Messages in this thread | | | Date | Tue, 5 Jul 2011 17:28:25 +0400 | From | Cyrill Gorcunov <> | Subject | Re: [PATCH 1/3] x86: drop unnecessary kernel_eflags variable from 64 bit. |
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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@citrix.com> > Cc: x86@kernel.org
The whole series looks good to me, thanks Ian! I hope I don't miss anything, so lets wait for more feedback ;)
Cyrill
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