Re: [PATCH 1/3] x86: drop unnecessary kernel_eflags variable from64 bit.

[Ian Campbell]

On Tue, 2011-07-05 at 17:28 +0400, Cyrill Gorcunov wrote:
> On Tue, Jul 05, 2011 at 02:00:12PM +0100, Ian Campbell wrote:
> > For no reason that I can determine 64 bit x86 saves the current eflags
> > in cpu_init purely for use in ret_from_fork. The equivalent 32 bit
> > code simply hard codes 0x0202 as the new EFLAGS which seems safer than
> > relying on a potentially arbitrary EFLAGS saved during cpu_init.
> > 
> > Original i386 changeset
> > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=47a5c6fa0e204a2b63309c648bb2fde36836c826
> > Original x86_64 changset
> > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=658fdbef66e5e9be79b457edc2cbbb3add840aa9
> > 
> > The only comment in the later indicates that it is following the
> > former, but not why it differs in this way.
> > 
> > This change makes 64 bit use the same mechanism to setup the initial
> > EFLAGS on fork. Note that 64 bit resets EFLAGS before calling
> > schedule_tail() as opposed to 32 bit which calls schedule_tail()
> > first. Therefore the correct value for EFLAGS has opposite IF
> > bit. This will be fixed in a subsequent patch.
> > 
> > Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> > Cc: x86@xxxxxxxxxx
> 
> The whole series looks good to me, thanks Ian! I hope I don't
> miss anything, so lets wait for more feedback ;)

Thanks. Actually I missed the extern declaration in asm/processor.h so
this updated patch should be used instead:

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