Add Linux ptrace() tutorial

libc/calls/calls.h

@@ -202,7 +202,7 @@ int wait3(int *, int, struct rusage *);
 int wait4(int, int *, int, struct rusage *);
 int waitpid(int, int *, int);
 intptr_t syscall(int, ...);
-long ptrace(int, int, void *, void *);
+long ptrace(int, ...);
 long telldir(DIR *);
 long times(struct tms *);
 size_t GetFileSize(const char *);

libc/calls/directmap-nt.c

@@ -21,7 +21,6 @@
 #include "libc/nt/enum/pageflags.h"
 #include "libc/nt/memory.h"
 #include "libc/nt/runtime.h"
-#include "libc/nt/struct/overlapped.h"
 #include "libc/runtime/directmap.internal.h"
 #include "libc/sysv/consts/map.h"
 #include "libc/sysv/consts/prot.h"

libc/calls/ptrace.c

@@ -17,16 +17,73 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/internal.h"
+#include "libc/calls/strace.internal.h"
+#include "libc/dce.h"
+#include "libc/sysv/consts/ptrace.h"
 #include "libc/sysv/errfuns.h"
 
+static const char *__ptrace_describe_request(int x) {
+  if (x == -1) return "-1";
+  if (x == PTRACE_TRACEME) return "PTRACE_TRACEME";
+  if (x == PTRACE_PEEKDATA) return "PTRACE_PEEKDATA";
+  if (x == PTRACE_GETFPREGS) return "PTRACE_GETFPREGS";
+  if (x == PTRACE_PEEKTEXT) return "PTRACE_PEEKTEXT";
+  if (x == PTRACE_POKEDATA) return "PTRACE_POKEDATA";
+  if (x == PTRACE_PEEKUSER) return "PTRACE_PEEKUSER";
+  if (x == PTRACE_POKETEXT) return "PTRACE_POKETEXT";
+  if (x == PTRACE_POKEUSER) return "PTRACE_POKEUSER";
+  if (x == PTRACE_GETREGS) return "PTRACE_GETREGS";
+  if (x == PTRACE_GETREGSET) return "PTRACE_GETREGSET";
+  if (x == PTRACE_SETFPREGS) return "PTRACE_SETFPREGS";
+  if (x == PTRACE_SETREGS) return "PTRACE_SETREGS";
+  if (x == PTRACE_SETREGSET) return "PTRACE_SETREGSET";
+  if (x == PTRACE_GETSIGINFO) return "PTRACE_GETSIGINFO";
+  if (x == PTRACE_SETSIGINFO) return "PTRACE_SETSIGINFO";
+  if (x == PTRACE_PEEKSIGINFO) return "PTRACE_PEEKSIGINFO";
+  if (x == PTRACE_GETSIGMASK) return "PTRACE_GETSIGMASK";
+  if (x == PTRACE_SETSIGMASK) return "PTRACE_SETSIGMASK";
+  if (x == PTRACE_SETOPTIONS) return "PTRACE_SETOPTIONS";
+  if (x == PTRACE_GETEVENTMSG) return "PTRACE_GETEVENTMSG";
+  if (x == PTRACE_CONT) return "PTRACE_CONT";
+  if (x == PTRACE_SINGLESTEP) return "PTRACE_SINGLESTEP";
+  if (x == PTRACE_SYSCALL) return "PTRACE_SYSCALL";
+  if (x == PTRACE_LISTEN) return "PTRACE_LISTEN";
+  if (x == PTRACE_KILL) return "PTRACE_KILL";
+  if (x == PTRACE_INTERRUPT) return "PTRACE_INTERRUPT";
+  if (x == PTRACE_ATTACH) return "PTRACE_ATTACH";
+  if (x == PTRACE_SEIZE) return "PTRACE_SEIZE";
+  if (x == PTRACE_SECCOMP_GET_FILTER) return "PTRACE_SECCOMP_GET_FILTER";
+  if (x == PTRACE_DETACH) return "PTRACE_DETACH";
+  return "PTRACE_WUT";
+}
+
 /**
  * Traces process.
  *
  * @param request can be PTRACE_xxx
  * @note de facto linux only atm
  */
-long ptrace(int request, int pid, void *addr, void *data) {
+long ptrace(int request, ...) {
-  /* TODO(jart): FreeBSD addr and data args are different */
+  // TODO(jart): FreeBSD addr and data args are different
-  if (request == -1) return einval(); /* see consts.sh */
+  int pid;
-  return sys_ptrace(request, pid, addr, data);
+  va_list va;
+  bool ispeek;
+  long rc, peek;
+  void *addr, *data;
+  va_start(va, request);
+  pid = va_arg(va, int);
+  addr = va_arg(va, void *);
+  data = va_arg(va, void *);
+  va_end(va);
+  if (request == -1) {
+    rc = einval(); /* see consts.sh */
+  } else {
+    ispeek = IsLinux() && request - 1u < 3;
+    if (ispeek) data = &peek;
+    rc = sys_ptrace(request, pid, addr, data);
+    if (rc != -1 && ispeek) rc = peek;
+  }
+  STRACE("ptrace(%s, %d, %p, %p) → %ld% m", __ptrace_describe_request(request),
+         pid, addr, data);
+  return rc;
 }

