fedisableexcept - Linux
Overview
fedisableexcept is a command designed primarily for kernel development and debugging. It allows advanced users to disable specific Floating-Point Exception (FPE) signals within a specified region of memory. This fine-grained control enables developers to isolate and troubleshoot issues related to FPEs in the kernel or user-space applications.
Syntax
fedisableexcept [flags] [start_address] [end_address]
Options/Flags
- –filter (MASK): Specify a bitmask to select which exceptions to disable. See the FPU Control Word documentation for available masks. (Default: 0)
- –debug (bool): Enable debugging output. (Default: false)
- –help (-h): Display help text.
- –version (-v): Display version information.
Examples
Disable all FPEs in a memory region:
fedisableexcept 0x01000000 0x02000000
Disable specific FPEs (e.g., invalid operation) in a region:
fedisableexcept --filter 0x00000001 0x01000000 0x02000000
Enable debugging output:
fedisableexcept --debug 0x01000000 0x02000000
Common Issues
Insufficient privileges: Ensure you run the command as root or with sufficient privileges to modify memory settings.
Invalid address range: Verify that the specified memory addresses are valid and accessible.
Integration
Debugging kernel FPEs:
fedisableexcept --debug 0x80000000 0x81000000
Testing FPE behavior in user-space applications:
fedisableexcept --filter 0x00000001 ./my_app