Messages in this thread | | | Date | Tue, 29 Apr 2008 21:28:33 -0700 (PDT) | Subject | Re: [PATCH] /dev/mem gcc weak function workaround | From | David Miller <> |
| |
From: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue, 29 Apr 2008 18:31:09 -0700
> Some flavors of gcc 4.1.0 and 4.1.1 seems to have trouble understanding > weak function definitions. Calls to function from the same file where it is > defined as weak _may_ get inlined, even when there is a non-weak definition of > the function elsewhere. I tried using attribute 'noinline' which does not > seem to help either. > > One workaround for this is to have weak functions defined in different > file as below. Other possible way is to not use weak functions and go back > to ifdef logic. > > There are few other usages in kernel that seem to depend on weak (and noinline) > working correctly, which can also potentially break and needs such workarounds. > Example - > mach_reboot_fixups() in arch/x86/kernel/reboot.c is one such call which > is getting inlined with a flavor of gcc 4.1.1. > > Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> > Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
This sounds like a bug. And if gcc does multi-file compilation it can in theory do the same mistake even if you move it to another file.
We need something more bulletproof here.
Also, we have a macro for marking things weak "__weak" which should be used here.
| |