From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/um/os-Linux/main.c | 254 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 254 insertions(+) create mode 100644 arch/um/os-Linux/main.c (limited to 'arch/um/os-Linux/main.c') diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c new file mode 100644 index 000000000..c8a42ecbd --- /dev/null +++ b/arch/um/os-Linux/main.c @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de) + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define PGD_BOUND (4 * 1024 * 1024) +#define STACKSIZE (8 * 1024 * 1024) +#define THREAD_NAME_LEN (256) + +long elf_aux_hwcap; + +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); + } + } +} + +static void last_ditch_exit(int sig) +{ + uml_cleanup(); + exit(1); +} + +static void install_fatal_handler(int sig) +{ + struct sigaction action; + + /* All signals are enabled in this handler ... */ + sigemptyset(&action.sa_mask); + + /* + * ... including the signal being handled, plus we want the + * handler reset to the default behavior, so that if an exit + * handler is hanging for some reason, the UML will just die + * after this signal is sent a second time. + */ + action.sa_flags = SA_RESETHAND | SA_NODEFER; + action.sa_restorer = NULL; + action.sa_handler = last_ditch_exit; + if (sigaction(sig, &action, NULL) < 0) { + os_warn("failed to install handler for signal %d " + "- errno = %d\n", sig, errno); + exit(1); + } +} + +#define UML_LIB_PATH ":" OS_LIB_PATH "/uml" + +static void setup_env_path(void) +{ + char *new_path = NULL; + char *old_path = NULL; + int path_len = 0; + + old_path = getenv("PATH"); + /* + * if no PATH variable is set or it has an empty value + * just use the default + /usr/lib/uml + */ + if (!old_path || (path_len = strlen(old_path)) == 0) { + if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH)) + perror("couldn't putenv"); + return; + } + + /* append /usr/lib/uml to the existing path */ + path_len += strlen("PATH=" UML_LIB_PATH) + 1; + new_path = malloc(path_len); + if (!new_path) { + perror("couldn't malloc to set a new PATH"); + return; + } + snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path); + if (putenv(new_path)) { + perror("couldn't putenv to set a new PATH"); + free(new_path); + } +} + +extern void scan_elf_aux( char **envp); + +int __init main(int argc, char **argv, char **envp) +{ + char **new_argv; + int ret, i, err; + + set_stklim(); + + setup_env_path(); + + setsid(); + + 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; + + /* + * Allow these signals to bring down a UML if all other + * methods of control fail. + */ + install_fatal_handler(SIGINT); + install_fatal_handler(SIGTERM); + +#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA + scan_elf_aux(envp); +#endif + + change_sig(SIGPIPE, 0); + 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 timer signal 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 timer signal to be ignored */ + os_timer_disable(); + + /* disable SIGIO for the fds and set SIGIO to be ignored */ + err = deactivate_all_fds(); + if (err) + os_warn("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(); + + os_info("\n"); + /* Reboot */ + if (ret) { + execvp(new_argv[0], new_argv); + perror("Failed to exec kernel"); + ret = 1; + } + return uml_exitcode; +} + +extern void *__real_malloc(int); + +void *__wrap_malloc(int size) +{ + void *ret; + + if (!kmalloc_ok) + return __real_malloc(size); + else if (size <= UM_KERN_PAGE_SIZE) + /* finding contiguous pages can be hard*/ + ret = uml_kmalloc(size, UM_GFP_KERNEL); + else ret = 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 (kmalloc_ok) + kfree(ptr); + } + else if ((addr >= start_vm) && (addr < end_vm)) { + if (kmalloc_ok) + vfree(ptr); + } + else __real_free(ptr); +} -- cgit v1.2.3