static int cn_printf(struct core_name *cn, const char *fmt, ...) { char *cur; int need; int ret; va_list arg; va_start(arg, fmt); need = vsnprintf(NULL, 0, fmt, arg); va_end(arg); if (likely(need < cn->size - cn->used - 1)) goto out_printf; ret = expand_corename(cn); if (ret) goto expand_fail; out_printf: cur = cn->corename + cn->used; va_start(arg, fmt); vsnprintf(cur, need + 1, fmt, arg); va_end(arg); cn->used += need; return 0; expand_fail: return ret; }
static int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg) { int free, need; again: free = cn->size - cn->used; need = vsnprintf(cn->corename + cn->used, free, fmt, arg); if (need < free) { cn->used += need; return 0; } if (!expand_corename(cn, cn->size + need - free + 1)) goto again; return -ENOMEM; }
/* format_corename 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 int format_corename(struct core_name *cn, struct coredump_params *cprm) { const struct cred *cred = current_cred(); const char *pat_ptr = core_pattern; int ispipe = (*pat_ptr == '|'); int pid_in_pattern = 0; int err = 0; cn->used = 0; cn->corename = NULL; if (expand_corename(cn, core_name_size)) return -ENOMEM; cn->corename[0] = '\0'; if (ispipe) ++pat_ptr; /* Repeat as long as we have more pattern to process and more output space */ while (*pat_ptr) { 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': { struct timeval tv; do_gettimeofday(&tv); err = cn_printf(cn, "%lu", tv.tv_sec); break; } /* hostname */ case 'h': down_read(&uts_sem); err = cn_esc_printf(cn, "%s", utsname()->nodename); up_read(&uts_sem); break; /* executable */ case 'e': err = cn_esc_printf(cn, "%s", current->comm); break; case 'E': err = cn_print_exe_file(cn); break; /* core limit size */ case 'c': err = cn_printf(cn, "%lu", rlimit(RLIMIT_CORE)); break; default: break; } ++pat_ptr; } if (err) return err; } 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 (!ispipe && !pid_in_pattern && core_uses_pid) { err = cn_printf(cn, ".%d", task_tgid_vnr(current)); if (err) return err; } return ispipe; }