cosmopolitan/libc/intrin/kprintf.greg.c
Justine Tunney 791f79fcb3
Make improvements
- We now serialize the file descriptor table when spawning / executing
  processes on Windows. This means you can now inherit more stuff than
  just standard i/o. It's needed by bash, which duplicates the console
  to file descriptor #255. We also now do a better job serializing the
  environment variables, so you're less likely to encounter E2BIG when
  using your bash shell. We also no longer coerce environ to uppercase

- execve() on Windows now remotely controls its parent process to make
  them spawn a replacement for itself. Then it'll be able to terminate
  immediately once the spawn succeeds, without having to linger around
  for the lifetime as a shell process for proxying the exit code. When
  process worker thread running in the parent sees the child die, it's
  given a handle to the new child, to replace it in the process table.

- execve() and posix_spawn() on Windows will now provide CreateProcess
  an explicit handle list. This allows us to remove handle locks which
  enables better fork/spawn concurrency, with seriously correct thread
  safety. Other codebases like Go use the same technique. On the other
  hand fork() still favors the conventional WIN32 inheritence approach
  which can be a little bit messy, but is *controlled* by guaranteeing
  perfectly clean slates at both the spawning and execution boundaries

- sigset_t is now 64 bits. Having it be 128 bits was a mistake because
  there's no reason to use that and it's only supported by FreeBSD. By
  using the system word size, signal mask manipulation on Windows goes
  very fast. Furthermore @asyncsignalsafe funcs have been rewritten on
  Windows to take advantage of signal masking, now that it's much more
  pleasant to use.

- All the overlapped i/o code on Windows has been rewritten for pretty
  good signal and cancelation safety. We're now able to ensure overlap
  data structures are cleaned up so long as you don't longjmp() out of
  out of a signal handler that interrupted an i/o operation. Latencies
  are also improved thanks to the removal of lots of "busy wait" code.
  Waits should be optimal for everything except poll(), which shall be
  the last and final demon we slay in the win32 i/o horror show.

- getrusage() on Windows is now able to report RUSAGE_CHILDREN as well
  as RUSAGE_SELF, thanks to aggregation in the process manager thread.
2023-10-08 08:59:53 -07:00

1154 lines
34 KiB
C

/*-*- 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/intrin/kprintf.h"
#include "ape/sections.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/state.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/fmt/divmod10.internal.h"
#include "libc/fmt/fmt.h"
#include "libc/fmt/itoa.h"
#include "libc/fmt/magnumstrs.internal.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/asancodes.h"
#include "libc/intrin/asmflag.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/bits.h"
#include "libc/intrin/cmpxchg.h"
#include "libc/intrin/getenv.internal.h"
#include "libc/intrin/kprintf.h"
#include "libc/intrin/likely.h"
#include "libc/intrin/nomultics.internal.h"
#include "libc/intrin/safemacros.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/limits.h"
