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-rw-r--r--src/common/backtrace.c69
-rw-r--r--src/common/backtrace.h2
-rw-r--r--src/common/log.c125
-rw-r--r--src/common/sandbox.c47
-rw-r--r--src/common/sandbox.h1
-rw-r--r--src/common/torlog.h5
-rw-r--r--src/or/config.c16
-rw-r--r--src/or/main.c2
8 files changed, 135 insertions, 132 deletions
diff --git a/src/common/backtrace.c b/src/common/backtrace.c
index d3f59b2c70..2c49146a05 100644
--- a/src/common/backtrace.c
+++ b/src/common/backtrace.c
@@ -5,6 +5,7 @@
#include "backtrace.h"
#include "compat.h"
#include "util.h"
+#include "torlog.h"
#ifdef HAVE_EXECINFO_H
#include <execinfo.h>
@@ -25,34 +26,8 @@
#define NO_BACKTRACE_IMPL
#endif
-static char *bt_filename = NULL;
static char *bt_version = NULL;
-#ifndef NO_BACKTRACE_IMPL
-/**DOCDOC*/
-static int
-open_bt_target(void)
-{
- int fd = -1;
- if (bt_filename)
- fd = open(bt_filename, O_WRONLY|O_CREAT|O_APPEND, 0700);
- return fd;
-}
-#endif
-
-/**DOCDOC*/
-static void
-bt_write(int fd, const char *s, ssize_t n)
-{
- int r;
- if (n < 0) n = strlen(s);
-
- r = write(STDERR_FILENO, s, n);
- if (fd >= 0)
- r = write(fd, s, n);
- (void)r;
-}
-
#ifdef USE_BACKTRACE
#define MAX_DEPTH 256
static void *cb_buf[MAX_DEPTH];
@@ -61,33 +36,20 @@ static void *cb_buf[MAX_DEPTH];
void
dump_backtrace(const char *msg)
{
- char timebuf[32];
- time_t t = time(NULL);
- int timebuf_len;
int depth;
- int fd;
+ const int *fds;
+ int n_fds;
+ int i;
+
if (!msg) msg = "unspecified crash";
depth = backtrace(cb_buf, MAX_DEPTH);
- t /= 900; t *= 900; /* Round to the previous 15 minutes */
- timebuf[0] = '\0';
- timebuf_len = format_dec_number_sigsafe(t, timebuf, sizeof(timebuf));
-
- fd = open_bt_target();
- bt_write(fd, "========================================"
- "====================================\n", -1);
- bt_write(fd, bt_version, -1);
- bt_write(fd, " died around T=", -1);
- bt_write(fd, timebuf, timebuf_len);
- bt_write(fd, ": ", 2);
- bt_write(fd, msg, -1);
- bt_write(fd, "\n", 1);
- backtrace_symbols_fd(cb_buf, depth, STDERR_FILENO);
- if (fd >= 0)
- backtrace_symbols_fd(cb_buf, depth, fd);
-
- close(fd);
+ tor_log_err_sigsafe(bt_version, " died: ", msg, "\n",
+ NULL);
+ n_fds = tor_log_get_sigsafe_err_fds(&fds);
+ for (i=0; i < n_fds; ++i)
+ backtrace_symbols_fd(cb_buf, depth, fds[i]);
}
/**DOCDOC*/
@@ -110,10 +72,7 @@ remove_bt_handler(void)
void
dump_backtrace(const char *msg)
{
- bt_write(-1, bt_version, -1);
- bt_write(-1, " died: ", -1);
- bt_write(-1, msg, -1);
- bt_write(-1, "\n", -1);
+ tor_log_err_sigsafe(bt_version, " died: ", msg, "\n", NULL);
}
/**DOCDOC*/
@@ -132,11 +91,8 @@ remove_bt_handler(void)
/**DOCDOC*/
int
-configure_backtrace_handler(const char *filename, const char *tor_version)
+configure_backtrace_handler(const char *tor_version)
{
- tor_free(bt_filename);
- if (filename)
- bt_filename = tor_strdup(filename);
tor_free(bt_version);
if (!tor_version)
tor_version = "Tor";
@@ -151,7 +107,6 @@ clean_up_backtrace_handler(void)
{
remove_bt_handler();
- tor_free(bt_filename);
tor_free(bt_version);
}
diff --git a/src/common/backtrace.h b/src/common/backtrace.h
index bb2396080a..7d7c10a800 100644
--- a/src/common/backtrace.h
+++ b/src/common/backtrace.h
@@ -5,7 +5,7 @@
#define TOR_BACKTRACE_H
void dump_backtrace(const char *msg);
-int configure_backtrace_handler(const char *filename, const char *tor_version);
+int configure_backtrace_handler(const char *tor_version);
void clean_up_backtrace_handler(void);
#endif
diff --git a/src/common/log.c b/src/common/log.c
index 303fba93a1..3ce4df190c 100644
--- a/src/common/log.c
+++ b/src/common/log.c
@@ -443,6 +443,115 @@ tor_log(int severity, log_domain_mask_t domain, const char *format, ...)
