uml: throw out CONFIG_MODE_TT

This patchset throws out tt mode, which has been non-functional for a while.

This is done in phases, interspersed with code cleanups on the affected files.

The removal is done as follows:
	remove all code, config options, and files which depend on
CONFIG_MODE_TT
	get rid of the CHOOSE_MODE macro, which decided whether to
call tt-mode or skas-mode code, and replace invocations with their
skas portions
	replace all now-trivial procedures with their skas equivalents

There are now a bunch of now-redundant pieces of data structures, including
mode-specific pieces of the thread structure, pt_regs, and mm_context.  These
are all replaced with their skas-specific contents.

As part of the ongoing style compliance project, I made a style pass over all
files that were changed.  There are three such patches, one for each phase,
covering the files affected by that phase but no later ones.

I noticed that we weren't freeing the LDT state associated with a process when
it exited, so that's fixed in one of the later patches.

The last patch is a tidying patch which I've had for a while, but which caused
inexplicable crashes under tt mode.  Since that is no longer a problem, this
can now go in.

This patch:

Start getting rid of tt mode support.

This patch throws out CONFIG_MODE_TT and all config options, code, and files
which depend on it.

CONFIG_MODE_SKAS is gone and everything that depends on it is included
unconditionally.

The few changed lines are in re-written Kconfig help, lines which needed
something skas-related removed from them, and a few more which weren't
strictly deletions.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 461 deletions

