Ignore SIGSYS on BSD by default

jart · Nov 3, 2022 · 37d40e0 · 37d40e0
1 parent 179e048
commit 37d40e0
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Showing 7 changed files with 48 additions and 16 deletions.
diff --git a/libc/stdio/getrandom.c b/libc/stdio/getrandom.c
@@ -127,25 +127,14 @@ ssize_t getrandom(void *p, size_t n, unsigned f) {
   return rc;
 }
 
-static textstartup void getrandom_init(void) {
+__attribute__((__constructor__)) static textstartup void getrandom_init(void) {
   int e, rc;
-  struct sigaction sa, oldsa;
   if (IsWindows()) return;
   e = errno;
-  if (IsBsd()) {
-    sa.sa_flags = 0;
-    sa.sa_handler = SIG_IGN;
-    sigemptyset(&sa.sa_mask);
-    sigaction(SIGSYS, &sa, &oldsa);
-  }
   if (!(rc = sys_getrandom(0, 0, 0))) {
     have_getrandom = true;
+  } else {
+    errno = e;
   }
   STRACE("sys_getrandom(0,0,0) → %d% m", rc);
-  if (IsBsd()) {
-    sigaction(SIGSYS, &oldsa, 0);
-  }
-  errno = e;
 }
-
-const void *const g_getrandom_init[] initarray = {getrandom_init};
diff --git a/libc/sysv/calls/sys_bogus.s b/libc/sysv/calls/sys_bogus.s
@@ -1,2 +1,2 @@
 .include "o/libc/sysv/macros.internal.inc"
-.scall sys_bogus,0x5005005002500500,globl
+.scall sys_bogus,0x00b5005002500500,globl
diff --git a/libc/sysv/syscalls.sh b/libc/sysv/syscalls.sh
@@ -372,7 +372,7 @@ scall	sys_io_uring_register	0xfffffffffffff1ab	globl
 #────────────────────────RHEL CLOUD────────────────────────── # ←──────┬─ red hat terminates community release of enterprise linux circa 2020
 scall	sys_pledge		0xfff06cffffffffff	globl hidden # └─ online linux services ban the president of united states of america
 scall	sys_msyscall		0xfff025ffffffffff	globl # no wrapper
-scall	sys_bogus		0x5005005002500500	globl
+scall	sys_bogus		0x00b5005002500500	globl
 scall	sys_open_tree		0xfffffffffffff1ac	globl # no wrapper
 scall	sys_move_mount		0xfffffffffffff1ad	globl # no wrapper
 scall	sys_fsopen		0xfffffffffffff1ae	globl # no wrapper

diff --git a/libc/sysv/systemfive.S b/libc/sysv/systemfive.S
@@ -20,8 +20,11 @@
 #include "libc/dce.h"
 #include "libc/macros.internal.h"
 #include "libc/nexgen32e/macros.h"
+#include "libc/sysv/consts/sig.h"
 #include "libc/sysv/consts/nr.h"
 
+#define SIG_IGN 1
+
 /*                                           ▄▄▄
                        ▄▄▄                    ▀▓▓▒▄
                      ▄▓▒▒░                      ▀▓▒▒▒▄
@@ -363,6 +366,31 @@ _init_systemfive_pid:
 1:	stosq
 	.endfn	_init_systemfive_pid
 #endif
+#if SupportsBsd() && !defined(TINY)
+_init_systemfive_sigsys:
+	testb	IsBsd()					# BSDs will trap SIGSYS!
+	jz	1f					# We want ENOSYS instead
+	push	%rdi					# XNU removed some calls
+	push	%rsi					# in past, so this makes
+	xor	%eax,%eax				# troubleshooting easier
+	push	%rax					# but it's non-essential
+	push	%rax
+	push	%rax
+	push	%rax
+	push	%rax
+	push	$SIG_IGN				# sigaction_meta size 48
+	mov	__NR_sigaction,%eax			# mag
+	mov	SIGSYS,%edi				# sig
+	mov	%rsp,%rsi				# new
+	xor	%edx,%edx				# old
+	mov	$8,%r10d				# for linux
+	xor	%r8d,%r8d				# for netbsd
+	syscall
+	add	$6*8,%rsp
+	pop	%rsi
+	pop	%rdi
+1:	.endfn	_init_systemfive_sigsys
+#endif
 #if SupportsSystemv() && !defined(TINY)
 _init_systemfive_syscall:
 	mov	__NR_msyscall,%eax			# syscall origin protect

diff --git a/test/libc/calls/sigaction_test.c b/test/libc/calls/sigaction_test.c
@@ -21,6 +21,7 @@
 #include "libc/calls/struct/sigaction.h"
 #include "libc/calls/struct/siginfo.h"
 #include "libc/calls/struct/sigset.h"
+#include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/calls/ucontext.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
@@ -204,3 +205,9 @@ TEST(sigaction, autoZombieSlayer) {
   // clean up
   ASSERT_SYS(0, 0, sigaction(SIGCHLD, &sa, 0));
 }
+
+TEST(sigaction, enosys_returnsErrnoRatherThanSigsysByDefault) {
+  if (IsTiny()) return;     // systemfive.S disables the fix w/ tiny
+  if (IsOpenbsd()) return;  // TODO: Why does OpenBSD raise SIGABRT?
+  ASSERT_SYS(ENOSYS, -1, sys_bogus());
+}
diff --git a/tool/emacs/cosmo-cpp-constants.el b/tool/emacs/cosmo-cpp-constants.el
@@ -16,6 +16,11 @@
     "__GNUC_PATCHLEVEL__"
     "__GNUC__"
     "__APPLE__"
+    "__FreeBSD__"
+    "__NetBSD__"
+    "__NetBSD_Version__"
+    "__OpenBSD__"
+    "__linux"
     "__MACH__"
     "__GNUG__"
     "__INCLUDE_LEVEL__"

diff --git a/tool/net/redbean.c b/tool/net/redbean.c
@@ -54,6 +54,7 @@
 #include "libc/nexgen32e/crc32.h"
 #include "libc/nexgen32e/nt2sysv.h"
 #include "libc/nexgen32e/rdtsc.h"
+#include "libc/nexgen32e/vendor.internal.h"
 #include "libc/nexgen32e/x86feature.h"
 #include "libc/nt/enum/fileflagandattributes.h"
 #include "libc/nt/thread.h"
@@ -7259,6 +7260,8 @@ static void TlsDestroy(void) {
 static void GetOpts(int argc, char *argv[]) {
   int opt;
   bool storeasset = false;
+  // only generate ecp cert under blinkenlights (rsa is slow)
+  norsagen = IsGenuineCosmo();
   while ((opt = getopt(argc, argv, GETOPTS)) != -1) {
     switch (opt) {
       CASE('S', ++sandboxed);