Line data    Source code

       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * pqsignal.c
       4             :  *    Backend signal(2) support (see also src/port/pqsignal.c)
       5             :  *
       6             :  * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/libpq/pqsignal.c
      12             :  *
      13             :  * ------------------------------------------------------------------------
      14             :  */
      15             : 
      16             : #include "postgres.h"
      17             : 
      18             : #include "libpq/pqsignal.h"
      19             : 
      20             : 
      21             : /* Global variables */
      22             : sigset_t    UnBlockSig,
      23             :             BlockSig,
      24             :             StartupBlockSig;
      25             : 
      26             : 
      27             : /*
      28             :  * Initialize BlockSig, UnBlockSig, and StartupBlockSig.
      29             :  *
      30             :  * BlockSig is the set of signals to block when we are trying to block
      31             :  * signals.  This includes all signals we normally expect to get, but NOT
      32             :  * signals that should never be turned off.
      33             :  *
      34             :  * StartupBlockSig is the set of signals to block during startup packet
      35             :  * collection; it's essentially BlockSig minus SIGTERM, SIGQUIT, SIGALRM.
      36             :  *
      37             :  * UnBlockSig is the set of signals to block when we don't want to block
      38             :  * signals.
      39             :  */
      40             : void
      41        2196 : pqinitmask(void)
      42             : {
      43        2196 :     sigemptyset(&UnBlockSig);
      44             : 
      45             :     /* Note: InitializeWaitEventSupport() modifies UnBlockSig. */
      46             : 
      47             :     /* First set all signals, then clear some. */
      48        2196 :     sigfillset(&BlockSig);
      49        2196 :     sigfillset(&StartupBlockSig);
      50             : 
      51             :     /*
      52             :      * Unmark those signals that should never be blocked. Some of these signal
      53             :      * names don't exist on all platforms.  Most do, but might as well ifdef
      54             :      * them all for consistency...
      55             :      */
      56             : #ifdef SIGTRAP
      57        2196 :     sigdelset(&BlockSig, SIGTRAP);
      58        2196 :     sigdelset(&StartupBlockSig, SIGTRAP);
      59             : #endif
      60             : #ifdef SIGABRT
      61        2196 :     sigdelset(&BlockSig, SIGABRT);
      62        2196 :     sigdelset(&StartupBlockSig, SIGABRT);
      63             : #endif
      64             : #ifdef SIGILL
      65        2196 :     sigdelset(&BlockSig, SIGILL);
      66        2196 :     sigdelset(&StartupBlockSig, SIGILL);
      67             : #endif
      68             : #ifdef SIGFPE
      69        2196 :     sigdelset(&BlockSig, SIGFPE);
      70        2196 :     sigdelset(&StartupBlockSig, SIGFPE);
      71             : #endif
      72             : #ifdef SIGSEGV
      73        2196 :     sigdelset(&BlockSig, SIGSEGV);
      74        2196 :     sigdelset(&StartupBlockSig, SIGSEGV);
      75             : #endif
      76             : #ifdef SIGBUS
      77        2196 :     sigdelset(&BlockSig, SIGBUS);
      78        2196 :     sigdelset(&StartupBlockSig, SIGBUS);
      79             : #endif
      80             : #ifdef SIGSYS
      81        2196 :     sigdelset(&BlockSig, SIGSYS);
      82        2196 :     sigdelset(&StartupBlockSig, SIGSYS);
      83             : #endif
      84             : #ifdef SIGCONT
      85        2196 :     sigdelset(&BlockSig, SIGCONT);
      86        2196 :     sigdelset(&StartupBlockSig, SIGCONT);
      87             : #endif
      88             : 
      89             : /* Signals unique to startup */
      90             : #ifdef SIGQUIT
      91        2196 :     sigdelset(&StartupBlockSig, SIGQUIT);
      92             : #endif
      93             : #ifdef SIGTERM
      94        2196 :     sigdelset(&StartupBlockSig, SIGTERM);
      95             : #endif
      96             : #ifdef SIGALRM
      97        2196 :     sigdelset(&StartupBlockSig, SIGALRM);
      98             : #endif
      99        2196 : }