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/intrin/describesigaction.c

@@ -16,23 +16,68 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
 #include "libc/calls/struct/sigaction.h"
+#include "libc/calls/struct/sigset.h"
 #include "libc/calls/struct/sigset.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/kprintf.h"
+#include "libc/mem/alloca.h"
+#include "libc/sysv/consts/sa.h"
 
-const char *(DescribeSigaction)(char buf[256], int rc,
+static const char *DescribeSigHandler(char buf[64], void f(int)) {
+  if (f == SIG_ERR) return "SIG_ERR";
+  if (f == SIG_DFL) return "SIG_DFL";
+  if (f == SIG_IGN) return "SIG_IGN";
+  ksnprintf(buf, 64, "%t", f);
+  return buf;
+}
+
+static const char *DescribeSigFlags(char buf[64], int x) {
+  const struct DescribeFlags kSigFlags[] = {
+      {SA_NOCLDSTOP, "NOCLDSTOP"},  //
+      {SA_NOCLDWAIT, "NOCLDWAIT"},  //
+      {SA_SIGINFO, "SIGINFO"},      //
+      {SA_ONSTACK, "ONSTACK"},      //
+      {SA_RESTART, "RESTART"},      //
+      {SA_NODEFER, "NODEFER"},      //
+      {SA_RESETHAND, "RESETHAND"},  //
+      {SA_NOMASK, "NOMASK"},        //
+      {SA_ONESHOT, "ONESHOT"},      //
+  };
+  return DescribeFlags(buf, 64, kSigFlags, ARRAYLEN(kSigFlags), "SA_", x);
+}
+
+#define N 256
+
+#define append(...) o += ksnprintf(buf + o, N - o, __VA_ARGS__)
+
+const char *(DescribeSigaction)(char buf[N], int rc,
                                 const struct sigaction *sa) {
+  int o = 0;
+  char b64[64];
+
   if (rc == -1) return "n/a";
   if (!sa) return "NULL";
   if ((!IsAsan() && kisdangerous(sa)) ||
       (IsAsan() && !__asan_is_valid(sa, sizeof(*sa)))) {
-    ksnprintf(buf, 256, "%p", sa);
-  } else {
-    ksnprintf(buf, 256, "{.sa_handler=%t, .sa_flags=%#lx, .sa_mask=%s}",
-              sa->sa_handler, sa->sa_flags, DescribeSigset(rc, &sa->sa_mask));
+    ksnprintf(buf, N, "%p", sa);
+    return buf;
   }
+
+  append("{.sa_handler=%s", DescribeSigHandler(b64, sa->sa_handler));
+
+  if (sa->sa_flags) {
+    append(", .sa_flags=%s", DescribeSigFlags(b64, sa->sa_flags));
+  }
+
+  if (!sigisemptyset(&sa->sa_mask)) {
+    append(", .sa_mask=%s", DescribeSigset(rc, &sa->sa_mask));
+  }
+
+  append("}");
+
   return buf;
 }