Syzkaller Description Workflow

Full Build Loop for New Descriptions

When adding new syscall descriptions, follow this workflow:

cd /opt/syzkaller

# 1. Write/edit your .txt file in sys/linux/

# 2. Create a .const file with constant values (see syz-extract-constants skill)
#    The .const file should be named: sys/linux/your_file.txt.const

# 3. Compile descriptions
make descriptions

# 4. Build syzkaller
make all

Quick Rebuild (After Minor Edits)

If you only changed descriptions (not constants):

cd /opt/syzkaller
make descriptions   # Runs syz-sysgen to compile descriptions

If you add new constants, update the .const file first.

Common Errors

Unknown type

unknown type foo_bar

• Type not defined, or defined after first use
• Define all types before using them

Constant not available / defined for none of the arches

SOME_CONST is defined for none of the arches

• The constant isn't in the .const file
• Add it to sys/linux/your_file.txt.const with the correct value

Missing reference

undefined reference to 'some_type'

• Type defined in another file not being found
• Check includes or existing type definitions

Exploring Existing Code

Find examples of patterns:

grep -r "pattern" /opt/syzkaller/sys/linux/

Useful searches:

• resource fd_ - How other fd resources are defined
• ioctl\$ - Ioctl definition patterns
• read\$ / write\$ - Read/write specializations
• struct.*{ - Struct definition patterns

Files to Reference

• sys/linux/socket.txt - Network types (ifreq_t, sockaddr, etc.)
• sys/linux/sys.txt - Basic syscall patterns
• sys/linux/fs.txt - File operations