[PATCH] uml: separate libc-dependent early initialization

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

This moves all systemcalls from main.c file under os-Linux dir and joins mem.c
and um_arch.c files.

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

2 files changed, 263 insertions, 4 deletions

diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index d389c58b18b2..0b761a08f0df 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -3,11 +3,11 @@
 # Licensed under the GPL
 #
 
-obj-y = aio.o elf_aux.o file.o mem.o process.o signal.o start_up.o time.o \
-        tt.o tty.o uaccess.o user_syms.o drivers/ sys-$(SUBARCH)/
+obj-y = aio.o elf_aux.o file.o main.o mem.o process.o signal.o start_up.o \
+        time.o tt.o tty.o uaccess.o user_syms.o drivers/ sys-$(SUBARCH)/
 
-USER_OBJS := aio.o elf_aux.o file.o mem.o process.o signal.o start_up.o \
-        time.o tt.o tty.o uaccess.o
+USER_OBJS := aio.o elf_aux.o file.o main.o mem.o process.o signal.o \
+        start_up.o time.o tt.o tty.o uaccess.o
 
 elf_aux.o: $(ARCH_DIR)/kernel-offsets.h
 CFLAGS_elf_aux.o += -I$(objtree)/arch/um
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
new file mode 100644
index 000000000000..23da27d22569
--- /dev/null
+++ b/arch/um/os-Linux/main.c
@@ -0,0 +1,259 @@
+/*
+ * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/resource.h>
+#include <sys/mman.h>
+#include <sys/user.h>
+#include <asm/page.h>
+#include "user_util.h"
+#include "kern_util.h"
+#include "mem_user.h"
+#include "signal_user.h"
+#include "time_user.h"
+#include "irq_user.h"
+#include "user.h"
+#include "init.h"
+#include "mode.h"
+#include "choose-mode.h"
+#include "uml-config.h"
+#include "os.h"
+
+/* Set in set_stklim, which is called from main and __wrap_malloc.
+ * __wrap_malloc only calls it if main hasn't started.
+ */
+unsigned long stacksizelim;
+
+/* Set in main */
+char *linux_prog;
+
+#define PGD_BOUND (4 * 1024 * 1024)
+#define STACKSIZE (8 * 1024 * 1024)
+#define THREAD_NAME_LEN (256)
+
+static void set_stklim(void)
+{
+        struct rlimit lim;
+
+        if(getrlimit(RLIMIT_STACK, &lim) < 0){
+                perror("getrlimit");
+                exit(1);
+        }
+        if((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)){
+                lim.rlim_cur = STACKSIZE;
+                if(setrlimit(RLIMIT_STACK, &lim) < 0){
+                        perror("setrlimit");
+                        exit(1);
+                }
+        }
+        stacksizelim = (lim.rlim_cur + PGD_BOUND - 1) & ~(PGD_BOUND - 1);
+}
+
+static __init void do_uml_initcalls(void)
+{
+        initcall_t *call;
+
+        call = &__uml_initcall_start;
+        while (call < &__uml_initcall_end){;
+                (*call)();
+                call++;
+        }
+}
+
+static void last_ditch_exit(int sig)
+{
+        signal(SIGINT, SIG_DFL);
+        signal(SIGTERM, SIG_DFL);
+        signal(SIGHUP, SIG_DFL);
+        uml_cleanup();
+        exit(1);
+}
+
+extern int uml_exitcode;
+
+extern void scan_elf_aux( char **envp);
+
+int main(int argc, char **argv, char **envp)
+{
+        char **new_argv;
+        sigset_t mask;
+        int ret, i, err;
+
+        /* Enable all signals except SIGIO - in some environments, we can
+         * enter with some signals blocked
+         */
+
+        sigemptyset(&mask);
+        sigaddset(&mask, SIGIO);
+        if(sigprocmask(SIG_SETMASK, &mask, NULL) < 0){
+                perror("sigprocmask");
+                exit(1);
+        }
+
+#ifdef UML_CONFIG_CMDLINE_ON_HOST
+        /* Allocate memory for thread command lines */
+        if(argc < 2 || strlen(argv[1]) < THREAD_NAME_LEN - 1){
+
+                char padding[THREAD_NAME_LEN] = {
+                        [ 0 ...  THREAD_NAME_LEN - 2] = ' ', '\0'
+                };
+
+                new_argv = malloc((argc + 2) * sizeof(char*));
+                if(!new_argv) {
+                        perror("Allocating extended argv");
+                        exit(1);
+                }
+
+                new_argv[0] = argv[0];
+                new_argv[1] = padding;
+
+                for(i = 2; i <= argc; i++)
+                        new_argv[i] = argv[i - 1];
+                new_argv[argc + 1] = NULL;
+
+                execvp(new_argv[0], new_argv);
+                perror("execing with extended args");
+                exit(1);
+        }
+#endif
+