#include "libc/log/internal.h"
#include "libc/macros.internal.h"
#include "libc/mem/alloca.h"
#include "libc/nexgen32e/rdtsc.h"
#include "libc/nexgen32e/uart.internal.h"
#include "libc/nt/createfile.h"
#include "libc/nt/enum/accessmask.h"
#include "libc/nt/enum/creationdisposition.h"
#include "libc/nt/enum/fileflagandattributes.h"
#include "libc/nt/enum/filesharemode.h"
#include "libc/nt/errors.h"
#include "libc/nt/files.h"
#include "libc/nt/process.h"
#include "libc/nt/runtime.h"
#include "libc/nt/thunk/msabi.h"
#include "libc/nt/winsock.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/memtrack.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/runtime/symbols.internal.h"
#include "libc/stdckdint.h"
#include "libc/str/str.h"
#include "libc/str/tab.internal.h"
#include "libc/str/utf16.h"
#include "libc/sysv/consts/at.h"
#include "libc/sysv/consts/auxv.h"
#include "libc/sysv/consts/f.h"
#include "libc/sysv/consts/fd.h"
#include "libc/sysv/consts/fileno.h"
#include "libc/sysv/consts/nr.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
#include "libc/thread/posixthread.internal.h"
#include "libc/thread/tls.h"
#include "libc/thread/tls2.internal.h"
#include "libc/vga/vga.internal.h"
#define STACK_ERROR "kprintf error: stack is about to overflow\n"
#define KGETINT(x, va, t, s) \
switch (t) { \
case -3: \
x = !!va_arg(va, int); \
break; \
case -2: \
if (s) { \
x = (signed char)va_arg(va, int); \
} else { \
x = (unsigned char)va_arg(va, int); \
} \
break; \
case -1: \
if (s) { \
x = (signed short)va_arg(va, int); \
} else { \
x = (unsigned short)va_arg(va, int); \
} \
break; \
case 0: \
default: \
if (s) { \
x = va_arg(va, int); \
} else { \
x = va_arg(va, unsigned int); \
} \
break; \
case 1: \
if (s) { \
x = va_arg(va, long); \
} else { \
x = va_arg(va, unsigned long); \
} \
break; \
case 2: \
if (s) { \
x = va_arg(va, long long); \
} else { \
x = va_arg(va, unsigned long long); \
} \
break; \
}
// clang-format off
__msabi extern typeof(CreateFile) *const __imp_CreateFileW;
__msabi extern typeof(DuplicateHandle) *const __imp_DuplicateHandle;
__msabi extern typeof(GetEnvironmentVariable) *const __imp_GetEnvironmentVariableW;
__msabi extern typeof(GetLastError) *const __imp_GetLastError;
__msabi extern typeof(GetStdHandle) *const __imp_GetStdHandle;
__msabi extern typeof(SetLastError) *const __imp_SetLastError;
__msabi extern typeof(WriteFile) *const __imp_WriteFile;
// clang-format on
long __klog_handle;
extern struct SymbolTable *__symtab;
__funline char *kadvance(char *p, char *e, long n) {
intptr_t t = (intptr_t)p;
if (ckd_add(&t, t, n)) t = (intptr_t)e;
return (char *)t;
}
__funline char *kemitquote(char *p, char *e, signed char t, unsigned c) {
if (t) {
if (p < e) {
*p = t < 0 ? 'u' : 'L';
}
++p;
}
if (p < e) {
*p = c;
}
++p;
return p;
}
__funline bool kiskernelpointer(const void *p) {
return 0x7f0000000000 <= (intptr_t)p && (intptr_t)p < 0x800000000000;
}
__funline bool kistextpointer(const void *p) {
return __executable_start <= (const unsigned char *)p &&
(const unsigned char *)p < _etext;
}
__funline bool kisimagepointer(const void *p) {
return __executable_start <= (const unsigned char *)p &&
(const unsigned char *)p < _end;
}
