[PATCH] uml: move libc-dependent startup and signal code

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

This moves all systemcalls from process.c file under os-Linux dir and join
process.c and process_kern.c files.

Signed-off-by: Gennady Sharapov <gennady.v.sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 7 insertions, 447 deletions

diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index a9cdd00775a3..614b8ebeb0ed 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -8,11 +8,10 @@ clean-files :=
 
 obj-y = config.o exec_kern.o exitcode.o \
         helper.o init_task.o irq.o irq_user.o ksyms.o main.o mem.o mem_user.o \
-        physmem.o process.o process_kern.o ptrace.o reboot.o resource.o \
-        sigio_user.o sigio_kern.o signal_kern.o signal_user.o smp.o \
-        syscall_kern.o sysrq.o tempfile.o time.o time_kern.o \
-        tlb.o trap_kern.o trap_user.o uaccess_user.o um_arch.o umid.o \
-        user_util.o
+        physmem.o process_kern.o ptrace.o reboot.o resource.o sigio_user.o \
+        sigio_kern.o signal_kern.o signal_user.o smp.o syscall_kern.o sysrq.o \
+        tempfile.o time.o time_kern.o tlb.o trap_kern.o trap_user.o \
+        uaccess_user.o um_arch.o umid.o user_util.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)     += gprof_syms.o
@@ -25,8 +24,8 @@ obj-$(CONFIG_MODE_SKAS) += skas/
 
 user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
-USER_OBJS := $(user-objs-y) config.o helper.o main.o process.o tempfile.o \
-        time.o tty_log.o umid.o user_util.o
+USER_OBJS := $(user-objs-y) config.o helper.o main.o tempfile.o time.o \
+        tty_log.o umid.o user_util.o
 
