On Tue, Mar 23, 2021 at 01:39:32PM -0700, Sami Tolvanen wrote: > With CONFIG_CFI_CLANG, the compiler replaces function addresses > in instrumented C code with jump table addresses. This means that > __pa_symbol(function) returns the physical address of the jump table > entry instead of the actual function, which may not work as the jump > table code will immediately jump to a virtual address that may not be > mapped. > > To avoid this address space confusion, this change adds generic > definitions for __va_function and __pa_function, which architectures > that support CFI can override. The typical implementation of the > __va_function macro would use inline assembly to take the function > address, which avoids compiler instrumentation. I think these helper are sensible, but shouldn't they have somewhat less arcane names and proper documentation?
