diff options
Diffstat (limited to 'arch/tile/mm/elf.c')
| -rw-r--r-- | arch/tile/mm/elf.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/arch/tile/mm/elf.c b/arch/tile/mm/elf.c new file mode 100644 index 0000000..55e58e9 --- /dev/null +++ b/arch/tile/mm/elf.c @@ -0,0 +1,164 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/mm.h> +#include <linux/pagemap.h> +#include <linux/binfmts.h> +#include <linux/compat.h> +#include <linux/mman.h> +#include <linux/elf.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/sections.h> + +/* Notify a running simulator, if any, that an exec just occurred. */ +static void sim_notify_exec(const char *binary_name) +{ + unsigned char c; + do { + c = *binary_name++; + __insn_mtspr(SPR_SIM_CONTROL, + (SIM_CONTROL_OS_EXEC + | (c << _SIM_CONTROL_OPERATOR_BITS))); + + } while (c); +} + +static int notify_exec(void) +{ + int retval = 0; /* failure */ + struct vm_area_struct *vma = current->mm->mmap; + while (vma) { + if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) + break; + vma = vma->vm_next; + } + if (vma) { + char *buf = (char *) __get_free_page(GFP_KERNEL); + if (buf) { + char *path = d_path(&vma->vm_file->f_path, + buf, PAGE_SIZE); + if (!IS_ERR(path)) { + sim_notify_exec(path); + retval = 1; + } + free_page((unsigned long)buf); + } + } + return retval; +} + +/* Notify a running simulator, if any, that we loaded an interpreter. */ +static void sim_notify_interp(unsigned long load_addr) +{ + size_t i; + for (i = 0; i < sizeof(load_addr); i++) { + unsigned char c = load_addr >> (i * 8); + __insn_mtspr(SPR_SIM_CONTROL, + (SIM_CONTROL_OS_INTERP + | (c << _SIM_CONTROL_OPERATOR_BITS))); + } +} + + +/* Kernel address of page used to map read-only kernel data into userspace. */ +static void *vdso_page; + +/* One-entry array used for install_special_mapping. */ +static struct page *vdso_pages[1]; + +static int __init vdso_setup(void) +{ + vdso_page = (void *)get_zeroed_page(GFP_ATOMIC); + memcpy(vdso_page, __rt_sigreturn, __rt_sigreturn_end - __rt_sigreturn); + vdso_pages[0] = virt_to_page(vdso_page); + return 0; +} +device_initcall(vdso_setup); + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + if (vma->vm_private_data == vdso_pages) + return "[vdso]"; +#ifndef __tilegx__ + if (vma->vm_start == MEM_USER_INTRPT) + return "[intrpt]"; +#endif + return NULL; +} + +int arch_setup_additional_pages(struct linux_binprm *bprm, + int executable_stack) +{ + struct mm_struct *mm = current->mm; + unsigned long vdso_base; + int retval = 0; + + /* + * Notify the simulator that an exec just occurred. + * If we can't find the filename of the mapping, just use + * whatever was passed as the linux_binprm filename. + */ + if (!notify_exec()) + sim_notify_exec(bprm->filename); + + down_write(&mm->mmap_sem); + + /* + * MAYWRITE to allow gdb to COW and set breakpoints + * + * Make sure the vDSO gets into every core dump. Dumping its + * contents makes post-mortem fully interpretable later + * without matching up the same kernel and hardware config to + * see what PC values meant. + */ + vdso_base = VDSO_BASE; + retval = install_special_mapping(mm, vdso_base, PAGE_SIZE, + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| + VM_ALWAYSDUMP, + vdso_pages); + +#ifndef __tilegx__ + /* + * Set up a user-interrupt mapping here; the user can't + * create one themselves since it is above TASK_SIZE. + * We make it unwritable by default, so the model for adding + * interrupt vectors always involves an mprotect. + */ + if (!retval) { + unsigned long addr = MEM_USER_INTRPT; + addr = mmap_region(NULL, addr, INTRPT_SIZE, + MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE, + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 0); + if (addr > (unsigned long) -PAGE_SIZE) + retval = (int) addr; + } +#endif + + up_write(&mm->mmap_sem); + + return retval; +} + + +void elf_plat_init(struct pt_regs *regs, unsigned long load_addr) +{ + /* Zero all registers. */ + memset(regs, 0, sizeof(*regs)); + + /* Report the interpreter's load address. */ + sim_notify_interp(load_addr); +} |