env,kill,timeout: support unnamed signals

Some signals with values less that the max signal number for the system
do not have defined names.  For example, currently on amd64 Linux,
signals 32 and 33 do not have defined names, and Android has a wider
gap of undefined names where it reserves some realtime signals.

Previously the signal listing in env ended up reusing the name
of the last printed valid signal (the repeated HUP below):

    $ env --list-signal-handling true
    HUP        ( 1): IGNORE
    HUP        (32): BLOCK
    HUP        (38): IGNORE

..and the corresponding signal numbers were rejected as operands for the
env, kill, and timeout commands.

This patch removes the requirement that sig2str returns 0 for a signal
number associated with an operand.  This allows unnamed signals to be in
the sets `env' attempts to manipulate when a --*-signal option is used
with no argument, and kill(1) and timeout(1) to send such unnamed
signals.

* src/operand2sig.c (operand2sig): Drop signame argument, accept all
signal numbers <= SIGNUM_BOUND.  All callers updated.
* src/env.c (parse_signal_action_params, reset_signal_handlers)
(parse_block_signal_params, set_signal_proc_mask)
(list_signal_handling): Accept all signal numbers <= SIGNUM_BOUND,
use SIG%d for printing if necessary.
* src/kill.c (list_signals, main): Likewise.
(send_signals): Check errno from kill(3) for bad signo.
* src/timeout.c (main): Update operand2sig call.
* tests/misc/kill.sh: Test listing all signal numbers.
* NEWS: Mention the improvement.

diff --git a/NEWS b/NEWS
index 20cadf183fd7a0c27be14c991fc89f7505518098..f21efc7c026f2016e0f30a3d6c24815f1c379b74 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -92,6 +92,9 @@ GNU coreutils NEWS                                    -*- outline -*-
   This was previously 128KiB and increasing to 256KiB was seen to increase
   throughput by 10-20% when reading cached files on modern systems.
 
+  env,kill,timeout now support unnamed signals. kill(1) for example now
+  supports sending such signals, and env(1) will list them appropriately.
+
   SELinux operations in file copy operations are now more efficient,
   avoiding unneeded MCS/MLS label translation.
 

diff --git a/src/env.c b/src/env.c
index 73d9847f4f56a1045db364bc8953ad45c46f0da8..ed6628f8f1beaa5466ea18028d98717a5dd15f9c 100644 (file)
--- a/src/env.c
+++ b/src/env.c
@@ -538,7 +538,6 @@ parse_split_string (char const *str, int *orig_optind,
 static void
 parse_signal_action_params (char const *arg, bool set_default)
 {
-  char signame[SIG2STR_MAX];
   char *opt_sig;
   char *optarg_writable;
 
@@ -548,8 +547,7 @@ parse_signal_action_params (char const *arg, bool set_default)
          Some signals cannot be set to ignore or default (e.g., SIGKILL,
          SIGSTOP on most OSes, and SIGCONT on AIX.) - so ignore errors.  */
       for (int i = 1 ; i <= SIGNUM_BOUND; i++)
-        if (sig2str (i, signame) == 0)
-          signals[i] = set_default ? DEFAULT_NOERR : IGNORE_NOERR;
+        signals[i] = set_default ? DEFAULT_NOERR : IGNORE_NOERR;
       return;
     }
 
@@ -558,7 +556,7 @@ parse_signal_action_params (char const *arg, bool set_default)
   opt_sig = strtok (optarg_writable, ",");
   while (opt_sig)
     {
-      int signum = operand2sig (opt_sig, signame);
+      int signum = operand2sig (opt_sig);
       /* operand2sig accepts signal 0 (EXIT) - but we reject it.  */
       if (signum == 0)
         error (0, 0, _("%s: invalid signal"), quote (opt_sig));
@@ -607,7 +605,8 @@ reset_signal_handlers (void)
       if (dev_debug)
         {
           char signame[SIG2STR_MAX];
-          sig2str (i, signame);
+          if (sig2str (i, signame) != 0)
+            snprintf (signame, sizeof signame, "SIG%d", i);
           devmsg ("Reset signal %s (%d) to %s%s\n",
                   signame, i,
                   set_to_default ? "DEFAULT" : "IGNORE",
@@ -620,7 +619,6 @@ reset_signal_handlers (void)
 static void
 parse_block_signal_params (char const *arg, bool block)
 {
-  char signame[SIG2STR_MAX];
   char *opt_sig;
   char *optarg_writable;
 
