Commit f0171973 authored by Kan Liang's avatar Kan Liang Committed by Peter Zijlstra
Browse files

perf/x86/intel/uncore: Validate MMIO address before accessing 



An oops will be triggered, if perf tries to access an invalid address
which exceeds the mapped area.

Check the address before the actual access to MMIO sapce of an uncore
unit.

Suggested-by: default avatarDavid Laight <David.Laight@ACULAB.COM>
Signed-off-by: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1590679169-61823-3-git-send-email-kan.liang@linux.intel.com
parent 1b94d31d

arch/x86/events/intel/uncore.c

+3 −0
Original line number Diff line number Diff line
@@ -132,6 +132,9 @@ u64 uncore_mmio_read_counter(struct intel_uncore_box *box, 
	if (!box->io_addr)

		return 0;



	if (!uncore_mmio_is_valid_offset(box, event->hw.event_base))

		return 0;



	return readq(box->io_addr + event->hw.event_base);

}

arch/x86/events/intel/uncore.h

+12 −0
Original line number Diff line number Diff line
@@ -197,6 +197,18 @@ static inline bool uncore_pmc_freerunning(int idx) 
	return idx == UNCORE_PMC_IDX_FREERUNNING;

}



static inline bool uncore_mmio_is_valid_offset(struct intel_uncore_box *box,

					       unsigned long offset)

{

	if (offset < box->pmu->type->mmio_map_size)

		return true;



	pr_warn_once("perf uncore: Invalid offset 0x%lx exceeds mapped area of %s.\n",

		     offset, box->pmu->type->name);



	return false;

}



static inline

unsigned int uncore_mmio_box_ctl(struct intel_uncore_box *box)

{

arch/x86/events/intel/uncore_snbep.c

+6 −0
Original line number Diff line number Diff line
@@ -4483,6 +4483,9 @@ static void snr_uncore_mmio_enable_event(struct intel_uncore_box *box, 
	if (!box->io_addr)

		return;



	if (!uncore_mmio_is_valid_offset(box, hwc->config_base))

		return;



	writel(hwc->config | SNBEP_PMON_CTL_EN,

	       box->io_addr + hwc->config_base);

}
@@ -4495,6 +4498,9 @@ static void snr_uncore_mmio_disable_event(struct intel_uncore_box *box, 
	if (!box->io_addr)

		return;



	if (!uncore_mmio_is_valid_offset(box, hwc->config_base))

		return;



	writel(hwc->config, box->io_addr + hwc->config_base);

}

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