In kdb_md(), the `mdcount` variable is the number of lines that the
"md" command will output.
In kdb_md(), the `repeat` variable is the number of "words" that the
"md" command will output.
The relationship between these two variables and how they are
specified is a bit convoluted.
You can adjust `mdcount` via the MDCOUNT environment variable. You can
then override the MDCOUNT environment variable by passing a number of
<lines> as an argument to the command.
You can adjust `repeat` using the `mdWcN` variant of the command where
"N" is the number of words to output.
The rules for how these get applied right now:
* By default, we'll the MDCOUNT environment variable.
* If `mdWcN` is used, the repeat will override.
* If <lines> is specified, the mdcount will override.
* When we're "repeating" a previous command (AKA argc is 0) then we'll
load in the last_repeat.
If you've specified `repeat` then the `mdcount` can be calculated as:
mdcount = DIV_ROUND_UP(repeat * bytes_per_word, bytes_per_line)
In other words, if you want to display 9 words, each word is 2 bytes,
and you want 16 bytes per line then you'll take up 2 lines. This would
look like:
[1]kdb> md2c9 0xffffff80e000c340
0xffffff80e000c340 0204 0000 0000 0000 e000 8235 0000 0000
0xffffff80e000c350 0003
If you've specified `mdcount` then `repeat` is simply:
repeat = mdcount * bytes_per_line / bytes_per_word
Let's make all this logic more obvious by initializing `repeat` to 0
and then setting it to non-zero when it should override. Then we can
do all the math at once.
While changing this, use the proper DIV_ROUND_UP() macro and introcue
a constant for KDB_MD_BYTES_PER_LINE. We'll also make and "if else"
more obvious so we know things always get initialized.
Signed-off-by: Douglas Anderson <diand...@chromium.org>
---
kernel/debug/kdb/kdb_main.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 3c6fffa8509a..fcd5292351a7 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1589,11 +1589,13 @@ static void kdb_md_line(const char *fmtstr, unsigned
long addr,
" ", cbuf);
}
+#define KDB_MD_BYTES_PER_LINE 16
+
static int kdb_md(int argc, const char **argv)
{
static unsigned long last_addr;
static int last_radix, last_bytesperword, last_repeat;
- int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
+ int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat = 0;
char fmtchar, fmtstr[64];
unsigned long addr;
unsigned long word;
@@ -1606,18 +1608,13 @@ static int kdb_md(int argc, const char **argv)
kdbgetintenv("RADIX", &radix);
kdbgetintenv("BYTESPERWORD", &bytesperword);
- /* Assume 'md <addr>' and start with environment values */
- repeat = mdcount * 16 / bytesperword;
-
if (isdigit(argv[0][2])) {
bytesperword = (int)(argv[0][2] - '0');
- repeat = mdcount * 16 / bytesperword;
if (!argv[0][3])
valid = true;
else if (argv[0][3] == 'c' && argv[0][4]) {
char *p;
repeat = simple_strtoul(argv[0] + 4, &p, 10);
- mdcount = ((repeat * bytesperword) + 15) / 16;
valid = !*p;
}
} else if (strcmp(argv[0], "md") == 0)
@@ -1637,10 +1634,7 @@ static int kdb_md(int argc, const char **argv)
radix = last_radix;
bytesperword = last_bytesperword;
repeat = last_repeat;
- mdcount = ((repeat * bytesperword) + 15) / 16;
- }
-
- if (argc) {
+ } else {
unsigned long val;
int diag, nextarg = 1;
diag = kdbgetaddrarg(argc, argv, &nextarg, &addr);
@@ -1652,8 +1646,9 @@ static int kdb_md(int argc, const char **argv)
if (argc >= nextarg) {
diag = kdbgetularg(argv[nextarg], &val);
if (!diag) {
- mdcount = (int) val;
- repeat = mdcount * 16 / bytesperword;
+ mdcount = val;
+ /* Specifying <lines> overrides repeat count. */
+ repeat = 0;
}
}
if (argc >= nextarg+1) {
@@ -1699,6 +1694,13 @@ static int kdb_md(int argc, const char **argv)
return KDB_BADWIDTH;
}
+ /* If repeat is non-zero then it overrides */
+ if (repeat)
+ mdcount = DIV_ROUND_UP(repeat * bytesperword,
KDB_MD_BYTES_PER_LINE);
+ else
+ repeat = mdcount * 16 / bytesperword;
+
+ /* Always just save `repeat` since `mdcount` can be calculated from it
*/
last_repeat = repeat;
last_bytesperword = bytesperword;
--
2.45.2.627.g7a2c4fd464-goog
_______________________________________________
Kgdb-bugreport mailing list
Kgdb-bugreport@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
