Kill processes which ignore signals thatshould not be ignored

diff --git a/man/man2/sigaction.2 b/man/man2/sigaction.2
index 9c1fa71fdecbae48fd8331ee30b24c648c419887..91ee36df4d3b855100efb7a2fef76ff859c617a1 100644 (file)
--- a/man/man2/sigaction.2
+++ b/man/man2/sigaction.2
@@ -130,19 +130,19 @@ signal    num     notes   description
 SIGHUP 1       km      Hangup
 SIGINT 2       k       Interrupt (usually DEL or CTRL\-C)
 SIGQUIT        3       kcm     Quit (usually CTRL\-\e)
-SIGILL 4       kc      Illegal instruction
-SIGTRAP        5       kc      Trace trap
+SIGILL 4       Kc      Illegal instruction
+SIGTRAP        5       Kc      Trace trap
 SIGABRT        6       kcm     Abort program
-SIGBUS 7       kc      Bus error
-SIGFPE 8       kc      Floating point exception
+SIGBUS 7       Kc      Bus error
+SIGFPE 8       Kc      Floating point exception
 SIGKILL        9       k       Kill
 SIGUSR1        10      k       User defined signal #1
-SIGSEGV        11      kc      Segmentation fault
+SIGSEGV        11      Kc      Segmentation fault
 SIGUSR2        12      k       User defined signal #2
 SIGPIPE        13      k       Write to a pipe with no reader
 SIGALRM        14      k       Alarm clock
 SIGTERM        15      km      Terminate (default for kill(1))
-SIGEMT 16      xkc     Emulator trap
+SIGEMT 16      xKc     Emulator trap
 SIGCHLD        17      pi      Child process terminated
 SIGCONT        18      pi      Continue if stopped
 SIGSTOP        19      ps      Stop signal
@@ -161,6 +161,11 @@ The letters in the notes column indicate:
 .B k
 The process is killed if the signal is not caught.
 .TP
+.B K
+The process is killed if the signal is not caught. If the signal is received
+while ignored or masked, the process is killed even if a handler is defined to 
+catch the signal.
+.TP
 .B c
 The signal causes a core dump.
 .TP

diff --git a/servers/pm/glo.h b/servers/pm/glo.h
index 9bafc65333aa8850d42785b980732a2349c5a94d..4485e9710e7b72474ead5a9f1503849609d8615e 100644 (file)
--- a/servers/pm/glo.h
+++ b/servers/pm/glo.h
@@ -21,6 +21,7 @@ EXTERN int call_nr;           /* system call number */
 extern _PROTOTYPE (int (*call_vec[]), (void) );        /* system call handlers */
 EXTERN sigset_t core_sset;     /* which signals cause core images */
 EXTERN sigset_t ign_sset;      /* which signals are by default ignored */
+EXTERN sigset_t noign_sset;    /* which signals cannot be ignored */
 
 EXTERN u32_t system_hz;                /* System clock frequency. */
 EXTERN int abort_flag;

diff --git a/servers/pm/main.c b/servers/pm/main.c
index ede2edcb23566f15eba5ee09601ec0c67499e040..3a59900b016045b9a7156de249e69bbcf14fd47c 100644 (file)
--- a/servers/pm/main.c
+++ b/servers/pm/main.c
@@ -200,6 +200,8 @@ PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
                                SIGEMT, SIGFPE, SIGBUS, SIGSEGV };
   static char ign_sigs[] = { SIGCHLD, SIGWINCH, SIGCONT };
   static char mess_sigs[] = { SIGTERM, SIGHUP, SIGABRT, SIGQUIT };
+  static char noign_sigs[] = { SIGILL, SIGTRAP, SIGEMT, SIGFPE, 
+                               SIGBUS, SIGSEGV };
   register struct mproc *rmp;
   register char *sig_ptr;
   message mess;
@@ -218,6 +220,9 @@ PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
   sigemptyset(&ign_sset);
   for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++)
        sigaddset(&ign_sset, *sig_ptr);
+  sigemptyset(&noign_sset);
+  for (sig_ptr = noign_sigs; sig_ptr < noign_sigs+sizeof(noign_sigs); sig_ptr++)
+       sigaddset(&noign_sset, *sig_ptr);
 
