abrt-hook-ccpp.cpp -> abrt-hook-ccpp.c

Pure rename, no code changes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

1 files changed, 548 insertions, 0 deletions

diff --git a/src/hooks/abrt-hook-ccpp.c b/src/hooks/abrt-hook-ccpp.c
new file mode 100644
index 00000000..5beabbac
--- /dev/null
+++ b/src/hooks/abrt-hook-ccpp.c
@@ -0,0 +1,548 @@
+/*
+    abrt-hook-ccpp.cpp - the hook for C/C++ crashing program
+
+    Copyright (C) 2009	Zdenek Prikryl (zprikryl@redhat.com)
+    Copyright (C) 2009	RedHat inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+#include "abrtlib.h"
+#include "hooklib.h"
+#include <syslog.h>
+
+static char* malloc_readlink(const char *linkname)
+{
+    char buf[PATH_MAX + 1];
+    int len;
+
+    len = readlink(linkname, buf, sizeof(buf)-1);
+    if (len >= 0)
+    {
+        buf[len] = '\0';
+        return xstrdup(buf);
+    }
+    return NULL;
+}
+
+/* Custom version of copyfd_xyz,
+ * one which is able to write into two descriptors at once.
+ */
+#define CONFIG_FEATURE_COPYBUF_KB 4
+static off_t copyfd_sparse(int src_fd, int dst_fd1, int dst_fd2, off_t size2)
+{
+	off_t total = 0;
+	int last_was_seek = 0;
+#if CONFIG_FEATURE_COPYBUF_KB <= 4
+	char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
+	enum { buffer_size = sizeof(buffer) };
+#else
+	char *buffer;
+	int buffer_size;
+
+	/* We want page-aligned buffer, just in case kernel is clever
+	 * and can do page-aligned io more efficiently */
+	buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024,
+			PROT_READ | PROT_WRITE,
+			MAP_PRIVATE | MAP_ANON,
+			/* ignored: */ -1, 0);
+	buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024;
+	if (buffer == MAP_FAILED) {
+		buffer = alloca(4 * 1024);
+		buffer_size = 4 * 1024;
+	}
+#endif
+
+	while (1) {
+		ssize_t rd = safe_read(src_fd, buffer, buffer_size);
+		if (!rd) { /* eof */
+			if (last_was_seek) {
+				if (lseek(dst_fd1, -1, SEEK_CUR) < 0
+				 || safe_write(dst_fd1, "", 1) != 1
+				 || (dst_fd2 >= 0
+				     && (lseek(dst_fd2, -1, SEEK_CUR) < 0
+					 || safe_write(dst_fd2, "", 1) != 1
+				        )
+				    )
+				) {
+					perror_msg("write error");
+					total = -1;
+					goto out;
+				}
+			}
+			/* all done */
+			goto out;
+		}
+		if (rd < 0) {
+			perror_msg("read error");
+			total = -1;
+			goto out;
+		}
+
+		/* checking sparseness */
+		ssize_t cnt = rd;
+		while (--cnt >= 0) {
+			if (buffer[cnt] != 0) {
+				/* not sparse */
+				errno = 0;
+				ssize_t wr1 = full_write(dst_fd1, buffer, rd);
+				ssize_t wr2 = (dst_fd2 >= 0 ? full_write(dst_fd2, buffer, rd) : rd);
+				if (wr1 < rd || wr2 < rd) {
+					perror_msg("write error");
+					total = -1;
+					goto out;
+				}
+				last_was_seek = 0;
+				goto adv;
+			}
+		}
+		/* sparse */
+		xlseek(dst_fd1, rd, SEEK_CUR);
+		if (dst_fd2 >= 0)
+			xlseek(dst_fd2, rd, SEEK_CUR);
+		last_was_seek = 1;
+ adv:
+		total += rd;
+		size2 -= rd;
+		if (size2 < 0)
+			dst_fd2 = -1;
+	}
+ out:
+
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+	if (buffer_size != 4 * 1024)
+		munmap(buffer, buffer_size);
+#endif
+	return total;
+}
+
+static char* get_executable(pid_t pid, int *fd_p)
+{
+    char buf[sizeof("/proc/%lu/exe") + sizeof(long)*3];
+
+    sprintf(buf, "/proc/%lu/exe", (long)pid);
+    *fd_p = open(buf, O_RDONLY); /* might fail and return -1, it's ok */
+    char *executable = malloc_readlink(buf);
+    if (!executable)
+        return NULL;
+    /* find and cut off " (deleted)" from the path */
+    char *deleted = executable + strlen(executable) - strlen(" (deleted)");
+    if (deleted > executable && strcmp(deleted, " (deleted)") == 0)
+    {
+        *deleted = '\0';
+        log("file %s seems to be deleted", executable);
+    }
+    /* find and cut off prelink suffixes from the path */