 include arch/um/scripts/Makefile.rules
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
deleted file mode 100644
index 67acd92c5322..000000000000
--- a/arch/um/kernel/process.c
+++ /dev/null
@@ -1,439 +0,0 @@
-/* 
- * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <stdio.h>
-#include <unistd.h>
-#include <signal.h>
-#include <sched.h>
-#include <errno.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <setjmp.h>
-#include <sys/time.h>
-#include <sys/wait.h>
-#include <sys/mman.h>
-#include <asm/unistd.h>
-#include <asm/page.h>
-#include "user_util.h"
-#include "kern_util.h"
-#include "user.h"
-#include "process.h"
-#include "signal_kern.h"
-#include "signal_user.h"
-#include "sysdep/ptrace.h"
-#include "sysdep/sigcontext.h"
-#include "irq_user.h"
-#include "ptrace_user.h"
-#include "time_user.h"
-#include "init.h"
-#include "os.h"
-#include "uml-config.h"
-#include "choose-mode.h"
-#include "mode.h"
-#include "tempfile.h"
-#ifdef UML_CONFIG_MODE_SKAS
-#include "skas.h"
-#include "skas_ptrace.h"
-#include "registers.h"
-#endif
-
-void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
-{
-        int flags = 0, pages;
-
-        if(sig_stack != NULL){
-                pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER);
-                set_sigstack(sig_stack, pages * page_size());
-                flags = SA_ONSTACK;
-        }
-        if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1);
-}
-
-void init_new_thread_signals(int altstack)
-{
-        int flags = altstack ? SA_ONSTACK : 0;
-
-        set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags,
-                    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-        set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags, 
-                    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-        set_handler(SIGFPE, (__sighandler_t) sig_handler, flags, 
-                    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-        set_handler(SIGILL, (__sighandler_t) sig_handler, flags, 
-                    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-        set_handler(SIGBUS, (__sighandler_t) sig_handler, flags, 
-                    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-        set_handler(SIGUSR2, (__sighandler_t) sig_handler, 
-                    flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-        signal(SIGHUP, SIG_IGN);
-
-        init_irq_signals(altstack);
-}
-
-struct tramp {
-        int (*tramp)(void *);
-        void *tramp_data;
-        unsigned long temp_stack;
-        int flags;
-        int pid;
-};
-
-/* See above for why sigkill is here */
-
-int sigkill = SIGKILL;
-
-int outer_tramp(void *arg)
-{
-        struct tramp *t;
-        int sig = sigkill;
-
-        t = arg;
-        t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2,
-                       t->flags, t->tramp_data);
-        if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL);
-        kill(os_getpid(), sig);
-        _exit(0);
-}
-
-int start_fork_tramp(void *thread_arg, unsigned long temp_stack, 
-                     int clone_flags, int (*tramp)(void *))
-{
-        struct tramp arg;
-        unsigned long sp;
-        int new_pid, status, err;
-
-        /* The trampoline will run on the temporary stack */
-        sp = stack_sp(temp_stack);
-
-        clone_flags |= CLONE_FILES | SIGCHLD;
-
-        arg.tramp = tramp;
-        arg.tramp_data = thread_arg;
-        arg.temp_stack = temp_stack;
-        arg.flags = clone_flags;
-
-        /* Start the process and wait for it to kill itself */
-        new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
-        if(new_pid < 0)
-                return(new_pid);
-
-        CATCH_EINTR(err = waitpid(new_pid, &status, 0));
-        if(err < 0)
-                panic("Waiting for outer trampoline failed - errno = %d",
-                      errno);
-
-        if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
-                panic("outer trampoline didn't exit with SIGKILL, "
-                      "status = %d", status);
-
-        return(arg.pid);
-}
-
-static int ptrace_child(void *arg)
-{
-        int ret;
-        int pid = os_getpid(), ppid = getppid();
-        int sc_result;
-
-        if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){
-                perror("ptrace");
-                os_kill_process(pid, 0);
-        }
-        os_stop_process(pid);
-
-        /*This syscall will be intercepted by the parent. Don't call more than
-         * once, please.*/
-        sc_result = os_getpid();
-
-        if (sc_result == pid)
-                ret = 1; /*Nothing modified by the parent, we are running
-                           normally.*/
-        else if (sc_result == ppid)
-                ret = 0; /*Expected in check_ptrace and check_sysemu when they
-                           succeed in modifying the stack frame*/
-        else
-                ret = 2; /*Serious trouble! This could be caused by a bug in
-                           host 2.6 SKAS3/2.6 patch before release -V6, together
-                           with a bug in the UML code itself.*/
-        _exit(ret);
-}
-
-static int start_ptraced_child(void **stack_out)
-{
-        void *stack;
-        unsigned long sp;
-        int pid, n, status;
-        
-        stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
-                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-        if(stack == MAP_FAILED)
-                panic("check_ptrace : mmap failed, errno = %d", errno);
-        sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
-        pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
-        if(pid < 0)
-                panic("check_ptrace : clone failed, errno = %d", errno);
-        CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-        if(n < 0)
-                panic("check_ptrace : wait failed, errno = %d", errno);
-        if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-                panic("check_ptrace : expected SIGSTOP, got status = %d",
-                      status);
-
-        *stack_out = stack;
-        return(pid);
-}
-
-/* When testing for SYSEMU support, if it is one of the broken versions, we must
- * just avoid using sysemu, not panic, but only if SYSEMU features are broken.
- * So only for SYSEMU features we test mustpanic, while normal host features
- * must work anyway!*/
-static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic)
-{
-        int status, n, ret = 0;
-
-        if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-                panic("check_ptrace : ptrace failed, errno = %d", errno);
-        CATCH_EINTR(n = waitpid(pid, &status, 0));
-        if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
-                int exit_with = WEXITSTATUS(status);
-                if (exit_with == 2)
-                        printk("check_ptrace : child exited with status 2. "
-                               "Serious trouble happening! Try updating your "
-                               "host skas patch!\nDisabling SYSEMU support.");
-                printk("check_ptrace : child exited with exitcode %d, while "
-                      "expecting %d; status 0x%x", exit_with,
-                      exitcode, status);
-                if (mustpanic)
-                        panic("\n");
-                else
-                        printk("\n");
-                ret = -1;
-        }
-
-        if(munmap(stack, PAGE_SIZE) < 0)
-                panic("check_ptrace : munmap failed, errno = %d", errno);
-        return ret;
-}
-
-static int force_sysemu_disabled = 0;
-
-int ptrace_faultinfo = 1;
-int proc_mm = 1;
-
-static int __init skas0_cmd_param(char *str, int* add)
-{
-        ptrace_faultinfo = proc_mm = 0;
-        return 0;
-}
-
