diff options
Diffstat (limited to 'arch/um/os-Linux/main.c')
-rw-r--r-- | arch/um/os-Linux/main.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c new file mode 100644 index 0000000..23da27d --- /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); +} |