zephyr/lib/os/printk.c

513 lines
10 KiB
C

/*
* Copyright (c) 2010, 2013-2014 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Low-level debug output
*
* Low-level debugging output. Platform installs a character output routine at
* init time. If no routine is installed, a nop routine is called.
*/
#include <kernel.h>
#include <sys/printk.h>
#include <stdarg.h>
#include <toolchain.h>
#include <linker/sections.h>
#include <syscall_handler.h>
#include <logging/log.h>
#include <sys/types.h>
typedef int (*out_func_t)(int c, void *ctx);
enum pad_type {
PAD_NONE,
PAD_ZERO_BEFORE,
PAD_SPACE_BEFORE,
PAD_SPACE_AFTER,
};
#ifdef CONFIG_PRINTK64
typedef uint64_t printk_val_t;
#else
typedef uint32_t printk_val_t;
#endif
/* Maximum number of digits in a printed decimal value (hex is always
* less, obviously). Funny formula produces 10 max digits for 32 bit,
* 21 for 64.
*/
#define DIGITS_BUFLEN (11 * (sizeof(printk_val_t) / 4) - 1)
#ifdef CONFIG_PRINTK_SYNC
static struct k_spinlock lock;
#endif
#ifdef CONFIG_PRINTK
/**
* @brief Default character output routine that does nothing
* @param c Character to swallow
*
* Note this is defined as a weak symbol, allowing architecture code
* to override it where possible to enable very early logging.
*
* @return 0
*/
/* LCOV_EXCL_START */
__attribute__((weak)) int arch_printk_char_out(int c)
{
ARG_UNUSED(c);
/* do nothing */
return 0;
}
/* LCOV_EXCL_STOP */
int (*_char_out)(int) = arch_printk_char_out;
/**
* @brief Install the character output routine for printk
*
* To be called by the platform's console driver at init time. Installs a
* routine that outputs one ASCII character at a time.
* @param fn putc routine to install
*
* @return N/A
*/
void __printk_hook_install(int (*fn)(int))
{
_char_out = fn;
}
/**
* @brief Get the current character output routine for printk
*
* To be called by any console driver that would like to save
* current hook - if any - for later re-installation.
*
* @return a function pointer or NULL if no hook is set
*/
void *__printk_get_hook(void)
{
return _char_out;
}
#endif /* CONFIG_PRINTK */
static void print_digits(out_func_t out, void *ctx, printk_val_t num, int base,
bool pad_before, char pad_char, int min_width)
{
char buf[DIGITS_BUFLEN];
int i;
/* Print it backwards into the end of the buffer, low digits first */
for (i = DIGITS_BUFLEN - 1; num != 0; i--) {
buf[i] = "0123456789abcdef"[num % base];
num /= base;
}
if (i == DIGITS_BUFLEN - 1) {
buf[i] = '0';
} else {
i++;
}
int pad = MAX(min_width - (DIGITS_BUFLEN - i), 0);
for (/**/; pad > 0 && pad_before; pad--) {
out(pad_char, ctx);
}
for (/**/; i < DIGITS_BUFLEN; i++) {
out(buf[i], ctx);
}
for (/**/; pad > 0; pad--) {
out(pad_char, ctx);
}
}
static void print_hex(out_func_t out, void *ctx, printk_val_t num,
enum pad_type padding, int min_width)
{
print_digits(out, ctx, num, 16, padding != PAD_SPACE_AFTER,
padding == PAD_ZERO_BEFORE ? '0' : ' ', min_width);
}
static void print_dec(out_func_t out, void *ctx, printk_val_t num,
enum pad_type padding, int min_width)
{
print_digits(out, ctx, num, 10, padding != PAD_SPACE_AFTER,
padding == PAD_ZERO_BEFORE ? '0' : ' ', min_width);
}
static bool ok64(out_func_t out, void *ctx, long long val)
{
if (sizeof(printk_val_t) < 8 && val != (long) val) {
out('E', ctx);
out('R', ctx);
out('R', ctx);
return false;
}
return true;
}
static bool negative(printk_val_t val)
{
const printk_val_t hibit = ~(((printk_val_t) ~1) >> 1);
return (val & hibit) != 0;
}
/**
* @brief Printk internals
*
* See printk() for description.
