* Why set ORIG_EAX(%esp) to -1 in arch/i386/kernel/entry.S:error_code?
@ 2006-08-29 19:03 Jeremy Fitzhardinge
2006-08-29 21:55 ` Linus Torvalds
0 siblings, 1 reply; 3+ messages in thread
From: Jeremy Fitzhardinge @ 2006-08-29 19:03 UTC (permalink / raw)
To: Linux Kernel Mailing List, Andi Kleen, Zachary Amsden,
Linus Torvalds, Chuck Ebbert
There doesn't seem much point; nothing seems to use it on the
trap-handling paths. Is it a historical left-over?
J
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Why set ORIG_EAX(%esp) to -1 in arch/i386/kernel/entry.S:error_code? 2006-08-29 19:03 Why set ORIG_EAX(%esp) to -1 in arch/i386/kernel/entry.S:error_code? Jeremy Fitzhardinge @ 2006-08-29 21:55 ` Linus Torvalds 2006-08-29 22:29 ` Jeremy Fitzhardinge 0 siblings, 1 reply; 3+ messages in thread From: Linus Torvalds @ 2006-08-29 21:55 UTC (permalink / raw) To: Jeremy Fitzhardinge Cc: Linux Kernel Mailing List, Andi Kleen, Zachary Amsden, Chuck Ebbert On Tue, 29 Aug 2006, Jeremy Fitzhardinge wrote: > > There doesn't seem much point; nothing seems to use it on the trap-handling > paths. Is it a historical left-over? No. It's important that ORIG_EAX be set to some value that is _not_ a valid system call number, so that the system call restart logic (see the signal handling code) doesn't trigger. Linus ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Why set ORIG_EAX(%esp) to -1 in arch/i386/kernel/entry.S:error_code? 2006-08-29 21:55 ` Linus Torvalds @ 2006-08-29 22:29 ` Jeremy Fitzhardinge 0 siblings, 0 replies; 3+ messages in thread From: Jeremy Fitzhardinge @ 2006-08-29 22:29 UTC (permalink / raw) To: Linus Torvalds Cc: Linux Kernel Mailing List, Andi Kleen, Zachary Amsden, Chuck Ebbert Linus Torvalds wrote: > No. It's important that ORIG_EAX be set to some value that is _not_ a > valid system call number, so that the system call restart logic (see the > signal handling code) doesn't trigger. > Ah, yes, I see. I'll add a comment in my i386-pda patch to entry.S. J ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2006-08-29 22:30 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2006-08-29 19:03 Why set ORIG_EAX(%esp) to -1 in arch/i386/kernel/entry.S:error_code? Jeremy Fitzhardinge 2006-08-29 21:55 ` Linus Torvalds 2006-08-29 22:29 ` Jeremy Fitzhardinge
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