Messages in this thread Patch in this message |  | | | Date | Mon, 4 Apr 2005 15:37:25 +1000 | | From | Paul Mackerras <> | | Subject | [PATCH] ppc: 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: Paul Mackerras <paulus@samba.org>
diff -urN linux-2.5/arch/ppc/kernel/traps.c pmac-2.5/arch/ppc/kernel/traps.c --- linux-2.5/arch/ppc/kernel/traps.c 2005-03-29 16:24:53.000000000 +1000 +++ pmac-2.5/arch/ppc/kernel/traps.c 2005-03-31 08:37:53.000000000 +1000 @@ -805,6 +828,13 @@ 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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