__funline bool kischarmisaligned(const char *p, signed char t) {
if (t == -1) return (intptr_t)p & 1;
if (t >= 1) return !!((intptr_t)p & 3);
return false;
}
__funline bool kismemtrackhosed(void) {
return !((_weaken(_mmi)->i <= _weaken(_mmi)->n) &&
(_weaken(_mmi)->p == _weaken(_mmi)->s ||
_weaken(_mmi)->p == (struct MemoryInterval *)kMemtrackStart));
}
privileged static bool kismapped(int x) {
// xxx: we can't lock because no reentrant locks yet
size_t m, r, l = 0;
if (!_weaken(_mmi)) return true;
if (kismemtrackhosed()) return false;
r = _weaken(_mmi)->i;
while (l < r) {
m = (l & r) + ((l ^ r) >> 1); // floor((a+b)/2)
if (_weaken(_mmi)->p[m].y < x) {
l = m + 1;
} else {
r = m;
}
}
if (l < _weaken(_mmi)->i && x >= _weaken(_mmi)->p[l].x) {
return !!(_weaken(_mmi)->p[l].prot & PROT_READ);
} else {
return false;
}
}
privileged bool kisdangerous(const void *p) {
int frame;
if (kisimagepointer(p)) return false;
if (kiskernelpointer(p)) return false;
if (IsOldStack(p)) return false;
if (IsLegalPointer(p)) {
frame = (uintptr_t)p >> 16;
if (IsStackFrame(frame)) return false;
if (kismapped(frame)) return false;
}
if (GetStackAddr() + GetGuardSize() <= (uintptr_t)p &&
(uintptr_t)p < GetStackAddr() + GetStackSize()) {
return false;
}
return true;
}
privileged static void klogclose(long fd) {
#ifdef __x86_64__
long ax = __NR_close;
asm volatile("syscall"
: "+a"(ax), "+D"(fd)
: /* inputs already specified */
: "rsi", "rdx", "rcx", "r8", "r9", "r10", "r11", "memory", "cc");
#elif defined(__aarch64__)
register long x0 asm("x0") = fd;
register int x8 asm("x8") = __NR_close;
register int x16 asm("x16") = __NR_close;
asm volatile("svc\t0" : "+r"(x0) : "r"(x8), "r"(x16) : "x9", "memory");
#else
#error "unsupported architecture"
#endif
}
privileged static long klogfcntl(long fd, long cmd, long arg) {
#ifdef __x86_64__
char cf;
long ax = __NR_fcntl;
asm volatile("clc\n\tsyscall"
: CFLAG_CONSTRAINT(cf), "+a"(ax), "+D"(fd), "+S"(cmd), "+d"(arg)
: /* inputs already specified */
: "rcx", "r8", "r9", "r10", "r11", "memory");
if (cf) ax = -ax;
return ax;
#elif defined(__aarch64__)
register long x0 asm("x0") = fd;
register long x1 asm("x1") = cmd;
register long x2 asm("x2") = arg;
register int x8 asm("x8") = __NR_fcntl;
register int x16 asm("x16") = __NR_fcntl;
asm volatile("mov\tx9,0\n\t" // clear carry flag
"adds\tx9,x9,0\n\t" // clear carry flag
"svc\t0\n\t"
"bcs\t1f\n\t"
"b\t2f\n1:\t"
"neg\tx0,x0\n2:"
: "+r"(x0)
: "r"(x1), "r"(x2), "r"(x8), "r"(x16)
: "x9", "memory");
return x0;
#else
#error "unsupported architecture"
#endif
}
privileged static long klogopen(const char *path) {
long dirfd = AT_FDCWD;
long flags = O_WRONLY | O_CREAT | O_APPEND;
long mode = 0600;
#ifdef __x86_64__
char cf;
long ax = __NR_openat;
register long r10 asm("r10") = mode;
asm volatile(CFLAG_ASM("clc\n\tsyscall")
: CFLAG_CONSTRAINT(cf), "+a"(ax), "+D"(dirfd), "+S"(path),
"+d"(flags), "+r"(r10)
: /* inputs already specified */
: "rcx", "r8", "r9", "r11", "memory");
if (cf) ax = -ax;
return ax;
#elif defined(__aarch64__)
register long x0 asm("x0") = dirfd;
register long x1 asm("x1") = (long)path;
register long x2 asm("x2") = flags;
register long x3 asm("x3") = mode;
register int x8 asm("x8") = __NR_openat;
register int x16 asm("x16") = __NR_openat;
