Messages in this thread | | | From | Marco Elver <> | Date | Wed, 8 Feb 2023 17:59:05 +0100 | Subject | Re: [PATCH 4/4] objtool: add UACCESS exceptions for __tsan_volatile_read/write |
| |
On Wed, 8 Feb 2023 at 17:40, Arnd Bergmann <arnd@kernel.org> wrote: > > From: Arnd Bergmann <arnd@arndb.de> > > A lot of the tsan helpers are already excempt from the UACCESS warnings, > but some more functions were added that need the same thing: > > kernel/kcsan/core.o: warning: objtool: __tsan_volatile_read16+0x0: call to __tsan_unaligned_read16() with UACCESS enabled > kernel/kcsan/core.o: warning: objtool: __tsan_volatile_write16+0x0: call to __tsan_unaligned_write16() with UACCESS enabled > vmlinux.o: warning: objtool: __tsan_unaligned_volatile_read16+0x4: call to __tsan_unaligned_read16() with UACCESS enabled > vmlinux.o: warning: objtool: __tsan_unaligned_volatile_write16+0x4: call to __tsan_unaligned_write16() with UACCESS enabled
That's odd - this has never been needed, because all __tsan_unaligned are aliases for the non-unaligned functions. And all those are in the uaccess_safe_builtin list already.
So if suddenly the alias name becomes the symbol that objtool sees, we might need to add all the other functions as well.
Is this a special build with a new compiler?
> Fixes: 75d75b7a4d54 ("kcsan: Support distinguishing volatile accesses") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > tools/objtool/check.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/tools/objtool/check.c b/tools/objtool/check.c > index e8fb3bf7a2e3..d89ef6957021 100644 > --- a/tools/objtool/check.c > +++ b/tools/objtool/check.c > @@ -1200,6 +1200,8 @@ static const char *uaccess_safe_builtin[] = { > "__tsan_atomic64_compare_exchange_val", > "__tsan_atomic_thread_fence", > "__tsan_atomic_signal_fence", > + "__tsan_unaligned_read16", > + "__tsan_unaligned_write16", > /* KCOV */ > "write_comp_data", > "check_kcov_mode", > -- > 2.39.1 > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/20230208164011.2287122-4-arnd%40kernel.org.
| |