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powerpc: Rate-limit users spamming kernel log buffer

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The facility unavailable exception can be triggered from userspace by
accessing PMU registers when EBB is not enabled.  This causes the
included pr_err() to run, hence spamming the kernel log buffer.

This avoids this by rate limiting these messages.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Michael Neuling 2014-03-14 17:03:58 +11:00 committed by Benjamin Herrenschmidt
parent e9aaac1ac3
commit ee4ed6fa5a
1 changed files with 3 additions and 2 deletions
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5
arch/powerpc/kernel/traps.c
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@ -1379,8 +1379,9 @@ void facility_unavailable_exception(struct pt_regs *regs)
if (!arch_irq_disabled_regs(regs))
local_irq_enable();
pr_err("%sFacility '%s' unavailable, exception at 0x%lx, MSR=%lx\n",
hv ? "Hypervisor " : "", facility, regs->nip, regs->msr);
pr_err_ratelimited(
"%sFacility '%s' unavailable, exception at 0x%lx, MSR=%lx\n",
hv ? "Hypervisor " : "", facility, regs->nip, regs->msr);
if (user_mode(regs)) {
_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);