PageRenderTime 33ms CodeModel.GetById 13ms app.highlight 16ms RepoModel.GetById 1ms app.codeStats 0ms

/arch/um/os-Linux/skas/mem.c

http://github.com/mirrors/linux
C | 207 lines | 157 code | 35 blank | 15 comment | 17 complexity | a9c97ec889a8229052b1ef171c156cdd MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  4 */
  5
  6#include <stddef.h>
  7#include <unistd.h>
  8#include <errno.h>
  9#include <string.h>
 10#include <sys/mman.h>
 11#include <init.h>
 12#include <as-layout.h>
 13#include <mm_id.h>
 14#include <os.h>
 15#include <ptrace_user.h>
 16#include <registers.h>
 17#include <skas.h>
 18#include <sysdep/ptrace.h>
 19#include <sysdep/stub.h>
 20
 21extern char batch_syscall_stub[], __syscall_stub_start[];
 22
 23extern void wait_stub_done(int pid);
 24
 25static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
 26					      unsigned long *stack)
 27{
 28	if (stack == NULL) {
 29		stack = (unsigned long *) mm_idp->stack + 2;
 30		*stack = 0;
 31	}
 32	return stack;
 33}
 34
 35static unsigned long syscall_regs[MAX_REG_NR];
 36
 37static int __init init_syscall_regs(void)
 38{
 39	get_safe_registers(syscall_regs, NULL);
 40	syscall_regs[REGS_IP_INDEX] = STUB_CODE +
 41		((unsigned long) batch_syscall_stub -
 42		 (unsigned long) __syscall_stub_start);
 43	return 0;
 44}
 45
 46__initcall(init_syscall_regs);
 47
 48static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
 49{
 50	int n, i;
 51	long ret, offset;
 52	unsigned long * data;
 53	unsigned long * syscall;
 54	int err, pid = mm_idp->u.pid;
 55
 56	n = ptrace_setregs(pid, syscall_regs);
 57	if (n < 0) {
 58		printk(UM_KERN_ERR "Registers - \n");
 59		for (i = 0; i < MAX_REG_NR; i++)
 60			printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
 61		panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
 62		      -n);
 63	}
 64
 65	err = ptrace(PTRACE_CONT, pid, 0, 0);
 66	if (err)
 67		panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
 68		      errno);
 69
 70	wait_stub_done(pid);
 71
 72	/*
 73	 * When the stub stops, we find the following values on the
 74	 * beginning of the stack:
 75	 * (long )return_value
 76	 * (long )offset to failed sycall-data (0, if no error)
 77	 */
 78	ret = *((unsigned long *) mm_idp->stack);
 79	offset = *((unsigned long *) mm_idp->stack + 1);
 80	if (offset) {
 81		data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
 82		printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
 83		       "data = %p\n", ret, offset, data);
 84		syscall = (unsigned long *)((unsigned long)data + data[0]);
 85		printk(UM_KERN_ERR "do_syscall_stub: syscall %ld failed, "
 86		       "return value = 0x%lx, expected return value = 0x%lx\n",
 87		       syscall[0], ret, syscall[7]);
 88		printk(UM_KERN_ERR "    syscall parameters: "
 89		       "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
 90		       syscall[1], syscall[2], syscall[3],
 91		       syscall[4], syscall[5], syscall[6]);
 92		for (n = 1; n < data[0]/sizeof(long); n++) {
 93			if (n == 1)
 94				printk(UM_KERN_ERR "    additional syscall "
 95				       "data:");
 96			if (n % 4 == 1)
 97				printk("\n" UM_KERN_ERR "      ");
 98			printk("  0x%lx", data[n]);
 99		}
100		if (n > 1)
101			printk("\n");
102	}
103	else ret = 0;
104
105	*addr = check_init_stack(mm_idp, NULL);
106
107	return ret;
108}
109
110long run_syscall_stub(struct mm_id * mm_idp, int syscall,
111		      unsigned long *args, long expected, void **addr,
112		      int done)
113{
114	unsigned long *stack = check_init_stack(mm_idp, *addr);
115
116	*stack += sizeof(long);
117	stack += *stack / sizeof(long);
118
119	*stack++ = syscall;
120	*stack++ = args[0];
121	*stack++ = args[1];
122	*stack++ = args[2];
123	*stack++ = args[3];
124	*stack++ = args[4];
125	*stack++ = args[5];
126	*stack++ = expected;
127	*stack = 0;
128
129	if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
130		     UM_KERN_PAGE_SIZE - 10 * sizeof(long))) {
131		*addr = stack;
132		return 0;
133	}
134
135	return do_syscall_stub(mm_idp, addr);
136}
137
138long syscall_stub_data(struct mm_id * mm_idp,
139		       unsigned long *data, int data_count,
140		       void **addr, void **stub_addr)
141{
142	unsigned long *stack;
143	int ret = 0;
144
145	/*
146	 * If *addr still is uninitialized, it *must* contain NULL.
147	 * Thus in this case do_syscall_stub correctly won't be called.
148	 */
149	if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
150	   UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
151		ret = do_syscall_stub(mm_idp, addr);
152		/* in case of error, don't overwrite data on stack */
153		if (ret)
154			return ret;
155	}
156
157	stack = check_init_stack(mm_idp, *addr);
158	*addr = stack;
159
160	*stack = data_count * sizeof(long);
161
162	memcpy(stack + 1, data, data_count * sizeof(long));
163
164	*stub_addr = (void *)(((unsigned long)(stack + 1) &
165			       ~UM_KERN_PAGE_MASK) + STUB_DATA);
166
167	return 0;
168}
169
170int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
171	int phys_fd, unsigned long long offset, int done, void **data)
172{
173	int ret;
174	unsigned long args[] = { virt, len, prot,
175				 MAP_SHARED | MAP_FIXED, phys_fd,
176				 MMAP_OFFSET(offset) };
177
178	ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
179			       data, done);
180
181	return ret;
182}
183
184int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
185	  int done, void **data)
186{
187	int ret;
188	unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
189				 0 };
190
191	ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
192			       data, done);
193
194	return ret;
195}
196
197int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
198	    unsigned int prot, int done, void **data)
199{
200	int ret;
201	unsigned long args[] = { addr, len, prot, 0, 0, 0 };
202
203	ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
204			       data, done);
205
206	return ret;
207}