[PATCH] uml: move libc-dependent skas memory mapping code

The serial UML OS-abstraction layer patch (um/kernel/skas dir).

This moves all systemcalls from skas/mem_user.c file under os-Linux dir and
join skas/mem_user.c and skas/mem.c files.

Signed-off-by: Gennady Sharapov <gennady.v.sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 285 insertions, 2 deletions

diff --git a/arch/um/os-Linux/skas/Makefile b/arch/um/os-Linux/skas/Makefile
index eab5386d60a7..79cc6c72aa92 100644
--- a/arch/um/os-Linux/skas/Makefile
+++ b/arch/um/os-Linux/skas/Makefile
@@ -3,8 +3,8 @@
 # Licensed under the GPL
 #
 
-obj-y := trap.o
+obj-y := mem.o trap.o
 
-USER_OBJS := trap.o
+USER_OBJS := mem.o trap.o
 
 include arch/um/scripts/Makefile.rules
diff --git a/arch/um/os-Linux/skas/mem.c b/arch/um/os-Linux/skas/mem.c
new file mode 100644
index 000000000000..9890e9090f58
--- /dev/null
+++ b/arch/um/os-Linux/skas/mem.c
@@ -0,0 +1,283 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <signal.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+#include <asm/page.h>
+#include <asm/unistd.h>
+#include "mem_user.h"
+#include "mem.h"
+#include "skas.h"
+#include "user.h"
+#include "os.h"
+#include "proc_mm.h"
+#include "ptrace_user.h"
+#include "user_util.h"
+#include "kern_util.h"
+#include "task.h"
+#include "registers.h"
+#include "uml-config.h"
+#include "sysdep/ptrace.h"
+#include "sysdep/stub.h"
+
+extern unsigned long batch_syscall_stub, __syscall_stub_start;
+
+extern void wait_stub_done(int pid, int sig, char * fname);
+
+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;
+}
+
+extern int proc_mm;
+
+int single_count = 0;
+int multi_count = 0;
+int multi_op_count = 0;
+
+static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
+{
+	unsigned long regs[MAX_REG_NR];
+	int n;
+	long ret, offset;
+	unsigned long * data;
+	unsigned long * syscall;
+	int pid = mm_idp->u.pid;
+
+	if(proc_mm)
+#warning Need to look up userspace_pid by cpu
+		pid = userspace_pid[0];
+
+	multi_count++;
+
+	get_safe_registers(regs);
+	regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+		((unsigned long) &batch_syscall_stub -
+		 (unsigned long) &__syscall_stub_start);
+
+	n = ptrace_setregs(pid, regs);
+	if(n < 0)
+		panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
+		      n);
+
+	wait_stub_done(pid, 0, "do_syscall_stub");
+
+	/* 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 - UML_CONFIG_STUB_DATA);
+		printk("do_syscall_stub : ret = %d, offset = %d, "
+		       "data = 0x%x\n", ret, offset, data);
+		syscall = (unsigned long *)((unsigned long)data + data[0]);
+		printk("do_syscall_stub: syscall %ld failed, return value = "
+		       "0x%lx, expected return value = 0x%lx\n",
+		       syscall[0], ret, syscall[7]);
+		printk("    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("    additional syscall data:");
+			if(n % 4 == 1)
+				printk("\n      ");
+			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);
+
+	if(done && *addr == NULL)
+		single_count++;
+
+	*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;
+	multi_op_count++;
+
+	if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
+		     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) & ~PAGE_MASK) >=
+	   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) & ~PAGE_MASK) +
+			      UML_CONFIG_STUB_DATA);
+
+	return 0;
+}
+
+int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
+	int r, int w, int x, int phys_fd, unsigned long long offset,
+	int done, void **data)
+{
+	int prot, ret;
+
+	prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
+		(x ? PROT_EXEC : 0);
+
+	if(proc_mm){
+		struct proc_mm_op map;
+		int fd = mm_idp->u.mm_fd;
+
+		map = ((struct proc_mm_op) { .op	= MM_MMAP,
+				       .u		=
+				       { .mmap	=
+					 { .addr	= virt,
+					   .len	= len,
+					   .prot	= prot,
+					   .flags	= MAP_SHARED |
+					   MAP_FIXED,
+					   .fd	= phys_fd,
+					   .offset= offset
+					 } } } );
+		ret = os_write_file(fd, &map, sizeof(map));
+		if(ret != sizeof(map))
+			printk("map : /proc/mm map failed, err = %d\n", -ret);
+		else ret = 0;
+	}
+	else {
+		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, void *addr, unsigned long len, int done,
+	  void **data)
+{
+	int ret;
+
+	if(proc_mm){
+		struct proc_mm_op unmap;
+		int fd = mm_idp->u.mm_fd;
+
+		unmap = ((struct proc_mm_op) { .op	= MM_MUNMAP,
+					 .u	=
+					 { .munmap	=
+					   { .addr	=
+					     (unsigned long) addr,
+					     .len		= len } } } );
+		ret = os_write_file(fd, &unmap, sizeof(unmap));
+		if(ret != sizeof(unmap))
+			printk("unmap - proc_mm write returned %d\n", ret);
+		else ret = 0;
+	}
+	else {
+		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,
+	    int r, int w, int x, int done, void **data)
+{
+	struct proc_mm_op protect;
+	int prot, ret;
+
+	prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
+		(x ? PROT_EXEC : 0);
+	if(proc_mm){
+		int fd = mm_idp->u.mm_fd;
+
+		protect = ((struct proc_mm_op) { .op	= MM_MPROTECT,
+					   .u	=
+					   { .mprotect	=
+					     { .addr	=
+					       (unsigned long) addr,
+					       .len	= len,
+					       .prot	= prot } } } );
+
+		ret = os_write_file(fd, &protect, sizeof(protect));
+		if(ret != sizeof(protect))
+			printk("protect failed, err = %d", -ret);
+		else ret = 0;
+	}
+	else {
+		unsigned long args[] = { addr, len, prot, 0, 0, 0 };
+
+		ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
+				       data, done);
+	}
+
+	return ret;
+}
+
+void before_mem_skas(unsigned long unused)
+{
+}