1 files changed, 207 insertions, 0 deletions
diff --git a/arch/um/os-Linux/skas/mem.c b/arch/um/os-Linux/skas/mem.c
new file mode 100644
index 000000000..c546d16f8
--- /dev/null
+++ b/arch/um/os-Linux/skas/mem.c
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <init.h>
+#include <as-layout.h>
+#include <mm_id.h>
+#include <os.h>
+#include <ptrace_user.h>
+#include <registers.h>
+#include <skas.h>
+#include <sysdep/ptrace.h>
+#include <sysdep/stub.h>
+
+extern char batch_syscall_stub[], __syscall_stub_start[];
+
+extern void wait_stub_done(int pid);
+
+static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
+					      unsigned long *stack)
+{
+	if (stack == NULL) {
+		stack = (unsigned long *) mm_idp->stack + 2;
+		*stack = 0;
+	}
+	return stack;
+}
+
+static unsigned long syscall_regs[MAX_REG_NR];
+
+static int __init init_syscall_regs(void)
+{
+	get_safe_registers(syscall_regs, NULL);
+	syscall_regs[REGS_IP_INDEX] = STUB_CODE +
+		((unsigned long) batch_syscall_stub -
+		 (unsigned long) __syscall_stub_start);
+	return 0;
+}
+
+__initcall(init_syscall_regs);
+
+static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
+{
+	int n, i;
+	long ret, offset;
+	unsigned long * data;
+	unsigned long * syscall;
+	int err, pid = mm_idp->u.pid;
+
+	n = ptrace_setregs(pid, syscall_regs);
+	if (n < 0) {
+		printk(UM_KERN_ERR "Registers - \n");
+		for (i = 0; i < MAX_REG_NR; i++)
+			printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
+		panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
+		      -n);
+	}
+
+	err = ptrace(PTRACE_CONT, pid, 0, 0);
+	if (err)
+		panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
+		      errno);
+
+	wait_stub_done(pid);
+
+	/*
+	 * When the stub stops, we find the following values on the
+	 * beginning of the stack:
+	 * (long )return_value
+	 * (long )offset to failed sycall-data (0, if no error)
+	 */
+	ret = *((unsigned long *) mm_idp->stack);
+	offset = *((unsigned long *) mm_idp->stack + 1);
+	if (offset) {
+		data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
+		printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
+		       "data = %p\n", ret, offset, data);
+		syscall = (unsigned long *)((unsigned long)data + data[0]);
+		printk(UM_KERN_ERR "do_syscall_stub: syscall %ld failed, "
+		       "return value = 0x%lx, expected return value = 0x%lx\n",
+		       syscall[0], ret, syscall[7]);
+		printk(UM_KERN_ERR "    syscall parameters: "
+		       "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
+		       syscall[1], syscall[2], syscall[3],
+		       syscall[4], syscall[5], syscall[6]);
+		for (n = 1; n < data[0]/sizeof(long); n++) {
+			if (n == 1)
+				printk(UM_KERN_ERR "    additional syscall "
+				       "data:");
+			if (n % 4 == 1)
+				printk("\n" UM_KERN_ERR "      ");
+			printk("  0x%lx", data[n]);
+		}
+		if (n > 1)
+			printk("\n");
+	}
+	else ret = 0;
+
+	*addr = check_init_stack(mm_idp, NULL);
+
+	return ret;
+}
+
+long run_syscall_stub(struct mm_id * mm_idp, int syscall,
+		      unsigned long *args, long expected, void **addr,
+		      int done)
+{
+	unsigned long *stack = check_init_stack(mm_idp, *addr);
+
+	*stack += sizeof(long);
+	stack += *stack / sizeof(long);
+
+	*stack++ = syscall;
+	*stack++ = args[0];
+	*stack++ = args[1];
+	*stack++ = args[2];
+	*stack++ = args[3];
+	*stack++ = args[4];
+	*stack++ = args[5];
+	*stack++ = expected;
+	*stack = 0;
+
+	if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
+		     UM_KERN_PAGE_SIZE - 10 * sizeof(long))) {
+		*addr = stack;
+		return 0;
+	}
+
+	return do_syscall_stub(mm_idp, addr);
+}
+
+long syscall_stub_data(struct mm_id * mm_idp,
+		       unsigned long *data, int data_count,
+		       void **addr, void **stub_addr)
+{
+	unsigned long *stack;
+	int ret = 0;
+
+	/*
+	 * If *addr still is uninitialized, it *must* contain NULL.
+	 * Thus in this case do_syscall_stub correctly won't be called.
+	 */
+	if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
+	   UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
+		ret = do_syscall_stub(mm_idp, addr);
+		/* in case of error, don't overwrite data on stack */
+		if (ret)
+			return ret;
+	}
+
+	stack = check_init_stack(mm_idp, *addr);
+	*addr = stack;
+
+	*stack = data_count * sizeof(long);
+
+	memcpy(stack + 1, data, data_count * sizeof(long));
+
+	*stub_addr = (void *)(((unsigned long)(stack + 1) &
+			       ~UM_KERN_PAGE_MASK) + STUB_DATA);
+
+	return 0;
+}
+
+int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
+	int phys_fd, unsigned long long offset, int done, void **data)
+{
+	int ret;
+	unsigned long args[] = { virt, len, prot,
+				 MAP_SHARED | MAP_FIXED, phys_fd,
+				 MMAP_OFFSET(offset) };
+
+	ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
+			       data, done);
+
+	return ret;
+}
+
+int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
+	  int done, void **data)
+{
+	int ret;
+	unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
+				 0 };
+
+	ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
+			       data, done);
+
+	return ret;
+}
+
+int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
+	    unsigned int prot, int done, void **data)
+{
+	int ret;
+	unsigned long args[] = { addr, len, prot, 0, 0, 0 };
+
+	ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
+			       data, done);
+
+	return ret;
+}