+    char *prelink = executable + strlen(executable) - strlen(".#prelink#.XXXXXX");
+    if (prelink > executable && strncmp(prelink, ".#prelink#.", strlen(".#prelink#.")) == 0)
+    {
+        log("file %s seems to be a prelink temporary file", executable);
+        *prelink = '\0';
+    }
+    return executable;
+}
+
+static char* get_cwd(pid_t pid)
+{
+    char buf[sizeof("/proc/%lu/cwd") + sizeof(long)*3];
+
+    sprintf(buf, "/proc/%lu/cwd", (long)pid);
+    return malloc_readlink(buf);
+}
+
+static char core_basename[sizeof("core.%lu") + sizeof(long)*3] = "core";
+
+static int open_user_core(const char *user_pwd, uid_t uid, pid_t pid)
+{
+    struct passwd* pw = getpwuid(uid);
+    gid_t gid = pw ? pw->pw_gid : uid;
+    xsetegid(gid);
+    xseteuid(uid);
+
+    errno = 0;
+    if (user_pwd == NULL
+     || chdir(user_pwd) != 0
+    ) {
+        perror_msg("can't cd to %s", user_pwd);
+        return 0;
+    }
+
+    /* Mimic "core.PID" if requested */
+    char buf[] = "0\n";
+    int fd = open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
+    if (fd >= 0)
+    {
+        read(fd, buf, sizeof(buf));
+        close(fd);
+    }
+    if (strcmp(buf, "1\n") == 0)
+    {
+        sprintf(core_basename, "core.%lu", (long)pid);
+    }
+
+    /* man core:
+     * There are various circumstances in which a core dump file
+     * is not produced:
+     *
+     * [skipped obvious ones]
+     * The process does not have permission to write the core file.
+     * ...if a file with the same name exists and is not writable
+     * or is not a regular file (e.g., it is a directory or a symbolic link).
+     *
+     * A file with the same name already exists, but there is more
+     * than one hard link to that file.
+     *
+     * The file system where the core dump file would be created is full;
+     * or has run out of inodes; or is mounted read-only;
+     * or the user has reached their quota for the file system.
+     *
+     * The RLIMIT_CORE or RLIMIT_FSIZE resource limits for the process
+     * are set to zero.
+     * [shouldn't it be checked by kernel? 2.6.30.9-96 doesn't, still
+     * calls us even if "ulimit -c 0"]
+     *
+     * The binary being executed by the process does not have
+     * read permission enabled. [how we can check it here?]
+     *
+     * The process is executing a set-user-ID (set-group-ID) program
+     * that is owned by a user (group) other than the real
+     * user (group) ID of the process. [TODO?]
+     * (However, see the description of the prctl(2) PR_SET_DUMPABLE operation,
+     * and the description of the /proc/sys/fs/suid_dumpable file in proc(5).)
+     */
+
+    /* Do not O_TRUNC: if later checks fail, we do not want to have file already modified here */
+    struct stat sb;
+    errno = 0;
+    int user_core_fd = open(core_basename, O_WRONLY | O_CREAT | O_NOFOLLOW, 0600); /* kernel makes 0600 too */
+    xsetegid(0);
+    xseteuid(0);
+    if (user_core_fd < 0
+     || fstat(user_core_fd, &sb) != 0
+     || !S_ISREG(sb.st_mode)
+     || sb.st_nlink != 1
+    /* kernel internal dumper checks this too: if (inode->i_uid != current->fsuid) <fail>, need to mimic? */
+    ) {
+        perror_msg("%s/%s is not a regular file with link count 1", user_pwd, core_basename);
+        return -1;
+    }
+    if (ftruncate(user_core_fd, 0) != 0) {
+        /* perror first, otherwise unlink may trash errno */
+        perror_msg("truncate %s/%s", user_pwd, core_basename);
+        return -1;
+    }
+
+    return user_core_fd;
+}
+
+int main(int argc, char** argv)
+{
+    int i;
+    struct stat sb;
+
+    if (argc < 5)
+    {
+        error_msg_and_die("Usage: %s: DUMPDIR PID SIGNO UID CORE_SIZE_LIMIT", argv[0]);
+    }
+
+    /* Not needed on 2.6.30.