@@ -647,15 +645,22 @@ parse_block_signal_params (char const *arg, bool block)
   opt_sig = strtok (optarg_writable, ",");
   while (opt_sig)
     {
-      int signum = operand2sig (opt_sig, signame);
+      int signum = operand2sig (opt_sig);
       /* operand2sig accepts signal 0 (EXIT) - but we reject it.  */
       if (signum == 0)
         error (0, 0, _("%s: invalid signal"), quote (opt_sig));
       if (signum <= 0)
         usage (exit_failure);
 
-      sigaddset (block ? &block_signals : &unblock_signals, signum);
-      sigdelset (block ? &unblock_signals : &block_signals, signum);
+      if (sigaddset (block ? &block_signals : &unblock_signals, signum) == -1)
+        {
+          if (block)
+            error (EXIT_CANCELED, errno,
+                   _("failed to block signal %d"), signum);
+          /* else diagnosed in parse_signal_action_params().  */
+        }
+      else
+        sigdelset (block ? &unblock_signals : &block_signals, signum);
 
       opt_sig = strtok (nullptr, ",");
     }
@@ -695,7 +700,8 @@ set_signal_proc_mask (void)
       if (dev_debug && debug_act)
         {
           char signame[SIG2STR_MAX];
-          sig2str (i, signame);
+          if (sig2str (i, signame) != 0)
+            snprintf (signame, sizeof signame, "SIG%d", i);
           devmsg ("signal %s (%d) mask set to %s\n",
                   signame, i, debug_act);
         }
@@ -728,7 +734,8 @@ list_signal_handling (void)
       if (! *ignored && ! *blocked)
         continue;
 
-      sig2str (i, signame);
+      if (sig2str (i, signame) != 0)
+        snprintf (signame, sizeof signame, "SIG%d", i);
       fprintf (stderr, "%-10s (%2d): %s%s%s\n", signame, i,
                blocked, connect, ignored);
     }

diff --git a/src/kill.c b/src/kill.c
index 9c8b6c191e948c6d0f7a9165c93adff6c21dcb5b..8b9a2650fbf55715828e966dafaf383e3f6fc558 100644 (file)
--- a/src/kill.c
+++ b/src/kill.c
@@ -131,11 +131,15 @@ list_signals (bool table, char *const *argv)
       if (argv)
         for (; *argv; argv++)
           {
-            signum = operand2sig (*argv, signame);
+            signum = operand2sig (*argv);
             if (signum < 0)
               status = EXIT_FAILURE;
             else
-              print_table_row (num_width, signum, name_width, signame);
+              {
+                if (sig2str (signum, signame) != 0)
+                  snprintf (signame, sizeof signame, "SIG%d", signum);
+                print_table_row (num_width, signum, name_width, signame);
+              }
           }
       else
         for (signum = 1; signum <= SIGNUM_BOUND; signum++)
@@ -147,16 +151,18 @@ list_signals (bool table, char *const *argv)
       if (argv)
         for (; *argv; argv++)
           {
-            signum = operand2sig (*argv, signame);
+            signum = operand2sig (*argv);
             if (signum < 0)
               status = EXIT_FAILURE;
-            else
+            else if (ISDIGIT (**argv))
               {
-                if (ISDIGIT (**argv))
+                if (sig2str (signum, signame) == 0)
                   puts (signame);
                 else
                   printf ("%d\n", signum);
               }
+            else
+              printf ("%d\n", signum);
           }
       else
         for (signum = 1; signum <= SIGNUM_BOUND; signum++)
@@ -190,7 +196,10 @@ send_signals (int signum, char *const *argv)
         }
       else if (kill (pid, signum) != 0)
         {
-          error (0, errno, "%s", quote (arg));
+          if (errno == EINVAL)
+            error (0, errno, "%d", signum);
+          else
+            error (0, errno, "%s", quote (arg));
           status = EXIT_FAILURE;
         }
     }
@@ -206,7 +215,6 @@ main (int argc, char **argv)
   bool list = false;
   bool table = false;
   int signum = -1;
-  char signame[SIG2STR_MAX];
 
