kdbus: set kernel attach mask before creating the first bus

3 files changed, 38 insertions, 1 deletions

diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index 3bf7b074ef..759d566eb3 100644
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -32,6 +32,8 @@
 #include "util.h"
 #include "strv.h"
 #include "memfd-util.h"
+#include "cgroup-util.h"
+#include "fileio.h"
 
 #include "bus-internal.h"
 #include "bus-message.h"
@@ -39,7 +41,6 @@
 #include "bus-bloom.h"
 #include "bus-util.h"
 #include "bus-label.h"
-#include "cgroup-util.h"
 
 #define UNIQUE_NAME_MAX (3+DECIMAL_STR_MAX(uint64_t))
 
@@ -1796,3 +1797,35 @@ int bus_kernel_realize_attach_flags(sd_bus *bus) {
 
         return 0;
 }
+
+int bus_kernel_fix_attach_mask(void) {
+        _cleanup_free_ char *mask = NULL;
+        uint64_t m = (uint32_t) -1;
+        char buf[2+16+2];
+        int r;
+
+        r = get_proc_cmdline_key("systemd.kdbus_attach_flags_mask=", &mask);
+        if (r < 0) {
+                log_warning_errno(-r, "Failed to read kernel command line: %m");
+                return r;
+        }
+
+        if (mask) {
+                const char *p = mask;
+
+                if (startswith(p, "0x"))
+                        p += 2;
+
+                if (sscanf(p, "%" PRIx64, &m) != 1)
+                        log_warning("Couldn't parse systemd.kdbus_attach_flags_mask= kernel command line parameter.");
+        }
+
+        sprintf(buf, "0x%" PRIx64 "\n", m);
+        r = write_string_file("/sys/module/kdbus/parameters/attach_flags_mask", buf);
+        if (r < 0) {
+                log_warning_errno(-r, "Failed to write kdbus attach mask: %m");
+                return r;
+        }
+
+        return 0;
+}
diff --git a/src/libsystemd/sd-bus/bus-kernel.h b/src/libsystemd/sd-bus/bus-kernel.h
index 8994b35f52..0db8fd35a7 100644
--- a/src/libsystemd/sd-bus/bus-kernel.h
+++ b/src/libsystemd/sd-bus/bus-kernel.h
@@ -89,3 +89,5 @@ int bus_kernel_try_close(sd_bus *bus);
 int bus_kernel_drop_one(int fd);
 
 int bus_kernel_realize_attach_flags(sd_bus *bus);
+
+int bus_kernel_fix_attach_mask(void);
diff --git a/src/libsystemd/sd-bus/test-bus-kernel.c b/src/libsystemd/sd-bus/test-bus-kernel.c
index 0e6c2ac402..485c396bdb 100644
--- a/src/libsystemd/sd-bus/test-bus-kernel.c
+++ b/src/libsystemd/sd-bus/test-bus-kernel.c
@@ -45,6 +45,8 @@ int main(int argc, char *argv[]) {
 
         assert_se(asprintf(&name, "deine-mutter-%u", (unsigned) getpid()) >= 0);
 
+        bus_kernel_fix_attach_mask();
+
         bus_ref = bus_kernel_create_bus(name, false, &bus_name);
         if (bus_ref == -ENOENT)
                 return EXIT_TEST_SKIP;