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vfprintf: Use struct scratch_buffer for positional arguments allocation

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Florian Weimer 2017-06-29 09:37:04 +02:00
parent cd00e12d31
commit 12d5853e22
2 changed files with 34 additions and 40 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2017-06-29 Florian Weimer <fweimer@redhat.com>
* stdio-common/vfprintf.c (printf_positional): Use struct
scratch_buffer to allocate backing storage for the args_value,
args_size, args_type arrays.
2017-06-29 Florian Weimer <fweimer@redhat.com>
* stdio-common/_i18n_number.h (_i18n_number_rewrite): Use struct

68
stdio-common/vfprintf.c
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@ -1708,15 +1708,17 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
CHAR_T *work_buffer, int save_errno,
const char *grouping, THOUSANDS_SEP_T thousands_sep)
{
/* For the argument descriptions, which may be allocated on the heap. */
void *args_malloced = NULL;
/* For positional argument handling. */
struct scratch_buffer specsbuf;
scratch_buffer_init (&specsbuf);
struct printf_spec *specs = specsbuf.data;
size_t specs_limit = specsbuf.length / sizeof (specs[0]);
/* Used as a backing store for args_value, args_size, args_type
below. */
struct scratch_buffer argsbuf;
scratch_buffer_init (&argsbuf);
/* Array with information about the needed arguments. This has to
be dynamically extensible. */
size_t nspecs = 0;
@ -1725,10 +1727,6 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
determine the size of the array needed to store the argument
attributes. */
size_t nargs = 0;
size_t bytes_per_arg;
union printf_arg *args_value;
int *args_size;
int *args_type;
/* Positional parameters refer to arguments directly. This could
also determine the maximum number of arguments. Track the
@ -1778,38 +1776,29 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
/* Determine the number of arguments the format string consumes. */
nargs = MAX (nargs, max_ref_arg);
/* Calculate total size needed to represent a single argument across
all three argument-related arrays. */
bytes_per_arg = (sizeof (*args_value) + sizeof (*args_size)
+ sizeof (*args_type));
/* Check for potential integer overflow. */
if (__glibc_unlikely (nargs > INT_MAX / bytes_per_arg))
{
__set_errno (EOVERFLOW);
done = -1;
goto all_done;
}
/* Allocate memory for all three argument arrays. */
if (__libc_use_alloca (nargs * bytes_per_arg))
args_value = alloca (nargs * bytes_per_arg);
else
{
args_value = args_malloced = malloc (nargs * bytes_per_arg);
if (args_value == NULL)
{
done = -1;
goto all_done;
}
}
/* Set up the remaining two arrays to each point past the end of the
prior array, since space for all three has been allocated now. */
args_size = &args_value[nargs].pa_int;
args_type = &args_size[nargs];
memset (args_type, s->_flags2 & _IO_FLAGS2_FORTIFY ? '\xff' : '\0',
nargs * sizeof (*args_type));
union printf_arg *args_value;
int *args_size;
int *args_type;
{
/* Calculate total size needed to represent a single argument
across all three argument-related arrays. */
size_t bytes_per_arg
= sizeof (*args_value) + sizeof (*args_size) + sizeof (*args_type);
if (!scratch_buffer_set_array_size (&argsbuf, nargs, bytes_per_arg))
{
done = -1;
goto all_done;
}
args_value = argsbuf.data;
/* Set up the remaining two arrays to each point past the end of
the prior array, since space for all three has been allocated
now. */
args_size = &args_value[nargs].pa_int;
args_type = &args_size[nargs];
memset (args_type, s->_flags2 & _IO_FLAGS2_FORTIFY ? '\xff' : '\0',
nargs * sizeof (*args_type));
}
/* XXX Could do sanity check here: If any element in ARGS_TYPE is
still zero after this loop, format is invalid. For now we
@ -2075,10 +2064,9 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format,
- specs[nspecs_done].end_of_fmt);
}
all_done:
if (__glibc_unlikely (args_malloced != NULL))
free (args_malloced);
if (__glibc_unlikely (workstart != NULL))
free (workstart);
scratch_buffer_free (&argsbuf);
scratch_buffer_free (&specsbuf);
return done;
}