commit 1a1c8a87cb6e966c8d716a90d516ee9ed23f5bef
author: prettyboy
date: 2020-05-28T12:04:46+03:00
revision: 6879742

    Dump extra siginfo if term signal is received
    
    issue:DEVTOOLSSUPPORT-1110
    
    REVIEW: 1279268

--- contrib/deprecated/python/faulthandler/faulthandler.c	(b4ffd42d61e5a2398623b2c73b681b72896da86b)
+++ contrib/deprecated/python/faulthandler/faulthandler.c	(1a1c8a87cb6e966c8d716a90d516ee9ed23f5bef)
@@ -43,6 +43,8 @@
 
 /* defined in traceback.c */
 extern Py_ssize_t _Py_write_noraise(int fd, const char *buf, size_t count);
+extern void dump_decimal(int fd, int value);
+extern void reverse_string(char *text, const size_t len);
 
 /* cast size_t to int because write() takes an int on Windows
    (anyway, the length is smaller than 30 characters) */
@@ -378,6 +380,81 @@ faulthandler_fatal_error(int signum)
     raise(signum);
 }
 
+static size_t
+uitoa(size_t val, char* ss) {
+    char* start = ss;
+    size_t len = 0;
+    do {
+        *ss = '0' + (val % 10);
+        val /= 10;
+        ss++; len++;
+    } while (val);
+    reverse_string(start, len);
+    return len;
+}
+
+static void
+read_proc_exe(pid_t pid, char* buff, size_t len) {
+    char pathname[32] = {0};
+    strcpy(pathname, "/proc/");
+    size_t pos = uitoa(pid, &pathname[6]) + 6;
+    strcpy(&pathname[pos], "/exe");
+
+    ssize_t l = readlink(pathname, buff, len);
+    if (l > 0) {
+        // readlink() does not append a null byte to buf
+        buff[l] = '\0';
+    } else {
+        strncpy(buff, "unknown_program", len);
+    }
+}
+
+static void
+faulthandler_fatal_error_siginfo(int signum, siginfo_t* siginfo, void* ctx)
+{
+    const int fd = fatal_error.fd;
+    int save_errno = errno;
+
+    if (!fatal_error.enabled)
+        return;
+
+    PUTS(fd, "\n*** Signal {si_signo=");
+    dump_decimal(fd, siginfo->si_signo);
+
+    PUTS(fd, ", si_code=");
+    dump_decimal(fd, siginfo->si_code);
+    switch (siginfo->si_code) {
+    case SEGV_ACCERR: PUTS(fd, " SEGV_ACCERR"); break;
+    case SEGV_MAPERR: PUTS(fd, " SEGV_MAPERR"); break;
+    case SI_KERNEL: PUTS(fd, " SI_KERNEL"); break;
+    case SI_TIMER: PUTS(fd, " SI_TIMER"); break;
+    case SI_TKILL: PUTS(fd, " SI_TKILL"); break;
+    case SI_USER: PUTS(fd, " SI_USER"); break;
+    }
+
+    if (siginfo->si_pid > 0) {
+        PUTS(fd, ", si_pid=");
+        dump_decimal(fd, siginfo->si_pid);
+        PUTS(fd, " ");
+        char buffer[PATH_MAX] = {0};
+        read_proc_exe(siginfo->si_pid, &buffer[0], PATH_MAX - 1);
+        PUTS(fd, &buffer[0]);
+    }
+
+    PUTS(fd, ", si_uid=");
+    dump_decimal(fd, siginfo->si_uid);
+
+    PUTS(fd, "} received by proc {pid=");
+    dump_decimal(fd, getpid());
+    PUTS(fd, ", uid=");
+    dump_decimal(fd, getuid());
+    PUTS(fd, "} ***\n");
+
+    faulthandler_fatal_error(signum);
+
+    errno = save_errno;
+}
+
 #ifdef MS_WINDOWS
 extern void _Py_dump_hexadecimal(int fd, unsigned long value, size_t bytes);
 
@@ -489,11 +566,17 @@ faulthandler_enable(PyObject *self, PyObject *args, PyObject *kwargs)
         for (i=0; i < faulthandler_nsignals; i++) {
             handler = &faulthandler_handlers[i];
 #ifdef HAVE_SIGACTION
+            action.sa_flags = 0;
+#ifdef USE_SIGINFO
+            action.sa_handler = faulthandler_fatal_error_siginfo;
+            action.sa_flags |= SA_SIGINFO;
+#else
             action.sa_handler = faulthandler_fatal_error;
+#endif
             sigemptyset(&action.sa_mask);
             /* Do not prevent the signal from being received from within
                its own signal handler */
-            action.sa_flags = SA_NODEFER;
+            action.sa_flags |= SA_NODEFER;
 #ifdef HAVE_SIGALTSTACK
             if (stack.ss_sp != NULL) {
                 /* Call the signal handler on an alternate signal stack
--- contrib/deprecated/python/faulthandler/traceback.c	(b4ffd42d61e5a2398623b2c73b681b72896da86b)
+++ contrib/deprecated/python/faulthandler/traceback.c	(1a1c8a87cb6e966c8d716a90d516ee9ed23f5bef)
@@ -45,7 +45,7 @@ _Py_write_noraise(int fd, const char *buf, size_t count)
 
    This function is signal safe. */
 
-static void
+void
 reverse_string(char *text, const size_t len)
 {
     char tmp;
@@ -59,17 +59,17 @@ reverse_string(char *text, const size_t len)
     }
 }
 
-/* Format an integer in range [0; 999999] to decimal,
+/* Format an integer in range [0; 999999999] to decimal,
    and write it into the file fd.
 
    This function is signal safe. */
 
-static void
+void
 dump_decimal(int fd, int value)
 {
-    char buffer[7];
+    char buffer[10];
     int len;
-    if (value < 0 || 999999 < value)
+    if (value < 0 || 999999999 < value)
         return;
     len = 0;
     do {