asm volatile("mov\tx9,0\n\t" // clear carry flag
"adds\tx9,x9,0\n\t" // clear carry flag
"svc\t0\n\t"
"bcs\t1f\n\t"
"b\t2f\n1:\t"
"neg\tx0,x0\n2:"
: "+r"(x0)
: "r"(x1), "r"(x2), "r"(x3), "r"(x8), "r"(x16)
: "x9", "memory");
return x0;
#else
#error "unsupported architecture"
#endif
}
// returns log handle or -1 if logging shouldn't happen
privileged long kloghandle(void) {
// kprintf() needs to own a file descriptor in case apps closes stderr
// our close() and dup() implementations will trigger this initializer
// to minimize a chance that the user accidentally closes their logger
// while at the same time, avoiding a mandatory initialization syscall
if (!__klog_handle) {
long hand;
// setting KPRINTF_LOG="/tmp/foo.log" will override stderr
// setting KPRINTF_LOG="INTEGER" logs to a file descriptor
// setting KPRINTF_LOG="" shall disable kprintf altogether
if (IsMetal()) {
hand = STDERR_FILENO;
} else if (IsWindows()) {
uint32_t e, n;
char16_t path[512];
e = __imp_GetLastError();
n = __imp_GetEnvironmentVariableW(u"KPRINTF_LOG", path, 512);
if (!n && __imp_GetLastError() == kNtErrorEnvvarNotFound) {
hand = __imp_GetStdHandle(kNtStdErrorHandle);
__imp_DuplicateHandle(-1, hand, -1, &hand, 0, false,
kNtDuplicateSameAccess);
} else if (n && n < 512) {
hand = __imp_CreateFileW(
path, kNtFileAppendData,
kNtFileShareRead | kNtFileShareWrite | kNtFileShareDelete, 0,
kNtOpenAlways, kNtFileAttributeNormal, 0);
} else {
hand = -1; // KPRINTF_LOG was empty string or too long
}
__imp_SetLastError(e);
} else {
long fd, fd2;
bool closefd;
const char *path;
if (!__NR_write || !__envp) {
// it's too early in the initialization process for kprintf
return -1;
}
path = __getenv(__envp, "KPRINTF_LOG").s;
closefd = false;
if (!path) {
fd = STDERR_FILENO;
} else if (*path) {
const char *p;
for (fd = 0, p = path; *p; ++p) {
if ('0' <= *p && *p <= '9') {
fd *= 10;
fd += *p - '0';
} else {
fd = klogopen(path);
closefd = true;
break;
}
}
} else {
fd = -1;
}
if (fd >= 0) {
// avoid interfering with hard-coded assumptions about fds
if ((fd2 = klogfcntl(fd, F_DUPFD, 100)) >= 0) {
klogfcntl(fd2, F_SETFD, FD_CLOEXEC);
if (closefd) {
klogclose(fd);
}
} else {
// RLIMIT_NOFILE was probably too low for safe duplicate
fd2 = fd;
}
} else {
fd2 = -1;
}
hand = fd2;
}
__klog_handle = hand;
}
return __klog_handle;
}
privileged void klog(const char *b, size_t n) {
#ifdef __x86_64__
int e;
long h;
size_t i;
uint16_t dx;
uint32_t wrote;
unsigned char al;
long rax, rdi, rsi, rdx;
if ((h = kloghandle()) == -1) {
return;
}
if (IsWindows()) {
e = __imp_GetLastError();
if (!__imp_WriteFile(h, b, n, &wrote, 0)) {
__imp_SetLastError(e);
__klog_handle = 0;
}
} else if (IsMetal()) {
if (_weaken(_klog_vga)) {
_weaken(_klog_vga)(b, n);
}
for (i = 0; i < n; ++i) {
for (;;) {
dx = 0x3F8 + UART_LSR;
asm("inb\t%1,%0" : "=a"(al) : "dN"(dx));
if (al & UART_TTYTXR) break;
asm("pause");
}
dx = 0x3F8;
asm volatile("outb\t%0,%1"
: /* no inputs */
: "a"(b[i]), "dN"(dx));
}
} else {
asm volatile("syscall"
: "=a"(rax), "=D"(rdi), "=S"(rsi), "=d"(rdx)
: "0"(__NR_write), "1"(h), "2"(b), "3"(n)
: "rcx", "r8", "r9", "r10", "r11", "memory", "cc");
}
#elif defined(__aarch64__)
// this isn't a cancelation point because we don't acknowledge eintr
