Cygwin: /proc/<PID>/status: Fill SigPnd, SigBlk and SigIgn values with life

So far the values of SigPnd and SigBlk were always 0 and SigIgn
was incorrectly set to the block mask of the current thread of
the calling process.

Fix that by adding a _pinfo::siginfo method and a PICOM_SIGINFO
message to allow to request actual signal info of any running process.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/fhandler_process.cc

@@ -1199,6 +1199,8 @@ format_process_status (void *data, char *&destbuf)
   int state = 'R';
   const char *state_str = "unknown";
   size_t vmsize = 0, vmrss = 0, vmdata = 0, vmlib = 0, vmtext = 0, vmshare = 0;
+  sigset_t pnd = 0, blk = 0, ign = 0;
+  bool fetch_siginfo = false;
 
   PWCHAR last_slash = wcsrchr (p->progname, L'\\');
   sys_wcstombs (cmd, NAME_MAX + 1, last_slash ? last_slash + 1 : p->progname);
@@ -1221,13 +1223,16 @@ format_process_status (void *data, char *&destbuf)
     {
     case 'O':
       state_str = "running";
+      fetch_siginfo = true;
       break;
     case 'D':
     case 'S':
       state_str = "sleeping";
+      fetch_siginfo = true;
       break;
     case 'R':
       state_str = "runnable";
+      fetch_siginfo = true;
       break;
     case 'Z':
       state_str = "zombie";
@@ -1238,6 +1243,8 @@ format_process_status (void *data, char *&destbuf)
     }
   get_mem_values (p->dwProcessId, vmsize, vmrss, vmtext, vmdata,
 		  vmlib, vmshare);
+  if (fetch_siginfo)
+    p->siginfo (pnd, blk, ign);
   /* The real uid value for *this* process is stored at cygheap->user.real_uid
      but we can't get at the real uid value for any other process, so
      just fake it as p->uid.  Similar for p->gid. */
@@ -1270,7 +1277,7 @@ format_process_status (void *data, char *&destbuf)
 			  vmsize * kb_per_page, 0UL, vmrss * kb_per_page,
 			  vmdata * kb_per_page, 0UL, vmtext * kb_per_page,
 			  vmlib * kb_per_page,
-			  0, 0, _my_tls.sigmask
+			  pnd, blk, ign
 			  );
 }
 

winsup/cygwin/pinfo.cc

@@ -668,6 +668,20 @@ commune_process (void *arg)
 	  sigproc_printf ("WritePipeOverlapped root failed, %E");
 	break;
       }
+    case PICOM_SIGINFO:
+      {
+	sigproc_printf ("processing PICOM_SIGINFO");
+	commune_result cr;
+	sigpending (&cr.pnd);
+	cr.pnd = sig_send (myself, __SIGPENDINGALL, NULL);
+	cr.blk = cygheap->compute_sigblkmask ();
+	for (int sig = 1; sig < NSIG; ++sig)
+	  if (global_sigs[sig].sa_handler == SIG_IGN)
+	    cr.ign |= SIGTOMASK (sig);
+	if (!WritePipeOverlapped (tothem, &cr, sizeof cr, &nr, 1000L))
+	  sigproc_printf ("WritePipeOverlapped siginfo failed, %E");
+	break;
+      }
     case PICOM_FDS:
       {
 	sigproc_printf ("processing PICOM_FDS");
@@ -788,16 +802,13 @@ commune_result
 _pinfo::commune_request (__uint32_t code, ...)
 {
   DWORD nr;
-  commune_result res;
+  commune_result res = { 0 };
   va_list args;
   siginfo_t si = {0};
   HANDLE& hp = si._si_commune._si_process_handle;
   HANDLE& fromthem = si._si_commune._si_read_handle;
   HANDLE request_sync = NULL;
 
-  res.s = NULL;
-  res.n = 0;
-
   if (!pid)
     {
       set_errno (ESRCH);
@@ -877,6 +888,14 @@ _pinfo::commune_request (__uint32_t code, ...)
 	  res.n = p - res.s;
 	}
       break;
+    case PICOM_SIGINFO:
+      if (!ReadPipeOverlapped (fromthem, &res, sizeof res, &nr, 1000L)
+	  || nr != sizeof res)
+	{
+	  __seterrno ();
+	  goto err;
+	}
+      break;
     }
   goto out;
 
@@ -996,6 +1015,30 @@ _pinfo::root (size_t& n)
   return s;
 }
 
+int
+_pinfo::siginfo (sigset_t &pnd, sigset_t &blk, sigset_t &ign)
+{
+  if (!pid)
+    return -1;
+  if (pid != myself->pid && !ISSTATE (this, PID_NOTCYGWIN))
+    {
+      commune_result cr = commune_request (PICOM_SIGINFO);
+      pnd = cr.pnd;
+      blk = cr.blk;
+      ign = cr.ign;
+    }
+  else
+    {
+      pnd = sig_send (myself, __SIGPENDING, NULL);
+      blk = cygheap->compute_sigblkmask ();
+      ign = 0;
+      for (int sig = 1; sig < NSIG; ++sig)
+	if (global_sigs[sig].sa_handler == SIG_IGN)
+	  ign |= SIGTOMASK (sig);
+    }
+  return -1;
+}
+
 static HANDLE
 open_commune_proc_parms (DWORD pid, PRTL_USER_PROCESS_PARAMETERS prupp)
 {

winsup/cygwin/pinfo.h

@@ -11,11 +11,17 @@ details. */
 #include <sys/resource.h>
 #include "thread.h"
 
-struct commune_result
+union commune_result
 {
-  char *s;
-  DWORD n;
-  HANDLE handles[2];
+  struct {
+    char *s;
+    size_t n;
+  };
+  struct {
+    sigset_t pnd;
+    sigset_t blk;
+    sigset_t ign;
+  };
 };
 
 enum picom
@@ -28,7 +34,8 @@ enum picom
   PICOM_FD = 5,
   PICOM_PIPE_FHANDLER = 6,
   PICOM_FILE_PATHCONV = 7,
-  PICOM_ENVIRON = 8
+  PICOM_ENVIRON = 8,
+  PICOM_SIGINFO = 9
 };
 
 #define EXITCODE_SET		0x8000000
@@ -109,6 +116,7 @@ public:
   char *cmdline (size_t &);
   char *environ (size_t &);
   char *win_heap_info (size_t &);
+  int siginfo (sigset_t &, sigset_t &, sigset_t &);
   bool set_ctty (class fhandler_termios *, int);
   bool alert_parent (char);
   int __reg2 kill (siginfo_t&);

winsup/cygwin/sigproc.cc

@@ -683,7 +683,7 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
   sigset_t pending;
   if (!its_me)
     pack.mask = NULL;
-  else if (si.si_signo == __SIGPENDING)
+  else if (si.si_signo == __SIGPENDING || si.si_signo == __SIGPENDINGALL)
     pack.mask = &pending;
   else if (si.si_signo == __SIGFLUSH || si.si_signo > 0)
     {
@@ -801,7 +801,7 @@ out:
     }
   if (pack.wakeup)
     ForceCloseHandle (pack.wakeup);
-  if (si.si_signo != __SIGPENDING)
+  if (si.si_signo != __SIGPENDING && si.si_signo != __SIGPENDINGALL)
     /* nothing */;
   else if (!rc)
     rc = pending;