Re: [PATCH] powerpc: fix altivec_unavailable_exception Oopses
From: Kumar Gala <hidden>
Date: 2006-02-22 00:52:13
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On Feb 21, 2006, at 5:39 PM, Alan Curry wrote:
quoted hunk ↗ jump to hunk
altivec_unavailable_exception is called without setting r3... it looks like the r3 that actually gets passed in as struct pt_regs *regs is the undisturbed value of r3 at the time the altivec instruction was encountered. The user actually gets to choose the pt_regs printed in the Oops! After applying the following patch to 2.6.16-rc4, I can no longer cause an Oops by executing an altivec instruction with CONFIG_ALTIVEC=n. The same change would probably also be good for arch/ppc/kernel/head.S to fix the same Oops in 2.6.15.4, though I haven't tested that.--- arch/powerpc/kernel/head_32.S.orig 2006-02-2115:58:18.000000000 -0500+++ arch/powerpc/kernel/head_32.S 2006-02-21 15:59:23.000000000 -0500@@ -714,6 +714,7 @@ #ifdef CONFIG_ALTIVEC bne load_up_altivec /* if from user, just load it up */ #endif /* CONFIG_ALTIVEC */ + addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_EE_LITE(0xf20, altivec_unavailable_exception) PerformanceMonitor:
Would you mine providing a patch for arch/ppc/kernel/head.S and adding a signed-off-by line. - k