| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Christian Brauner | 2574 | 35.34% | 31 | 11.57% |
| Alex Kelly | 882 | 12.11% | 2 | 0.75% |
| Jann Horn | 859 | 11.79% | 9 | 3.36% |
| Oleg Nesterov | 399 | 5.48% | 30 | 11.19% |
| Al Viro | 366 | 5.03% | 17 | 6.34% |
| Eric W. Biedermann | 206 | 2.83% | 10 | 3.73% |
| Linus Torvalds | 181 | 2.49% | 13 | 4.85% |
| Neil Horman | 159 | 2.18% | 6 | 2.24% |
| Paul Wise | 139 | 1.91% | 1 | 0.37% |
| Linus Torvalds (pre-git) | 126 | 1.73% | 29 | 10.82% |
| Mateusz Guzik | 116 | 1.59% | 2 | 0.75% |
| Geert Uytterhoeven | 111 | 1.52% | 1 | 0.37% |
| Xiaotian Feng | 87 | 1.19% | 1 | 0.37% |
| Luis R. Rodriguez | 82 | 1.13% | 2 | 0.75% |
| Brian Mak | 78 | 1.07% | 1 | 0.37% |
| Alan Cox | 75 | 1.03% | 2 | 0.75% |
| Allen Pais | 72 | 0.99% | 1 | 0.37% |
| Kees Cook | 66 | 0.91% | 5 | 1.87% |
| Nicolas Iooss | 64 | 0.88% | 2 | 0.75% |
| Christoph Hellwig | 56 | 0.77% | 5 | 1.87% |
| David Howells | 56 | 0.77% | 9 | 3.36% |
| Lepton Wu | 48 | 0.66% | 1 | 0.37% |
| Matthew Wilcox | 45 | 0.62% | 1 | 0.37% |
| nixiaoming | 36 | 0.49% | 1 | 0.37% |
| Ingo Molnar | 36 | 0.49% | 10 | 3.73% |
| Sudip Mukherjee | 28 | 0.38% | 1 | 0.37% |
| Eric Dumazet | 24 | 0.33% | 2 | 0.75% |
| Art Haas | 24 | 0.33% | 1 | 0.37% |
| Roland McGrath | 23 | 0.32% | 6 | 2.24% |
| Alexey Dobriyan | 22 | 0.30% | 3 | 1.12% |
| Jiri Slaby | 21 | 0.29% | 1 | 0.37% |
| Masami Hiramatsu | 20 | 0.27% | 2 | 0.75% |
| Oleksandr Natalenko | 14 | 0.19% | 1 | 0.37% |
| Hugh Dickins | 12 | 0.16% | 3 | 1.12% |
| Arnd Bergmann | 11 | 0.15% | 1 | 0.37% |
| Peter Zijlstra | 11 | 0.15% | 4 | 1.49% |
| Nicolas Bouchinet | 11 | 0.15% | 1 | 0.37% |
| Omar Sandoval | 9 | 0.12% | 1 | 0.37% |
| David Woodhouse | 9 | 0.12% | 2 | 0.75% |
| Andrew Morton | 8 | 0.11% | 3 | 1.12% |
| Menglong Dong | 8 | 0.11% | 1 | 0.37% |
| Liam R. Howlett | 7 | 0.10% | 1 | 0.37% |
| Andi Kleen | 7 | 0.10% | 1 | 0.37% |
| david.oberhollenzer@sigma-star.at | 6 | 0.08% | 1 | 0.37% |
| Stéphane Graber | 6 | 0.08% | 1 | 0.37% |
| Suresh B. Siddha | 6 | 0.08% | 1 | 0.37% |
| Roman Kisel | 5 | 0.07% | 1 | 0.37% |
| Daisuke Hatayama | 4 | 0.05% | 1 | 0.37% |
| Greg Kroah-Hartman | 4 | 0.05% | 2 | 0.75% |
| Jason A. Donenfeld | 4 | 0.05% | 1 | 0.37% |
| Matt Helsley | 3 | 0.04% | 1 | 0.37% |
| Kamezawa Hiroyuki | 3 | 0.04% | 1 | 0.37% |
| Sukadev Bhattiprolu | 3 | 0.04% | 2 | 0.75% |
| Stephen Rothwell | 3 | 0.04% | 1 | 0.37% |
| Adrian Bunk | 3 | 0.04% | 1 | 0.37% |
| Rik Van Riel | 3 | 0.04% | 1 | 0.37% |
| Denys Vlasenko | 3 | 0.04% | 1 | 0.37% |
| Andrey Ryabinin | 3 | 0.04% | 1 | 0.37% |
| David Smith | 3 | 0.04% | 1 | 0.37% |
| Pavel Emelyanov | 3 | 0.04% | 1 | 0.37% |
| Joel Granados | 3 | 0.04% | 3 | 1.12% |
| Jay Lan | 3 | 0.04% | 2 | 0.75% |
| Johannes Berg | 3 | 0.04% | 1 | 0.37% |
| Michal Hocko | 2 | 0.03% | 1 | 0.37% |
| Alexei Starovoitov | 2 | 0.03% | 1 | 0.37% |
| Alexandre Ghiti | 2 | 0.03% | 1 | 0.37% |
| Kuniyuki Iwashima | 2 | 0.03% | 2 | 0.75% |
| James Morris | 2 | 0.03% | 1 | 0.37% |
| Christian Ehrhardt | 2 | 0.03% | 1 | 0.37% |
| Vladimir Sementsov-Ogievskiy | 1 | 0.01% | 1 | 0.37% |
| Dan Aloni | 1 | 0.01% | 1 | 0.37% |
| Dan Carpenter | 1 | 0.01% | 1 | 0.37% |
| Silesh C V | 1 | 0.01% | 1 | 0.37% |
| Jeremy Fitzhardinge | 1 | 0.01% | 1 | 0.37% |
| Eric Paris | 1 | 0.01% | 1 | 0.37% |
| Mike Galbraith | 1 | 0.01% | 1 | 0.37% |
| Miklos Szeredi | 1 | 0.01% | 1 | 0.37% |
| Kirill A. Shutemov | 1 | 0.01% | 1 | 0.37% |
| Total | 7283 | 268 |
// SPDX-License-Identifier: GPL-2.0 #include <linux/slab.h> #include <linux/file.h> #include <linux/fdtable.h> #include <linux/freezer.h> #include <linux/mm.h> #include <linux/stat.h> #include <linux/fcntl.h> #include <linux/swap.h> #include <linux/ctype.h> #include <linux/string.h> #include <linux/init.h> #include <linux/pagemap.h> #include <linux/perf_event.h> #include <linux/highmem.h> #include <linux/spinlock.h> #include <linux/key.h> #include <linux/personality.h> #include <linux/binfmts.h> #include <linux/coredump.h> #include <linux/sort.h> #include <linux/sched/coredump.h> #include <linux/sched/signal.h> #include <linux/sched/task_stack.h> #include <linux/utsname.h> #include <linux/pid_namespace.h> #include <linux/module.h> #include <linux/namei.h> #include <linux/mount.h> #include <linux/security.h> #include <linux/syscalls.h> #include <linux/tsacct_kern.h> #include <linux/cn_proc.h> #include <linux/audit.h> #include <linux/kmod.h> #include <linux/fsnotify.h> #include <linux/fs_struct.h> #include <linux/pipe_fs_i.h> #include <linux/oom.h> #include <linux/compat.h> #include <linux/fs.h> #include <linux/path.h> #include <linux/timekeeping.h> #include <linux/sysctl.h> #include <linux/elf.h> #include <linux/pidfs.h> #include <linux/net.h> #include <linux/socket.h> #include <net/af_unix.h> #include <net/net_namespace.h> #include <net/sock.h> #include <uapi/linux/pidfd.h> #include <uapi/linux/un.h> #include <uapi/linux/coredump.h> #include <linux/uaccess.h> #include <asm/mmu_context.h> #include <asm/tlb.h> #include <asm/exec.h> #include <trace/events/task.h> #include "internal.h" #include <trace/events/sched.h> static bool dump_vma_snapshot(struct coredump_params *cprm); static void free_vma_snapshot(struct coredump_params *cprm); #define CORE_FILE_NOTE_SIZE_DEFAULT (4*1024*1024) /* Define a reasonable max cap */ #define CORE_FILE_NOTE_SIZE_MAX (16*1024*1024) /* * File descriptor number for the pidfd for the thread-group leader of * the coredumping task installed into the usermode helper's file * descriptor table. */ #define COREDUMP_PIDFD_NUMBER 3 static int core_uses_pid; static unsigned int core_pipe_limit; static unsigned int core_sort_vma; static