journal: install sigbus handler for journal tools too

This makes them robust regarding truncation. Ideally, we'd export this
as an API, but given how messy SIGBUS handling is, and the uncertain
ownership logic of signal handlers we should not do this (unless libc
one day invents a scheme how to sanely install SIGBUS handlers for
specific memory areas only). However, for now we can still make all our
own tools robust.

Note that external tools will only have read-access to the journal
anyway, where SIGBUS is much more unlikely, given that only writes are
subject to disk full problems.

1 files changed, 26 insertions, 23 deletions

diff --git a/src/journal-remote/journal-gatewayd.c b/src/journal-remote/journal-gatewayd.c
index 7a99430a63..576f7cae7d 100644
--- a/src/journal-remote/journal-gatewayd.c
+++ b/src/journal-remote/journal-gatewayd.c
@@ -31,20 +31,21 @@
 #include <gnutls/gnutls.h>
 #endif
 
-#include "log.h"
-#include "util.h"
 #include "sd-journal.h"
 #include "sd-daemon.h"
 #include "sd-bus.h"
+#include "log.h"
+#include "util.h"
 #include "bus-util.h"
 #include "logs-show.h"
 #include "microhttpd-util.h"
 #include "build.h"
 #include "fileio.h"
+#include "sigbus.h"
 
-static char *key_pem = NULL;
-static char *cert_pem = NULL;
-static char *trust_pem = NULL;
+static char *arg_key_pem = NULL;
+static char *arg_cert_pem = NULL;
+static char *arg_trust_pem = NULL;
 
 typedef struct RequestMeta {
         sd_journal *journal;
@@ -833,7 +834,7 @@ static int request_handler(
                 return MHD_YES;
         }
 
-        if (trust_pem) {
+        if (arg_trust_pem) {
                 r = check_permissions(connection, &code, NULL);
                 if (r < 0)
                         return code;
@@ -904,37 +905,37 @@ static int parse_argv(int argc, char *argv[]) {
                         return 0;
 
                 case ARG_KEY:
-                        if (key_pem) {
+                        if (arg_key_pem) {
                                 log_error("Key file specified twice");
                                 return -EINVAL;
                         }
-                        r = read_full_file(optarg, &key_pem, NULL);
+                        r = read_full_file(optarg, &arg_key_pem, NULL);
                         if (r < 0)
                                 return log_error_errno(r, "Failed to read key file: %m");
-                        assert(key_pem);
+                        assert(arg_key_pem);
                         break;
 
                 case ARG_CERT:
-                        if (cert_pem) {
+                        if (arg_cert_pem) {
                                 log_error("Certificate file specified twice");
                                 return -EINVAL;
                         }
-                        r = read_full_file(optarg, &cert_pem, NULL);
+                        r = read_full_file(optarg, &arg_cert_pem, NULL);
                         if (r < 0)
                                 return log_error_errno(r, "Failed to read certificate file: %m");
-                        assert(cert_pem);
+                        assert(arg_cert_pem);
                         break;
 
                 case ARG_TRUST:
 #ifdef HAVE_GNUTLS
-                        if (trust_pem) {
+                        if (arg_trust_pem) {
                                 log_error("CA certificate file specified twice");
                                 return -EINVAL;
                         }
-                        r = read_full_file(optarg, &trust_pem, NULL);
+                        r = read_full_file(optarg, &arg_trust_pem, NULL);
                         if (r < 0)
                                 return log_error_errno(r, "Failed to read CA certificate file: %m");
-                        assert(trust_pem);
+                        assert(arg_trust_pem);
                         break;
 #else
                         log_error("Option --trust is not available.");
@@ -952,12 +953,12 @@ static int parse_argv(int argc, char *argv[]) {
                 return -EINVAL;
         }
 
-        if (!!key_pem != !!cert_pem) {
+        if (!!arg_key_pem != !!arg_cert_pem) {
                 log_error("Certificate and key files must be specified together");
                 return -EINVAL;
         }
 
-        if (trust_pem && !key_pem) {
+        if (arg_trust_pem && !arg_key_pem) {
                 log_error("CA certificate can only be used with certificate file");
                 return -EINVAL;
         }
@@ -979,6 +980,8 @@ int main(int argc, char *argv[]) {
         if (r == 0)
                 return EXIT_SUCCESS;
 
+        sigbus_install();
+
 #ifdef HAVE_GNUTLS
         gnutls_global_set_log_function(log_func_gnutls);
         log_reset_gnutls_level();
@@ -1008,18 +1011,18 @@ int main(int argc, char *argv[]) {
                 if (n > 0)
                         opts[opts_pos++] = (struct MHD_OptionItem)
                                 {MHD_OPTION_LISTEN_SOCKET, SD_LISTEN_FDS_START};
-                if (key_pem) {
-                        assert(cert_pem);
+                if (arg_key_pem) {
+                        assert(arg_cert_pem);
                         opts[opts_pos++] = (struct MHD_OptionItem)
-                                {MHD_OPTION_HTTPS_MEM_KEY, 0, key_pem};
+                                {MHD_OPTION_HTTPS_MEM_KEY, 0, arg_key_pem};
                         opts[opts_pos++] = (struct MHD_OptionItem)
-                                {MHD_OPTION_HTTPS_MEM_CERT, 0, cert_pem};
+                                {MHD_OPTION_HTTPS_MEM_CERT, 0, arg_cert_pem};
                         flags |= MHD_USE_SSL;
                 }
-                if (trust_pem) {
+                if (arg_trust_pem) {
                         assert(flags & MHD_USE_SSL);
                         opts[opts_pos++] = (struct MHD_OptionItem)
-                                {MHD_OPTION_HTTPS_MEM_TRUST, 0, trust_pem};
+                                {MHD_OPTION_HTTPS_MEM_TRUST, 0, arg_trust_pem};
                 }
 
                 d = MHD_start_daemon(flags, 19531,