Build on musl libc systems

core/lib/globals_shared.h

@@ -122,10 +122,12 @@
 
 #include <limits.h>  /* for USHRT_MAX */
 #ifdef UNIX
-#  include <sys/types.h>        /* Fix for case 5341. */
 #  include <signal.h>
 #endif
 /* DR_API EXPORT VERBATIM */
+#ifdef UNIX
+#  include <sys/types.h>  /* for pid_t (non-glibc, e.g. musl) */
+#endif
 #ifdef WINDOWS
 /* allow nameless struct/union */
 #  pragma warning(disable: 4201)

core/unix/injector.c

@@ -153,8 +153,9 @@ typedef struct _dr_inject_info_t {
 static bool
 inject_ptrace(dr_inject_info_t *info, const char *library_path);
 
+/* "enum __ptrace_request request" is used by glibc, but musl uses "int". */
 static long
-our_ptrace(enum __ptrace_request request, pid_t pid, void *addr, void *data);
+our_ptrace(int request, pid_t pid, void *addr, void *data);
 #endif
 
 /*******************************************************************************
@@ -889,7 +890,7 @@ static const enum_name_pair_t pt_req_map[] = {
  * libc from the injector process should always work.
  */
 static long
-our_ptrace(enum __ptrace_request request, pid_t pid, void *addr, void *data)
+our_ptrace(int request, pid_t pid, void *addr, void *data)
 {
     long r = dynamorio_syscall(SYS_ptrace, 4, request, pid, addr, data);
     if (verbose &&

core/unix/module.h

@@ -185,7 +185,9 @@ typedef FILE stdfile_t;
 # define STDFILE_FILENO _file
 #elif defined(LINUX)
 typedef struct _IO_FILE stdfile_t;
-# define STDFILE_FILENO _fileno
+# ifdef __GLIBC__
+#  define STDFILE_FILENO _fileno
+# endif
 #endif
 extern stdfile_t **privmod_stdout;
 extern stdfile_t **privmod_stderr;

core/unix/os.c

@@ -6168,6 +6168,23 @@ cleanup_after_vfork_execve(dcontext_t *dcontext)
                      HEAPACCT(ACCT_THREAD_MGT));
 }
 
+static void
+set_stdfile_fileno(stdfile_t **stdfile, file_t file_no)
+{
+#ifdef STDFILE_FILENO
+    (*stdfile)->STDFILE_FILENO = file_no;
+#else
+# warning stdfile_t is opaque; DynamoRIO will not set fds of libc FILEs.
+    /* i#1973: musl libc support (and potentially other non-glibcs) */
+    /* only called by handle_close_pre(), so warning is specific to that. */
+    SYSLOG_INTERNAL_WARNING_ONCE(
+        "DynamoRIO cannot set the file descriptors of private libc FILEs on "
+        "this platform. Client usage of stdio.h stdin, stdout, or stderr may "
+        "no longer work as expected, because the app is closing the UNIX fds "
+        "backing these.");
+#endif
+}
+
 /* returns whether to execute syscall */
 static bool
 handle_close_pre(dcontext_t *dcontext)
@@ -6204,7 +6221,7 @@ handle_close_pre(dcontext_t *dcontext)
         if (privmod_stdout != NULL &&
             IF_CLIENT_INTERFACE_ELSE(INTERNAL_OPTION(private_loader), false)) {
             /* update the privately loaded libc's stdout _fileno. */
-            (*privmod_stdout)->STDFILE_FILENO = our_stdout;
+            set_stdfile_fileno(privmod_stdout, our_stdout);
         }
     }
     if (DYNAMO_OPTION(dup_stderr_on_close) && fd == STDERR) {
@@ -6220,7 +6237,7 @@ handle_close_pre(dcontext_t *dcontext)
         if (privmod_stderr != NULL &&
             IF_CLIENT_INTERFACE_ELSE(INTERNAL_OPTION(private_loader), false)) {
             /* update the privately loaded libc's stderr _fileno. */
-            (*privmod_stderr)->STDFILE_FILENO = our_stderr;
+            set_stdfile_fileno(privmod_stderr, our_stderr);
         }
     }
     if (DYNAMO_OPTION(dup_stdin_on_close) && fd == STDIN) {
@@ -6236,7 +6253,7 @@ handle_close_pre(dcontext_t *dcontext)
         if (privmod_stdin != NULL &&
             IF_CLIENT_INTERFACE_ELSE(INTERNAL_OPTION(private_loader), false)) {
             /* update the privately loaded libc's stdout _fileno. */
-            (*privmod_stdin)->STDFILE_FILENO = our_stdin;
+            set_stdfile_fileno(privmod_stdin, our_stdin);
         }
     }
     return true;

core/unix/signal.c

@@ -96,9 +96,11 @@
 # include <errno.h>
 #endif
 
-#ifdef MACOS
 /* Define the Linux names, which the code is already using */
+#ifndef SA_NOMASK
 #  define SA_NOMASK       SA_NODEFER
+#endif
+#ifndef SA_ONESHOT
 #  define SA_ONESHOT      SA_RESETHAND
 #endif
 

core/unix/signal_linux.c

@@ -475,7 +475,7 @@ notify_signalfd(dcontext_t *dcontext, thread_sig_info_t *info, int sig,
 #ifdef ANDROID
         towrite.ssi_tid = frame->info._sifields._timer._tid;
 #else
-        towrite.ssi_tid = frame->info._sifields._timer.si_tid;
+        towrite.ssi_tid = frame->info.si_timerid;
 #endif
         towrite.ssi_overrun = frame->info.si_overrun;
         towrite.ssi_status = frame->info.si_status;

core/unix/signal_private.h

@@ -534,8 +534,11 @@ libc_sigismember(const sigset_t *set, int _sig)
     /* sigset_t is just a uint32 */
     return TEST(1UL << sig, *set);
 #else
+    /* "set->__val" would be cleaner, but is glibc specific (e.g. musl libc
+     * uses __bits as the field name on sigset_t).
+     */
     uint bits_per = 8*sizeof(ulong);
-    return TEST(1UL << (sig % bits_per), set->__val[sig / bits_per]);
+    return TEST(1UL << (sig % bits_per), ((const ulong *)set)[sig / bits_per]);
 #endif
 }