1 files changed, 75 insertions, 1 deletions

diff --git a/src/shared/sleep-config.c b/src/shared/sleep-config.c
index 2577dd84c8..cbaef4c857 100644
--- a/src/shared/sleep-config.c
+++ b/src/shared/sleep-config.c
@@ -9,9 +9,12 @@
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/utsname.h>
 #include <syslog.h>
 #include <unistd.h>
 
+#include "sd-id128.h"
+
 #include "alloc-util.h"
 #include "conf-parser.h"
 #include "def.h"
@@ -270,6 +273,72 @@ static bool enough_swap_for_hibernation(void) {
         return r;
 }
 
+static int kernel_exists(void) {
+        struct utsname u;
+        sd_id128_t m;
+        int i, r;
+
+        /* Do some superficial checks whether the kernel we are currently running is still around. If it isn't we
+         * shouldn't offer hibernation as we couldn't possible resume from hibernation again. Of course, this check is
+         * very superficial, as the kernel's mere existance is hardly enough to know whether the hibernate/resume cycle
+         * will succeed. However, the common case of kernel updates can be caught this way, and it's definitely worth
+         * covering that. */
+
+        for (i = 0;; i++) {
+                _cleanup_free_ char *path = NULL;
+
+                switch (i) {
+
+                case 0:
+                        /* First, let's look in /lib/modules/`uname -r`/vmlinuz. This is where current Fedora places
+                         * its RPM-managed kernels. It's a good place, as it means compiled vendor code is monopolized
+                         * in /usr, and then the kernel image is stored along with its modules in the same
+                         * hierarchy. It's also what our 'kernel-install' script is written for. */
+                        if (uname(&u) < 0)
+                                return log_debug_errno(errno, "Failed to acquire kernel release: %m");
+
+                        path = strjoin("/lib/modules/", u.release, "/vmlinuz");
+                        break;
+
+                case 1:
+                        /* Secondly, let's look in /boot/vmlinuz-`uname -r`. This is where older Fedora and other
+                         * distributions tend to place the kernel. */
+                        path = strjoin("/boot/vmlinuz-", u.release);
+                        break;
+
+                case 2:
+                        /* For the other cases, we look in the EFI/boot partition, at the place where our
+                         * "kernel-install" script copies the kernel on install by default. */
+                        r = sd_id128_get_machine(&m);
+                        if (r < 0)
+                                return log_debug_errno(r, "Failed to read machine ID: %m");
+
+                        (void) asprintf(&path, "/efi/" SD_ID128_FORMAT_STR "/%s/linux", SD_ID128_FORMAT_VAL(m), u.release);
+                        break;
+                case 3:
+                        (void) asprintf(&path, "/boot/" SD_ID128_FORMAT_STR "/%s/linux", SD_ID128_FORMAT_VAL(m), u.release);
+                        break;
+                case 4:
+                        (void) asprintf(&path, "/boot/efi/" SD_ID128_FORMAT_STR "/%s/linux", SD_ID128_FORMAT_VAL(m), u.release);
+                        break;
+
+                default:
+                        return false;
+                }
+
+                if (!path)
+                        return -ENOMEM;
+
+                log_debug("Testing whether %s exists.", path);
+
+                if (access(path, F_OK) >= 0)
+                        return true;
+
+                if (errno != ENOENT)
+                        log_debug_errno(errno, "Failed to determine whether '%s' exists, ignoring: %m", path);
+        }
+}
+
 int read_fiemap(int fd, struct fiemap **ret) {
         _cleanup_free_ struct fiemap *fiemap = NULL, *result_fiemap = NULL;
         struct stat statinfo;
@@ -367,7 +436,7 @@ static bool can_s2h(void) {
 
         FOREACH_STRING(p, "suspend", "hibernate") {
                 r = can_sleep(p);
-                if (IN_SET(r, 0, -ENOSPC)) {
+                if (IN_SET(r, 0, -ENOSPC, -ENOMEDIUM)) {
                         log_debug("Unable to %s system.", p);
                         return false;
                 }
@@ -397,6 +466,11 @@ int can_sleep(const char *verb) {
         if (streq(verb, "suspend"))
                 return true;
 
+        if (kernel_exists() <= 0) {
+                log_debug_errno(errno, "Couldn't find kernel, not offering hibernation.");
+                return -ENOMEDIUM;
+        }
+
         if (!enough_swap_for_hibernation())
                 return -ENOSPC;