// on xnu we use the "nocancel" version of the system call for safety
register long r0 asm("x0") = kloghandle();
register long r1 asm("x1") = (long)b;
register long r2 asm("x2") = (long)n;
register long r8 asm("x8") = (long)__NR_write;
register long r16 asm("x16") = (long)__NR_write;
register long res_x0 asm("x0");
asm volatile("svc\t0"
: "=r"(res_x0)
: "r"(r0), "r"(r1), "r"(r2), "r"(r8), "r"(r16)
: "memory");
#else
#error "unsupported architecture"
#endif
}
privileged static size_t kformat(char *b, size_t n, const char *fmt,
va_list va) {
int si;
wint_t t, u;
const char *abet;
signed char type;
const char *s, *f;
struct CosmoTib *tib;
unsigned long long x;
unsigned i, j, m, rem, sign, hash, cols, prec;
char c, *p, *e, pdot, zero, flip, dang, base, quot, uppr, ansi, z[128];
if (kistextpointer(b) || kisdangerous(b)) n = 0;
if (!kistextpointer(fmt)) fmt = "!!WONTFMT";
p = b;
f = fmt;
e = p + n; // assume if n was negative e < p will be the case
tib = __tls_enabled ? __get_tls_privileged() : 0;
for (;;) {
for (;;) {
if (!(c = *f++) || c == '%') break;
EmitFormatByte:
if (p < e) *p = c;
++p;
}
if (!c) break;
pdot = 0;
flip = 0;
dang = 0;
hash = 0;
sign = 0;
prec = 0;
quot = 0;
type = 0;
cols = 0;
zero = 0;
uppr = 0;
ansi = 0;
abet = "0123456789abcdef";
for (;;) {
switch ((c = *f++)) {
default:
goto EmitFormatByte;
case '\0':
break;
case '.':
pdot = 1;
continue;
case '-':
flip = 1;
continue;
case '#':
case '`':
hash = '0';
continue;
case '_':
case ',':
case '\'':
quot = c;
continue;
case ' ':
case '+':
sign = c;
continue;
case '^':
uppr = c;
continue;
case 'h':
--type;
continue;
case 'j':
case 'l':
case 'z':
++type;
continue;
case '!':
dang = 1;
continue;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
si = pdot ? prec : cols;
si *= 10;
si += c - '0';
goto UpdateCols;
case '*':
si = va_arg(va, int);
UpdateCols:
if (pdot) {
if (si >= 0) {
prec = si;
}
} else {
if (si < 0) {
flip = 1;
si = -si;
}
cols = si;
if (!cols) {
zero = 1;
}
}
continue;
case 'T':
x = (rdtsc() - kStartTsc) / 3 % 86400000000000;
goto FormatUnsigned;
case 'P':
if (!(tib && (tib->tib_flags & TIB_FLAG_VFORKED))) {
x = __pid;
#ifdef __x86_64__
} else if (IsLinux()) {
asm volatile("syscall"
: "=a"(x)
: "0"(__NR_getpid)
: "rcx", "rdx", "r11", "memory");
#endif
} else {
x = 666;
}
if (!__nocolor && p + 7 <= e) {
*p++ = '\e';
*p++ = '[';
*p++ = '1';
*p++ = ';';
*p++ = '3';
*p++ = '0' + x % 7;
*p++ = 'm';
ansi = 1;
}
goto FormatDecimal;
case 'H':
if (!(tib && (tib->tib_flags & TIB_FLAG_VFORKED))) {
if (tib) {
x = atomic_load_explicit(&tib->tib_tid, memory_order_relaxed);
} else {
x = __pid;
}
#ifdef __x86_64__
} else if (IsLinux()) {
asm volatile("syscall"
: "=a"(x)
: "0"(__NR_getpid)
: "rcx", "rdx", "r11", "memory");
#endif
} else {
x = 666;
}
if (!__nocolor && p + 7 <= e) {
// xnu thread ids are always divisible by 8
*p++ = '\e';
*p++ = '[';
*p++ = '1';
*p++ = ';';
*p++ = '3';
*p++ = '0' + x % 7;
*p++ = 'm';
ansi = 1;
}
goto FormatDecimal;
case 'u':
case 'd':
if (UNLIKELY(type <= -3)) {
s = va_arg(va, int) ? "true" : "false";
goto FormatString;
}
KGETINT(x, va, type, c == 'd');
FormatDecimal:
if ((long long)x < 0 && c != 'u') {
x = -x;
sign = '-';
}
FormatUnsigned:
if (x && hash) sign = hash;
for (i = j = 0;;) {