+     * At least 2.6.18 has a bug where
+     * argv[1] = "DUMPDIR PID SIGNO UID CORE_SIZE_LIMIT"
+     * argv[2] = "PID SIGNO UID CORE_SIZE_LIMIT"
+     * and so on. Fixing it:
+     */
+    for (i = 1; argv[i]; i++)
+    {
+        strchrnul(argv[i], ' ')[0] = '\0';
+    }
+
+    openlog("abrt", LOG_PID, LOG_DAEMON);
+    logmode = LOGMODE_SYSLOG;
+
+    errno = 0;
+    const char* dddir = argv[1];
+    pid_t pid = xatoi_u(argv[2]);
+    const char* signal_str = argv[3];
+    int signal_no = xatoi_u(argv[3]);
+    uid_t uid = xatoi_u(argv[4]);
+    off_t ulimit_c = strtoull(argv[5], NULL, 10);
+    if (ulimit_c < 0) /* unlimited? */
+    {
+        /* set to max possible >0 value */
+        ulimit_c = ~((off_t)1 << (sizeof(off_t)*8-1));
+    }
+    if (errno || pid <= 0)
+    {
+        error_msg_and_die("pid '%s' or limit '%s' is bogus", argv[2], argv[5]);
+    }
+
+    int src_fd_binary;
+    char *executable = get_executable(pid, &src_fd_binary);
+    if (executable && strstr(executable, "/abrt-hook-ccpp"))
+    {
+        error_msg_and_die("pid %lu is '%s', not dumping it to avoid recursion",
+                        (long)pid, executable);
+    }
+
+    char *user_pwd = get_cwd(pid); /* may be NULL on error */
+
+    /* Parse abrt.conf and plugins/CCpp.conf */
+    unsigned setting_MaxCrashReportsSize = 0;
+    bool setting_MakeCompatCore = false;
+    bool setting_SaveBinaryImage = false;
+    parse_conf(CONF_DIR"/plugins/CCpp.conf", &setting_MaxCrashReportsSize, &setting_MakeCompatCore, &setting_SaveBinaryImage);
+    if (!setting_SaveBinaryImage && src_fd_binary >= 0)
+    {
+        close(src_fd_binary);
+        src_fd_binary = -1;
+    }
+
+    /* Open a fd to compat coredump, if requested and is possible */
+    int user_core_fd = -1;
+    if (setting_MakeCompatCore && ulimit_c != 0)
+        /* note: checks "user_pwd == NULL" inside */
+        user_core_fd = open_user_core(user_pwd, uid, pid);
+
+    if (executable == NULL)
+    {
+        /* readlink on /proc/$PID/exe failed, don't create abrt dump dir */
+        error_msg("can't read /proc/%lu/exe link", (long)pid);
+        goto create_user_core;
+    }
+
+    const char *signame = NULL;
+    /* Tried to use array for this but C++ does not support v[] = { [IDX] = "str" } */
+    switch (signal_no)
+    {
+        case SIGILL : signame = "ILL" ; break;
+        case SIGFPE : signame = "FPE" ; break;
+        case SIGSEGV: signame = "SEGV"; break;
+        case SIGBUS : signame = "BUS" ; break; //Bus error (bad memory access)
+        case SIGABRT: signame = "ABRT"; break; //usually when abort() was called
+      //case SIGQUIT: signame = "QUIT"; break; //Quit from keyboard
+      //case SIGSYS : signame = "SYS" ; break; //Bad argument to routine (SVr4)
+      //case SIGTRAP: signame = "TRAP"; break; //Trace/breakpoint trap
+      //case SIGXCPU: signame = "XCPU"; break; //CPU time limit exceeded (4.2BSD)
+      //case SIGXFSZ: signame = "XFSZ"; break; //File size limit exceeded (4.2BSD)
+        default: goto create_user_core; // not a signal we care about
+    }
+
+    if (!daemon_is_ok())
+    {
+        /* not an error, exit with exitcode 0 */
+        log("abrt daemon is not running. If it crashed, "
+            "/proc/sys/kernel/core_pattern contains a stale value, "
+            "consider resetting it to 'core'"
+        );
+        goto create_user_core;
+    }
+
+    if (setting_MaxCrashReportsSize > 0)
+    {
+        check_free_space(setting_MaxCrashReportsSize);
+    }
+
+    char path[PATH_MAX];
+
+    /* Check /var/spool/abrt/last-ccpp marker, do not dump repeated crashes
+     * if they happen too often. Else, write new marker value.
