These variables are either of an unsigned integer type per POSIX;
or of an integer type per POSIX, that Linux defines as an unsigned integer type.
Print them with 'uintmax_t' instead of 'intmax_t' to avoid
big positive numbers being printed as negative numbers.
Bug report:
From: Konstantin Bukin @ 2020-09-13 15:04 UTC
To: mtk.manpages; +Cc: Konstantin Bukin, linux-man
inode numbers are expected to be positive. Casting them to a signed type
may result in printing negative values. E.g. running example program on
the following file:
$ ls -li test.txt
9280843260537405888 -r--r--r-- 1 kbukin hardware 300 Jul 21 06:36 test.txt
resutls in the following output:
$ ./example test.txt
ID of containing device: [0,480]
File type: regular file
I-node number: -9165900813172145728
Mode: 100444 (octal)
Link count: 1
Ownership: UID=2743 GID=30
Preferred I/O block size: 32768 bytes
File size: 300 bytes
Blocks allocated: 8
Last status change: Tue Jul 21 06:36:50 2020
Last file access: Sat Sep 12 14:13:38 2020
Last file modification: Tue Jul 21 06:36:50 2020
Such erroneous reporting happens for inode values greater than maximum
value which can be stored in signed long. Casting does not seem to be
necessary here. Printing inode as unsigned long fixes the issue.
Reported-by: Konstantin Bukin <kbukin@xxxxxxxxx>
Signed-off-by: Alejandro Colomar <colomar.6.4.3@xxxxxxxxx>
---
Hi Michael,
I wrote a patch similar to Konstantin's patch,
but using `uintmax_t` as we discussed.
I further fixed a few more cases of incorrect casts.
I found all of those related to `struct stat`'s members,
but there may be more incorrect casts out there.
Cheers,
Alex
man2/ioctl_ns.2 | 8 ++++----
man2/stat.2 | 8 ++++----
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/man2/ioctl_ns.2 b/man2/ioctl_ns.2
index b83db74e0..87b5168a7 100644
--- a/man2/ioctl_ns.2
+++ b/man2/ioctl_ns.2
@@ -317,10 +317,10 @@ main(int argc, char *argv[])
exit(EXIT_FAILURE);
}
printf("Device/Inode of owning user namespace is: "
- "[%jx,%jx] / %jd\en",
+ "[%jx,%jx] / %ju\en",
(uintmax_t) major(sb.st_dev),
(uintmax_t) minor(sb.st_dev),
- (intmax_t) sb.st_ino);
+ (uintmax_t) sb.st_ino);
close(userns_fd);
}
@@ -347,10 +347,10 @@ main(int argc, char *argv[])
perror("fstat\-parentns");
exit(EXIT_FAILURE);
}
- printf("Device/Inode of parent namespace is: [%jx,%jx] / %jd\en",
+ printf("Device/Inode of parent namespace is: [%jx,%jx] / %ju\en",
(uintmax_t) major(sb.st_dev),
(uintmax_t) minor(sb.st_dev),
- (intmax_t) sb.st_ino);
+ (uintmax_t) sb.st_ino);
close(parent_fd);
}
diff --git a/man2/stat.2 b/man2/stat.2
index f71cc3831..13a1f37f7 100644
--- a/man2/stat.2
+++ b/man2/stat.2
@@ -682,14 +682,14 @@ main(int argc, char *argv[])
default: printf("unknown?\en"); break;
}
- printf("I\-node number: %jd\en", (intmax_t) sb.st_ino);
+ printf("I\-node number: %ju\en", (uintmax_t) sb.st_ino);
printf("Mode: %jo (octal)\en",
(uintmax_t) sb.st_mode);
- printf("Link count: %jd\en", (intmax_t) sb.st_nlink);
- printf("Ownership: UID=%jd GID=%jd\en",
- (intmax_t) sb.st_uid, (intmax_t) sb.st_gid);
+ printf("Link count: %ju\en", (uintmax_t) sb.st_nlink);
+ printf("Ownership: UID=%ju GID=%ju\en",
+ (uintmax_t) sb.st_uid, (uintmax_t) sb.st_gid);
printf("Preferred I/O block size: %jd bytes\en",
(intmax_t) sb.st_blksize);
--
2.28.0
