Commit Graph

8 Commits

Author SHA1 Message Date
Peter Oberparleiter
75ab455cf6 libutil: Avoid realloc() with zero size
According to the valgrind man-page, "the behaviour of realloc() with a
size of zero is implementation defined in C17 and undefined in C23."

The current glibc implementation frees the specified buffer, returns
NULL and doesn't set errno. While this behavior is unlikely to change
in the near future, code relying on it may not be compatible with other
libc implementations. Also this realloc() use is flagged as an error in
valgrind runs, making valgrind output less usable.

Fix this by explicitly adding code to cover the realloc(buffer, 0) case
in util_realloc(). Also change libutil users of realloc() to use
util_realloc() instead.

Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2026-01-19 13:03:19 +01:00
Jan Höppner
0eac97542d libutil/util_file: Handle over-read in util_file_read_fd()
In certain situations util_file_read_fd_buf() might return a larger
buffer than printable characters were read (e.g. a file was padded with
zeros). This can lead to util_file_read_fd() returning NULL with a freed
buffer even though a certain amount of printable characters were read.

This behaviour causes a regression introduced with commit 9efd1df31d
("ipl_tools: Refactor read helper using util_file_read_text_file()") in
ipl_tools were the scp_data sysfs attribute is padded with 0 to fit an 8
byte alignment required by the architecture.

Fix this by comparing the size read with the actual string length and
use the smaller value for further processing.

Fixes: 9efd1df31d ("ipl_tools: Refactor read helper using util_file_read_text_file()")
Tested-by: Jan Polensky <japo@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2025-05-05 17:15:01 +02:00
Peter Oberparleiter
a97a8f1cba libutil: fix util_file_write_* return code
By default, files opened via fopen are block-buffered. As a result,
I/O errors that occur during file write operations via util_file_write_*
are silently ignored because fputs() only buffers data while actual I/O
occurs during the flush operation that is part of the final fclose()
library call.

Fix this by indicating errors that occur during fclose() via the
util_file_write_* function return code.

Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
2024-05-27 16:52:07 +02:00
Niklas Schnelle
19f3842292 libutil: fix util_file_read_*() using wrong format specifiers
The sscanf() format specifiers for signed and unsigned int mistakenly
used "%d"/"%u" prefix analogous to "%l" for long but those do not exist.

Fixes: 37348ef662 ("libutil: add util_file_read_i()/util_file_read_ui()")
Acked-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
2023-12-01 10:24:48 +01:00
Matthew Rosato
f64b4087dd libutil: Move some zdev file reading functions into util
In preparation for sharing some zdev udev code with other libraries, move
some file operation code from zdev into util_file.

Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2022-05-17 13:20:27 +02:00
Sven Schnelle
1df4d66387 libutil: add util_file_read_va()
Takes a format string and parses a file accordingly and returns the
parsed values.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2020-10-12 13:12:55 +02:00
Sven Schnelle
37348ef662 libutil: add util_file_read_i()/util_file_read_ui()
These functions parse a sysfs file and return either an
unsigned integer or signed integer.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2020-10-12 13:12:55 +02:00
Michael Holzheu
b627b8d8e1 Initial s390-tools-2.0.0 import
This commit is based on the s390-tools-1.39.0 version.

Changes on top of s390-tools-1.39.0:

 - Add MIT license to all source files
 - Add LICENSE file
 - Transform REAMDE to README.md (markdown)
 - Add AUTHORS.md file
 - Add CONTRIBUTING.md file
 - Move changelog from README to CHANGELOG.md file

Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
2017-08-21 10:55:40 +02:00