char core_pattern[CORENAME_MAX_SIZE] = "core"; static int core_name_size = CORENAME_MAX_SIZE; unsigned int core_file_note_size_limit = CORE_FILE_NOTE_SIZE_DEFAULT; static atomic_t core_pipe_count = ATOMIC_INIT(0); enum coredump_type_t { COREDUMP_FILE = 1, COREDUMP_PIPE = 2, COREDUMP_SOCK = 3, COREDUMP_SOCK_REQ = 4, }; struct core_name { char *corename; int used, size; unsigned int core_pipe_limit; bool core_dumped; enum coredump_type_t core_type; u64 mask; }; static int expand_corename(struct core_name *cn, int size) { char *corename; size = kmalloc_size_roundup(size); corename = krealloc(cn->corename, size, GFP_KERNEL); if (!corename) return -ENOMEM; if (size > core_name_size) /* racy but harmless */ core_name_size = size; cn->size = size; cn->corename = corename; return 0; } static __printf(2, 0) int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg) { int free, need; va_list arg_copy; again: free = cn->size - cn->used; va_copy(arg_copy, arg); need = vsnprintf(cn->corename + cn->used, free, fmt, arg_copy); va_end(arg_copy); if (need < free) { cn->used += need; return 0; } if (!expand_corename(cn, cn->size + need - free + 1)) goto again; return -ENOMEM; } static __printf(2, 3) int cn_printf(struct core_name *cn, const char *fmt, ...) { va_list arg; int ret; va_start(arg, fmt); ret = cn_vprintf(cn, fmt, arg); va_end(arg); return ret; } static __printf(2, 3) int cn_esc_printf(struct core_name *cn, const char *fmt, ...) { int cur = cn->used; va_list arg; int ret; va_start(arg, fmt); ret = cn_vprintf(cn, fmt, arg); va_end(arg); if (ret == 0) { /* * Ensure that this coredump name component can't cause the * resulting corefile path to consist of a ".." or ".". */ if ((cn->used - cur == 1 && cn->corename[cur] == '.') || (cn->used - cur == 2 && cn->corename[cur] == '.' && cn->corename[cur+1] == '.')) cn->corename[cur] = '!'; /* * Empty names are fishy and could be used to create a "//" in a * corefile name, causing the coredump to happen one directory * level too high. Enforce that all components of the core * pattern are at least one character long. */ if (cn->used == cur) ret = cn_printf(cn, "!"); } for (; cur < cn->used; ++cur) { if (cn->corename[cur] == '/') cn->corename[cur] = '!'; } return ret; } static int cn_print_exe_file(struct core_name *cn, bool name_only) { struct file *exe_file; char *pathbuf, *path, *ptr; int ret; exe_file = get_mm_exe_file(current->mm); if (!exe_file) return cn_esc_printf(cn, "%s (path unknown)", current->comm); pathbuf = kmalloc(PATH_MAX, GFP_KERNEL); if (!pathbuf) { ret = -ENOMEM; goto put_exe_file; } path = file_path(exe_file, pathbuf, PATH_MAX); if (IS_ERR(path)) { ret = PTR_ERR(path); goto free_buf; } if (name_only) { ptr = strrchr(path, '/'); if (ptr) path = ptr + 1; } ret = cn_esc_printf(cn, "%s", path); free_buf: kfree(pathbuf); put_exe_file: fput(exe_file); return ret; } /* * coredump_parse will inspect the pattern parameter, and output a name * into corename, which must have space for at least CORENAME_MAX_SIZE * bytes plus one byte for the zero terminator. */ static bool coredump_parse(struct core_name *cn, struct coredump_params *cprm, size_t **argv, int *argc) { const struct cred *cred = current_cred(); const char *pat_ptr = core_pattern; bool was_space = false; int pid_in_pattern = 0; int err = 0; cn->mask = COREDUMP_KERNEL; if (core_pipe_limit) cn->mask |= COREDUMP_WAIT; cn->used = 0; cn->corename = NULL; cn->core_pipe_limit = 0; cn->core_dumped = false; if (*pat_ptr == '|') cn->core_type = COREDUMP_PIPE; else if (*pat_ptr == '@') cn->core_type = COREDUMP_SOCK; else cn->core_type = COREDUMP_FILE; if (expand_corename(cn, core_name_size)) return false; cn->corename[0] = '\0'; switch (cn->core_type) { case COREDUMP_PIPE: { int argvs = sizeof(core_pattern) / 2; (*argv) = kmalloc_array(argvs, sizeof(**argv), GFP_KERNEL); if (!(*argv)) return false; (*argv)[(*argc)++] = 0; ++pat_ptr; if (!(*pat_ptr)) return false; break; } case COREDUMP_SOCK: { /* skip the @ */ pat_ptr++; if (!(*pat_ptr)) return false; if (*pat_ptr == '@') { pat_ptr++; if (!(*pat_ptr)) return false; cn->core_type = COREDUMP_SOCK_REQ; } err = cn_printf(cn, "%s", pat_ptr); if (err) return false; /* Require absolute paths. */ if (cn->corename[0] != '/') return false; /* * Ensure we can uses spaces to indicate additional * parameters in the future. */ if (strchr(cn->corename, ' ')) { coredump_report_failure("Coredump socket may not %s contain spaces", cn->corename); return false; } /* Must not contain ".." in the path. */ if (name_contains_dotdot(cn->corename)) { coredump_report_failure("Coredump socket may not %s contain '..' spaces", cn->corename); return false; } if (strlen(cn->corename) >= UNIX_PATH_MAX) { coredump_report_failure("Coredump socket path %s too long", cn->corename); return false; } /* * Currently no need to parse any other options. * Relevant information can be retrieved from the peer * pidfd retrievable via SO_PEERPIDFD by the receiver or * via /proc/<pid>, using the SO_PEERPIDFD to guard * against pid recycling when opening /proc/<pid>. */ return true; } case COREDUMP_FILE: break; default: WARN_ON_ONCE(true); return false; } /* Repeat as long as we have more pattern to process and more output space */ while (*pat_ptr) { /* * Split on spaces before doing template expansion so that * %e and %E don't get split if they have spaces in them */ if (cn->core_type == COREDUMP_PIPE) { if (isspace(*pat_ptr)) { if (cn->used != 0) was_space = true; pat_ptr++; continue; } else if (was_space) { was_space = false; err = cn_printf(cn, "%c", '\0'); if (err) return false; (*argv)[(*argc)++] = cn->used; } } if (*pat_ptr != '%') { err = cn_printf(cn, "%c", *pat_ptr++); } else { switch (*++pat_ptr) { /* single % at the end, drop that */ case 0: goto out; /* Double percent, output one percent */ case '%': err = cn_printf(cn, "%c", '%'); break; /* pid */ case 'p': pid_in_pattern = 1; err = cn_printf(cn, "%d", task_tgid_vnr(current)); break; /* global pid */ case 'P': err = cn_printf(cn, "%d", task_tgid_nr(current)); break; case 'i': err = cn_printf(cn, "%d", task_pid_vnr(current)); break; case 'I': err = cn_printf(cn, "%d", task_pid_nr(current)); break; /* uid */ case 'u': err = cn_printf(cn, "%u", from_kuid(&init_user_ns, cred->uid)); break; /* gid */ case 'g': err = cn_printf(cn, "%u", from_kgid(&init_user_ns, cred->gid)); break; case 'd': err = cn_printf(cn, "%d", __get_dumpable(cprm->mm_flags)); break; /* signal that caused the coredump */ case 's': err = cn_printf(cn, "%d", cprm->siginfo->si_signo); break; /* UNIX time of coredump */ case 't': { time64_t time; time = ktime_get_real_seconds(); err = cn_printf(cn, "%lld", time); break; } /* hostname */ case 'h': down_read(&uts_sem); err = cn_esc_printf(cn, "%s", utsname()->nodename); up_read(&uts_sem); break; /* executable, could be changed by prctl PR_SET_NAME etc */ case 'e': err = cn_esc_printf(cn, "%s", current->comm); break; /* file name of executable */ case 'f': err = cn_print_exe_file(cn, true); break; case 'E': err = cn_print_exe_file(cn, false); break; /* core limit size */ case 'c': err = cn_printf(cn, "%lu", rlimit(RLIMIT_CORE)); break; /* CPU the task ran on */ case 'C': err = cn_printf(cn, "%d", cprm->cpu); break; /* pidfd number */ case 'F': { /* * Installing a pidfd only makes sense if * we actually spawn a usermode helper. */ if (cn->core_type != COREDUMP_PIPE) break; /* * Note that we'll install a pidfd for the * thread-group leader. We know that task * linkage hasn't been removed yet and even if * this @current isn't the actual thread-group * leader we know that the thread-group leader * cannot be reaped until @current has exited. */ cprm->pid = task_tgid(current); err = cn_printf(cn, "%d", COREDUMP_PIDFD_NUMBER); break; } default: break; } ++pat_ptr; } if (err) return false; } out: /* Backward compatibility with core_uses_pid: * * If core_pattern does not include a %p (as is the default) * and core_uses_pid is set, then .%pid will be appended to * the filename. Do not do this for piped commands. */ if (cn->core_type == COREDUMP_FILE && !pid_in_pattern && core_uses_pid) return cn_printf(cn, ".%d", task_tgid_vnr(current)) == 0; return true; } static int zap_process(struct signal_struct *signal, int exit_code) { struct task_struct *t; int nr = 0; signal->flags = SIGNAL_GROUP_EXIT; signal->group_exit_code = exit_code; signal->group_stop_count = 0; __for_each_thread(signal, t) { task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); if (t != current && !(t->flags & PF_POSTCOREDUMP)) { sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); nr++; } } return nr; } static int zap_threads(struct task_struct *tsk, struct core_state *core_state, int exit_code) { struct signal_struct *signal = tsk->signal; int nr = -EAGAIN; spin_lock_irq(&tsk->sighand->siglock); if (!(signal->flags & SIGNAL_GROUP_EXIT) && !signal->group_exec_task) { /* Allow SIGKILL, see prepare_signal() */ signal->core_state = core_state; nr = zap_process(signal, exit_code); clear_tsk_thread_flag(tsk, TIF_SIGPENDING); tsk->flags |= PF_DUMPCORE; atomic_set(&core_state->nr_threads, nr); } spin_unlock_irq(&tsk->sighand->siglock); return nr; } static int coredump_wait(int exit_code, struct core_state *core_state) { struct task_struct *tsk = current; int core_waiters = -EBUSY; init_completion(&core_state->startup); core_state->dumper.task = tsk; core_state->dumper.next = NULL; core_waiters = zap_threads(tsk, core_state, exit_code); if (core_waiters > 0) { struct core_thread *ptr; wait_for_completion_state(&core_state->startup, TASK_UNINTERRUPTIBLE|TASK_FREEZABLE); /* * Wait for all the threads to become inactive, so that * all the thread context (extended register state, like * fpu etc) gets copied to the memory. */ ptr = core_state->dumper.next; while (ptr != NULL) { wait_task_inactive(ptr->task, TASK_ANY); ptr = ptr->next; } } return core_waiters; } static void coredump_finish(bool core_dumped) { struct core_thread *curr, *next; struct task_struct *task; spin_lock_irq(¤t->sighand->siglock); if (core_dumped && !__fatal_signal_pending(current)) current->signal->group_exit_code |= 0x80; next = current->signal->core_state->dumper.next; current->signal->core_state = NULL; spin_unlock_irq(¤t->sighand->siglock); while ((curr = next) != NULL) { next = curr->next; task = curr->task; /* * see coredump_task_exit(), curr->task must not see * ->task == NULL before we read ->next. */ smp_mb(); curr->task = NULL; wake_up_process(task); } } static bool dump_interrupted(void) { /* * SIGKILL or freezing() interrupt the coredumping. Perhaps we * can do try_to_freeze() and check __fatal_signal_pending(), * but then we need to teach dump_write() to restart and clear * TIF_SIGPENDING. */ return fatal_signal_pending(current) || freezing(current); } static void wait_for_dump_helpers(struct file *file) { struct pipe_inode_info *pipe = file->private_data; pipe_lock(pipe); pipe->readers++; pipe->writers--; wake_up_interruptible_sync(&pipe->rd_wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); pipe_unlock(pipe); /* * We actually want wait_event_freezable() but then we need * to clear TIF_SIGPENDING and improve dump_interrupted(). */ wait_event_interruptible(pipe->rd_wait, pipe->readers == 1); pipe_lock(pipe); pipe->readers--; pipe->writers++; pipe_unlock(pipe); } /* * umh_coredump_setup * helper function to customize the process