x = __divmod10(x, &rem);
z[i++ & 127] = '0' + rem;
if (pdot ? i >= prec : !x) break;
if (quot && ++j == 3) {
z[i++ & 127] = quot;
j = 0;
}
}
EmitNumber:
if (flip || pdot) zero = 0;
while (zero && sign) {
if (p < e) *p = sign;
if (cols) --cols;
sign >>= 8;
++p;
}
t = !!sign + !!(sign >> 8);
if (!flip && cols >= t) {
for (j = i; j < cols - t; ++j) {
if (p < e) {
*p++ = zero ? '0' : ' ';
} else {
p = kadvance(p, e, cols - t - j);
break;
}
}
}
while (sign) {
if (p < e) *p = sign;
sign >>= 8;
++p;
}
for (j = i; j; ++p) {
--j;
if (p < e) {
*p = z[j & 127];
}
}
if (flip && cols >= t) {
for (j = i; j < cols - t; ++j) {
if (p < e) {
*p++ = ' ';
} else {
p = kadvance(p, e, cols - t - j);
break;
}
}
}
break;
case 'b':
base = 1;
if (hash) hash = '0' | 'b' << 8;
BinaryNumber:
KGETINT(x, va, type, false);
FormatNumber:
i = 0;
m = (1 << base) - 1;
if (hash && x) sign = hash;
do z[i++ & 127] = abet[x & m];
while ((x >>= base) || (pdot && i < prec));
goto EmitNumber;
case 'X':
abet = "0123456789ABCDEF";
/* fallthrough */
case 'x':
base = 4;
if (hash) hash = '0' | 'x' << 8;
goto BinaryNumber;
case 'o':
base = 3;
goto BinaryNumber;
case 'p':
x = va_arg(va, intptr_t);
if (!x && pdot) pdot = 0;
if ((long)x == -1) {
pdot = 0;
goto FormatDecimal;
}
hash = '0' | 'x' << 8;
base = 4;
goto FormatNumber;
case 'C':
c = 'c';
type = 1;
// fallthrough
case 'c':
i = 1;
j = 0;
x = 0;
s = (const char *)&x;
t = va_arg(va, int);
if (!type) t &= 255;
if (hash) {
quot = 1;
hash = '\'';
p = kemitquote(p, e, type, hash);
if (cols && type) --cols; // u/L
if (cols) --cols; // start quote
if (cols) --cols; // end quote
}
goto EmitChar;
case 'm': {
int e;
if (!(e = tib ? tib->tib_errno : __errno) && sign == ' ') {
break;
} else {
type = 0;
#if defined(SYSDEBUG) && _NTTRACE
strerror_r(e, z, sizeof(z));
s = z;
#else
s = _strerrno(e);
if (!s) {
FormatInt32(z, e);
s = z;
}
#endif
goto FormatString;
}
}
case 'G':
x = va_arg(va, int);
s = strsignal_r(x, z);
goto FormatString;
case 't': {
// %t will print the &symbol associated with an address. this
// requires that some other code linked GetSymbolTable() and
// called it beforehand to ensure the symbol table is loaded.
// if the symbol table isn't linked or available, then this
// routine will display &hexaddr so objdump -dS foo.com.dbg
// can be manually consulted to look up the faulting code.
int idx;
x = va_arg(va, intptr_t);
if (_weaken(__symtab) && *_weaken(__symtab) &&
(idx = _weaken(__get_symbol)(0, x)) != -1) {
if (p + 1 <= e) *p++ = '&';
s = (*_weaken(__symtab))->name_base +
(*_weaken(__symtab))->names[idx];
goto FormatString;
}
base = 4;
hash = '&';
goto FormatNumber;
}
case 'n':
// nonstandard %n specifier
if (p < e) *p = '\n';
++p;
break;
case 'r':
// undocumented %r specifier
// used for good carriage return
// helps integrate loggers with repls
if (!__ttyconf.replstderr || __nocolor) {
break;
} else {
s = "\r\e[K";
goto FormatString;
}
case 's':
if (!(s = va_arg(va, const void *))) {
s = sign != ' ' ? "NULL" : "";
FormatString:
hash = 0;
type = 0;
} else if (!dang && (kisdangerous(s) || kischarmisaligned(s, type))) {
if (sign == ' ') {
if (p < e) *p = ' ';
++p;
}
x = (intptr_t)s;
base = 4;
hash = '!' | '!' << 8;
goto FormatNumber;
} else if (hash) {
quot = 1;
hash = '"';
