[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 d389c58b18b..0b761a08f0d 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 00000000000..23da27d2256
--- /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);
+}