Messages in this thread Patch in this message | | | Subject | [patch 028/198] ppc32: oops on kernel altivec assist exceptions | From | akpm@osdl ... | Date | Tue, 12 Apr 2005 03:30:59 -0700 |
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From: Paul Mackerras <paulus@samba.org>
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> ---
25-akpm/arch/ppc/kernel/traps.c | 7 +++++++ 1 files changed, 7 insertions(+)
diff -puN arch/ppc/kernel/traps.c~ppc32-oops-on-kernel-altivec-assist-exceptions arch/ppc/kernel/traps.c --- 25/arch/ppc/kernel/traps.c~ppc32-oops-on-kernel-altivec-assist-exceptions 2005-04-12 03:21:10.167591192 -0700 +++ 25-akpm/arch/ppc/kernel/traps.c 2005-04-12 03:21:10.171590584 -0700 @@ -805,6 +805,13 @@ void AltivecAssistException(struct pt_re 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) { _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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