On Wed, Mar 24, 2021 at 12:14 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > 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? Good point, I'll add comments in the next version. I thought __pa_function would be a fairly straightforward replacement for __pa_symbol, but I'm fine with renaming these. Any suggestions for less arcane names? Sami
