oomd: Prevent corruption of cgroup paths in Killed signal

While looking at oomd behaviour in production I noticed that I always
get garbage cgroup paths for the Killed event. Looking more closely, I
noticed that while the signature is (string cgroup, string reason), we
currently erroneously pass the `OomdCGroupContext*` pointer itself as
the first argument to sd_bus_emit_signal(), rather than the ctx->path
string it contains.

The in-memory layout on affected machines in my case is:

    struct OomdCGroupContext {
        unsigned n_ref;
        /* padding */
        char *path;
        /* ... */
    }

...which explains the control characters, since they're garbage from
parsing n_ref, the path pointer, and later fields. At runtime, sd-bus
treats ctx as `const char *` and reads struct bytes as string data,
resulting in garbage being sent.

Pass ctx->path correctly so listeners receive the valid cgroup path.

mkosi/mkosi.conf

@@ -106,7 +106,6 @@ Packages=
         kexec-tools
         kmod
         less
-        llvm
         lsof
         lvm2
         mdadm
@@ -125,7 +124,6 @@ Packages=
         socat
         strace
         tar
-        tmux
         tree
         util-linux
         valgrind

mkosi/mkosi.conf.d/arch/mkosi.conf

@@ -17,15 +17,12 @@ Packages=
         bind
         bpf
         btrfs-progs
-        compsize
         cryptsetup
         dbus-broker
         dbus-broker-units
         dhcp
         elfutils
         erofs-utils
-        f2fs-tools
-        git
         gnutls
         inetutils
         iproute
@@ -44,7 +41,6 @@ Packages=
         pkgconf
         polkit
         procps-ng
-        psmisc
         python-pexpect
         python-psutil
         qrencode
@@ -56,6 +52,5 @@ Packages=
         stress-ng
         tgt
         tpm2-tools
-        vim
         # kernel-bootcfg --add-uri= is just too useful
         virt-firmware

mkosi/mkosi.conf.d/centos-fedora/mkosi.conf

@@ -30,7 +30,6 @@ Packages=
         elfutils-devel
         elfutils-libs
         erofs-utils
-        git-core
         glibc-langpack-de
         glibc-langpack-en
         gnutls-utils

mkosi/mkosi.conf.d/debian-ubuntu/mkosi.conf

@@ -41,9 +41,7 @@ Packages=
         dbus-user-session
         dmsetup
         erofs-utils
-        f2fs-tools
         fdisk
-        git-core
         gnutls-bin
         hostname
         iproute2
@@ -64,7 +62,6 @@ Packages=
         polkitd
         pkgconf
         procps
-        psmisc
         python3-pexpect
         python3-psutil
         # kernel-bootcfg --add-uri= is just too useful
@@ -77,4 +74,3 @@ Packages=
         tgt
         tpm2-tools
         tzdata
-        xxd

mkosi/mkosi.conf.d/fedora/mkosi.conf

@@ -9,10 +9,8 @@ Release=rawhide
 [Content]
 Packages=
         btrfs-progs
-        compsize
         dhcp-server
         dnf5
-        f2fs-tools
         # Required for systemd-networkd-tests.py (netdevsim and sch_xxx modules)
         kernel-modules-extra
         kernel-modules-internal

mkosi/mkosi.conf.d/opensuse/mkosi.conf

@@ -40,9 +40,7 @@ Packages=
         dhcp-server
         docbook-xsl-stylesheets
         erofs-utils
-        f2fs-tools
         gawk
-        git-core
         glibc-locale-base
         gnutls
         grep
@@ -72,7 +70,6 @@ Packages=
         policycoreutils
         pkgconf
         procps4
-        psmisc
         python3-pefile
         python3-pexpect
         python3-psutil
@@ -91,7 +88,6 @@ Packages=
         tpm2.0-tools
         util-linux-systemd
         veritysetup
-        vim
         # kernel-bootcfg --add-uri= is just too useful
         virt-firmware
         xz

src/oom/oomd-util.c

@@ -287,7 +287,7 @@ int oomd_cgroup_kill(Manager *m, OomdCGroupContext *ctx, bool recurse) {
                                           "org.freedesktop.oom1.Manager",
                                           "Killed",
                                           "ss",
-                                          ctx,
+                                          ctx->path,
                                           "oom");
 