used * to collect the core in userspace. Specifically * it sets up a pipe and installs it as fd 0 (stdin) * for the process. Returns 0 on success, or * PTR_ERR on failure. * Note that it also sets the core limit to 1. This * is a special value that we use to trap recursive * core dumps */ static int umh_coredump_setup(struct subprocess_info *info, struct cred *new) { struct file *files[2]; struct coredump_params *cp = (struct coredump_params *)info->data; int err; if (cp->pid) { struct file *pidfs_file __free(fput) = NULL; pidfs_file = pidfs_alloc_file(cp->pid, 0); if (IS_ERR(pidfs_file)) return PTR_ERR(pidfs_file); pidfs_coredump(cp); /* * Usermode helpers are childen of either * system_unbound_wq or of kthreadd. So we know that * we're starting off with a clean file descriptor * table. So we should always be able to use * COREDUMP_PIDFD_NUMBER as our file descriptor value. */ err = replace_fd(COREDUMP_PIDFD_NUMBER, pidfs_file, 0); if (err < 0) return err; } err = create_pipe_files(files, 0); if (err) return err; cp->file = files[1]; err = replace_fd(0, files[0], 0); fput(files[0]); if (err < 0) return err; /* and disallow core files too */ current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; return 0; } #ifdef CONFIG_UNIX static bool coredump_sock_connect(struct core_name *cn, struct coredump_params *cprm) { struct file *file __free(fput) = NULL; struct sockaddr_un addr = { .sun_family = AF_UNIX, }; ssize_t addr_len; int retval; struct socket *socket; addr_len = strscpy(addr.sun_path, cn->corename); if (addr_len < 0) return false; addr_len += offsetof(struct sockaddr_un, sun_path) + 1; /* * It is possible that the userspace process which is supposed * to handle the coredump and is listening on the AF_UNIX socket * coredumps. Userspace should just mark itself non dumpable. */ retval = sock_create_kern(&init_net, AF_UNIX, SOCK_STREAM, 0, &socket); if (retval < 0) return false; file = sock_alloc_file(socket, 0, NULL); if (IS_ERR(file)) return false; /* * Set the thread-group leader pid which is used for the peer * credentials during connect() below. Then immediately register * it in pidfs... */ cprm->pid = task_tgid(current); retval = pidfs_register_pid(cprm->pid); if (retval) return false; /* * ... and set the coredump information so userspace has it * available after connect()... */ pidfs_coredump(cprm); retval = kernel_connect(socket, (struct sockaddr *)(&addr), addr_len, O_NONBLOCK | SOCK_COREDUMP); if (retval) { if (retval == -EAGAIN) coredump_report_failure("Coredump socket %s receive queue full", addr.sun_path); else coredump_report_failure("Coredump socket connection %s failed %d", addr.sun_path, retval); return false; } /* ... and validate that @sk_peer_pid matches @cprm.pid. */ if (WARN_ON_ONCE(unix_peer(socket->sk)->sk_peer_pid != cprm->pid)) return false; cprm->limit = RLIM_INFINITY; cprm->file = no_free_ptr(file); return true; } static inline bool coredump_sock_recv(struct file *file, struct coredump_ack *ack, size_t size, int flags) { struct msghdr msg = {}; struct kvec iov = { .iov_base = ack, .iov_len = size }; ssize_t ret; memset(ack, 0, size); ret = kernel_recvmsg(sock_from_file(file), &msg, &iov, 1, size, flags); return ret == size; } static inline bool coredump_sock_send(struct file *file, struct coredump_req *req) { struct msghdr msg = { .msg_flags = MSG_NOSIGNAL }; struct kvec iov = { .iov_base = req, .iov_len = sizeof(*req) }; ssize_t ret; ret = kernel_sendmsg(sock_from_file(file), &msg, &iov, 1, sizeof(*req)); return ret == sizeof(*req); } static_assert(sizeof(enum coredump_mark) == sizeof(__u32)); static inline bool coredump_sock_mark(struct file *file, enum coredump_mark mark) { struct msghdr msg = { .msg_flags = MSG_NOSIGNAL }; struct kvec iov = { .iov_base = &mark, .iov_len = sizeof(mark) }; ssize_t ret; ret = kernel_sendmsg(sock_from_file(file), &msg, &iov, 1, sizeof(mark)); return ret == sizeof(mark); } static inline void coredump_sock_wait(struct file *file) { ssize_t n; /* * We use a simple read to wait for the coredump processing to * finish. Either the socket is closed or we get sent unexpected * data. In both cases, we're done. */ n = __kernel_read(file, &(char){ 0 }, 1, NULL); if (n > 0) coredump_report_failure("Coredump socket had unexpected data"); else if (n < 0) coredump_report_failure("Coredump socket failed"); } static inline void coredump_sock_shutdown(struct file *file) { struct socket *socket; socket = sock_from_file(file); if (!socket) return; /* Let userspace know we're done processing the coredump. */ kernel_sock_shutdown(socket, SHUT_WR); } static bool coredump_sock_request(struct core_name *cn, struct coredump_params *cprm) { struct coredump_req req = { .size = sizeof(struct coredump_req), .mask = COREDUMP_KERNEL | COREDUMP_USERSPACE | COREDUMP_REJECT | COREDUMP_WAIT, .size_ack = sizeof(struct coredump_ack), }; struct coredump_ack ack = {}; ssize_t usize; if (cn->core_type != COREDUMP_SOCK_REQ) return true; /* Let userspace know what we support. */ if (!coredump_sock_send(cprm->file, &req)) return false; /* Peek the size of the coredump_ack. */ if (!coredump_sock_recv(cprm->file, &ack, sizeof(ack.size), MSG_PEEK | MSG_WAITALL)) return false; /* Refuse unknown coredump_ack sizes. */ usize = ack.size; if (usize < COREDUMP_ACK_SIZE_VER0) { coredump_sock_mark(cprm->file, COREDUMP_MARK_MINSIZE); return false; } if (usize > sizeof(ack)) { coredump_sock_mark(cprm->file, COREDUMP_MARK_MAXSIZE); return false; } /* Now retrieve the coredump_ack. */ if (!coredump_sock_recv(cprm->file, &ack, usize, MSG_WAITALL)) return false; if (ack.size != usize) return false; /* Refuse unknown coredump_ack flags. */ if (ack.mask & ~req.mask) { coredump_sock_mark(cprm->file, COREDUMP_MARK_UNSUPPORTED); return false; } /* Refuse mutually exclusive options. */ if (hweight64(ack.mask & (COREDUMP_USERSPACE | COREDUMP_KERNEL | COREDUMP_REJECT)) != 1) { coredump_sock_mark(cprm->file, COREDUMP_MARK_CONFLICTING); return false; } if (ack.spare) { coredump_sock_mark(cprm->file, COREDUMP_MARK_UNSUPPORTED); return false; } cn->mask = ack.mask; return coredump_sock_mark(cprm->file, COREDUMP_MARK_REQACK); } static bool coredump_socket(struct core_name *cn, struct coredump_params *cprm) { if (!coredump_sock_connect(cn, cprm)) return false; return coredump_sock_request(cn, cprm); } #else static inline void coredump_sock_wait(struct file *file) { } static inline void coredump_sock_shutdown(struct file *file) { } static inline bool coredump_socket(struct core_name *cn, struct coredump_params *cprm) { return false; } #endif /* cprm->mm_flags contains a stable snapshot of dumpability flags. */ static inline bool coredump_force_suid_safe(const struct coredump_params *cprm) { /* Require nonrelative corefile path and be extra careful. */ return __get_dumpable(cprm->mm_flags) == SUID_DUMP_ROOT; } static bool coredump_file(struct core_name *cn, struct coredump_params *cprm, const struct linux_binfmt *binfmt) { struct mnt_idmap *idmap; struct inode *inode; struct file *file __free(fput) = NULL; int open_flags = O_CREAT | O_WRONLY | O_NOFOLLOW | O_LARGEFILE | O_EXCL; if (cprm->limit < binfmt->min_coredump) return false; if (coredump_force_suid_safe(cprm) && cn->corename[0] != '/') { coredump_report_failure("this process can only dump core to a fully qualified path, skipping core dump"); return false; } /* * Unlink the file if it exists unless this is a SUID * binary - in that case, we're running around with root * privs and don't want to unlink another user's coredump. */ if (!coredump_force_suid_safe(cprm)) { /* * If it doesn't exist, that's fine. If there's some * other problem, we'll catch it at the filp_open(). */ do_unlinkat(AT_FDCWD, getname_kernel(cn->corename)); } /* * There is a race between unlinking and creating the * file, but if that causes an EEXIST here, that's * fine - another process raced with us while creating * the corefile, and the other process won. To userspace, * what matters is that at least one of the two processes * writes its coredump successfully, not which one. */ if (coredump_force_suid_safe(cprm)) { /* * Using user namespaces, normal user tasks can change * their current->fs->root to point to arbitrary * directories. Since the intention of the "only dump * with a fully qualified path" rule is to control where * coredumps may be placed using root privileges, * current->fs->root must not be used. Instead, use the * root directory of init_task. */ struct path root; task_lock(&init_task); get_fs_root(init_task.fs, &root); task_unlock(&init_task); file = file_open_root(&root, cn->corename, open_flags, 0600); path_put(&root); } else { file = filp_open(cn->corename, open_flags, 0600); } if (IS_ERR(file)) return false; inode = file_inode(file); if (inode->i_nlink > 1) return false; if (d_unhashed(file->f_path.dentry)) return false; /* * AK: actually i see no reason to not allow this for named * pipes etc, but keep the previous behaviour for now. */ if (!S_ISREG(inode->i_mode)) return false; /* * Don't dump core if the filesystem changed owner or mode * of the file during file creation. This is an issue when * a process dumps core while its cwd is e.g. on a vfat * filesystem. */ idmap = file_mnt_idmap(file); if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode), current_fsuid())) { coredump_report_failure("Core dump to %s aborted: cannot preserve file owner", cn->corename); return false; } if ((inode->i_mode & 0677) != 0600) { coredump_report_failure("Core dump to %s aborted: cannot preserve file permissions", cn->corename); return false; } if (!(file->f_mode & FMODE_CAN_WRITE)) return false; if (do_truncate(idmap, file->f_path.dentry, 0, 0, file)) return false; cprm->file = no_free_ptr(file); return true; } static bool coredump_pipe(struct core_name *cn, struct coredump_params *cprm, size_t *argv, int argc) { int argi; char **helper_argv __free(kfree) = NULL; struct subprocess_info *sub_info; if (cprm->limit == 1) { /* See umh_coredump_setup() which sets RLIMIT_CORE = 1. * * Normally core limits are irrelevant to pipes, since * we're not writing to the file system, but we use * cprm.limit of 1 here as a special value, this is a * consistent way to catch recursive crashes. * We can still crash if the core_pattern binary sets * RLIM_CORE = !1, but it runs as root, and can do * lots of stupid things. * * Note that we use task_tgid_vnr here to grab the pid * of the process group leader. That way we get the * right pid if a thread in a multi-threaded * core_pattern process dies. */ coredump_report_failure("RLIMIT_CORE is set to 1, aborting core"); return false; } cprm->limit = RLIM_INFINITY; cn->core_pipe_limit = atomic_inc_return(&core_pipe_count); if (core_pipe_limit && (core_pipe_limit < cn->core_pipe_limit)) { coredump_report_failure("over core_pipe_limit, skipping core dump"); return false; } helper_argv = kmalloc_array(argc + 1, sizeof(*helper_argv), GFP_KERNEL); if (!helper_argv) { coredump_report_failure("%s failed to allocate memory", __func__); return false; } for (argi = 0; argi < argc; argi++) helper_argv[argi] = cn->corename + argv[argi]; helper_argv[argi] = NULL; sub_info = call_usermodehelper_setup(helper_argv[0], helper_argv, NULL, GFP_KERNEL, umh_coredump_setup, NULL, cprm); if (!sub_info) return false; if (call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC)) { coredump_report_failure("|%s