-static int __init nosysemu_cmd_param(char *str, int* add)
-{
-        force_sysemu_disabled = 1;
-        return 0;
-}
-
-__uml_setup("skas0", skas0_cmd_param,
-                "skas0\n"
-                "    Disables SKAS3 usage, so that SKAS0 is used, unless you \n"
-                "    specify mode=tt.\n\n");
-
-__uml_setup("nosysemu", nosysemu_cmd_param,
-                "nosysemu\n"
-                "    Turns off syscall emulation patch for ptrace (SYSEMU) on.\n"
-                "    SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n"
-                "    behaviour of ptrace() and helps reducing host context switch rate.\n"
-                "    To make it working, you need a kernel patch for your host, too.\n"
-                "    See http://perso.wanadoo.fr/laurent.vivier/UML/ for further information.\n\n");
-
-static void __init check_sysemu(void)
-{
-        void *stack;
-        int pid, syscall, n, status, count=0;
-
-        printk("Checking syscall emulation patch for ptrace...");
-        sysemu_supported = 0;
-        pid = start_ptraced_child(&stack);
-
-        if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
-                goto fail;
-
-        CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-        if (n < 0)
-                panic("check_sysemu : wait failed, errno = %d", errno);
-        if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-                panic("check_sysemu : expected SIGTRAP, "
-                      "got status = %d", status);
-
-        n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
-                   os_getpid());
-        if(n < 0)
-                panic("check_sysemu : failed to modify system "
-                      "call return, errno = %d", errno);
-
-        if (stop_ptraced_child(pid, stack, 0, 0) < 0)
-                goto fail_stopped;
-
-        sysemu_supported = 1;
-        printk("OK\n");
-        set_using_sysemu(!force_sysemu_disabled);
-
-        printk("Checking advanced syscall emulation patch for ptrace...");
-        pid = start_ptraced_child(&stack);
-        while(1){
-                count++;
-                if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
-                        goto fail;
-                CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-                if(n < 0)
-                        panic("check_ptrace : wait failed, errno = %d", errno);
-                if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-                        panic("check_ptrace : expected (SIGTRAP|SYSCALL_TRAP), "
-                              "got status = %d", status);
-
-                syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
-                                 0);
-                if(syscall == __NR_getpid){
-                        if (!count)
-                                panic("check_ptrace : SYSEMU_SINGLESTEP doesn't singlestep");
-                        n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
-                                   os_getpid());
-                        if(n < 0)
-                                panic("check_sysemu : failed to modify system "
-                                      "call return, errno = %d", errno);
-                        break;
-                }
-        }
-        if (stop_ptraced_child(pid, stack, 0, 0) < 0)
-                goto fail_stopped;
-
-        sysemu_supported = 2;
-        printk("OK\n");
-
-        if ( !force_sysemu_disabled )
-                set_using_sysemu(sysemu_supported);
-        return;
-
-fail:
-        stop_ptraced_child(pid, stack, 1, 0);
-fail_stopped:
-        printk("missing\n");
-}
-
-void __init check_ptrace(void)
-{
-        void *stack;
-        int pid, syscall, n, status;
-
-        printk("Checking that ptrace can change system call numbers...");
-        pid = start_ptraced_child(&stack);
-
-        if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
-                panic("check_ptrace: PTRACE_SETOPTIONS failed, errno = %d", errno);
-
-        while(1){
-                if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
-                        panic("check_ptrace : ptrace failed, errno = %d", 
-                              errno);
-                CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-                if(n < 0)
-                        panic("check_ptrace : wait failed, errno = %d", errno);
-                if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP + 0x80))
-                        panic("check_ptrace : expected SIGTRAP + 0x80, "
-                              "got status = %d", status);
-                
-                syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
-                                 0);
-                if(syscall == __NR_getpid){
-                        n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
-                                   __NR_getppid);
-                        if(n < 0)
-                                panic("check_ptrace : failed to modify system "
-                                      "call, errno = %d", errno);
-                        break;
-                }
-        }
-        stop_ptraced_child(pid, stack, 0, 1);
-        printk("OK\n");
-        check_sysemu();
-}
-
-int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
-{
-        sigjmp_buf buf;
-        int n;
-
-        *jmp_ptr = &buf;
-        n = sigsetjmp(buf, 1);
-        if(n != 0)
-                return(n);
-        (*fn)(arg);
-        return(0);
-}
-
-void forward_pending_sigio(int target)
-{
-        sigset_t sigs;
-
-        if(sigpending(&sigs)) 
-                panic("forward_pending_sigio : sigpending failed");
-        if(sigismember(&sigs, SIGIO))
-                kill(target, SIGIO);
-}
-
-extern void *__syscall_stub_start, __syscall_stub_end;
-
-#ifdef UML_CONFIG_MODE_SKAS
-
-static inline void check_skas3_ptrace_support(void)
-{
-        struct ptrace_faultinfo fi;
-        void *stack;
-        int pid, n;
-
-        printf("Checking for the skas3 patch in the host...");
-        pid = start_ptraced_child(&stack);
-
-        n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
-        if (n < 0) {
-                ptrace_faultinfo = 0;
-                if(errno == EIO)
-                        printf("not found\n");
-                else {
-                        perror("not found");
-                }
-        }
-        else {
-                if (!ptrace_faultinfo)
-                        printf("found but disabled on command line\n");
-                else
-                        printf("found\n");
-        }
-
-        init_registers(pid);
-        stop_ptraced_child(pid, stack, 1, 1);
-}
-
-int can_do_skas(void)
-{
-        printf("Checking for /proc/mm...");
-        if (os_access("/proc/mm", OS_ACC_W_OK) < 0) {
-                proc_mm = 0;
-                printf("not found\n");
-        } else {
-                if (!proc_mm)
-                        printf("found but disabled on command line\n");
-                else
-                        printf("found\n");
-        }
-
-        check_skas3_ptrace_support();
-        return 1;
-}
-#else
-int can_do_skas(void)
-{
-        return(0);
-}
-#endif
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index b781b6f94283..09f6f7ce4695 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -333,6 +333,7 @@ int linux_main(int argc, char **argv)
         if(have_root == 0)
                 add_arg(DEFAULT_COMMAND_LINE);
 
+        os_early_checks();
         mode_tt = force_tt ? 1 : !can_do_skas();
 #ifndef CONFIG_MODE_TT
         if (mode_tt) {
@@ -470,7 +471,6 @@ void __init setup_arch(char **cmdline_p)
 void __init check_bugs(void)
 {
         arch_check_bugs();
-        check_ptrace();
         check_sigio();
         check_devanon();
 }