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printk: add ptr support and minor refactor

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Felix Kopp 2021-01-04 14:56:57 +01:00
parent 2f8404678b
commit 6f10f507da
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GPG key ID: C478BA0A85F75728
1 changed files with 65 additions and 28 deletions
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93
kernel/printk.c
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@ -5,22 +5,52 @@
/* Using GCC's stdarg.h is recommended even with -nodefaultlibs and -fno-builtin */
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <ardix/malloc.h>
#include <ardix/printk.h>
#include <ardix/serial.h>
#include <ardix/string.h>
#define PRINTK_BUFSZ 24
#include <toolchain.h>
static int handle_uint(unsigned int u)
/*
* TODO: THIS CAUSES A STACK BUFFER OVERFLOW ON SYSTEMS WHERE INT IS 64 BITS
*/
/* 10 decimal digits (2 ** 32 - 1) + ASCII NUL */
#define PRINTK_UINT_BUFSZ 11
__rodata static const char fmt_hex_table[] = {
'0', '1', '2', '3',
'4', '5', '6', '7',
'8', '9', 'a', 'b',
'c', 'd', 'e', 'f',
};
static int fmt_handle_ptr(uintptr_t ptr)
{
int ret = 0;
char *buf = malloc(PRINTK_BUFSZ);
char *pos = buf + PRINTK_BUFSZ - 1;
int ret;
/* 2 chars per byte, plus 2 for the "0x" hex prefix */
char buf[2 * sizeof(uintptr_t) + 2];
char *pos = &buf[2 * sizeof(uintptr_t) + 1];
if (buf == NULL)
return -ENOMEM;
buf[0] = '0';
buf[1] = 'x';
do {
*pos-- = fmt_hex_table[ptr & 0xf];
ptr >>= 4;
} while (pos != &buf[2]);
ret = serial_write(serial_default_interface, &buf[0], 2 * sizeof(uintptr_t) + 2);
return ret;
}
static int fmt_handle_uint(unsigned int u)
{
int ret;
char buf[PRINTK_UINT_BUFSZ];
char *pos = &buf[PRINTK_UINT_BUFSZ - 1];
do {
/* stupid big endian humans, forcing us to do the whole thing in reverse */
@ -30,13 +60,11 @@ static int handle_uint(unsigned int u)
pos++;
ret = serial_write(serial_default_interface, pos,
PRINTK_BUFSZ - ( (size_t)pos - (size_t)buf ));
free(buf);
PRINTK_UINT_BUFSZ - ( (size_t)pos - (size_t)&buf[0] ));
return ret;
}
static inline int handle_int(int i)
static inline int fmt_handle_int(int i)
{
int ret = 0;
char minus = '-';
@ -46,7 +74,7 @@ static inline int handle_int(int i)
i = -i;
}
ret += handle_uint((unsigned int)i);
ret += fmt_handle_uint((unsigned int)i);
return ret;
}
@ -61,37 +89,46 @@ static inline int handle_int(int i)
* @param args: A pointer to the varargs list. Will be manipulated.
* @returns The amount of bytes written, or a negative POSIX error code.
*/
static inline int handle_fmt(const char **pos, va_list args)
static inline int fmt_handle(const char **pos, va_list args)
{
int ret = 0;
int i;
unsigned int u;
char *tmp;
union {
int c;
int d;
uintptr_t p;
char *s;
unsigned int u;
} val;
switch (**pos) {
case '%': /* literal percent sign */
ret = serial_write(serial_default_interface, *pos, sizeof(**pos));
break;
case 'c': /* single char */
i = va_arg(args, int);
ret = serial_write(serial_default_interface, &i, sizeof(char));
case 'c': /* char */
val.c = va_arg(args, typeof(val.c));
ret = serial_write(serial_default_interface, &val.c, sizeof(val.c));
break;
case 'd': /* int */
i = va_arg(args, int);
ret = handle_int(i);
val.d = va_arg(args, typeof(val.d));
ret = fmt_handle_int(val.d);
break;
case 'p': /* ptr */
val.p = va_arg(args, typeof(val.p));
ret = fmt_handle_ptr(val.p);
break;
case 's': /* string */
tmp = va_arg(args, char *);
ret = (int)strlen(tmp);
ret = serial_write(serial_default_interface, tmp, (size_t)ret);
val.s = va_arg(args, typeof(val.s));
ret = (int)strlen(val.s);
ret = serial_write(serial_default_interface, val.s, (size_t)ret);
break;
case 'u': /* unsigned int */
u = va_arg(args, unsigned int);
ret = handle_uint(u);
val.u = va_arg(args, typeof(val.u));
ret = fmt_handle_uint(val.u);
break;
}
@ -115,7 +152,7 @@ int printk(const char *fmt, ...)
ret += (int)serial_write(serial_default_interface, fmt,
(size_t)tmp - (size_t)fmt - 1);
tmpret = handle_fmt(&tmp, args);
tmpret = fmt_handle(&tmp, args);
/*
* act as if the current position were the beginning in
* order to make the first step of this if block easier