linux-kernel - [ 020/103] powerpc/perf: Dont enable if we have zero events

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 23 Jul 2013 15:25:31 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Michael Ellerman <michael@...erman.id.au>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>
Subject: [ 020/103] powerpc/perf: Dont enable if we have zero events

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michael Ellerman <michael@...erman.id.au>

commit 4ea355b5368bde0574c12430df53334c4be3bdcf upstream.

In power_pmu_enable() we still enable the PMU even if we have zero
events. This should have no effect but doesn't make much sense. Instead
just return after telling the hypervisor that we are not using the PMCs.

Signed-off-by: Michael Ellerman <michael@...erman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@...nel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/powerpc/perf/core-book3s.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -926,6 +926,11 @@ static void power_pmu_enable(struct pmu
 	if (!cpuhw->disabled)
 		goto out;
 
+	if (cpuhw->n_events == 0) {
+		ppc_set_pmu_inuse(0);
+		goto out;
+	}
+
 	cpuhw->disabled = 0;
 
 	/*
@@ -937,8 +942,6 @@ static void power_pmu_enable(struct pmu
 	if (!cpuhw->n_added) {
 		mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
 		mtspr(SPRN_MMCR1, cpuhw->mmcr[1]);
-		if (cpuhw->n_events == 0)
-			ppc_set_pmu_inuse(0);
 		goto out_enable;
 	}
 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/