2022-08-03 17:34:17

by Petr Vorel

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Subject: [PATCH 1/1] aiodio: Fix format string for 32bit

On 32bit char pointer is int and size_t is unsigned int,
Cast to long / unsigned long.

Signed-off-by: Petr Vorel <[email protected]>
---
Hi,

IMHO %zu is C99, we don't define -std and my gcc 12 uses by default -std=gnu17.
Therefore I'm surprised that %zu does not work.

Based on Andrea patch:
https://patchwork.ozlabs.org/project/ltp/patch/[email protected]/

Kind regards,
Petr

testcases/kernel/io/ltp-aiodio/common.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/testcases/kernel/io/ltp-aiodio/common.h b/testcases/kernel/io/ltp-aiodio/common.h
index d9cbd8611..283f7f5db 100644
--- a/testcases/kernel/io/ltp-aiodio/common.h
+++ b/testcases/kernel/io/ltp-aiodio/common.h
@@ -19,7 +19,7 @@ static inline char *check_zero(char *buf, int size)
if (*buf != 0) {
tst_res(TINFO,
"non zero buffer at buf[%lu] => 0x%02x,%02x,%02x,%02x",
- buf - p, (unsigned int)buf[0],
+ (long)(buf - p), (unsigned int)buf[0],
size > 1 ? (unsigned int)buf[1] : 0,
size > 2 ? (unsigned int)buf[2] : 0,
size > 3 ? (unsigned int)buf[3] : 0);
@@ -78,8 +78,8 @@ static inline void io_read(const char *filename, int filesize, volatile int *run
if (r > 0) {
bufoff = check_zero(buff, r);
if (bufoff) {
- tst_res(TINFO, "non-zero read at offset %zu",
- offset + (bufoff - buff));
+ tst_res(TINFO, "non-zero read at offset %lu",
+ (long int)offset + (bufoff - buff));
break;
}
offset += r;
--
2.37.1



2022-08-05 09:38:30

by Cyril Hrubis

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Subject: Re: [PATCH 1/1] aiodio: Fix format string for 32bit

Hi!
> On 32bit char pointer is int and size_t is unsigned int,
> Cast to long / unsigned long.

Actually char pointer is char pointer, that is not an integer type at
all. If you do a pointer difference you end up with an signed integer
value of ptrdiff_t type, because unlike the result of sizeof(foo)
pointer difference can be negative as well. In C99 ptrdiff_t can be
printed as %td see the "Length modifier" part of man 3 printf.

--
Cyril Hrubis
[email protected]