pipe failed", cn->corename); return false; } /* * umh disabled with CONFIG_STATIC_USERMODEHELPER_PATH="" would * have this set to NULL. */ if (!cprm->file) { coredump_report_failure("Core dump to |%s disabled", cn->corename); return false; } return true; } static bool coredump_write(struct core_name *cn, struct coredump_params *cprm, struct linux_binfmt *binfmt) { if (dump_interrupted()) return true; if (!dump_vma_snapshot(cprm)) return false; file_start_write(cprm->file); cn->core_dumped = binfmt->core_dump(cprm); /* * Ensures that file size is big enough to contain the current * file postion. This prevents gdb from complaining about * a truncated file if the last "write" to the file was * dump_skip. */ if (cprm->to_skip) { cprm->to_skip--; dump_emit(cprm, "", 1); } file_end_write(cprm->file); free_vma_snapshot(cprm); return true; } static void coredump_cleanup(struct core_name *cn, struct coredump_params *cprm) { if (cprm->file) filp_close(cprm->file, NULL); if (cn->core_pipe_limit) { VFS_WARN_ON_ONCE(cn->core_type != COREDUMP_PIPE); atomic_dec(&core_pipe_count); } kfree(cn->corename); coredump_finish(cn->core_dumped); } static inline bool coredump_skip(const struct coredump_params *cprm, const struct linux_binfmt *binfmt) { if (!binfmt) return true; if (!binfmt->core_dump) return true; if (!__get_dumpable(cprm->mm_flags)) return true; return false; } void vfs_coredump(const kernel_siginfo_t *siginfo) { struct cred *cred __free(put_cred) = NULL; size_t *argv __free(kfree) = NULL; struct core_state core_state; struct core_name cn; struct mm_struct *mm = current->mm; struct linux_binfmt *binfmt = mm->binfmt; const struct cred *old_cred; int argc = 0; struct coredump_params cprm = { .siginfo = siginfo, .limit = rlimit(RLIMIT_CORE), /* * We must use the same mm->flags while dumping core to avoid * inconsistency of bit flags, since this flag is not protected * by any locks. */ .mm_flags = mm->flags, .vma_meta = NULL, .cpu = raw_smp_processor_id(), }; audit_core_dumps(siginfo->si_signo); if (coredump_skip(&cprm, binfmt)) return; cred = prepare_creds(); if (!cred) return; /* * We cannot trust fsuid as being the "true" uid of the process * nor do we know its entire history. We only know it was tainted * so we dump it as root in mode 2, and only into a controlled * environment (pipe handler or fully qualified path). */ if (coredump_force_suid_safe(&cprm)) cred->fsuid = GLOBAL_ROOT_UID; if (coredump_wait(siginfo->si_signo, &core_state) < 0) return; old_cred = override_creds(cred); if (!coredump_parse(&cn, &cprm, &argv, &argc)) { coredump_report_failure("format_corename failed, aborting core"); goto close_fail; } switch (cn.core_type) { case COREDUMP_FILE: if (!coredump_file(&cn, &cprm, binfmt)) goto close_fail; break; case COREDUMP_PIPE: if (!coredump_pipe(&cn, &cprm, argv, argc)) goto close_fail; break; case COREDUMP_SOCK_REQ: fallthrough; case COREDUMP_SOCK: if (!coredump_socket(&cn, &cprm)) goto close_fail; break; default: WARN_ON_ONCE(true); goto close_fail; } /* Don't even generate the coredump. */ if (cn.mask & COREDUMP_REJECT) goto close_fail; /* get us an unshared descriptor table; almost always a no-op */ /* The cell spufs coredump code reads the file descriptor tables */ if (unshare_files()) goto close_fail; if ((cn.mask & COREDUMP_KERNEL) && !coredump_write(&cn, &cprm, binfmt)) goto close_fail; coredump_sock_shutdown(cprm.file); /* Let the parent know that a coredump was generated. */ if (cn.mask & COREDUMP_USERSPACE) cn.core_dumped = true; /* * When core_pipe_limit is set we wait for the coredump server * or usermodehelper to finish before exiting so it can e.g., * inspect /proc/<pid>. */ if (cn.mask & COREDUMP_WAIT) { switch (cn.core_type) { case COREDUMP_PIPE: wait_for_dump_helpers(cprm.file); break; case COREDUMP_SOCK_REQ: fallthrough; case COREDUMP_SOCK: coredump_sock_wait(cprm.file); break; default: break; } } close_fail: coredump_cleanup(&cn, &cprm); revert_creds(old_cred); return; } /* * Core dumping helper functions. These are the only things you should * do on a core-file: use only these functions to write out all the * necessary info. */ static int __dump_emit(struct coredump_params *cprm, const void *addr, int nr) { struct file *file = cprm->file; loff_t pos = file->f_pos; ssize_t n; if (cprm->written + nr > cprm->limit) return 0; if (dump_interrupted()) return 0; n = __kernel_write(file, addr, nr, &pos); if (n != nr) return 0; file->f_pos = pos; cprm->written += n; cprm->pos += n; return 1; } static int __dump_skip(struct coredump_params *cprm, size_t nr) { static char zeroes[PAGE_SIZE]; struct file *file = cprm->file; if (file->f_mode & FMODE_LSEEK) { if (dump_interrupted() || vfs_llseek(file, nr, SEEK_CUR) < 0) return 0; cprm->pos += nr; return 1; } while (nr > PAGE_SIZE) { if (!__dump_emit(cprm, zeroes, PAGE_SIZE)) return 0; nr -= PAGE_SIZE; } return __dump_emit(cprm, zeroes, nr); } int dump_emit(struct coredump_params *cprm, const void *addr, int nr) { if (cprm->to_skip) { if (!__dump_skip(cprm, cprm->to_skip)) return 0; cprm->to_skip = 0; } return __dump_emit(cprm, addr, nr); } EXPORT_SYMBOL(dump_emit); void dump_skip_to(struct coredump_params *cprm, unsigned long pos) { cprm->to_skip = pos - cprm->pos; } EXPORT_SYMBOL(dump_skip_to); void dump_skip(struct coredump_params *cprm, size_t nr) { cprm->to_skip += nr; } EXPORT_SYMBOL(dump_skip); #ifdef CONFIG_ELF_CORE static int dump_emit_page(struct coredump_params *cprm, struct page *page) { struct bio_vec bvec; struct iov_iter iter; struct file *file = cprm->file; loff_t pos; ssize_t n; if (!page) return 0; if (cprm->to_skip) { if (!