if (cols && type) --cols; // u/L
if (cols) --cols; // start quote
if (cols) --cols; // end quote
p = kemitquote(p, e, type, hash);
}
if (sign == ' ' && (!pdot || prec) && s && *s) {
if (p < e) *p = ' ';
++p;
}
for (i = j = 0; !pdot || j < prec; ++j) {
if (UNLIKELY(!((intptr_t)s & 4095))) {
if (!dang && kisdangerous(s)) break;
}
if (!type) {
if (!(t = *s++ & 255)) break;
if ((t & 0300) == 0200) goto ActuallyEmitByte;
++i;
EmitByte:
if (uppr && 'a' <= t && t <= 'z') {
t -= 'a' - 'A';
}
if (UNLIKELY(quot) && (t == '\\' || ((t == '"' && c == 's') ||
(t == '\'' && c == 'c')))) {
if (p + 2 <= e) {
p[0] = '\\';
p[1] = t;
}
p += 2;
i += 1;
continue;
}
if (pdot ||
(t != 0x7F && (t >= 0x20 || (t == '\n' || t == '\t' ||
t == '\r' || t == '\e')))) {
ActuallyEmitByte:
if (p < e) *p = t;
p += 1;
continue;
} else if (quot) {
if (p + 4 <= e) {
p[0] = '\\';
p[1] = '0' + ((t & 0300) >> 6);
p[2] = '0' + ((t & 0070) >> 3);
p[3] = '0' + ((t & 0007) >> 0);
}
p += 4;
i += 3;
continue;
} else {
/* Control Pictures
═══════════════════════════════════════════════════════
2400 │ 0 1 2 3 4 5 6 7 8 9 a b c d e f
───────────────────────────────────────────────────────
2400 │ ␀ ␁ ␂ ␃ ␄ ␅ ␆ ␇ ␈ ␉ ␊ ␋ ␌ ␍ ␎ ␏
2410 │ ␐ ␑ ␒ ␓ ␔ ␕ ␖ ␗ ␘ ␙ ␚ ␛ ␜ ␝ ␞ ␟
2420 │ ␠ ␡ ␢ ␣ ␤ ␥ ␦ */
if (t != 0x7F) {
t += 0x2400;
} else {
t = 0x2421;
}
goto EmitChar;
}
} else if (type < -1) {
if ((t = *s++ & 255) || prec) {
t = kCp437[t];
}
} else if (type < 0) {
t = *(const char16_t *)s;
s += sizeof(char16_t);
if (IsHighSurrogate(t)) {
if (!pdot || j + 1 < prec) {
if (UNLIKELY(!((intptr_t)s & 4095))) {
if (!dang && kisdangerous(s)) break;
}
u = *(const char16_t *)s;
if (IsLowSurrogate(u)) {
t = MergeUtf16(t, u);
s += sizeof(char16_t);
j += 1;
}
} else {
break;
}
} else if (!t) {
break;
}
} else {
t = *(const wchar_t *)s;
s += sizeof(wchar_t);
}
if (!t) break;
++i;
EmitChar:
if (t <= 0x7f) goto EmitByte;
if (uppr) {
if (_weaken(towupper)) {
t = _weaken(towupper)(t);
} else if (uppr && 'a' <= t && t <= 'z') {
t -= 'a' - 'A';
}
}
if (t <= 0x7ff) {
if (p + 2 <= e) {
p[0] = 0300 | (t >> 6);
p[1] = 0200 | (t & 077);
}
p += 2;
} else if (t <= 0xffff) {
if (UNLIKELY(IsSurrogate(t))) {
EncodeReplacementCharacter:
t = 0xfffd;
}
if (p + 3 <= e) {
p[0] = 0340 | (t >> 12);
p[1] = 0200 | ((t >> 6) & 077);
p[2] = 0200 | (t & 077);
}
p += 3;
} else if (~(t >> 18) & 007) {
if (p + 4 <= e) {
p[0] = 0360 | (t >> 18);
p[1] = 0200 | ((t >> 12) & 077);
p[2] = 0200 | ((t >> 6) & 077);
p[3] = 0200 | (t & 077);
}
p += 4;
} else {
goto EncodeReplacementCharacter;
}
}
if (hash) {
if (p < e) *p = hash;
++p;
}
while (cols > i) {
if (p + 8 < e && cols - i > 8) {
WRITE64LE(p, 0x2020202020202020);
cols -= 8;
p += 8;
} else if (p < e) {
*p++ = ' ';
--cols;
} else {
p = kadvance(p, e, cols - i);
break;
}
}
break;
}
if (ansi) {
if (p + 4 <= e) {
*p++ = '\e';
*p++ = '[';
*p++ = '0';
*p++ = 'm';
}
ansi = 0;
}
break;
}
}
if (p < e) {
*p = 0;
} else if (e > b) {
u = 0;
*--e = 0;
s = "\n...";
if (!(((f - fmt) >= 2 && f[-2] == '\n') ||
((f - fmt) >= 3 && f[-3] == '%' && f[-2] == 'n'))) {
++s;
}
while ((t = *s++) && e > b) {
u = *--e;
*e = t;
}
if ((u & 0300) == 0200) {
while (e > b) {
u = *--e;
*e = '.';
if ((u & 0300) != 0200) {
break;
}
}
}
}
return p - b;
}
/**
* Privileged snprintf().