libc/fmt/fmt.c

@@ -41,6 +41,7 @@
   } while (0)
 
 extern bool __nomultics;
+extern bool __replmode;
 
 static const char kSpecialFloats[2][2][4] = {{"INF", "inf"}, {"NAN", "nan"}};
 
@@ -377,8 +378,15 @@ hidden int __fmt(void *fn, void *arg, const char *format, va_list va) {
         goto FormatString;
 
       case 'r':
-        flags |= FLAGS_REPR;
+        // undocumented %r specifier
-        /* fallthrough */
+        // used for good carriage return
+        // helps integrate loggers with repls
+        if (!__replmode) {
+          break;
+        } else {
+          p = "\r\e[K";
+          goto FormatString;
+        }
 
       case 'q':
         flags |= FLAGS_QUOTE;
@@ -393,6 +401,8 @@ hidden int __fmt(void *fn, void *arg, const char *format, va_list va) {
         break;
 
       case 'n':
+        // nonstandard %n specifier
+        // used to print newlines that work in raw terminal modes
         if (__nomultics) PUT('\r');
         PUT('\n');
         break;

libc/intrin/kprintf.greg.c

@@ -468,6 +468,7 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, va_list va,
             if (cols) --cols;         /* end quote */
           }
           goto EmitChar;
+
         case 'm':
           if (!(x = errno) && sign == ' ' &&
               (!IsWindows() || !__imp_GetLastError())) {
@@ -479,7 +480,10 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, va_list va,
           } else {
             goto FormatDecimal;
           }
+
         case 'n':
+          // nonstandard %n specifier
+          // used to print newlines that work in raw terminal modes
           if (__nomultics) {
             if (p < e) *p = '\r';
             ++p;
@@ -487,13 +491,18 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, va_list va,
           if (p < e) *p = '\n';
           ++p;
           break;
+
         case 'r':
+          // undocumented %r specifier
+          // used for good carriage return
+          // helps integrate loggers with repls
           if (!__replmode) {
             break;
           } else {
             s = "\r\033[K";
             goto FormatString;
           }
+
         case 'S':
           c = 's';
           type = 1;
@@ -695,10 +704,12 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, va_list va,
 privileged size_t ksnprintf(char *b, size_t n, const char *fmt, ...) {
   size_t m;
   va_list v;
-  struct Timestamps t = {0};
+  struct Timestamps t;
+  t = kenter();
   va_start(v, fmt);
   m = kformat(b, n, fmt, v, t);
   va_end(v);
+  kleave(t);
   return m;
 }
 
@@ -713,8 +724,12 @@ privileged size_t ksnprintf(char *b, size_t n, const char *fmt, ...) {
  * @vforksafe
  */
 privileged size_t kvsnprintf(char *b, size_t n, const char *fmt, va_list v) {
-  struct Timestamps t = {0};
+  size_t m;
-  return kformat(b, n, fmt, v, t);
+  struct Timestamps t;
+  t = kenter();
+  m = kformat(b, n, fmt, v, t);
+  kleave(t);
+  return m;
 }
 