va_end(ap);
}
+/** Maximum number of fds that will get notifications if we crash */
+#define MAX_SIGSAFE_FDS 8
+/** Array of fds to log crash-style warnings to. */
+static int sigsafe_log_fds[MAX_SIGSAFE_FDS] = { STDERR_FILENO };
+/** The number of elements used in sigsafe_log_fds */
+static int n_sigsafe_log_fds = 1;
+
+/** Write <b>s</b> to each element of sigsafe_log_fds. Return 0 on success, -1
+ * on failure. */
+static int
+tor_log_err_sigsafe_write(const char *s)
+{
+ int i;
+ ssize_t r;
+ size_t len = strlen(s);
+ int err = 0;
+ for (i=0; i < n_sigsafe_log_fds; ++i) {
+ r = write(sigsafe_log_fds[i], s, len);
+ err += (r != (ssize_t)len);
+ }
+ return err ? -1 : 0;
+}
+
+/** Given a list of string arguments ending with a NULL, writes them
+ * to our logs and to stderr (if possible). This function is safe to call
+ * from within a signal handler. */
+void
+tor_log_err_sigsafe(const char *m, ...)
+{
+ va_list ap;
+ const char *x;
+ char timebuf[32];
+ time_t now = time(NULL);
+
+ if (!m)
+ return;
+ if (log_time_granularity >= 2000) {
+ int g = log_time_granularity / 1000;
+ now -= now % g;
+ }
+ timebuf[0] = '\0';
+ format_dec_number_sigsafe(now, timebuf, sizeof(timebuf));
+ tor_log_err_sigsafe_write("\n=========================================="
+ "================== T=");
+ tor_log_err_sigsafe_write(timebuf);
+ tor_log_err_sigsafe_write("\n");
+ tor_log_err_sigsafe_write(m);
+ va_start(ap, m);
+ while ((x = va_arg(ap, const char*))) {
+ tor_log_err_sigsafe_write(x);
+ }
+ va_end(ap);
+}
+
+/** Set *<b>out</b> to a pointer to an array of the fds to log errors to from
+ * inside a signal handler. Return the number of elements in the array. */
+int
+tor_log_get_sigsafe_err_fds(const int **out)
+{
+ *out = sigsafe_log_fds;
+ return n_sigsafe_log_fds;
+}
+
+/** Helper function; return true iff the <b>n</b>-element array <b>array</b>
+ * contains <b>item</b>. */
+static int
+int_array_contains(const int *array, int n, int item)
+{
+ int j;
+ for (j = 0; j < n; ++j) {
+ if (array[j] == item)
+ return 1;
+ }
+ return 0;
+}
+
+/** Function to call whenever the list of logs changes to get ready to log
+ * from signal handlers. */
+void
+tor_log_update_sigsafe_err_fds(void)
+{
+ const logfile_t *lf;
+
+ LOCK_LOGS();
+ /* Always try for stderr. This is safe because when we daemonize, we dup2
+ * /dev/null to stderr, */
+ sigsafe_log_fds[0] = STDERR_FILENO;
+ n_sigsafe_log_fds = 1;
+
+ for (lf = logfiles; lf; lf = lf->next) {
+ /* Don't try callback to the control port, or syslogs: We can't
+ * do them from a signal handler. Don't try stdout: we always do stderr.
