Make fixes and improvements

- Invent iso8601us() for faster timestamps
- Improve --strace descriptions of sigset_t
- Rebuild the Landlock Make bootstrap binary
- Introduce MODE=sysv for non-Windows builds
- Permit OFD fcntl() locks under pledge(flock)
- redbean can now protect your kernel from ddos
- Have vfork() fallback to sys_fork() not fork()
- Change kmalloc() to not die when out of memory
- Improve documentation for some termios functions
- Rewrite putenv() and friends to conform to POSIX
- Fix linenoise + strace verbosity issue on Windows
- Fix regressions in our ability to show backtraces
- Change redbean SetHeader() to no-op if value is nil
- Improve fcntl() so SQLite locks work in non-WAL mode
- Remove some unnecessary work during fork() on Windows
- Create redbean-based SSL reverse proxy for IPv4 TurfWar
- Fix ape/apeinstall.sh warning when using non-bash shells
- Add ProgramTrustedIp(), and IsTrustedIp() APIs to redbean
- Support $PWD, $UID, $GID, and $EUID in command interpreter
- Introduce experimental JTqFpD APE prefix for non-Windows builds
- Invent blackhole daemon for firewalling IP addresses via UNIX named socket
- Add ProgramTokenBucket(), AcquireToken(), and CountTokens() APIs to redbean

libc/calls/sigaction.c

@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
+#include "libc/calls/blocksigs.internal.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/sig.internal.h"
@@ -29,6 +30,7 @@
 #include "libc/calls/struct/sigaction.h"
 #include "libc/calls/struct/sigaction.internal.h"
 #include "libc/calls/struct/siginfo.internal.h"
+#include "libc/calls/struct/sigset.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/calls/ucontext.h"
@@ -474,9 +476,11 @@ int sigaction(int sig, const struct sigaction *act, struct sigaction *oldact) {
   if (sig == SIGKILL || sig == SIGSTOP) {
     rc = einval();
   } else {
+    BLOCK_SIGNALS;
     __sig_lock();
     rc = __sigaction(sig, act, oldact);
     __sig_unlock();
+    ALLOW_SIGNALS;
   }
   STRACE("sigaction(%G, %s, [%s]) → %d% m", sig, DescribeSigaction(0, act),
          DescribeSigaction(rc, oldact), rc);