[PATCH AUTOSEL for 4.4 06/20] dynamic-debug-howto: fix optional/omitted ending line number to be LARGE instead of 0

[alexander . levin]

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

[ Upstream commit 1f3c790bd5989fcfec9e53ad8fa09f5b740c958f ]

line-range is supposed to treat "1-" as "1-endoffile", so
handle the special case by setting last_lineno to UINT_MAX.

Fixes this error:

  dynamic_debug:ddebug_parse_query: last-line:0 < 1st-line:1
  dynamic_debug:ddebug_exec_query: query parse failed

Link: http://lkml.kernel.org/r/10a6a101-e2be-209f-1f41-54637824788e@xxxxxxxxxxxxx
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Acked-by: Jason Baron <jbaron@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
 lib/dynamic_debug.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e3952e9c8ec0..c6368ae93fe6 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -353,6 +353,10 @@ static int ddebug_parse_query(char *words[], int nwords,
 				if (parse_lineno(last, &query->last_lineno) < 0)
 					return -EINVAL;
 
+				/* special case for last lineno not specified */
+				if (query->last_lineno == 0)
+					query->last_lineno = UINT_MAX;
+
 				if (query->last_lineno < query->first_lineno) {
 					pr_err("last-line:%d < 1st-line:%d\n",
 						query->last_lineno,
-- 
2.11.0