[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)
+{
+}