diff --git a/arch/um/kernel/tt/tracer.c b/arch/um/kernel/tt/tracer.c
deleted file mode 100644
index c23588393f6..00000000000
--- a/arch/um/kernel/tt/tracer.c
+++ /dev/null
@@ -1,461 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdarg.h>
-#include <unistd.h>
-#include <signal.h>
-#include <errno.h>
-#include <sched.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/time.h>
-#include <sys/wait.h>
-#include "user.h"
-#include "sysdep/ptrace.h"
-#include "sigcontext.h"
-#include "sysdep/sigcontext.h"
-#include "os.h"
-#include "mem_user.h"
-#include "process.h"
-#include "kern_util.h"
-#include "chan_user.h"
-#include "ptrace_user.h"
-#include "irq_user.h"
-#include "mode.h"
-#include "tt.h"
-
-static int tracer_winch[2];
-
-int is_tracer_winch(int pid, int fd, void *data)
-{
-	if(pid != os_getpgrp())
-		return(0);
-
-	register_winch_irq(tracer_winch[0], fd, -1, data);
-	return(1);
-}
-
-static void tracer_winch_handler(int sig)
-{
-	int n;
-	char c = 1;
-
-	n = os_write_file(tracer_winch[1], &c, sizeof(c));
-	if(n != sizeof(c))
-		printk("tracer_winch_handler - write failed, err = %d\n", -n);
-}
-
-/* Called only by the tracing thread during initialization */
-
-static void setup_tracer_winch(void)
-{
-	int err;
-
-	err = os_pipe(tracer_winch, 1, 1);
-	if(err < 0){
-		printk("setup_tracer_winch : os_pipe failed, err = %d\n", -err);
-		return;
-	}
-	signal(SIGWINCH, tracer_winch_handler);
-}
-
-void attach_process(int pid)
-{
-	if((ptrace(PTRACE_ATTACH, pid, 0, 0) < 0) ||
-	   (ptrace(PTRACE_CONT, pid, 0, 0) < 0))
-		tracer_panic("OP_FORK failed to attach pid");
-	wait_for_stop(pid, SIGSTOP, PTRACE_CONT, NULL);
-	if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
-		tracer_panic("OP_FORK: PTRACE_SETOPTIONS failed, errno = %d", errno);
-	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		tracer_panic("OP_FORK failed to continue process");
-}
-
-void tracer_panic(char *format, ...)
-{
-	va_list ap;
-
-	va_start(ap, format);
-	vprintf(format, ap);
-	va_end(ap);
-	printf("\n");
-	while(1) pause();
-}
-
-static void tracer_segv(int sig, struct sigcontext sc)
-{
-        struct faultinfo fi;
-        GET_FAULTINFO_FROM_SC(fi, &sc);
-	printf("Tracing thread segfault at address 0x%lx, ip 0x%lx\n",
-               FAULT_ADDRESS(fi), SC_IP(&sc));
-	while(1)
-		pause();
-}
-
-/* Changed early in boot, and then only read */
-int debug = 0;
-int debug_stop = 1;
-int debug_parent = 0;
-int honeypot = 0;
-
-static int signal_tramp(void *arg)
-{
-	int (*proc)(void *);
-
-	if(honeypot && munmap((void *) (host_task_size - 0x10000000),
-			      0x10000000)) 
-		panic("Unmapping stack failed");
-	if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0)
-		panic("ptrace PTRACE_TRACEME failed");
-	os_stop_process(os_getpid());
-	change_sig(SIGWINCH, 0);
-	signal(SIGUSR1, SIG_IGN);
-	change_sig(SIGCHLD, 0);
-	signal(SIGSEGV, (__sighandler_t) sig_handler);
-	set_cmdline("(idle thread)");
-	set_init_pid(os_getpid());
-	init_irq_signals(0);
-	proc = arg;
-	return((*proc)(NULL));
-}
-
-static void sleeping_process_signal(int pid, int sig)
-{
-	switch(sig){
-	/* These two result from UML being ^Z-ed and bg-ed.  PTRACE_CONT is
-	 * right because the process must be in the kernel already.
-	 */
-	case SIGCONT:
-	case SIGTSTP:
-		if(ptrace(PTRACE_CONT, pid, 0, sig) < 0)
-			tracer_panic("sleeping_process_signal : Failed to "
-				     "continue pid %d, signal = %d, "
-				     "errno = %d\n", pid, sig, errno);
-		break;
-
-	/* This happens when the debugger (e.g. strace) is doing system call 
-	 * tracing on the kernel.  During a context switch, the current task
-	 * will be set to the incoming process and the outgoing process will
-	 * hop into write and then read.  Since it's not the current process
-	 * any more, the trace of those will land here.  So, we need to just 
-	 * PTRACE_SYSCALL it.
-	 */
-	case (SIGTRAP + 0x80):
