_PRIVATE); + if (!vma || (call_syscall & ~PAGE_MASK)) { + up_write(¤t->mm->mmap_sem); + if (vma) kmem_cache_free(vm_area_cachep, vma); + return 1; + } + + if (pax_insert_vma(vma, call_syscall)) { + up_write(¤t->mm->mmap_sem); + kmem_cache_free(vm_area_cachep, vma); + return 1; + } + + current->mm->call_syscall = call_syscall; + up_write(¤t->mm->mmap_sem); + +rt_emulate: + regs->gpr[PT_R0] = __NR_rt_sigreturn; + regs->nip = call_syscall; + return 6; + } + } while (0); +#endif + + return 1; +} + +void pax_report_insns(void *pc, void *sp) +{ + unsigned long i; + + printk(KERN_ERR "PAX: bytes at PC: "); + for (i = 0; i < 5; i++) { + unsigned int c; + if (get_user(c, (unsigned int*)pc+i)) + printk("???????? "); + else + printk("%08x ", c); + } + printk("\n"); +} +#endif + /* * Check whether the instruction at regs->nip is a store using * an update addressing form which will update r1. @@ -168,7 +532,7 @@ * indicate errors in DSISR but can validly be set in SRR1. */ if (trap == 0x400) - error_code &= 0x48200000; + error_code &= 0x58200000; else is_write = error_code & DSISR_ISSTORE; #else @@ -295,9 +659,9 @@ /* protection fault */ if (error_code & DSISR_PROTFAULT) goto bad_area; +#endif if (!(vma->vm_flags & VM_EXEC)) goto bad_area; -#endif #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) pte_t *ptep; pmd_t *pmdp; @@ -368,6 +732,37 @@ bad_area_nosemaphore: /* User mode accesses cause a SIGSEGV */ if (user_mode(regs)) { + +#ifdef CONFIG_PAX_PAGEEXEC + if (mm->pax_flags & MF_PAX_PAGEEXEC) { +#ifdef CONFIG_PPC64 + if (is_exec && (error_code & DSISR_PROTFAULT)) { +#else + if (is_exec && regs->nip == address) { +#endif + switch (pax_handle_fetch_fault(regs)) { + +#ifdef CONFIG_PAX_EMUPLT + case 2: + case 3: + case 4: + return 0; +#endif + +#ifdef CONFIG_PAX_EMUSIGRT + case 5: + case 6: + return 0; +#endif + + } + + pax_report_fault(regs, (void*)regs->nip, (void*)regs->gpr[PT_R1]); + do_exit(SIGKILL); + } + } +#endif + _exception(SIGSEGV, regs, code, address); return 0; }