         return !set_isempty(pids_killed);

test/units/TEST-17-UDEV.device_is_processing.sh

@@ -15,7 +15,7 @@ at_exit() {
     systemctl stop testsleep.service
     rm -f /run/udev/udev.conf.d/timeout.conf
     rm -f /run/udev/rules.d/99-testsuite.rules
-    killall --regexp '(|/usr/bin/)sleep'
+    pkill -f '(/usr/bin/)?sleep'
     udevadm control --reload
     ip link del "$IFNAME"
 }
@@ -60,7 +60,7 @@ done
 grep -q -F 'ID_PROCESSING=1' "/run/udev/data/n${IFINDEX}"
 
 # Forcibly kill sleep command invoked by the udev rule to finish processing the add event.
-killall --regexp '(|/usr/bin/)sleep'
+pkill -f '(/usr/bin/)?sleep'
 udevadm settle --timeout=30
 
 # Check if ID_PROCESSING flag is unset, and the device units are active.

test/units/TEST-17-UDEV.failed-event.sh

@@ -83,7 +83,7 @@ run_test_killed() {
     for _ in {1..40}; do
         if [[ -z "$killed" ]]; then
             if [[ -e /tmp/test-udev-marker ]]; then
-                killall --signal ABRT --regexp udev-worker
+                pkill -ABRT udev-worker
                 killed=1
             fi
         elif grep -q 'UDEV_WORKER_FAILED=1' "$TMPDIR"/monitor.txt; then

test/units/TEST-70-TPM2.nvpcr.sh

@@ -38,8 +38,8 @@ test -f /run/systemd/nvpcr/test.anchor
 /usr/lib/systemd/systemd-pcrextend --nvpcr=test schrumpel
 # To calculate the current value we need the anchor measurement
 DIGEST_BASE="$(cat /run/systemd/nvpcr/test.anchor)"
-DIGEST_MEASURED="$(echo -n "schrumpel" | openssl dgst -sha256 -binary | xxd -p -c200)"
-DIGEST_EXPECTED="$(echo "$DIGEST_BASE$DIGEST_MEASURED" | xxd -r -p | openssl dgst -sha256 -binary | xxd -p -c200)"
+DIGEST_MEASURED="$(echo -n "schrumpel" | openssl dgst -sha256 -hex -r | cut -d' ' -f1)"
+DIGEST_EXPECTED="$(echo "$DIGEST_BASE$DIGEST_MEASURED" | tr '[:lower:]' '[:upper:]' | basenc --base16 -d | openssl dgst -sha256 -hex -r | cut -d' ' -f1)"
 DIGEST_ACTUAL="$(systemd-analyze nvpcrs test --json=pretty | jq -r '.[] | select(.name=="test") | .value')"
 test "$DIGEST_ACTUAL" = "$DIGEST_EXPECTED"
 
@@ -49,6 +49,6 @@ DIGEST_ACTUAL2="$(systemd-analyze nvpcrs test --json=pretty | jq -r '.[] | selec
 test "$DIGEST_ACTUAL2" != "$DIGEST_EXPECTED"
 
 # And calculate the new result
-DIGEST_MEASURED2="$(echo -n "schnurz" | openssl dgst -sha256 -binary | xxd -p -c200)"
-DIGEST_EXPECTED2="$(echo "$DIGEST_EXPECTED$DIGEST_MEASURED2" | xxd -r -p | openssl dgst -sha256 -binary | xxd -p -c200)"
+DIGEST_MEASURED2="$(echo -n "schnurz" | openssl dgst -sha256 -hex -r | cut -d' ' -f1)"
+DIGEST_EXPECTED2="$(echo "$DIGEST_EXPECTED$DIGEST_MEASURED2" | tr '[:lower:]' '[:upper:]' | basenc --base16 -d | openssl dgst -sha256 -hex -r | cut -d' ' -f1)"
 test "$DIGEST_ACTUAL2" = "$DIGEST_EXPECTED2"