ExternalVendorCode/genode
1
0
Fork 0
mirror of https://github.com/genodelabs/genode.git synced 2025-02-21 10:01:57 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

lib/format: parse precision and lalign

Browse Source 
Prevent errors if precision and left alignment are part of the string.
String precision is applied to limit access to the configured number of
characters but ignored for other types.

Issue #5083
This commit is contained in:
Christian Helmuth 2023-12-18 11:40:42 +01:00
parent a5b8090e14
commit a6b30d58df
1 changed files with 23 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
repos/libports/src/lib/format/console.cc
View File

@ -56,7 +56,9 @@ class Format_command
Type type = INVALID; /* format argument type */
Length length = DEFAULT; /* format argument length */
int padding = 0; /* min number of characters to print */
int precision = 0; /* max number of characters to print */
int base = 10; /* base of numeric arguments */
bool lalign = false; /* align left */
bool zeropad = false; /* pad with zero instead of space */
bool uppercase = false; /* use upper case for hex numbers */
int consumed = 0; /* nb of consumed format string chars */
@ -72,6 +74,12 @@ class Format_command
if (format[consumed] != '%') return;
if (!format[++consumed]) return;
/* read left alignment */
if (format[consumed] == '-') {
lalign = true;
if (!format[++consumed]) return;
}
/* heading zero indicates zero-padding */
zeropad = (format[consumed] == '0');
@ -79,6 +87,11 @@ class Format_command
padding = decode_decimal(format, &consumed);
if (!format[consumed]) return;
/* read precision value */
if (format[consumed] == '.')
precision = decode_decimal(format, &(++consumed));
if (!format[consumed]) return;
/* decode length */
switch (format[consumed]) {
@ -157,7 +170,6 @@ void Console::printf(const char *format, ...)
void Console::vprintf(const char *format, va_list list)
{
while (*format) {
/* eat and output plain characters */
@ -234,7 +246,16 @@ void Console::vprintf(const char *format, va_list list)
case Format_command::STRING:
_out_string(va_arg(list, const char *));
if (cmd.precision) {
int p = 0;
char const *a = va_arg(list, const char *);
for (; a && *a && p < cmd.precision; ++a, ++p)
_out_char(*a);
for (; p < cmd.padding; ++p)
_out_char(' ');
} else {
_out_string(va_arg(list, const char *));
}
break;
case Format_command::PERCENT: