um: Remove SKAS3/4 support

Before we had SKAS0 UML had two modes of operation
TT (tracing thread) and SKAS3/4 (separated kernel address space).
TT was known to be insecure and got removed a long time ago.
SKAS3/4 required a few (3 or 4) patches on the host side which never went
mainline. The last host patch is 10 years old.

With SKAS0 mode (separated kernel address space using 0 host patches),
default since 2005, SKAS3/4 is obsolete and can be removed.

Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 12 insertions, 88 deletions

diff --git a/arch/um/os-Linux/skas/mem.c b/arch/um/os-Linux/skas/mem.c
index 689b18db798f..e7f8c945a573 100644
--- a/arch/um/os-Linux/skas/mem.c
+++ b/arch/um/os-Linux/skas/mem.c
@@ -12,7 +12,6 @@
 #include <as-layout.h>
 #include <mm_id.h>
 #include <os.h>
-#include <proc_mm.h>
 #include <ptrace_user.h>
 #include <registers.h>
 #include <skas.h>
@@ -46,8 +45,6 @@ static int __init init_syscall_regs(void)
 
 __initcall(init_syscall_regs);
 
-extern int proc_mm;
-
 static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
 {
 	int n, i;
@@ -56,10 +53,6 @@ static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
 	unsigned long * syscall;
 	int err, pid = mm_idp->u.pid;
 
-	if (proc_mm)
-		/* FIXME: Need to look up userspace_pid by cpu */
-		pid = userspace_pid[0];
-
 	n = ptrace_setregs(pid, syscall_regs);
 	if (n < 0) {
 		printk(UM_KERN_ERR "Registers - \n");
@@ -178,38 +171,12 @@ 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) };
 
-	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
-					 } } } );
-		CATCH_EINTR(ret = write(fd, &map, sizeof(map)));
-		if (ret != sizeof(map)) {
-			ret = -errno;
-			printk(UM_KERN_ERR "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);
-	}
+	ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
+			       data, done);
 
 	return ret;
 }
@@ -218,32 +185,11 @@ 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 };
 
-	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 } } } );
-		CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap)));
-		if (ret != sizeof(unmap)) {
-			ret = -errno;
-			printk(UM_KERN_ERR "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);
-	}
+	ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
+			       data, done);
 
 	return ret;
 }
@@ -251,33 +197,11 @@ int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 	    unsigned int prot, int done, void **data)
 {
-	struct proc_mm_op protect;
 	int ret;
+	unsigned long args[] = { addr, len, prot, 0, 0, 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 } } } );
-
-		CATCH_EINTR(ret = write(fd, &protect, sizeof(protect)));
-		if (ret != sizeof(protect)) {
-			ret = -errno;
-			printk(UM_KERN_ERR "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);
-	}
+	ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
+			       data, done);
 
 	return ret;
 }