+     */
+    snprintf(path, sizeof(path), "%s/last-ccpp", dddir);
+    int fd = open(path, O_RDWR | O_CREAT, 0600);
+    if (fd >= 0)
+    {
+        int sz;
+        fstat(fd, &sb); /* !paranoia. this can't fail. */
+
+        if (sb.st_size != 0 /* if it wasn't created by us just now... */
+         && (unsigned)(time(NULL) - sb.st_mtime) < 20 /* and is relatively new [is 20 sec ok?] */
+        ) {
+            sz = read(fd, path, sizeof(path)-1); /* (ab)using path as scratch buf */
+            if (sz > 0)
+            {
+                path[sz] = '\0';
+                if (strcmp(executable, path) == 0)
+                {
+                    error_msg("not dumping repeating crash in '%s'", executable);
+                    if (setting_MakeCompatCore)
+                        goto create_user_core;
+                    return 1;
+                }
+            }
+            lseek(fd, 0, SEEK_SET);
+        }
+        sz = write(fd, executable, strlen(executable));
+        if (sz >= 0)
+            ftruncate(fd, sz);
+        close(fd);
+    }
+
+    const char *last_slash = strrchr(executable, '/');
+    if (last_slash && strncmp(++last_slash, "abrt", 4) == 0)
+    {
+        /* If abrtd/abrt-foo crashes, we don't want to create a _directory_,
+         * since that can make new copy of abrtd to process it,
+         * and maybe crash again...
+         * Unlike dirs, mere files are ignored by abrtd.
+         */
+        snprintf(path, sizeof(path), "%s/%s-coredump", dddir, last_slash);
+        int abrt_core_fd = xopen3(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+        off_t core_size = copyfd_eof(STDIN_FILENO, abrt_core_fd, COPYFD_SPARSE);
+        if (core_size < 0 || fsync(abrt_core_fd) != 0)
+        {
+            unlink(path);
+            /* copyfd_eof logs the error including errno string,
+             * but it does not log file name */
+            error_msg_and_die("error saving coredump to %s", path);
+        }
+        log("saved core dump of pid %lu (%s) to %s (%llu bytes)", (long)pid, executable, path, (long long)core_size);
+        return 0;
+    }
+
+    unsigned path_len = snprintf(path, sizeof(path), "%s/ccpp-%ld-%lu.new",
+            dddir, (long)time(NULL), (long)pid);
+    if (path_len >= (sizeof(path) - sizeof("/"FILENAME_COREDUMP)))
+        return 1;
+
+    struct dump_dir *dd = dd_create(path, uid);
+    if (dd)
+    {
+        char *cmdline = get_cmdline(pid); /* never NULL */
+        char *reason = xasprintf("Process %s was killed by signal %s (SIG%s)", executable, signal_str, signame ? signame : signal_str);
+        dd_save_text(dd, FILENAME_ANALYZER, "CCpp");
+        dd_save_text(dd, FILENAME_EXECUTABLE, executable);
+        dd_save_text(dd, FILENAME_CMDLINE, cmdline);
+        dd_save_text(dd, FILENAME_REASON, reason);
+        free(cmdline);
+        free(reason);
+
+        if (src_fd_binary > 0)
+        {
+            strcpy(path + path_len, "/"FILENAME_BINARY);
+            int dst_fd_binary = xopen3(path, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+            off_t sz = copyfd_eof(src_fd_binary, dst_fd_binary, COPYFD_SPARSE);
+            if (sz < 0 || fsync(dst_fd_binary) != 0)
+            {
+                unlink(path);
+                error_msg_and_die("error saving binary image to %s", path);
+            }
+            close(dst_fd_binary);
+            close(src_fd_binary);
+        }
+
+        /* We need coredumps to be readable by all, because
+         * when abrt daemon processes coredump,
+         * process producing backtrace is run under the same UID
+         * as the crashed process.
