Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1597112

[PATCH 4.9 110/153] hv: dont reset hv_context.tsc_page on crash

From Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups linux.kernel
Subject [PATCH 4.9 110/153] hv: dont reset hv_context.tsc_page on crash
Date 2017-03-10 12:10 +0100
Message-ID <tjqAO-38Z-27@gated-at.bofh.it> (permalink)
References <tjoSl-1MV-7@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


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

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

From: Vitaly Kuznetsov <vkuznets@redhat.com>

commit 56ef6718a1d8d77745033c5291e025ce18504159 upstream.

It may happen that secondary CPUs are still alive and resetting
hv_context.tsc_page will cause a consequent crash in read_hv_clock_tsc()
as we don't check for it being not NULL there. It is safe as we're not
freeing this page anyways.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hv/hv.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -309,9 +309,10 @@ void hv_cleanup(bool crash)
 
 		hypercall_msr.as_uint64 = 0;
 		wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
-		if (!crash)
+		if (!crash) {
 			vfree(hv_context.tsc_page);
-		hv_context.tsc_page = NULL;
+			hv_context.tsc_page = NULL;
+		}
 	}
 #endif
 }

Back to linux.kernel | Previous | Next | Find similar | Unroll thread


Thread

[PATCH 4.9 110/153] hv: dont reset hv_context.tsc_page on crash Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-10 12:10 +0100

csiph-web