The
/dev/ksyms
character device provides a read-only interface to a snapshot of the kernel
symbol table.
The in-kernel symbol manager is designed to be able to handle
many types of symbols tables, however, only
elf(5)
symbol tables are supported by this device.
The ELF format image contains two
sections: a symbol table and a corresponding string table.
|
| Symbol Table
|
| |
The SYMTAB section contains the symbol table entries present in the current
running kernel, including the symbol table entries of any loaded modules.
The symbols are ordered by the kernel module load time starting with kernel file
symbols first, followed by the first loaded module's symbols and so on.
|
| String Table
|
| |
The STRTAB section contains the symbol name strings from the kernel and any
loaded modules that the symbol table entries reference.
|
|
Elf formatted symbol table data read from the
/dev/ksyms
file represents the state of the kernel at the time when the device is opened.
Since
/dev/ksyms
has no text or data, most of the fields are initialized to NULL.
The
ksyms
driver does not block the loading or unloading of modules into the kernel
while the
/dev/ksyms
file is open but may contain stale data.
