[PATCH v2 1/2] Fix wrong EOF compare

From: Minchan Kim
Date: Thu Jan 10 2013 - 21:29:57 EST


The C standards allows the character type char to be singed or unsinged,
depending on the platform and compiler. Most of systems uses signed char,
but those based on PowerPC and ARM processors typically use unsigned char.
This can lead to unexpected results when the variable is used to compare
with EOF(-1). It happens my ARM system and this patch fixes it.

Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Andy Whitcroft <apw@xxxxxxxxxxxx>
Cc: Alexander Nyberg <alexn@xxxxxxxxx>
Cc: Michal Nazarewicz <mina86@xxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
Documentation/page_owner.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Documentation/page_owner.c b/Documentation/page_owner.c
index f0156e1..43dde96 100644
--- a/Documentation/page_owner.c
+++ b/Documentation/page_owner.c
@@ -32,12 +32,13 @@ int read_block(char *buf, FILE *fin)
{
int ret = 0;
int hit = 0;
+ int val;
char *curr = buf;

for (;;) {
- *curr = getc(fin);
- if (*curr == EOF) return -1;
-
+ val = getc(fin);
+ if (val == EOF) return -1;
+ *curr = val;
ret++;
if (*curr == '\n' && hit == 1)
return ret - 1;
--
1.7.9.5

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