+         * Thus 644, not 600 */
+        strcpy(path + path_len, "/"FILENAME_COREDUMP);
+        int abrt_core_fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0644);
+        if (abrt_core_fd < 0)
+        {
+            int sv_errno = errno;
+            dd_delete(dd);
+            dd_close(dd);
+            if (user_core_fd >= 0)
+            {
+                xchdir(user_pwd);
+                unlink(core_basename);
+            }
+            errno = sv_errno;
+            perror_msg_and_die("can't open '%s'", path);
+        }
+
+        /* We write both coredumps at once.
+         * We can't write user coredump first, since it might be truncated
+         * and thus can't be copied and used as abrt coredump;
+         * and if we write abrt coredump first and then copy it as user one,
+         * then we have a race when process exits but coredump does not exist yet:
+         * $ echo -e '#include<signal.h>\nmain(){raise(SIGSEGV);}' | gcc -o test -x c -
+         * $ rm -f core*; ulimit -c unlimited; ./test; ls -l core*
+         * 21631 Segmentation fault (core dumped) ./test
+         * ls: cannot access core*: No such file or directory <=== BAD
+         */
+//TODO: fchown abrt_core_fd to uid:abrt?
+//Currently it is owned by 0:0 but is readable by anyone, so the owner
+//of the crashed binary still can access it, as he has
+//r-x access to the dump dir.
+        off_t core_size = copyfd_sparse(STDIN_FILENO, abrt_core_fd, user_core_fd, ulimit_c);
+        if (core_size < 0 || fsync(abrt_core_fd) != 0)
+        {
+            unlink(path);
+            dd_delete(dd);
+            dd_close(dd);
+            if (user_core_fd >= 0)
+            {
+                xchdir(user_pwd);
+                unlink(core_basename);
+            }
+            /* copyfd_sparse logs the error including errno string,
+             * but it does not log file name */
+            error_msg_and_die("error writing %s", path);
+        }
+        log("saved core dump of pid %lu (%s) to %s (%llu bytes)", (long)pid, executable, path, (long long)core_size);
+        if (user_core_fd >= 0 && core_size >= ulimit_c)
+        {
+            /* user coredump is too big, nuke it */
+            xchdir(user_pwd);
+            unlink(core_basename);
+        }
+
+        /* We close dumpdir before we start catering for crash storm case.
+         * Otherwise, delete_debug_dump_dir's from other concurrent
+         * CCpp's won't be able to delete our dump (their delete_debug_dump_dir
+         * will wait for us), and we won't be able to delete their dumps.
+         * Classic deadlock.
+         */
+        dd_close(dd);
+        path[path_len] = '\0'; /* path now contains only directory name */
+        char *newpath = xstrndup(path, path_len - (sizeof(".new")-1));
+        if (rename(path, newpath) == 0)
+            strcpy(path, newpath);
+        free(newpath);
+
+        /* rhbz#539551: "abrt going crazy when crashing process is respawned" */
+        if (setting_MaxCrashReportsSize > 0)
+        {
+            trim_debug_dumps(setting_MaxCrashReportsSize, path);
+        }
+
+        return 0;
+    }
+    else
+        xfunc_die();
+
+    /* We didn't create abrt dump, but may need to create compat coredump */
+ create_user_core:
+    if (user_core_fd < 0)
+        return 0;
+
+    off_t core_size = copyfd_size(STDIN_FILENO, user_core_fd, ulimit_c, COPYFD_SPARSE);
+    if (core_size < 0 || fsync(user_core_fd) != 0) {
+        /* perror first, otherwise unlink may trash errno */
+        perror_msg("error writing %s/%s", user_pwd, core_basename);
+        xchdir(user_pwd);
+        unlink(core_basename);
+        return 1;
+    }
+    if (core_size >= ulimit_c)
+    {
+        xchdir(user_pwd);
+        unlink(core_basename);
+        return 1;
+    }
+    log("saved core dump of pid %lu to %s/%s (%llu bytes)", (long)pid, user_pwd, core_basename, (long long)core_size);
+
+    return 0;
+}