[PATCH] efi: Fix free_end build warning
will.deacon at arm.com
Fri Nov 14 02:35:28 PST 2014
On Fri, Nov 14, 2014 at 10:29:59AM +0000, Ard Biesheuvel wrote:
> On 14 November 2014 11:22, Will Deacon <will.deacon at arm.com> wrote:
> > [Adding original authors]
> > On Wed, Nov 12, 2014 at 08:27:30PM +0000, Geoff Levand wrote:
> >> Initialize the free_end variable to zero. Fixes build warnings
> >> like these:
> >> arch/arm64/kernel/efi.c: warning: ‘free_end’ may be used uninitialized in this function
> >> Signed-off-by: Geoff Levand <geoff at infradead.org>
> >> ---
> >> Got this with the latest arm64/for-next/core branch. Please consider.
> >> -Geoff
> >> arch/arm64/kernel/efi.c | 1 +
> >> 1 file changed, 1 insertion(+)
> >> diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> >> index 4f39a18..83fc53c 100644
> >> --- a/arch/arm64/kernel/efi.c
> >> +++ b/arch/arm64/kernel/efi.c
> >> @@ -239,6 +239,7 @@ static void __init free_boot_services(void)
> >> * want to keep for UEFI.
> >> */
> >> + free_end = 0;
> >> keep_end = 0;
> >> free_start = 0;
> > Whilst I can't see how free_end gets used uninitialized in this function,
> > the code is really hard to read and I'd like to get an Ack from one of the
> > people on CC before merging this, just in case GCC is actually telling us
> > something useful for a change.
> We are planning to remove this code entirely in the 3.20 timeframe.
> Freeing boot services will not be necessary any longer once we stop
> reserving it in the first place, and I agree that the function is hard
> to read. Also, it depends on the UEFI memory map being sorted, which
> is not mandated by the spec so we can't actually rely on it. (Even if
> it usually is the case)
> So I don't object to this patch, if the warning is bothering people,
> but perhaps we can just wait for the warning to go away once the new
> stuff lands.
Ok, thanks Ard. I think I'll leave it alone for now, then.
More information about the linux-arm-kernel