Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
os
linux
1/*
2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 */
14
15#include <linux/mm.h>
16#include <linux/pagemap.h>
17#include <linux/binfmts.h>
18#include <linux/compat.h>
19#include <linux/mman.h>
20#include <linux/elf.h>
21#include <asm/pgtable.h>
22#include <asm/pgalloc.h>
23#include <asm/sections.h>
24#include <asm/vdso.h>
25#include <arch/sim.h>
26
27/* Notify a running simulator, if any, that an exec just occurred. */
28static void sim_notify_exec(const char *binary_name)
29{
30 unsigned char c;
31 do {
32 c = *binary_name++;
33 __insn_mtspr(SPR_SIM_CONTROL,
34 (SIM_CONTROL_OS_EXEC
35 | (c << _SIM_CONTROL_OPERATOR_BITS)));
36
37 } while (c);
38}
39
40static int notify_exec(struct mm_struct *mm)
41{
42 char *buf, *path;
43 struct vm_area_struct *vma;
44
45 if (!sim_is_simulator())
46 return 1;
47
48 if (mm->exe_file == NULL)
49 return 0;
50
51 for (vma = current->mm->mmap; ; vma = vma->vm_next) {
52 if (vma == NULL)
53 return 0;
54 if (vma->vm_file == mm->exe_file)
55 break;
56 }
57
58 buf = (char *) __get_free_page(GFP_KERNEL);
59 if (buf == NULL)
60 return 0;
61
62 path = d_path(&mm->exe_file->f_path, buf, PAGE_SIZE);
63 if (IS_ERR(path)) {
64 free_page((unsigned long)buf);
65 return 0;
66 }
67
68 /*
69 * Notify simulator of an ET_DYN object so we know the load address.
70 * The somewhat cryptic overuse of SIM_CONTROL_DLOPEN allows us
71 * to be backward-compatible with older simulator releases.
72 */
73 if (vma->vm_start == (ELF_ET_DYN_BASE & PAGE_MASK)) {
74 char buf[64];
75 int i;
76
77 snprintf(buf, sizeof(buf), "0x%lx:@", vma->vm_start);
78 for (i = 0; ; ++i) {
79 char c = buf[i];
80 __insn_mtspr(SPR_SIM_CONTROL,
81 (SIM_CONTROL_DLOPEN
82 | (c << _SIM_CONTROL_OPERATOR_BITS)));
83 if (c == '\0')
84 break;
85 }
86 }
87
88 sim_notify_exec(path);
89 free_page((unsigned long)buf);
90 return 1;
91}
92
93/* Notify a running simulator, if any, that we loaded an interpreter. */
94static void sim_notify_interp(unsigned long load_addr)
95{
96 size_t i;
97 for (i = 0; i < sizeof(load_addr); i++) {
98 unsigned char c = load_addr >> (i * 8);
99 __insn_mtspr(SPR_SIM_CONTROL,
100 (SIM_CONTROL_OS_INTERP
101 | (c << _SIM_CONTROL_OPERATOR_BITS)));
102 }
103}
104
105
106int arch_setup_additional_pages(struct linux_binprm *bprm,
107 int executable_stack)
108{
109 struct mm_struct *mm = current->mm;
110 int retval = 0;
111
112 down_write(&mm->mmap_sem);
113
114 /*
115 * Notify the simulator that an exec just occurred.
116 * If we can't find the filename of the mapping, just use
117 * whatever was passed as the linux_binprm filename.
118 */
119 if (!notify_exec(mm))
120 sim_notify_exec(bprm->filename);
121
122 retval = setup_vdso_pages();
123
124#ifndef __tilegx__
125 /*
126 * Set up a user-interrupt mapping here; the user can't
127 * create one themselves since it is above TASK_SIZE.
128 * We make it unwritable by default, so the model for adding
129 * interrupt vectors always involves an mprotect.
130 */
131 if (!retval) {
132 unsigned long addr = MEM_USER_INTRPT;
133 addr = mmap_region(NULL, addr, INTRPT_SIZE,
134 VM_READ|VM_EXEC|
135 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 0);
136 if (addr > (unsigned long) -PAGE_SIZE)
137 retval = (int) addr;
138 }
139#endif
140
141 up_write(&mm->mmap_sem);
142
143 return retval;
144}
145
146
147void elf_plat_init(struct pt_regs *regs, unsigned long load_addr)
148{
149 /* Zero all registers. */
150 memset(regs, 0, sizeof(*regs));
151
152 /* Report the interpreter's load address. */
153 sim_notify_interp(load_addr);
154}