   initialize_main (&argc, &argv);
   set_program_name (argv[0]);
@@ -251,7 +259,7 @@ main (int argc, char **argv)
             error (0, 0, _("%s: multiple signals specified"), quote (optarg));
             usage (EXIT_FAILURE);
           }
-        signum = operand2sig (optarg, signame);
+        signum = operand2sig (optarg);
         if (signum < 0)
           usage (EXIT_FAILURE);
         break;

diff --git a/src/operand2sig.c b/src/operand2sig.c
index 2a2563c6224154b90e67b173252dc0f5f05377b8..b46cb1bede2cee8d66eb2bd17c253b3f5de8dbc8 100644 (file)
--- a/src/operand2sig.c
+++ b/src/operand2sig.c
@@ -18,8 +18,8 @@
    FIXME: Move this to gnulib/str2sig.c */
 
 
-/* Convert OPERAND to a signal number with printable representation SIGNAME.
-   Return the signal number, or -1 if unsuccessful.  */
+/* Convert OPERAND to a signal number.  Return the signal number, or -1 if
+   unsuccessful.  */
 
 #include <config.h>
 #include <stdio.h>
@@ -32,7 +32,7 @@
 #include "operand2sig.h"
 
 extern int
-operand2sig (char const *operand, char *signame)
+operand2sig (char const *operand)
 {
   int signum;
 
@@ -82,7 +82,7 @@ operand2sig (char const *operand, char *signame)
       free (upcased);
     }
 
-  if (signum < 0 || sig2str (signum, signame) != 0)
+  if (0 > signum || signum > SIGNUM_BOUND)
     {
       error (0, 0, _("%s: invalid signal"), quote (operand));
       return -1;

diff --git a/src/operand2sig.h b/src/operand2sig.h
index e46689e7bda7d12a827e202d8be9407dca1411ef..3bc55105119adc13a9e49e2a4dfe48b82c0ae527 100644 (file)
--- a/src/operand2sig.h
+++ b/src/operand2sig.h
@@ -15,5 +15,5 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
-extern int operand2sig (char const *operand, char *signame)
+extern int operand2sig (char const *operand)
   _GL_ATTRIBUTE_NONNULL ();

diff --git a/src/timeout.c b/src/timeout.c
index 68d872b1251684583b771f126154623100f772f9..c102aff858b7075465067424261d1e39ec71ddff 100644 (file)
--- a/src/timeout.c
+++ b/src/timeout.c
@@ -467,7 +467,6 @@ int
 main (int argc, char **argv)
 {
   double timeout;
-  char signame[SIG2STR_MAX];
   int c;
 
   initialize_main (&argc, &argv);
@@ -488,7 +487,7 @@ main (int argc, char **argv)
           break;
 
         case 's':
-          term_signal = operand2sig (optarg, signame);
+          term_signal = operand2sig (optarg);
           if (term_signal == -1)
             usage (EXIT_CANCELED);
           break;

diff --git a/tests/misc/kill.sh b/tests/misc/kill.sh
index 69679e5a625784568c8ed19f86b9ab9f78cc2a8b..82812eada156005709945f3e534e6ef4d91cbf2a 100755 (executable)
--- a/tests/misc/kill.sh
+++ b/tests/misc/kill.sh
@@ -17,7 +17,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
-print_ver_ kill
+print_ver_ kill seq
 
 # params required
 returns_ 1 env kill || fail=1
@@ -60,4 +60,12 @@ returns_ 1 env kill -l -1 || fail=1
 returns_ 1 env kill -l -1 0 || fail=1
 returns_ 1 env kill -l INVALID TERM || fail=1
 
+# Verify all signal numbers can be listed
+SIG_LAST_STR=$(env kill -l | tail -n1) || framework_failure_
+SIG_LAST_NUM=$(env kill -l -- "$SIG_LAST_STR") || framework_failure_
+SIG_SEQ=$(env seq -- 0 "$SIG_LAST_NUM") || framework_failure_
+test -n "$SIG_SEQ" || framework_failure_
+env kill -l -- $SIG_SEQ || fail=1
+env kill -t -- $SIG_SEQ || fail=1
+
 Exit $fail