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[PATCH] ppc32: oops on kernel altivec assist exceptions

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If we should happen to get an altivec assist exception while executing in
the kernel, we will currently try to handle it and fail, and end up oopsing
with (apparently) a segfault.  (An altivec assist exception occurs for
floating-point altivec instructions with denormalized inputs or outputs if
the altivec unit is in java mode.)

This patch checks explicitly if we are in user mode and prints a useful
message if not.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Paul Mackerras 2005-04-16 15:24:17 -07:00 committed by Linus Torvalds
parent 6460b4cceb
commit e378cc16b0
1 changed files with 7 additions and 0 deletions
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7
arch/ppc/kernel/traps.c
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@ -805,6 +805,13 @@ void AltivecAssistException(struct pt_regs *regs)
if (regs->msr & MSR_VEC)
giveup_altivec(current);
preempt_enable();
if (!user_mode(regs)) {
printk(KERN_ERR "altivec assist exception in kernel mode"
" at %lx\n", regs->nip);
debugger(regs);
die("altivec assist exception", regs, SIGFPE);
return;
}
err = emulate_altivec(regs);
if (err == 0) {