 /**

libc/log/vflogf.c

@@ -98,7 +98,7 @@ void(vflogf)(unsigned level, const char *file, int line, FILE *f,
   prog = basename(program_invocation_name);
   bufmode = f->bufmode;
   if (bufmode == _IOLBF) f->bufmode = _IOFBF;
-  if ((fprintf)(f, "%c%s%06ld:%s:%d:%.*s:%d] ", "FEWIVDNT"[level & 7], buf32,
+  if ((fprintf)(f, "%r%c%s%06ld:%s:%d:%.*s:%d] ", "FEWIVDNT"[level & 7], buf32,
                 rem1000000int64(div1000int64(dots)), file, line,
                 strchrnul(prog, '.') - prog, prog, getpid()) <= 0) {
     vflogf_onfail(f);

libc/stdio/append.internal.h

@@ -19,6 +19,8 @@ ssize_t appendw(char **, uint64_t);
 ssize_t appends(char **, const char *);
 ssize_t appendf(char **, const char *, ...);
 ssize_t vappendf(char **, const char *, va_list);
+ssize_t kappendf(char **, const char *, ...);
+ssize_t kvappendf(char **, const char *, va_list);
 
 #if defined(__GNUC__) && !defined(__STRICT_ANSI__)
 #define appendf(BUF, FMT, ...) appendf(BUF, PFLINK(FMT), ##__VA_ARGS__)

libc/stdio/fopen.c

@@ -56,21 +56,18 @@ static int openpathname(const char *pathname, int flags, bool *out_noclose) {
  * @note microsoft unilaterally deprecated this function lool
  */
 FILE *fopen(const char *pathname, const char *mode) {
-  FILE *f;
+  FILE *f = 0;
   bool noclose;
   int fd, flags;
-  STRACE("fopen(%s)", pathname);
   flags = fopenflags(mode);
   pathname = fixpathname(pathname, flags);
   if ((fd = openpathname(pathname, flags, &noclose)) != -1) {
     if ((f = fdopen(fd, mode)) != NULL) {
       f->noclose = noclose;
-      return f;
+    } else if (!noclose) {
-    } else {
+      close(fd);
-      if (!noclose) close(fd);
-      return NULL;
     }
-  } else {
-    return NULL;
   }
+  STRACE("fopen(%#s, %#s) → %p% m", pathname, mode, f);
+  return f;
 }

libc/stdio/kappendf.c

@@ -0,0 +1,40 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/append.internal.h"
+
+/**
+ * Appends formatted string to buffer w/ kprintf, e.g.
+ *
+ *     char *b = 0;
+ *     kappendf(&b, "hello %d\n", 123);
+ *     free(b);
+ *
+ * @return bytes appended or -1 if `ENOMEM`
+ * @see appendz(b).i to get buffer length
+ * @note O(1) amortized buffer growth
+ * @see kprintf()
+ */
+ssize_t kappendf(char **b, const char *fmt, ...) {
+  int n;
+  va_list va;
+  va_start(va, fmt);
+  n = kvappendf(b, fmt, va);
+  va_end(va);
+  return n;
+}

libc/stdio/kvappendf.c

@@ -0,0 +1,68 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/macros.internal.h"
+#include "libc/mem/mem.h"
+#include "libc/stdio/append.internal.h"
+
+#define W sizeof(size_t)
+
+/**
+ * Appends formatted string to buffer.
+ *
+ * This is an alternative to vappendf() that uses the kprintf()
+ * formatting facility. This has some advantages in terms of
+ * performance, code size, and memory safety. There's also
+ * disadvantages, such as lack of floating-point directives.
+ *
+ * @see kprintf()
+ */
+ssize_t kvappendf(char **b, const char *f, va_list v) {
+  char *p;
+  int r, s;
+  size_t n;
+  va_list w;
+  struct appendz z;
+  z = appendz((p = *b));
+  va_copy(w, v);
+  if ((r = kvsnprintf(p + z.i, z.n ? z.n - W - z.i : 0, f, v)) >= 0) {
+    n = ROUNDUP(z.i + r + 1, 8) + W;
+    if (n > z.n) {
+      if (!z.n) z.n = W * 2;
+      while (n > z.n) z.n += z.n >> 1;
+      z.n = ROUNDUP(z.n, W);
+      if ((p = realloc(p, z.n))) {
+        z.n = malloc_usable_size(p);
+        assert(!(z.n & (W - 1)));
+        s = kvsnprintf(p + z.i, z.n - W - z.i, f, w);
+        assert(s == r);
+        *b = p;
+      } else {
+        va_end(w);
+        return -1;
+      }
+    }
+    z.i += r;
+    if (!IsTiny() && W == 8) z.i |= (size_t)APPEND_COOKIE << 48;
+    *(size_t *)(p + z.n - W) = z.i;
+  }
+  va_end(w);
+  return r;
+}