-		if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
-			tracer_panic("sleeping_process_signal : Failed to "
-				     "PTRACE_SYSCALL pid %d, errno = %d\n",
-				     pid, errno);
-		break;
-	case SIGSTOP:
-		break;
-	default:
-		tracer_panic("sleeping process %d got unexpected "
-			     "signal : %d\n", pid, sig);
-		break;
-	}
-}
-
-/* Accessed only by the tracing thread */
-int debugger_pid = -1;
-int debugger_parent = -1;
-int debugger_fd = -1;
-int gdb_pid = -1;
-
-struct {
-	int pid;
-	int signal;
-	unsigned long addr;
-	struct timeval time;
-} signal_record[1024][32];
-
-int signal_index[32];
-int nsignals = 0;
-int debug_trace = 0;
-
-extern void signal_usr1(int sig);
-
-int tracing_pid = -1;
-
-int tracer(int (*init_proc)(void *), void *sp)
-{
-	void *task = NULL;
-	int status, pid = 0, sig = 0, cont_type, tracing = 0, op = 0;
-	int proc_id = 0, n, err, old_tracing = 0, strace = 0;
-	int local_using_sysemu = 0;
-
-	signal(SIGPIPE, SIG_IGN);
-	setup_tracer_winch();
-	tracing_pid = os_getpid();
-	printf("tracing thread pid = %d\n", tracing_pid);
-
-	pid = clone(signal_tramp, sp, CLONE_FILES | SIGCHLD, init_proc);
-	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-	if(n < 0){
-		printf("waitpid on idle thread failed, errno = %d\n", errno);
-		exit(1);
-	}
-	if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) {
-		printf("Failed to PTRACE_SETOPTIONS for idle thread, errno = %d\n", errno);
-		exit(1);
-	}
-	if((ptrace(PTRACE_CONT, pid, 0, 0) < 0)){
-		printf("Failed to continue idle thread, errno = %d\n", errno);
-		exit(1);
-	}
-
-	signal(SIGSEGV, (sighandler_t) tracer_segv);
-	signal(SIGUSR1, signal_usr1);
-	if(debug_trace){
-		printf("Tracing thread pausing to be attached\n");
-		stop();
-	}
-	if(debug){
-		if(gdb_pid != -1) 
-			debugger_pid = attach_debugger(pid, gdb_pid, 1);
-		else debugger_pid = init_ptrace_proxy(pid, 1, debug_stop);
-		if(debug_parent){
-			debugger_parent = os_process_parent(debugger_pid);
-			init_parent_proxy(debugger_parent);
-			err = attach(debugger_parent);
-			if(err){
-				printf("Failed to attach debugger parent %d, "
-				       "errno = %d\n", debugger_parent, -err);
-				debugger_parent = -1;
-			}
-			else {
-				if(ptrace(PTRACE_SYSCALL, debugger_parent, 
-					  0, 0) < 0){
-					printf("Failed to continue debugger "
-					       "parent, errno = %d\n", errno);
-					debugger_parent = -1;
-				}
-			}
-		}
-	}
-	set_cmdline("(tracing thread)");
-	while(1){
-		CATCH_EINTR(pid = waitpid(-1, &status, WUNTRACED));
-		if(pid <= 0){
-			if(errno != ECHILD){
-				printf("wait failed - errno = %d\n", errno);
-			}
-			continue;
-		}
-		if(pid == debugger_pid){
-			int cont = 0;
-
-			if(WIFEXITED(status) || WIFSIGNALED(status))
-				debugger_pid = -1;
-			/* XXX Figure out how to deal with gdb and SMP */
-			else cont = debugger_signal(status, cpu_tasks[0].pid);
-			if(cont == PTRACE_SYSCALL) strace = 1;
-			continue;
-		}
-		else if(pid == debugger_parent){
-			debugger_parent_signal(status, pid);
-			continue;
-		}
-		nsignals++;
-		if(WIFEXITED(status)) ;
-#ifdef notdef
-		{
-			printf("Child %d exited with status %d\n", pid, 
-			       WEXITSTATUS(status));
-		}
-#endif
-		else if(WIFSIGNALED(status)){
-			sig = WTERMSIG(status);
-			if(sig != 9){
-				printf("Child %d exited with signal %d\n", pid,
-				       sig);
-			}
-		}
-		else if(WIFSTOPPED(status)){
-			proc_id = pid_to_processor_id(pid);
-			sig = WSTOPSIG(status);
-			if(proc_id == -1){
-				sleeping_process_signal(pid, sig);
-				continue;
-			}
-
-			task = cpu_tasks[proc_id].task;
-			tracing = is_tracing(task);
-			old_tracing = tracing;
-
-			/* Assume: no syscall, when coming from user */
-			if ( tracing )
-				do_sigtrap(task);
-
-			switch(sig){
-			case SIGUSR1:
-				sig = 0;
-				op = do_proc_op(task, proc_id);
-				switch(op){
-				/*
-				 * This is called when entering user mode; after
