i#5256 sigprocmask: enable linux.sigaction on MacOS

core/arch/x86/x86.asm

@@ -641,6 +641,10 @@ cat_have_lock:
         mov      REG_XDI, REG_XAX    /* esp to use */
 #endif
         mov      REG_XSI, [2*ARG_SZ + REG_XBP]  /* sysnum */
+#ifdef MACOS64
+        /* For now we assume a BSD syscall */
+        or       REG_XSI, SYSCALL_NUM_MARKER_BSD
+#endif
         pop      REG_XAX             /* syscall */
         pop      REG_XCX             /* dstack */
 #if defined(UNIX) && !defined(X64)
@@ -1261,7 +1265,7 @@ dynamorio_sys_exit_next:
         mov      ARG2, REG_XAX /* kernel port, which we just acquired */
         mov      ARG1, 0 /* join semaphore: SEMAPHORE_NULL */
         mov      eax, SYS_bsdthread_terminate
-        or       eax, HEX(2000000) /* 2<<24 for BSD syscall */
+        or       eax, SYSCALL_NUM_MARKER_BSD
         mov      r10, rcx
         syscall
 # else

core/drlibc/drlibc_x86.asm

@@ -43,7 +43,7 @@
 #include "../arch/asm_defines.asm"
 #include "../arch/x86/x86_asm_defines.asm" /* PUSHGPR, POPGPR, etc. */
 #ifdef MACOS
-# include "include/syscall_mach.h" /* SYSCALL_NUM_MARKER_MACH */
+# include "include/syscall_mach.h" /* SYSCALL_NUM_MARKER_* */
 #endif
 START_FILE
 
@@ -67,8 +67,8 @@ GLOBAL_LABEL(dynamorio_syscall:)
         mov      REG_XBX, ARG2 /* put num_args where we can reference it longer */
         mov      rax, ARG1 /* sysnum: only need eax, but need rax for ARG1 (or movzx) */
 #  ifdef MACOS
-        /* for now we assume a BSD syscall */
-        or       rax, 0x2000000
+        /* For now we assume a BSD syscall */
+        or       rax, SYSCALL_NUM_MARKER_BSD
 #  endif
         cmp      REG_XBX, 0
         je       syscall_ready

core/unix/include/syscall_mach.h

@@ -38,7 +38,7 @@
 #define _SYSCALL_MACH_H_ 1
 
 #define SYSCALL_NUM_MARKER_MACH 0x1000000
-#define SYSCALL_NUM_MARKER_UNIX 0x2000000
+#define SYSCALL_NUM_MARKER_BSD 0x2000000
 #define SYSCALL_NUM_MARKER_MACHDEP 0x3000000
 
 #define MACH__kernelrpc_mach_vm_allocate_trap 10

core/unix/os.c

@@ -4880,7 +4880,7 @@ os_normalized_sysnum(int num_raw, instr_t *gateway, dcontext_t *dcontext)
         }
     }
 #    ifdef X64
-    if (num_raw >> 24 == 0x2)
+    if (num_raw & SYSCALL_NUM_MARKER_BSD)
         return (int)(num_raw & 0xffffff); /* Drop BSD bit */
     else
         num = (int)num_raw; /* Keep Mach and Machdep bits */

core/unix/signal.c

@@ -2321,19 +2321,6 @@ handle_sigprocmask(dcontext_t *dcontext, int how, kernel_sigset_t *app_set,
             *error_code = EINVAL;
         return false;
     }
-    /* On MacOS, sigprocmask does not fail if the old sigset is not readable
-     * or not writeable.
-     */
-    if (IF_MACOS_ELSE(false, oset != NULL)) {
-        kernel_sigset_t safe_old_set;
-        /* Old sigset should be writable too. */
-        if (!d_r_safe_read(oset, sizeof(safe_old_set), &safe_old_set) ||
-            !safe_write_ex(oset, sizeof(safe_old_set), &safe_old_set, NULL)) {
-            if (error_code != NULL)
-                *error_code = EFAULT;
-            return false;
-        }
-    }
     /* If we're intercepting all, we emulate the whole thing */
     bool execute_syscall = !DYNAMO_OPTION(intercept_all_signals);
     LOG(THREAD, LOG_ASYNCH, 2, "handle_sigprocmask\n");
@@ -2408,7 +2395,10 @@ handle_sigprocmask(dcontext_t *dcontext, int how, kernel_sigset_t *app_set,
         check_signals_pending(dcontext, info);
     }
     if (!execute_syscall) {
-        handle_post_sigprocmask(dcontext, how, app_set, oset, sigsetsize);
+        int status = handle_post_sigprocmask(dcontext, how, app_set, oset, sigsetsize);
+        if (status != 0 && error_code != NULL) {
+            *error_code = status;
+        }
         return false; /* skip syscall */
     } else
         return true;
@@ -6205,7 +6195,7 @@ terminate_via_kill(dcontext_t *dcontext)
      * this may not exit all threads in the address space
      */
     block_cleanup_and_terminate(
-        dcontext, IF_MACOS(SYSCALL_NUM_MARKER_UNIX +) SYS_kill,
+        dcontext, SYS_kill,
         /* Pass -pid in case main thread has exited
          * in which case will get -ESRCH
          */

