[PATCH] strange work_notifysig code since 2.6.16

From: Joe Korty
Date: Tue Oct 24 2006 - 19:20:47 EST


tree 9b5daef5280800a0006343a17f63072658d91a1d is surely wrong.

[PATCH] Make vm86 support optional
Jan 8, 2006, tree first appears in 2.6.16

If the branch to work_notifysig_86 is taken and CONFIG_VM86=n,
then entry.S drops into unrelated assembly code.

The branch to work_notifysig_v86, a few lines above the patch, says:
"returning to kernel-space or vm86-space"
which implies if vm86-space isn't being supported we still need the
branch & jumped-to code in order to handle the kernel case.

However, I don't understand this area all that well, so take this patch
as more of an indication of a possible problem area than as a true fix.

Signed-off-by: Joe Korty <joe.korty@xxxxxxxx>

Index: 2.6.18.1/arch/i386/kernel/entry.S
===================================================================
--- 2.6.18.1.orig/arch/i386/kernel/entry.S 2006-09-19 23:42:06.000000000 -0400
+++ 2.6.18.1/arch/i386/kernel/entry.S 2006-10-24 19:08:36.000000000 -0400
@@ -457,7 +457,6 @@

ALIGN
work_notifysig_v86:
-#ifdef CONFIG_VM86
pushl %ecx # save ti_flags for do_notify_resume
CFI_ADJUST_CFA_OFFSET 4
call save_v86_state # %eax contains pt_regs pointer
@@ -467,7 +466,6 @@
xorl %edx, %edx
call do_notify_resume
jmp resume_userspace_sig
-#endif

# perform syscall exit tracing
ALIGN
-
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