feat: add streq

user/mmapprotvictim.c

@@ -0,0 +1,40 @@
+#include "ulib.h"
+
+/*
+ * Spawned by mmaptest.c to prove that a real write against a PROT_READ-only
+ * mapping turns into a genuine SIGSEGV (isr.c's #PF handler) rather than a
+ * kernel-wide panic -- this process is expected to die, not return 0. Its
+ * own final "FAIL" print/return only runs if that protection was somehow
+ * NOT enforced.
+ */
+
+int main(void)
+{
+    print("mmapprotvictim: start\n");
+
+    int fd = userOpen("/etc/motd.txt", oReadOnly);
+    if (fd < 0) {
+        print("mmapprotvictim: FAIL open\n");
+        return 1;
+    }
+
+    void* addr = userMmap(0, 4096, mmapProtRead, 0, fd, 0);
+    if (addr == userMmapFailed) {
+        print("mmapprotvictim: FAIL mmap\n");
+        return 1;
+    }
+
+    volatile char* p = (volatile char*)addr;
+    if (p[0] != 'f') {
+        print("mmapprotvictim: FAIL unexpected read content\n");
+        return 1;
+    }
+    print("mmapprotvictim: read-ok\n");
+
+    /* PROT_READ only -- this write must be refused by mmapFaultHandler and
+       turn into a real SIGSEGV delivered against THIS process alone. */
+    p[0] = 'X';
+
+    print("mmapprotvictim: FAIL write should have segfaulted\n");
+    return 1;
+}