architectures.
Notes:
- On alpha and ia64 the function is kept but gets renamed locally to avoid
symbol collision. This is because on these two arches, I am not sure
whether the ASM callers do not rely on fixed registers, so I prefer to
keep the ASM body for now.
- On Vax, only the symbol is removed, because the body is used from other
functions.
- On RISC-V, this change fixes a bug: copystr() was just a wrapper around
strlcpy(), but strlcpy() makes the operation less safe (strlen on the
source beyond its size).
- The kASan, kCSan and kMSan wrappers are removed, because now that
copystr() is in C, the compiler transformations are applied to it,
without the need for manual wrappers.
Could test on amd64 only, but should be fine.
to detect race conditions at runtime. It is a variation of TSan that is
easy to implement and more suited to kernel internals, albeit theoretically
less precise than TSan's happens-before.
We do basically two things:
- On every KCSAN_NACCESSES (=2000) memory accesses, we create a cell
describing the access, and delay the calling CPU (10ms).
- On all memory accesses, we verify if the memory we're reading/writing
is referenced in a cell already.
The combination of the two means that, if for example cpu0 does a read that
is selected and cpu1 does a write at the same address, kCSan will fire,
because cpu1's write collides with cpu0's read cell.
The coverage of the instrumentation is the same as that of kASan. Also, the
code is organized in a way similar to kASan, so it is easy to add support
for more architectures than amd64. kCSan is compatible with KCOV.
Reviewed by Kamil.