+ */
+ if (lf->is_temporary || lf->is_syslog ||
+ lf->callback || lf->seems_dead || lf->fd < 0)
+ continue;
+ if (lf->severities->masks[SEVERITY_MASK_IDX(LOG_ERR)] &
+ (LD_BUG|LD_GENERAL)) {
+ /* Avoid duplicates */
+ if (int_array_contains(sigsafe_log_fds, n_sigsafe_log_fds, lf->fd))
+ continue;
+ sigsafe_log_fds[n_sigsafe_log_fds++] = lf->fd;
+ if (n_sigsafe_log_fds == MAX_SIGSAFE_FDS)
+ break;
+ }
+ }
+ UNLOCK_LOGS();
+}
+
/** Output a message to the log, prefixed with a function name <b>fn</b>. */
#ifdef __GNUC__
/** GCC-based implementation of the log_fn backend, used when we have
@@ -1142,22 +1251,6 @@ get_min_log_level(void)
return min;
}
-/** Return the fd of a file log that is receiving ERR messages, or -1 if
- * no such log exists. */
-int
-get_err_logging_fd(void)
-{
- const logfile_t *lf;
- for (lf = logfiles; lf; lf = lf->next) {
- if (lf->is_temporary || lf->is_syslog || !lf->filename ||
- lf->callback || lf->seems_dead || lf->fd < 0)
- continue;
- if (lf->severities->masks[LOG_ERR] & LD_GENERAL)
- return lf->fd;
- }
- return -1;
-}
-
/** Switch all logs to output at most verbose level. */
void
switch_logs_debug(void)
diff --git a/src/common/sandbox.c b/src/common/sandbox.c
index dbb1657cdb..a37c74e4a3 100644
--- a/src/common/sandbox.c
+++ b/src/common/sandbox.c
@@ -184,16 +184,6 @@ install_glob_syscall_filter(void)
return (rc < 0 ? -rc : rc);
}
-/** Additional file descriptor to use when logging seccomp2 failures */
-static int sigsys_debugging_fd = -1;
-
-/** Use the file descriptor <b>fd</b> to log seccomp2 failures. */
-static void
-sigsys_set_debugging_fd(int fd)
-{
- sigsys_debugging_fd = fd;
-}
-
/**
* Function called when a SIGSYS is caught by the application. It notifies the
* user that an error has occurred and either terminates or allows the
@@ -203,8 +193,8 @@ static void
sigsys_debugging(int nr, siginfo_t *info, void *void_context)
{
ucontext_t *ctx = (ucontext_t *) (void_context);
- char message[256];
- int rv = 0, syscall, length, err;
+ char number[32];
+ int syscall;
(void) nr;
if (info->si_code != SYS_SECCOMP)
@@ -215,24 +205,11 @@ sigsys_debugging(int nr, siginfo_t *info, void *void_context)
syscall = ctx->uc_mcontext.gregs[REG_SYSCALL];
- strlcpy(message, "\n\n(Sandbox) Caught a bad syscall attempt (syscall 0x",
- sizeof(message));
- (void) format_hex_number_sigsafe(syscall, message+strlen(message),
- sizeof(message)-strlen(message));
- strlcat(message, ")\n", sizeof(message));
- length = strlen(message);
-
- err = 0;
- if (sigsys_debugging_fd >= 0) {
- rv = write(sigsys_debugging_fd, message, length);
- err += rv != length;
- }
-
- rv = write(STDOUT_FILENO, message, length);
- err += rv != length;
-
- if (err)
- _exit(2);
+ format_dec_number_sigsafe(syscall, number, sizeof(number));
+ tor_log_err_sigsafe("(Sandbox) Caught a bad syscall attempt (syscall ",
+ number,
+ ")\n",
+ NULL);
#if defined(DEBUGGING_CLOSE)