suite/tests/CMakeLists.txt

@@ -100,7 +100,8 @@ set(main_run_list
   # our main configuration
   "SHORT::-code_api"
   # no_intercept_all_signals tests.
-  "SHORT::ONLY::signal_intercept$::-no_code_api -no_intercept_all_signals"
+  # TODO i#5261: Remove this suite when -intercept_all_signals is deprecated.
+  "SHORT::LIN::ONLY::sigaction$::-no_code_api -no_intercept_all_signals"
   # sanity check: run single app to make sure these options aren't totally broken
   # i#1575: ARM doesn't yet support -coarse_units
   "SHORT::X86::ONLY::client.events$::-code_api -opt_memory"
@@ -4143,9 +4144,9 @@ if (UNIX)
   tobuild(linux.sigplain101 linux/sigplain101.c)
   tobuild(linux.sigplain110 linux/sigplain110.c)
   tobuild(linux.sigplain111 linux/sigplain111.c)
-  tobuild(linux.sigaction.signal_intercept   linux/sigaction.c)
+  tobuild(linux.sigaction   linux/sigaction.c)
   # We want a native run to verify our assumptions of kernel behaviour.
-  torunonly_native(code_api|linux.sigaction.native linux.sigaction.signal_intercept
+  torunonly_native(code_api|linux.sigaction.native linux.sigaction
     "" linux/sigaction.c "")
   if (LINUX)
     tobuild(linux.syscall_pwait linux/syscall_pwait.cpp)
@@ -4794,8 +4795,8 @@ if (APPLE)
     code_api|api.dis
     code_api|api.ir-static
     code_api|api.drdecode
-    code_api|linux.sigaction.signal_intercept
-    no_code_api,no_intercept_all_signals|linux.sigaction.signal_intercept
+    code_api|linux.sigaction
+    no_code_api,no_intercept_all_signals|linux.sigaction
     code_api|linux.sigaction.native
     PROPERTIES LABELS OSX)
   if (DEBUG) # FIXME i#1806: fails in release
@@ -4829,7 +4830,7 @@ if (NOT ANDROID AND AARCHXX)
     code_api|linux.infinite
     code_api|linux.longjmp
     code_api|linux.readlink
-    code_api|linux.sigaction.signal_intercept
+    code_api|linux.sigaction
     code_api|linux.signalfd
     code_api|linux.signal_racesys
     code_api|security-common.codemod

suite/tests/linux/sigaction.c

@@ -45,10 +45,16 @@
 
 #define SENTINEL 0x12345678UL
 
+#ifdef MACOS
+typedef int si_mask_t;
+#else
+typedef unsigned long si_mask_t;
+#endif
+
 #if !defined(MACOS) && !defined(X64)
 typedef struct old_sigaction_t {
     void (*handler)(int, siginfo_t *, void *);
-    unsigned int sa_mask;
+    si_mask_t sa_mask;
     unsigned long sa_flags;
     void (*sa_restorer)(void);
 } old_sigaction_t;
@@ -78,13 +84,9 @@ test_query(int sig)
     memset((void *)&old_act, 0xff, sizeof(old_act));
     rc = sigaction(sig, NULL, &old_act);
     assert(rc == 0 && old_act.sa_sigaction == first_act.sa_sigaction &&
-    /* The flags do not match due to SA_RESTORER. */
-    /* The rest of mask is uninit stack values from the libc wrapper. */
-#if defined(MACOS)
-           *(int *)&old_act.sa_mask == *(int *)&first_act.sa_mask);
-#else
-           *(long *)&old_act.sa_mask == *(long *)&first_act.sa_mask);
-#endif
+           /* The flags do not match due to SA_RESTORER. */
+           /* The rest of mask is uninit stack values from the libc wrapper. */
+           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);
 
     /* Test with a new action. */
     memset((void *)&old_act, 0xff, sizeof(old_act));
@@ -93,13 +95,9 @@ test_query(int sig)
     sigemptyset(&new_act.sa_mask);
     rc = sigaction(sig, &new_act, &old_act);
     assert(rc == 0 && old_act.sa_sigaction == first_act.sa_sigaction &&
-    /* The flags do not match due to SA_RESTORER. */
-    /* The rest of mask is uninit stack values from the libc wrapper. */
-#if defined(MACOS)
-           *(int *)&old_act.sa_mask == *(int *)&first_act.sa_mask);
-#else
-           *(long *)&old_act.sa_mask == *(long *)&first_act.sa_mask);
-#endif
+           /* The flags do not match due to SA_RESTORER. */
+           /* The rest of mask is uninit stack values from the libc wrapper. */
+           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);
 
