Commit e378cc16 authored by Paul Mackerras's avatar Paul Mackerras Committed by Linus Torvalds

[PATCH] ppc32: oops on kernel altivec assist exceptions

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: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6460b4cc
...@@ -805,6 +805,13 @@ void AltivecAssistException(struct pt_regs *regs) ...@@ -805,6 +805,13 @@ void AltivecAssistException(struct pt_regs *regs)
if (regs->msr & MSR_VEC) if (regs->msr & MSR_VEC)
giveup_altivec(current); giveup_altivec(current);
preempt_enable(); 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); err = emulate_altivec(regs);
if (err == 0) { if (err == 0) {
......
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