libc/stdio/tmpfile.c

@@ -18,7 +18,6 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/bits/safemacros.internal.h"
 #include "libc/calls/calls.h"
-#include "libc/calls/strace.internal.h"
 #include "libc/fmt/fmt.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/macros.internal.h"

tool/net/net.mk

@@ -22,6 +22,7 @@ TOOL_NET_COMS =									\
 	o/$(MODE)/tool/net/redbean-static.com					\
 	o/$(MODE)/tool/net/redbean-unsecure.com					\
 	o/$(MODE)/tool/net/redbean-original.com					\
+	o/$(MODE)/tool/net/redbean-assimilate.com				\
 	o/$(MODE)/tool/net/echoserver.com					\
 	o/$(MODE)/tool/net/wb.com
 
@@ -314,6 +315,33 @@ o/$(MODE)/tool/net/redbean-original.com.dbg:					\
 o/$(MODE)/tool/net/redbean-original.o: tool/net/redbean.c o/$(MODE)/tool/net/redbean.o
 	@$(COMPILE) -AOBJECTIFY.c $(OBJECTIFY.c) -DSTATIC -DUNSECURE -DREDBEAN=\"redbean-original\" $(OUTPUT_OPTION) $<
 
+# REDBEAN-ASSIMILATE.COM
+#
+# Same as REDBEAN.COM except without no-modify-self behavior.
+
+o/$(MODE)/tool/net/redbean-assimilate.com.dbg:					\
+		o/$(MODE)/tool/net/redbean.com.dbg
+	@cp -f $< $@
+
+o/$(MODE)/tool/net/redbean-assimilate.com:					\
+		o/$(MODE)/tool/net/redbean-assimilate.com.dbg			\
+		o/$(MODE)/third_party/infozip/zip.com				\
+		o/$(MODE)/tool/build/symtab.com					\
+		tool/net/net.mk							\
+		tool/net/help.txt						\
+		tool/net/.init.lua						\
+		tool/net/favicon.ico						\
+		tool/net/redbean.png
+	@$(COMPILE) -AOBJCOPY -T$@ $(OBJCOPY) -S -O binary $< $@
+	@$(COMPILE) -AMKDIR -T$@ mkdir -p o/$(MODE)/tool/net/.redbean-assimilate
+	@$(COMPILE) -ASYMTAB o/$(MODE)/tool/build/symtab.com -o o/$(MODE)/tool/net/.redbean-assimilate/.symtab $<
+	@$(COMPILE) -AZIP -T$@ o/$(MODE)/third_party/infozip/zip.com -9qj $@ 	\
+		o/$(MODE)/tool/net/.redbean-assimilate/.symtab			\
+		tool/net/help.txt						\
+		tool/net/.init.lua						\
+		tool/net/favicon.ico						\
+		tool/net/redbean.png
+
 .PHONY: o/$(MODE)/tool/net
 o/$(MODE)/tool/net:								\
 		$(TOOL_NET_BINS)						\

tool/net/redbean.c

@@ -2674,7 +2674,7 @@ static void LaunchBrowser(const char *path) {
     sigprocmask(SIG_BLOCK, &chldmask, &savemask);
     CHECK_NE(-1, (pid = fork()));
     if (!pid) {
-      setpgid(getpid(), getpid());
+      setpgid(getpid(), getpid());  // ctrl-c'ing redbean shouldn't kill browser
       sigaction(SIGINT, &saveint, 0);
       sigaction(SIGQUIT, &savequit, 0);
       sigprocmask(SIG_SETMASK, &savemask, 0);
@@ -6605,7 +6605,7 @@ static void RestoreApe(void) {
       WARNF("(srvr) can't restore .ape");
     free(p);
   } else {
-    WARNF("(srvr) /.ape not found");
+    INFOF("(srvr) /.ape not found");
   }
 }
 
@@ -6907,6 +6907,10 @@ void RedBean(int argc, char *argv[]) {
   if (daemonize) {
     Daemonize();
   } else {
+    // xxx: create process group to make it easier to propagate SIGTERM
+    //      to children. the downside to doing this seems to be that
+    //      ctrl-c isn't propagating as expected when running redbean
+    //      underneath strace.com :|
     setpgid(getpid(), getpid());
     if (logpath) {
       close(2);