   /* Obtain a copy of the boot monitor parameters and the kernel info struct.  
    * Parse the list of free memory chunks. This list is what the boot monitor 

diff --git a/servers/pm/signal.c b/servers/pm/signal.c
index 7a234c050e11bb694de319e948f6080ddbfd9dd3..a13756857e5965a98b4a13d60d550b079a1a7bef 100644 (file)
--- a/servers/pm/signal.c
+++ b/servers/pm/signal.c
@@ -351,7 +351,7 @@ int trace;                  /* pass signal to tracer first? */
  * context from the sigcontext structure.
  * If there is insufficient stack space, kill the process.
  */
-  int r, slot;
+  int r, slot, badignore;
 
   slot = (int) (rmp - mproc);
   if ((rmp->mp_flags & (IN_USE | EXITING)) != IN_USE) {
@@ -387,16 +387,22 @@ int trace;                        /* pass signal to tracer first? */
        return;
   }
 
-  if (sigismember(&rmp->mp_ignore, signo)) { 
+  /* some signals cannot be safely ignored */
+  badignore = sigismember(&noign_sset, signo) && (
+         sigismember(&rmp->mp_ignore, signo) ||
+         sigismember(&rmp->mp_sigmask, signo) ||
+         sigismember(&rmp->mp_sig2mess, signo));
+
+  if (!badignore && sigismember(&rmp->mp_ignore, signo)) { 
        /* Signal should be ignored. */
        return;
   }
-  if (sigismember(&rmp->mp_sigmask, signo)) {
+  if (!badignore && sigismember(&rmp->mp_sigmask, signo)) {
        /* Signal should be blocked. */
        sigaddset(&rmp->mp_sigpending, signo);
        return;
   }
-  if (sigismember(&rmp->mp_sig2mess, signo)) {
+  if (!badignore && sigismember(&rmp->mp_sig2mess, signo)) {
        /* Mark event pending in process slot and send notification. */
        sigaddset(&rmp->mp_sigpending, signo);
        notify(rmp->mp_endpoint);
@@ -412,7 +418,7 @@ int trace;                  /* pass signal to tracer first? */
        return;
   }
 
-  if (sigismember(&rmp->mp_catch, signo)) {
+  if (!badignore && sigismember(&rmp->mp_catch, signo)) {
        /* Signal is caught. First interrupt the process's current call, if
         * applicable. This may involve a roundtrip to FS, in which case we'll
         * have to check back later.
@@ -436,7 +442,7 @@ int trace;                  /* pass signal to tracer first? */
 
        /* We were unable to spawn a signal handler. Kill the process. */
   }
-  else if (sigismember(&ign_sset, signo)) {
+  else if (!badignore && sigismember(&ign_sset, signo)) {
        /* Signal defaults to being ignored. */
        return;
   }

diff --git a/test/test5.c b/test/test5.c
index 28482081311e9e9049f669f377799215be12b44a..9593584f66b8037ef81975ca36defee009865319 100644 (file)
--- a/test/test5.c
+++ b/test/test5.c
@@ -279,11 +279,11 @@ void test5g()
   int n;
 
   subtest = 7;
-  Signal(11, func11);
-  Signal(11, SIG_IGN);
+  Signal(SIGUSR1, func11);
+  Signal(SIGUSR1, SIG_IGN);
   n = getpid();
-  if (kill(n, 11) != 0) e(1);
-  Signal(11, SIG_DFL);
+  if (kill(n, SIGUSR1) != 0) e(1);
+  Signal(SIGUSR1, SIG_DFL);
 }
 
 void funcalrm(s)