_exit(1);
@@ -318,14 +295,4 @@ tor_global_sandbox(void)
#endif
}
-/** Use <b>fd</b> to log non-survivable sandbox violations. */
-void
-sandbox_set_debugging_fd(int fd)
-{
-#ifdef USE_LIBSECCOMP
- sigsys_set_debugging_fd(fd);
-#else
- (void)fd;
-#endif
-}
diff --git a/src/common/sandbox.h b/src/common/sandbox.h
index bd6f0cfb47..54f16ec86e 100644
--- a/src/common/sandbox.h
+++ b/src/common/sandbox.h
@@ -48,7 +48,6 @@
#endif // __linux__
-void sandbox_set_debugging_fd(int fd);
int tor_global_sandbox(void);
#endif /* SANDBOX_H_ */
diff --git a/src/common/torlog.h b/src/common/torlog.h
index ecd7e121eb..903237940e 100644
--- a/src/common/torlog.h
+++ b/src/common/torlog.h
@@ -136,7 +136,6 @@ int get_min_log_level(void);
void switch_logs_debug(void);
void logs_free_all(void);
void add_temp_log(int min_severity);
-int get_err_logging_fd(void);
void close_temp_logs(void);
void rollback_log_changes(void);
void mark_logs_temp(void);
@@ -149,6 +148,10 @@ void set_log_time_granularity(int granularity_msec);
void tor_log(int severity, log_domain_mask_t domain, const char *format, ...)
CHECK_PRINTF(3,4);
+void tor_log_err_sigsafe(const char *m, ...);
+int tor_log_get_sigsafe_err_fds(const int **out);
+void tor_log_update_sigsafe_err_fds(void);
+
#if defined(__GNUC__) || defined(RUNNING_DOXYGEN)
extern int log_global_min_severity_;
diff --git a/src/or/config.c b/src/or/config.c
index af5bf41d24..c62a25a7a9 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -12,7 +12,6 @@
#define CONFIG_PRIVATE
#include "or.h"
#include "addressmap.h"
-#include "backtrace.h"
#include "channel.h"
#include "circuitbuild.h"
#include "circuitlist.h"
@@ -1114,19 +1113,6 @@ options_act_reversible(const or_options_t *old_options, char **msg)
/* No need to roll back, since you can't change the value. */
}
- /* Enable crash logging to files */
- {
- /* XXXX we might want to set this up earlier, if possible! */
- char *backtrace_fname = NULL;
- char *progname = NULL;
- tor_asprintf(&backtrace_fname, "%s"PATH_SEPARATOR"stack_dump",
- options->DataDirectory);
- tor_asprintf(&progname, "Tor %s", get_version());
- configure_backtrace_handler(backtrace_fname, progname);
- tor_free(backtrace_fname);
- tor_free(progname);
- }
-
/* Write control ports to disk as appropriate */
control_ports_write_to_file();
@@ -1156,7 +1142,7 @@ options_act_reversible(const or_options_t *old_options, char **msg)
goto rollback;
}
- sandbox_set_debugging_fd(get_err_logging_fd());
+ tor_log_update_sigsafe_err_fds();
commit:
r = 0;
diff --git a/src/or/main.c b/src/or/main.c
index ea86df0738..a8f1c2306d 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -2685,7 +2685,7 @@ tor_main(int argc, char *argv[])
}
#endif
- configure_backtrace_handler(NULL, get_version());
+ configure_backtrace_handler(get_version());
update_approx_time(time(NULL));
tor_threads_init();
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