![Kees Cook](/assets/img/avatar_default.png)
This makes sure format strings cannot leak into printk (the string has already been correctly processed for format arguments). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
133 lines
2.2 KiB
C
133 lines
2.2 KiB
C
/*
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* Copyright (C) 1996-2005 Paul Mackerras.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/string.h>
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#include <asm/udbg.h>
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#include <asm/time.h>
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#include "nonstdio.h"
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static int xmon_write(const void *ptr, int nb)
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{
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return udbg_write(ptr, nb);
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}
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static int xmon_readchar(void)
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{
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if (udbg_getc)
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return udbg_getc();
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return -1;
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}
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int xmon_putchar(int c)
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{
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char ch = c;
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if (c == '\n')
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xmon_putchar('\r');
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return xmon_write(&ch, 1) == 1? c: -1;
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}
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static char line[256];
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static char *lineptr;
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static int lineleft;
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static int xmon_getchar(void)
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{
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int c;
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if (lineleft == 0) {
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lineptr = line;
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for (;;) {
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c = xmon_readchar();
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if (c == -1 || c == 4)
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break;
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if (c == '\r' || c == '\n') {
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*lineptr++ = '\n';
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xmon_putchar('\n');
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break;
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}
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switch (c) {
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case 0177:
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case '\b':
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if (lineptr > line) {
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xmon_putchar('\b');
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xmon_putchar(' ');
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xmon_putchar('\b');
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--lineptr;
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}
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break;
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case 'U' & 0x1F:
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while (lineptr > line) {
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xmon_putchar('\b');
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xmon_putchar(' ');
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xmon_putchar('\b');
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--lineptr;
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}
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break;
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default:
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if (lineptr >= &line[sizeof(line) - 1])
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xmon_putchar('\a');
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else {
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xmon_putchar(c);
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*lineptr++ = c;
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}
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}
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}
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lineleft = lineptr - line;
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lineptr = line;
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}
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if (lineleft == 0)
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return -1;
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--lineleft;
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return *lineptr++;
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}
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char *xmon_gets(char *str, int nb)
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{
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char *p;
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int c;
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for (p = str; p < str + nb - 1; ) {
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c = xmon_getchar();
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if (c == -1) {
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if (p == str)
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return NULL;
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break;
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}
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*p++ = c;
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if (c == '\n')
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break;
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}
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*p = 0;
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return str;
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}
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void xmon_printf(const char *format, ...)
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{
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va_list args;
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static char xmon_outbuf[1024];
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int rc, n;
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va_start(args, format);
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n = vsnprintf(xmon_outbuf, sizeof(xmon_outbuf), format, args);
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va_end(args);
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rc = xmon_write(xmon_outbuf, n);
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if (n && rc == 0) {
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/* No udbg hooks, fallback to printk() - dangerous */
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printk("%s", xmon_outbuf);
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}
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}
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void xmon_puts(const char *str)
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{
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xmon_write(str, strlen(str));
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}
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