GDB - Warning: Could Not Convert 'memset' From The Host Encoding (UTF-8) To UTF-32.

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GDB - warning: could not convert 'memset' from the host encoding (UTF-8) to UTF-32.

GDB (GNU Debugger) is a powerful tool used for debugging and troubleshooting issues in software applications. However, like any other complex software, GDB is not immune to bugs and errors. In this article, we will explore a specific issue that has been reported in the GDB community, where users encounter a warning message indicating that GDB could not convert a function name from the host encoding (UTF-8) to UTF-32.

The warning message in question is:

warning: could not convert 'memset' from the host encoding (UTF-8) to UTF-32.

This message is typically displayed when GDB is unable to convert a function name from the host encoding (UTF-8) to UTF-32. The host encoding is the character encoding used by the operating system, which in this case is UTF-8. UTF-32 is a fixed-width encoding that is used internally by GDB.

To reproduce the issue, follow these steps:

  1. Download Portable Release: Download the portable release of GDB (2025.04.18) from the official GDB website.
  2. Download Attached Files: Download the attached files, which include a sample ELF file (hello.elf) and a debug symbol file (hello.debug).
  3. Execute Commands: Execute the following commands in the GDB prompt:
$ ./pwndbg/bin/pwndbg ./hello.elf
Reading symbols from /usr/bin/hello...
(No debugging symbols found in /usr/bin/hello)
pwndbg> b memset
Breakpoint 1 at 0x1478
pwndbg> add-symbol-file ./hello.debug
add symbol table from file "./hello.debug"
Reading symbols from ./hello.debug...
warning: could not convert 'memset' from the host encoding (UTF-8) to UTF-32.
This normally should not happen, please file a bug report.
pwndbg> b main
Breakpoint 2 at 0x16e0: file src/hello.c, line 41.

The issue appears to be related to the way GDB handles function names and their conversion to UTF-32. The memset function is a standard C library function that is used to set a block of memory to a specific value. In this case, the function name is being converted from the host encoding (UTF-8) to UTF-32, but the conversion is failing.

There are several possible causes for this issue:

  1. Encoding Mismatch: The host encoding (UTF-8) and the internal encoding used by GDB (UTF-32) may be mismatched, leading to the conversion failure.
  2. Function Name Corruption: The function name memset may be corrupted or truncated, leading to the conversion failure.
  3. GDB Bug: The issue may be a bug in the GDB code itself, which is causing the conversion failure.

To work around this issue, you can try the following:

  1. Use a Different Encoding: Try using a different encoding, such as UTF-16 or ISO-8859-1, to see if the issue persists.
  2. Use a Different Function Name: Try using a different function name, such as memset_, to see if the issue persists.
  3. Update GDB: Update GDB to the latest version to see if the issue is fixed.

In conclusion, the warning message "could not convert 'memset' from the host encoding (UTF-8) to UTF-32" is a known issue in GDB that can be reproduced by following the steps outlined above. The issue appears to be related to the way GDB handles function names and their conversion to UTF-32. Possible causes include encoding mismatch, function name corruption, and GDB bugs. Workarounds and solutions include using a different encoding, using a different function name, and updating GDB to the latest version.

For more information on this issue, please refer to the following resources:

The following attachments are available for download:

This attachment contains the sample ELF file (hello.elf) and the debug symbol file (hello.debug) used to reproduce the issue.
GDB - warning: could not convert 'memset' from the host encoding (UTF-8) to UTF-32. - Q&A

In our previous article, we explored a specific issue in GDB (GNU Debugger) where users encounter a warning message indicating that GDB could not convert a function name from the host encoding (UTF-8) to UTF-32. In this article, we will provide a Q&A section to help users better understand the issue and its possible causes.

A: The warning message "could not convert 'memset' from the host encoding (UTF-8) to UTF-32" in GDB indicates that the debugger is unable to convert a function name from the host encoding (UTF-8) to UTF-32. This is typically displayed when GDB is unable to convert a function name from the host encoding to the internal encoding used by GDB.

A: The possible causes of this issue include:

  1. Encoding Mismatch: The host encoding (UTF-8) and the internal encoding used by GDB (UTF-32) may be mismatched, leading to the conversion failure.
  2. Function Name Corruption: The function name memset may be corrupted or truncated, leading to the conversion failure.
  3. GDB Bug: The issue may be a bug in the GDB code itself, which is causing the conversion failure.

A: To reproduce this issue, follow these steps:

  1. Download Portable Release: Download the portable release of GDB (2025.04.18) from the official GDB website.
  2. Download Attached Files: Download the attached files, which include a sample ELF file (hello.elf) and a debug symbol file (hello.debug).
  3. Execute Commands: Execute the following commands in the GDB prompt:
$ ./pwndbg/bin/pwndbg ./hello.elf
Reading symbols from /usr/bin/hello...
(No debugging symbols found in /usr/bin/hello)
pwndbg> b memset
Breakpoint 1 at 0x1478
pwndbg> add-symbol-file ./hello.debug
add symbol table from file "./hello.debug"
Reading symbols from ./hello.debug...
warning: could not convert 'memset' from the host encoding (UTF-8) to UTF-32.
This normally should not happen, please file a bug report.
pwndbg> b main
Breakpoint 2 at 0x16e0: file src/hello.c, line 41.

A: To work around this issue, you can try the following:

  1. Use a Different Encoding: Try using a different encoding, such as UTF-16 or ISO-8859-1, to see if the issue persists.
  2. Use a Different Function Name: Try using a different function name, such as memset_, to see if the issue persists.
  3. Update GDB: Update GDB to the latest version to see if issue is fixed.

A: For more information on this issue, please refer to the following resources:

A: The following attachments are available for download:

This attachment contains the sample ELF file (hello.elf) and the debug symbol file (hello.debug) used to reproduce the issue.

In conclusion, the warning message "could not convert 'memset' from the host encoding (UTF-8) to UTF-32" in GDB is a known issue that can be reproduced by following the steps outlined above. The possible causes include encoding mismatch, function name corruption, and GDB bugs. Workarounds and solutions include using a different encoding, using a different function name, and updating GDB to the latest version.