* @param fmt Format string
* @param ap Variable parameters
*
* @return N/A
*/
void z_vprintk(out_func_t out, void *ctx, const char *fmt, va_list ap)
{
int might_format = 0; /* 1 if encountered a '%' */
enum pad_type padding = PAD_NONE;
int min_width = -1;
char length_mod = 0;
/* fmt has already been adjusted if needed */
while (*fmt) {
if (!might_format) {
if (*fmt != '%') {
out((int)*fmt, ctx);
} else {
might_format = 1;
min_width = -1;
padding = PAD_NONE;
length_mod = 0;
}
} else {
switch (*fmt) {
case '-':
padding = PAD_SPACE_AFTER;
goto still_might_format;
case '0':
if (min_width < 0 && padding == PAD_NONE) {
padding = PAD_ZERO_BEFORE;
goto still_might_format;
}
/* Fall through */
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
/* Fall through */
case '9':
if (min_width < 0) {
min_width = *fmt - '0';
} else {
min_width = 10 * min_width + *fmt - '0';
}
if (padding == PAD_NONE) {
padding = PAD_SPACE_BEFORE;
}
goto still_might_format;
case 'h':
case 'l':
case 'z':
if (*fmt == 'h' && length_mod == 'h') {
length_mod = 'H';
} else if (*fmt == 'l' && length_mod == 'l') {
length_mod = 'L';
} else if (length_mod == 0) {
length_mod = *fmt;
} else {
out((int)'%', ctx);
out((int)*fmt, ctx);
break;
}
goto still_might_format;
case 'd':
case 'i':
case 'u': {
printk_val_t d;
if (length_mod == 'z') {
d = va_arg(ap, ssize_t);
} else if (length_mod == 'l') {
d = va_arg(ap, long);
} else if (length_mod == 'L') {
long long lld = va_arg(ap, long long);
if (!ok64(out, ctx, lld)) {
break;
}
d = (printk_val_t) lld;
} else {
d = va_arg(ap, int);
}
if (*fmt != 'u' && negative(d)) {
out((int)'-', ctx);
d = -d;
min_width--;
}
print_dec(out, ctx, d, padding, min_width);
break;
}
case 'p':
out('0', ctx);
out('x', ctx);
/* left-pad pointers with zeros */
padding = PAD_ZERO_BEFORE;
min_width = sizeof(void *) * 2;
/* Fall through */
case 'x':
case 'X': {
printk_val_t x;
if (*fmt == 'p') {
x = (uintptr_t)va_arg(ap, void *);
} else if (length_mod == 'l') {
x = va_arg(ap, unsigned long);
} else if (length_mod == 'L') {
x = va_arg(ap, unsigned long long);
} else {
x = va_arg(ap, unsigned int);
}
print_hex(out, ctx, x, padding, min_width);
break;
}
case 's': {
char *s = va_arg(ap, char *);
char *start = s;
while (*s) {
out((int)(*s++), ctx);
}
if (padding == PAD_SPACE_AFTER) {
int remaining = min_width - (s - start);
while (remaining-- > 0) {
out(' ', ctx);
}
}
break;
}
case 'c': {
int c = va_arg(ap, int);
out(c, ctx);
break;
}
case '%': {
out((int)'%', ctx);
break;
}
default:
out((int)'%', ctx);
out((int)*fmt, ctx);
break;
}
might_format = 0;
}
still_might_format:
++fmt;
}
}
#ifdef CONFIG_PRINTK
#ifdef CONFIG_USERSPACE
struct buf_out_context {
int count;
unsigned int buf_count;
char buf[CONFIG_PRINTK_BUFFER_SIZE];
};
static void buf_flush(struct buf_out_context *ctx)
{
k_str_out(ctx->buf, ctx->buf_count);
ctx->buf_count = 0U;
}
static int buf_char_out(int c, void *ctx_p)
{
struct buf_out_context *ctx = ctx_p;
ctx->count++;
ctx->buf[ctx->buf_count++] = c;
if (ctx->buf_count == CONFIG_PRINTK_BUFFER_SIZE) {
buf_flush(ctx);
}
return c;
}
#endif /* CONFIG_USERSPACE */
struct out_context {
int count;
};
static int char_out(int c, void *ctx_p)
{
struct out_context *ctx = ctx_p;
ctx->count++;
return _char_out(c);
}
#ifdef CONFIG_USERSPACE
void vprintk(const char *fmt, va_list ap)
{
if (_is_user_context()) {
struct buf_out_context ctx = { 0 };
z_vprintk(buf_char_out, &ctx, fmt, ap);
if (ctx.buf_count) {
buf_flush(&ctx);
}
} else {
struct out_context ctx = { 0 };
#ifdef CONFIG_PRINTK_SYNC
k_spinlock_key_t key = k_spin_lock(&lock);
#endif
z_vprintk(char_out, &ctx, fmt, ap);
#ifdef CONFIG_PRINTK_SYNC
k_spin_unlock(&lock, key);
#endif
}
}
#else
void vprintk(const char *fmt, va_list ap)
{
struct out_context ctx = { 0 };
#ifdef CONFIG_PRINTK_SYNC
k_spinlock_key_t key = k_spin_lock(&lock);
#endif
z_vprintk(char_out, &ctx, fmt, ap);
#ifdef CONFIG_PRINTK_SYNC
k_spin_unlock(&lock, key);
#endif
}
#endif /* CONFIG_USERSPACE */
void z_impl_k_str_out(char *c, size_t n)
{
size_t i;
#ifdef CONFIG_PRINTK_SYNC
k_spinlock_key_t key = k_spin_lock(&lock);
#endif
for (i = 0; i < n; i++) {
_char_out(c[i]);
}
#ifdef CONFIG_PRINTK_SYNC
k_spin_unlock(&lock, key);
#endif
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_str_out(char *c, size_t n)
{
Z_OOPS(Z_SYSCALL_MEMORY_READ(c, n));
z_impl_k_str_out((char *)c, n);
}
#include <syscalls/k_str_out_mrsh.c>
#endif /* CONFIG_USERSPACE */
/**
* @brief Output a string
*
* Output a string on output installed by platform at init time. Some
* printf-like formatting is available.
*
* Available formatting:
* - %x/%X: outputs a number in hexadecimal format
* - %s: outputs a null-terminated string
* - %p: pointer, same as %x with a 0x prefix
* - %u: outputs a number in unsigned decimal format
* - %d/%i: outputs a number in signed decimal format
*
* Field width (with or without leading zeroes) is supported.
* Length attributes h, hh, l, ll and z are supported. However, integral
* values with %lld and %lli are only printed if they fit in a long
* otherwise 'ERR' is printed. Full 64-bit values may be printed with %llx.
*
* @param fmt formatted string to output
*
* @return N/A
*/
void printk(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (IS_ENABLED(CONFIG_LOG_PRINTK)) {
log_printk(fmt, ap);
} else {
vprintk(fmt, ap);
}
va_end(ap);
}
#endif /* CONFIG_PRINTK */
struct str_context {
char *str;
int max;
int count;
};
static int str_out(int c, struct str_context *ctx)
{
if (ctx->str == NULL || ctx->count >= ctx->max) {
ctx->count++;
return c;
}
if (ctx->count == ctx->max - 1) {
ctx->str[ctx->count++] = '\0';
} else {
ctx->str[ctx->count++] = c;
}
return c;
}
int snprintk(char *str, size_t size, const char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
ret = vsnprintk(str, size, fmt, ap);
va_end(ap);
return ret;
}
int vsnprintk(char *str, size_t size, const char *fmt, va_list ap)
{
struct str_context ctx = { str, size, 0 };
z_vprintk((out_func_t)str_out, &ctx, fmt, ap);
if (ctx.count < ctx.max) {
str[ctx.count] = '\0';
}
return ctx.count;
}