-				 * this, we start intercepting syscalls.
-				 *
-				 * In fact, a process is started in kernel mode,
-				 * so with is_tracing() == 0 (and that is reset
-				 * when executing syscalls, since UML kernel has
-				 * the right to do syscalls);
-				 */
-				case OP_TRACE_ON:
-					arch_leave_kernel(task, pid);
-					tracing = 1;
-					break;
-				case OP_REBOOT:
-				case OP_HALT:
-					unmap_physmem();
-					kmalloc_ok = 0;
-					os_kill_ptraced_process(pid, 0);
-					/* Now let's reap remaining zombies */
-					errno = 0;
-					do {
-						waitpid(-1, &status,
-							WUNTRACED);
-					} while (errno != ECHILD);
-					return(op == OP_REBOOT);
-				case OP_NONE:
-					printf("Detaching pid %d\n", pid);
-					detach(pid, SIGSTOP);
-					continue;
-				default:
-					break;
-				}
-				/* OP_EXEC switches host processes on us,
-				 * we want to continue the new one.
-				 */
-				pid = cpu_tasks[proc_id].pid;
-				break;
-			case (SIGTRAP + 0x80):
-				if(!tracing && (debugger_pid != -1)){
-					child_signal(pid, status & 0x7fff);
-					continue;
-				}
-				tracing = 0;
-				/* local_using_sysemu has been already set
-				 * below, since if we are here, is_tracing() on
-				 * the traced task was 1, i.e. the process had
-				 * already run through one iteration of the
-				 * loop which executed a OP_TRACE_ON request.*/
-				do_syscall(task, pid, local_using_sysemu);
-				sig = SIGUSR2;
-				break;
-			case SIGTRAP:
-				if(!tracing && (debugger_pid != -1)){
-					child_signal(pid, status);
-					continue;
-				}
-				tracing = 0;
-				break;
-			case SIGPROF:
-				if(tracing) sig = 0;
-				break;
-			case SIGCHLD:
-			case SIGHUP:
-				sig = 0;
-				break;
-			case SIGSEGV:
-			case SIGIO:
-			case SIGALRM:
-			case SIGVTALRM:
-			case SIGFPE:
-			case SIGBUS:
-			case SIGILL:
-			case SIGWINCH:
-
-			default:
-				tracing = 0;
-				break;
-			}
-			set_tracing(task, tracing);
-
-			if(!tracing && old_tracing)
-				arch_enter_kernel(task, pid);
-
-			if(!tracing && (debugger_pid != -1) && (sig != 0) &&
-				(sig != SIGALRM) && (sig != SIGVTALRM) &&
-				(sig != SIGSEGV) && (sig != SIGTRAP) &&
-				(sig != SIGUSR2) && (sig != SIGIO) &&
-				(sig != SIGFPE)){
-				child_signal(pid, status);
-				continue;
-			}
-
-			local_using_sysemu = get_using_sysemu();
-
-			if(tracing)
-				cont_type = SELECT_PTRACE_OPERATION(local_using_sysemu,
-				                                    singlestepping(task));
-			else if((debugger_pid != -1) && strace)
-				cont_type = PTRACE_SYSCALL;
-			else
-				cont_type = PTRACE_CONT;
-
-			if(ptrace(cont_type, pid, 0, sig) != 0){
-				tracer_panic("ptrace failed to continue "
-					     "process - errno = %d\n", 
-					     errno);
-			}
-		}
-	}
-	return(0);
-}
-
-static int __init uml_debug_setup(char *line, int *add)
-{
-	char *next;
-
-	debug = 1;
-	*add = 0;
-	if(*line != '=') return(0);
-	line++;
-
-	while(line != NULL){
-		next = strchr(line, ',');
-		if(next) *next++ = '\0';
-		
-		if(!strcmp(line, "go"))	debug_stop = 0;
-		else if(!strcmp(line, "parent")) debug_parent = 1;
-		else printf("Unknown debug option : '%s'\n", line);
-
-		line = next;
-	}
-	return(0);
-}
-
-__uml_setup("debug", uml_debug_setup,
-"debug\n"
-"    Starts up the kernel under the control of gdb. See the \n"
-"    kernel debugging tutorial and the debugging session pages\n"
-"    at http://user-mode-linux.sourceforge.net/ for more information.\n\n"
-);
-
-static int __init uml_debugtrace_setup(char *line, int *add)
-{
-	debug_trace = 1;
-	return 0;
-}
-__uml_setup("debugtrace", uml_debugtrace_setup,
-"debugtrace\n"
-"    Causes the tracing thread to pause until it is attached by a\n"
-"    debugger and continued.  This is mostly for debugging crashes\n"
-"    early during boot, and should be pretty much obsoleted by\n"
-"    the debug switch.\n\n"
-);
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */