Merge pull request #25399 from DaanDeMeyer/siginfo-crash

crash-handler: Make sure we propagate the original siginfo

meson.build

@@ -599,6 +599,10 @@ foreach ident : [
                                  #include <unistd.h>
                                  #include <signal.h>
                                  #include <sys/wait.h>'''],
+        ['rt_tgsigqueueinfo', '''#include <stdlib.h>
+                                 #include <unistd.h>
+                                 #include <signal.h>
+                                 #include <sys/wait.h>'''],
         ['mallinfo',          '''#include <malloc.h>'''],
         ['mallinfo2',         '''#include <malloc.h>'''],
         ['execveat',          '''#include <unistd.h>'''],

src/basic/missing_syscall.h

@@ -363,6 +363,20 @@ static inline int missing_rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *info)
 
 /* ======================================================================= */
 
+#if !HAVE_RT_TGSIGQUEUEINFO
+static inline int missing_rt_tgsigqueueinfo(pid_t tgid, pid_t tid, int sig, siginfo_t *info) {
+#  if defined __NR_rt_tgsigqueueinfo && __NR_rt_tgsigqueueinfo >= 0
+        return syscall(__NR_rt_tgsigqueueinfo, tgid, tid, sig, info);
+#  else
+#    error "__NR_rt_tgsigqueueinfo not defined"
+#  endif
+}
+
+#  define rt_tgsigqueueinfo missing_rt_tgsigqueueinfo
+#endif
+
+/* ======================================================================= */
+
 #if !HAVE_EXECVEAT
 static inline int missing_execveat(int dirfd, const char *pathname,
                                    char *const argv[], char *const envp[],

src/basic/sigbus.c

@@ -102,7 +102,8 @@ static void sigbus_handler(int sn, siginfo_t *si, void *data) {
 
         if (si->si_code != BUS_ADRERR || !si->si_addr) {
                 assert_se(sigaction(SIGBUS, &old_sigaction, NULL) == 0);
-                rt_sigqueueinfo(getpid_cached(), SIGBUS, si);
+                if (rt_tgsigqueueinfo(getpid_cached(), gettid(), SIGBUS, si) < 0)
+                        (void) raise(SIGBUS);
                 return;
         }
 

src/core/crash-handler.c

@@ -47,10 +47,11 @@ _noreturn_ static void crash(int sig, siginfo_t *siginfo, void *context) {
          * memory allocation is not async-signal-safe anyway — see signal-safety(7) for details —, and thus
          * is not permissible in signal handlers.) */
 
-        if (getpid_cached() != 1)
+        if (getpid_cached() != 1) {
                 /* Pass this on immediately, if this is not PID 1 */
-                (void) raise(sig);
-        else if (!arg_dump_core)
+                if (rt_tgsigqueueinfo(getpid_cached(), gettid(), sig, siginfo) < 0)
+                        (void) raise(sig);
+        } else if (!arg_dump_core)
                 log_emergency("Caught <%s>, not dumping core.", signal_to_string(sig));
         else {
                 sa = (struct sigaction) {
@@ -80,7 +81,8 @@ _noreturn_ static void crash(int sig, siginfo_t *siginfo, void *context) {
 
                         /* Raise the signal again */
                         pid = raw_getpid();
-                        (void) kill(pid, sig); /* raise() would kill the parent */
+                        if (rt_tgsigqueueinfo(pid, gettid(), sig, siginfo) < 0)
+                                (void) kill(pid, sig); /* raise() would kill the parent */
 
                         assert_not_reached();
                         _exit(EXIT_EXCEPTION);