+        linux_prog = argv[0];
+
+        set_stklim();
+
+        new_argv = malloc((argc + 1) * sizeof(char *));
+        if(new_argv == NULL){
+                perror("Mallocing argv");
+                exit(1);
+        }
+        for(i=0;i<argc;i++){
+                new_argv[i] = strdup(argv[i]);
+                if(new_argv[i] == NULL){
+                        perror("Mallocing an arg");
+                        exit(1);
+                }
+        }
+        new_argv[argc] = NULL;
+
+        set_handler(SIGINT, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
+        set_handler(SIGTERM, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
+        set_handler(SIGHUP, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
+
+        scan_elf_aux( envp);
+
+        do_uml_initcalls();
+        ret = linux_main(argc, argv);
+
+        /* Disable SIGPROF - I have no idea why libc doesn't do this or turn
+         * off the profiling time, but UML dies with a SIGPROF just before
+         * exiting when profiling is active.
+         */
+        change_sig(SIGPROF, 0);
+
+        /* This signal stuff used to be in the reboot case.  However,
+         * sometimes a SIGVTALRM can come in when we're halting (reproducably
+         * when writing out gcov information, presumably because that takes
+         * some time) and cause a segfault.
+         */
+
+        /* stop timers and set SIG*ALRM to be ignored */
+        disable_timer();
+
+        /* disable SIGIO for the fds and set SIGIO to be ignored */
+        err = deactivate_all_fds();
+        if(err)
+                printf("deactivate_all_fds failed, errno = %d\n", -err);
+
+        /* Let any pending signals fire now.  This ensures
+         * that they won't be delivered after the exec, when
+         * they are definitely not expected.
+         */
+        unblock_signals();
+
+        /* Reboot */
+        if(ret){
+                printf("\n");
+                execvp(new_argv[0], new_argv);
+                perror("Failed to exec kernel");
+                ret = 1;
+        }
+        printf("\n");
+        return(uml_exitcode);
+}
+
+#define CAN_KMALLOC() \
+        (kmalloc_ok && CHOOSE_MODE((os_getpid() != tracing_pid), 1))
+
+extern void *__real_malloc(int);
+
+void *__wrap_malloc(int size)
+{
+        void *ret;
+
+        if(!CAN_KMALLOC())
+                return(__real_malloc(size));
+        else if(size <= PAGE_SIZE) /* finding contiguos pages can be hard*/
+                ret = um_kmalloc(size);
+        else ret = um_vmalloc(size);
+
+        /* glibc people insist that if malloc fails, errno should be
+         * set by malloc as well. So we do.
+         */
+        if(ret == NULL)
+                errno = ENOMEM;
+
+        return(ret);
+}
+
+void *__wrap_calloc(int n, int size)
+{
+        void *ptr = __wrap_malloc(n * size);
+
+        if(ptr == NULL) return(NULL);
+        memset(ptr, 0, n * size);
+        return(ptr);
+}
+
+extern void __real_free(void *);
+
+extern unsigned long high_physmem;
+
+void __wrap_free(void *ptr)
+{
+        unsigned long addr = (unsigned long) ptr;
+
+        /* We need to know how the allocation happened, so it can be correctly
+         * freed.  This is done by seeing what region of memory the pointer is
+         * in -
+         *      physical memory - kmalloc/kfree
+         *      kernel virtual memory - vmalloc/vfree
+         *      anywhere else - malloc/free
+         * If kmalloc is not yet possible, then either high_physmem and/or
+         * end_vm are still 0 (as at startup), in which case we call free, or
+         * we have set them, but anyway addr has not been allocated from those
+         * areas. So, in both cases __real_free is called.
+         *
+         * CAN_KMALLOC is checked because it would be bad to free a buffer
+         * with kmalloc/vmalloc after they have been turned off during
+         * shutdown.
+         * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so
+         * there is a possibility for memory leaks.
+         */
+
+        if((addr >= uml_physmem) && (addr < high_physmem)){
+                if(CAN_KMALLOC())
+                        kfree(ptr);
+        }
+        else if((addr >= start_vm) && (addr < end_vm)){
+                if(CAN_KMALLOC())
+                        vfree(ptr);
+        }
+        else __real_free(ptr);
+}