always log seccomp errors (#5110)

2 files changed, 8 insertions, 2 deletions

diff --git a/src/firejail/seccomp.c b/src/firejail/seccomp.c
index 0cd6ac7ec..9fcf74c02 100644
--- a/src/firejail/seccomp.c
+++ b/src/firejail/seccomp.c
@@ -70,9 +70,11 @@ int seccomp_install_filters(void) {
                         assert(fl->fname);
                         if (arg_debug)
                                 printf("Installing %s seccomp filter\n", fl->fname);
-
+#ifdef SECCOMP_FILTER_FLAG_LOG
+                        if (syscall(SYS_seccomp, SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, &fl->prog)) {
+#else
                         if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &fl->prog)) {
-
+#endif
                                 if (!err_printed)
                                         fwarning("seccomp disabled, it requires a Linux kernel version 3.5 or newer.\n");
                                 err_printed = 1;
diff --git a/src/libpostexecseccomp/libpostexecseccomp.c b/src/libpostexecseccomp/libpostexecseccomp.c
index e2339547e..c8f1fb3fb 100644
--- a/src/libpostexecseccomp/libpostexecseccomp.c
+++ b/src/libpostexecseccomp/libpostexecseccomp.c
@@ -55,6 +55,10 @@ static void load_seccomp(void) {
         };
 
         prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
+#ifdef SECCOMP_FILTER_FLAG_LOG
+        syscall(SYS_seccomp, SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, &prog);
+#else
         prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
+#endif
         munmap(filter, size);
 }