[PATCH v2 21/28] vsprintf: Refactor hex_string, bitmap_string_list, bitmap_string

From: Kent Overstreet
Date: Thu May 19 2022 - 13:27:39 EST


This patch cleans up printf_spec handling: these functions only use
spec.field_width and they do not interpret it in the normal way -
instead it's a number of bits/bytes passed in to print, so these
functions are changed to take that parameter directly.

Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
lib/vsprintf.c | 47 +++++++++++++++++++++++++----------------------
1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index ef8b06a25a..be2fa6053c 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1132,17 +1132,22 @@ void resource_string(struct printbuf *out, struct resource *res,

static noinline_for_stack
void hex_string(struct printbuf *out, const u8 *addr,
- struct printf_spec spec, const char *fmt)
+ int len, const char *fmt)
{
- int len = 1; /* if we pass '%ph[CDN]', field width remains
- negative value, fallback to the default */
char separator;

- if (spec.field_width == 0)
- /* nothing to print */
+ /* nothing to print */
+ if (len == 0)
return;

- if (check_pointer_spec(out, addr, spec))
+ /* if we pass '%ph[CDN]', field width remains
+ negative value, fallback to the default */
+ if (len < 0)
+ len = 1;
+
+ len = min(len, 64);
+
+ if (check_pointer(out, addr))
return;

switch (fmt[1]) {
@@ -1160,26 +1165,21 @@ void hex_string(struct printbuf *out, const u8 *addr,
break;
}

- if (spec.field_width > 0)
- len = min_t(int, spec.field_width, 64);
-
pr_hex_bytes(out, addr, len, separator);
}

static noinline_for_stack
-void bitmap_string(struct printbuf *out, unsigned long *bitmap,
- struct printf_spec spec, const char *fmt)
+void bitmap_string(struct printbuf *out, unsigned long *bitmap, int nr_bits)
{
+ struct printf_spec spec = { .flags = SMALL | ZEROPAD, .base = 16 };
const int CHUNKSZ = 32;
- int nr_bits = max_t(int, spec.field_width, 0);
int i, chunksz;
bool first = true;

- if (check_pointer_spec(out, bitmap, spec))
- return;
+ nr_bits = max(nr_bits, 0);

- /* reused to print numbers */
- spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
+ if (check_pointer(out, bitmap))
+ return;

chunksz = nr_bits & (CHUNKSZ - 1);
if (chunksz == 0)
@@ -1208,13 +1208,14 @@ void bitmap_string(struct printbuf *out, unsigned long *bitmap,

static noinline_for_stack
void bitmap_list_string(struct printbuf *out, unsigned long *bitmap,
- struct printf_spec spec, const char *fmt)
+ int nr_bits)
{
- int nr_bits = max_t(int, spec.field_width, 0);
bool first = true;
int rbot, rtop;

- if (check_pointer_spec(out, bitmap, spec))
+ nr_bits = max(nr_bits, 0);
+
+ if (check_pointer(out, bitmap))
return ;

for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
@@ -2235,13 +2236,15 @@ void pointer(struct printbuf *out, const char *fmt,
resource_string(out, ptr, fmt[0] == 'R');
return do_width_precision(out, prev_pos, spec);
case 'h':
- return hex_string(out, ptr, spec, fmt);
+ /* Uses field_width but _not_ as field size */
+ return hex_string(out, ptr, spec.field_width, fmt);
case 'b':
+ /* Uses field_width but _not_ as field size */
switch (fmt[1]) {
case 'l':
- return bitmap_list_string(out, ptr, spec, fmt);
+ return bitmap_list_string(out, ptr, spec.field_width);
default:
- return bitmap_string(out, ptr, spec, fmt);
+ return bitmap_string(out, ptr, spec.field_width);
}
case 'M': /* Colon separated: 00:01:02:03:04:05 */
case 'm': /* Contiguous: 000102030405 */
--
2.36.0