__dump_skip(cprm, cprm->to_skip)) return 0; cprm->to_skip = 0; } if (cprm->written + PAGE_SIZE > cprm->limit) return 0; if (dump_interrupted()) return 0; pos = file->f_pos; bvec_set_page(&bvec, page, PAGE_SIZE, 0); iov_iter_bvec(&iter, ITER_SOURCE, &bvec, 1, PAGE_SIZE); n = __kernel_write_iter(cprm->file, &iter, &pos); if (n != PAGE_SIZE) return 0; file->f_pos = pos; cprm->written += PAGE_SIZE; cprm->pos += PAGE_SIZE; return 1; } /* * If we might get machine checks from kernel accesses during the * core dump, let's get those errors early rather than during the * IO. This is not performance-critical enough to warrant having * all the machine check logic in the iovec paths. */ #ifdef copy_mc_to_kernel #define dump_page_alloc() alloc_page(GFP_KERNEL) #define dump_page_free(x) __free_page(x) static struct page *dump_page_copy(struct page *src, struct page *dst) { void *buf = kmap_local_page(src); size_t left = copy_mc_to_kernel(page_address(dst), buf, PAGE_SIZE); kunmap_local(buf); return left ? NULL : dst; } #else /* We just want to return non-NULL; it's never used. */ #define dump_page_alloc() ERR_PTR(-EINVAL) #define dump_page_free(x) ((void)(x)) static inline struct page *dump_page_copy(struct page *src, struct page *dst) { return src; } #endif int dump_user_range(struct coredump_params *cprm, unsigned long start, unsigned long len) { unsigned long addr; struct page *dump_page; int locked, ret; dump_page = dump_page_alloc(); if (!dump_page) return 0; ret = 0; locked = 0; for (addr = start; addr < start + len; addr += PAGE_SIZE) { struct page *page; if (!locked) { if (mmap_read_lock_killable(current->mm)) goto out; locked = 1; } /* * To avoid having to allocate page tables for virtual address * ranges that have never been used yet, and also to make it * easy to generate sparse core files, use a helper that returns * NULL when encountering an empty page table entry that would * otherwise have been filled with the zero page. */ page = get_dump_page(addr, &locked); if (page) { if (locked) { mmap_read_unlock(current->mm); locked = 0; } int stop = !dump_emit_page(cprm, dump_page_copy(page, dump_page)); put_page(page); if (stop) goto out; } else { dump_skip(cprm, PAGE_SIZE); } if (dump_interrupted()) goto out; if (!need_resched()) continue; if (locked) { mmap_read_unlock(current->mm); locked = 0; } cond_resched(); } ret = 1; out: if (locked) mmap_read_unlock(current->mm); dump_page_free(dump_page); return ret; } #endif int dump_align(struct coredump_params *cprm, int align) { unsigned mod = (cprm->pos + cprm->to_skip) & (align - 1); if (align & (align - 1)) return 0; if (mod) cprm->to_skip += align - mod; return 1; } EXPORT_SYMBOL(dump_align); #ifdef CONFIG_SYSCTL void validate_coredump_safety(void) { if (suid_dumpable == SUID_DUMP_ROOT && core_pattern[0] != '/' && core_pattern[0] != '|' && core_pattern[0] != '@') { coredump_report_failure("Unsafe core_pattern used with fs.suid_dumpable=2: " "pipe handler or fully qualified core dump path required. " "Set kernel.core_pattern before fs.suid_dumpable."); } } static inline bool check_coredump_socket(void) { const char *p; if (core_pattern[0] != '@') return true; /* * Coredump socket must be located in the initial mount * namespace. Don't give the impression that anything else is * supported right now. */ if (current->nsproxy->mnt_ns != init_task.nsproxy->mnt_ns) return false; /* Must be an absolute path... */ if (core_pattern[1] != '/') { /* ... or the socket request protocol... */ if (core_pattern[1] != '@') return false; /* ... and if so must be an absolute path. */ if (core_pattern[2] != '/') return false; p = &core_pattern[2]; } else { p = &core_pattern[1]; } /* The path obviously cannot exceed UNIX_PATH_MAX. */ if (strlen(p) >= UNIX_PATH_MAX) return false; /* Must not contain ".." in the path. */ if (name_contains_dotdot(core_pattern)) return false; return true; } static int proc_dostring_coredump(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { int error; ssize_t retval; char old_core_pattern[CORENAME_MAX_SIZE]; if (write) return proc_dostring(table, write, buffer, lenp, ppos); retval = strscpy(old_core_pattern, core_pattern, CORENAME_MAX_SIZE); error = proc_dostring(table, write, buffer, lenp, ppos); if (error) return error; if (!check_coredump_socket()) { strscpy(core_pattern, old_core_pattern, retval + 1); return -EINVAL; } validate_coredump_safety(); return error; } static const unsigned int core_file_note_size_min = CORE_FILE_NOTE_SIZE_DEFAULT; static const unsigned int core_file_note_size_max = CORE_FILE_NOTE_SIZE_MAX; static char core_modes[] = { "file\npipe" #ifdef CONFIG_UNIX "\nsocket" #endif }; static const struct ctl_table coredump_sysctls[] = { { .procname = "core_uses_pid", .data = &core_uses_pid, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "core_pattern", .data = core_pattern, .maxlen = CORENAME_MAX_SIZE, .mode = 0644, .proc_handler = proc_dostring_coredump, }, { .procname = "core_pipe_limit", .data = &core_pipe_limit, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_INT_MAX, }, { .procname = "core_file_note_size_limit", .data = &core_file_note_size_limit, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_douintvec_minmax, .extra1 = (unsigned int *)&core_file_note_size_min, .extra2 = (unsigned int *)&core_file_note_size_max, }, { .procname = "core_sort_vma", .data = &core_sort_vma, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_douintvec_minmax, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_ONE, }, { .procname = "core_modes", .data = core_modes, .maxlen = sizeof(core_modes) - 1, .mode = 0444, .proc_handler = proc_dostring, }, }; static int __init init_fs_coredump_sysctls(void) { register_sysctl_init("kernel", coredump_sysctls); return 0; } fs_initcall(init_fs_coredump_sysctls); #endif /* CONFIG_SYSCTL */ /* * The purpose of always_dump_vma() is to make sure that special kernel mappings * that are useful for post-mortem analysis are included in every core dump. * In that way we ensure that the core dump is fully interpretable later * without matching up the same kernel and hardware config to see what PC values * meant. These special mappings include - vDSO, vsyscall, and other * architecture specific mappings */ static bool always_dump_vma(struct vm_area_struct *vma) { /* Any vsyscall mappings? */ if (vma == get_gate_vma(vma->vm_mm)) return true; /* * Assume that all vmas with a .name op should always be dumped. * If this changes, a new vm_ops field can easily be added. */ if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma)) return true; /* * arch_vma_name() returns non-NULL for special architecture mappings, * such as vDSO sections. */ if (arch_vma_name(vma)) return true; return false; } #define DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER 1 /* * Decide how much of @vma's contents should be included in a core dump. */ static unsigned long vma_dump_size(struct vm_area_struct *vma, unsigned long mm_flags) { #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) /* always dump the vdso and vsyscall sections */ if (always_dump_vma(vma)) goto whole; if (vma->vm_flags & VM_DONTDUMP) return 0; /* support for DAX */ if (vma_is_dax(vma)) { if ((vma->vm_flags & VM_SHARED) && FILTER(DAX_SHARED)) goto whole; if (!(vma->vm_flags & VM_SHARED) && FILTER(DAX_PRIVATE)) goto whole; return 0; } /* Hugetlb memory check */ if (is_vm_hugetlb_page(vma)) { if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) goto whole; if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) goto whole; return 0; } /* Do not dump I/O mapped devices or special mappings */ if (vma->vm_flags & VM_IO) return 0; /* By default, dump shared memory if mapped from an anonymous file. */ if (vma->vm_flags & VM_SHARED) { if (file_inode(vma->vm_file)->i_nlink == 0 ? FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) goto whole; return 0; } /* Dump segments that have been written to. */ if ((!IS_ENABLED(CONFIG_MMU) || vma->anon_vma) && FILTER(ANON_PRIVATE)) goto whole; if (vma->vm_file == NULL) return 0; if (FILTER(MAPPED_PRIVATE)) goto whole; /* * If this is the beginning of an executable file mapping, * dump the first page to aid in determining what was mapped here. */ if (FILTER(ELF_HEADERS) && vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { if ((READ_ONCE(file_inode(vma->vm_file)->i_mode) & 0111) != 0) return PAGE_SIZE; /* * ELF libraries aren't always executable. * We'll want to check whether the mapping starts with the ELF * magic, but not now - we're holding the mmap lock, * so copy_from_user() doesn't work here. * Use a placeholder instead, and fix it up later in * dump_vma_snapshot(). */ return DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER; } #undef FILTER return 0; whole: return vma->vm_end - vma->vm_start; } /* * Helper function for iterating across a vma list. It ensures that the caller * will visit `gate_vma' prior to terminating the search. */ static struct vm_area_struct *coredump_next_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, struct vm_area_struct *gate_vma) { if (gate_vma && (vma == gate_vma)) return NULL; vma = vma_next(vmi); if (vma) return vma; return gate_vma; } static void free_vma_snapshot(struct coredump_params *cprm) { if (cprm->vma_meta) { int i; for (i = 0; i < cprm->vma_count; i++) { struct file *file = cprm->vma_meta[i].file; if (file) fput(file); } kvfree(cprm->vma_meta); cprm->vma_meta = NULL; } } static int cmp_vma_size(const void *vma_meta_lhs_ptr, const void *vma_meta_rhs_ptr) { const struct core_vma_metadata *vma_meta_lhs = vma_meta_lhs_ptr; const struct core_vma_metadata *vma_meta_rhs = vma_meta_rhs_ptr; if (vma_meta_lhs->dump_size < vma_meta_rhs->dump_size) return -1; if (vma_meta_lhs->dump_size > vma_meta_rhs->dump_size) return 1; return 0; } /* * Under the mmap_lock, take a snapshot of relevant information about the task's * VMAs. */ static bool dump_vma_snapshot(struct coredump_params *cprm) { struct vm_area_struct *gate_vma, *vma = NULL; struct mm_struct *mm = current->mm; VMA_ITERATOR(vmi, mm, 0); int i = 0; /* * Once the stack expansion code is fixed to not change VMA bounds * under mmap_lock in read mode, this can be changed to take the * mmap_lock in read mode. */ if (mmap_write_lock_killable(mm)) return false; cprm->vma_data_size = 0; gate_vma = get_gate_vma(mm); cprm->vma_count = mm->map_count + (gate_vma ? 1 : 0); cprm->vma_meta = kvmalloc_array(cprm->vma_count, sizeof(*cprm->vma_meta), GFP_KERNEL); if (!cprm->vma_meta) { mmap_write_unlock(mm); return false; } while ((vma = coredump_next_vma(&vmi, vma, gate_vma)) != NULL) { struct core_vma_metadata *m = cprm->vma_meta + i; m->start = vma->vm_start; m->end = vma->vm_end; m->flags = vma->vm_flags; m->dump_size = vma_dump_size(vma, cprm->mm_flags); m->pgoff = vma->vm_pgoff; m->file = vma->vm_file; if (m->file) get_file(m->file); i++; } mmap_write_unlock(mm); for (i = 0; i < cprm->vma_count; i++) { struct core_vma_metadata *m = cprm->vma_meta + i; if (m->dump_size == DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER) { char elfmag[SELFMAG]; if (copy_from_user(elfmag, (void __user *)m->start, SELFMAG) || memcmp(elfmag, ELFMAG, SELFMAG) != 0) { m->dump_size = 0; } else { m->dump_size = PAGE_SIZE; } } cprm->vma_data_size += m->dump_size; } if (core_sort_vma) sort(cprm->vma_meta, cprm->vma_count, sizeof(*cprm->vma_meta), cmp_vma_size, NULL); return true; }
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