     /* Test pattern from i#1984 issue and ensure no assert. */
     memset(&new_act, 0, sizeof(new_act));
@@ -138,14 +136,17 @@ static void
 test_sigprocmask()
 {
 #if defined(MACOS)
-    sigset_t new = 0xf00d, old, original;
+    sigset_t new = 0xf00d, new2 = 0x1234, old, original;
     /* We explicitly add SIGBUS to the blocked set as it is one of the
      * signals that DR intercepts.
      */
     sigaddset(&new, SIGBUS);
 #else
-    uint64 new = 0xf00d | (1 << SIGBUS), old, original;
+    uint64 new = 0xf00d | (1 << SIGBUS), new2 = 0x1234, old, original;
 #endif
+    void *fault_addr = (void *)0x123;
+    void *read_only_addr = test_sigprocmask;
+
     /* Save original sigprocmask. Both return the current sigprocmask. */
     assert(make_sigprocmask(SIG_SETMASK, NULL, &original,
                             /*sizeof(kernel_sigset_t)*/ 8) == 0);
@@ -167,23 +168,22 @@ test_sigprocmask()
      * readable or not writeable.
      */
     int expected_result_bad_old_sigset = IF_MACOS_ELSE(0, -1);
-    assert(make_sigprocmask(~0, NULL, (void *)0x123, 8) ==
-           expected_result_bad_old_sigset);
+    assert(make_sigprocmask(~0, NULL, fault_addr, 8) == expected_result_bad_old_sigset);
 #if !defined(MACOS)
     assert(errno == EFAULT);
 #endif
-    assert(make_sigprocmask(SIG_BLOCK, (void *)0x123, NULL, 8) == -1);
+    assert(make_sigprocmask(SIG_BLOCK, fault_addr, NULL, 8) == -1);
     assert(errno == EFAULT);
-    assert(make_sigprocmask(SIG_BLOCK, NULL, (void *)0x123, 8) ==
+    assert(make_sigprocmask(SIG_BLOCK, NULL, fault_addr, 8) ==
            expected_result_bad_old_sigset);
 #if !defined(MACOS)
     assert(errno == EFAULT);
 #endif
     /* Bad new sigmask EFAULT gets reported before bad 'how' EINVAL. */
-    assert(make_sigprocmask(~0, (void *)0x123, NULL, 8) == -1);
+    assert(make_sigprocmask(~0, fault_addr, NULL, 8) == -1);
     assert(errno == EFAULT);
     /* EFAULT due to unwritable address. */
-    assert(make_sigprocmask(SIG_BLOCK, NULL, test_sigprocmask, 8) ==
+    assert(make_sigprocmask(SIG_BLOCK, NULL, read_only_addr, 8) ==
            expected_result_bad_old_sigset);
 #if !defined(MACOS)
     assert(errno == EFAULT);
@@ -197,7 +197,7 @@ test_sigprocmask()
     assert(make_sigprocmask(SIG_SETMASK, &new, NULL, 7) == -1);
     assert(errno == EINVAL);
     /* Bad size EINVAL gets reported before bad new sigmask EFAULT. */
-    assert(make_sigprocmask(SIG_SETMASK, (void *)0x123, NULL, 7) == -1);
+    assert(make_sigprocmask(SIG_SETMASK, fault_addr, NULL, 7) == -1);
     assert(errno == EINVAL);
 
 #endif
@@ -207,9 +207,19 @@ test_sigprocmask()
     assert(make_sigprocmask(SIG_SETMASK + 1, &new, NULL, 8) == -1);
     assert(errno == EINVAL);
     /* Bad 'how' EINVAL gets reported before bad old sigset EFAULT. */
-    assert(make_sigprocmask(~0, &new, (void *)0x123, 8) == -1);
+    assert(make_sigprocmask(~0, &new, fault_addr, 8) == -1);
     assert(errno == EINVAL);
 
+    /* EFAULT due to bad old sigset still sets the new mask. */
+    assert(make_sigprocmask(SIG_SETMASK, &new, NULL, 8) == 0);
+    assert(make_sigprocmask(SIG_SETMASK, &new2, fault_addr, 8) ==
+           expected_result_bad_old_sigset);
+#if !defined(MACOS)
+    assert(errno == EFAULT);
+#endif
+    assert(make_sigprocmask(~0, NULL, &old, 8) == 0);
+    assert(new2 == old);
+
     /* Restore original sigprocmask. */
     assert(make_sigprocmask(SIG_SETMASK, &original, NULL, 8) == 0);
 }
@@ -239,7 +249,7 @@ test_non_rt_sigaction(int sig)
     assert(rc == 0 && old_act.handler == first_act.handler &&
            /* The flags do not match due to SA_RESTORER. */
            /* The rest of mask is uninit stack values from the libc wrapper. */
-           *(long *)&old_act.sa_mask == *(long *)&first_act.sa_mask);
+           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);
 
     /* Test with a new action. */
     memset((void *)&old_act, 0xff, sizeof(old_act));
@@ -249,7 +259,7 @@ test_non_rt_sigaction(int sig)
     assert(rc == 0 && old_act.handler == first_act.handler &&
            /* The flags do not match due to SA_RESTORER. */
            /* The rest of mask is uninit stack values from the libc wrapper. */
-           *(long *)&old_act.sa_mask == *(long *)&first_act.sa_mask);
+           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);
 
     /* Clear handler */
     memset((void *)&new_act, 0, sizeof(new_act));