*
* @param b is buffer, and guaranteed a NUL-terminator if `n>0`
* @param n is number of bytes available in buffer
* @return length of output excluding NUL, which may exceed `n`
* @see kprintf() for documentation
* @asyncsignalsafe
* @vforksafe
*/
privileged size_t ksnprintf(char *b, size_t n, const char *fmt, ...) {
size_t m;
va_list v;
va_start(v, fmt);
m = kformat(b, n, fmt, v);
va_end(v);
return m;
}
/**
* Privileged vsnprintf().
*
* @param b is buffer, and guaranteed a NUL-terminator if `n>0`
* @param n is number of bytes available in buffer
* @return length of output excluding NUL, which may exceed `n`
* @see kprintf() for documentation
* @asyncsignalsafe
* @vforksafe
*/
privileged size_t kvsnprintf(char *b, size_t n, const char *fmt, va_list v) {
return kformat(b, n, fmt, v);
}
/**
* Privileged vprintf.
*
* @see kprintf() for documentation
* @asyncsignalsafe
* @vforksafe
*/
privileged void kvprintf(const char *fmt, va_list v) {
#pragma GCC push_options
#pragma GCC diagnostic ignored "-Walloca-larger-than="
long size = __get_safe_size(8000, 3000);
if (size < 80) {
klog(STACK_ERROR, sizeof(STACK_ERROR) - 1);
return;
}
char *buf = alloca(size);
CheckLargeStackAllocation(buf, size);
#pragma GCC pop_options
size_t count = kformat(buf, size, fmt, v);
klog(buf, MIN(count, size - 1));
}
/**
* Privileged printf().
*
* This function is intended for crash reporting. It's designed to be as
* unbreakable as possible, so that error messages can always be printed
* even when the rest of the runtime is broken. As such, it has continue
* on error semantics, doesn't support buffering between invocations and
* floating point is not supported. Output is also truncated if the line
* gets too long, but care is taken to preserve your newline characters.
* Your errno and GetLastError() state will not be clobbered, and ftrace
* and other runtime magic won't be invoked, since all the runtime magic
* depends on this function.
*
* Directives:
*
* %[FLAGS][WIDTH|*][.[PRECISION|*]][TYPE]SPECIFIER
*
* Specifiers:
*
* - `c` char
* - `o` octal
* - `b` binary
* - `s` string
* - `t` symbol
* - `p` pointer
* - `d` decimal
* - `n` newline
* - `u` unsigned
* - `r` carriage
* - `m` strerror
* - `G` strsignal
* - `X` uppercase
* - `T` timestamp
* - `x` hexadecimal
* - `P` process id
* - `H` thread id
*
* Types:
*
* - `hhh` bool
* - `hh` char or cp437
* - `h` short or char16_t
* - `l` long or wchar_t
* - `ll` long long
*
* Flags:
*
* - `0` zero padding
* - `-` flip alignment
* - `!` bypass memory safety
* - `,` thousands grouping w/ comma
* - `'` thousands grouping w/ apostrophe
* - `_` thousands grouping w/ underscore
* - `+` plus leftpad if positive (aligns w/ negatives)
* - ` ` space leftpad if positive (aligns w/ negatives)
* - `#` represent value with literal syntax, e.g. 0x, 0b, quotes
* - `^` uppercasing w/ towupper() if linked, otherwise toupper()
*
* Error numbers:
*
* - `%m` formats error (if strerror_wr if is linked)
* - `%m` formats errno number (if strerror_wr isn't linked)
* - `% m` formats error with leading space if errno isn't zero
* - `%lm` means favor WSAGetLastError() over GetLastError() if linked
*
* You need to link and load the symbol table before `%t` will work. You
* can do that by calling `GetSymbolTable()`. If that hasn't happened it
* will print `&hexnumber` instead.
*
* @asyncsignalsafe
* @vforksafe
*/
privileged void kprintf(const char *fmt, ...) {
// system call support runtime depends on this function
// function tracing runtime depends on this function
// asan runtime depends on this function
va_list v;
va_start(v, fmt);
kvprintf(fmt, v);
va_end(v);
}