[Qemu-devel] [PATCH 29/36] s390x/tcg: Fix length calculation in probe_write_access()

Richard Henderson posted 36 patches 5 years, 7 months ago
Maintainers: Eduardo Habkost <ehabkost@redhat.com>, Claudio Fontana <claudio.fontana@huawei.com>, Stefan Hajnoczi <stefanha@redhat.com>, Alex Williamson <alex.williamson@redhat.com>, Palmer Dabbelt <palmer@sifive.com>, Richard Henderson <rth@twiddle.net>, Laurent Vivier <laurent@vivier.eu>, Halil Pasic <pasic@linux.ibm.com>, Alistair Francis <Alistair.Francis@wdc.com>, Peter Maydell <peter.maydell@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, "Michael S. Tsirkin" <mst@redhat.com>, Riku Voipio <riku.voipio@iki.fi>, Cornelia Huck <cohuck@redhat.com>, David Gibson <david@gibson.dropbear.id.au>, Aleksandar Rikalo <arikalo@wavecomp.com>, Aleksandar Markovic <amarkovic@wavecomp.com>, Aurelien Jarno <aurelien@aurel32.net>, Stafford Horne <shorne@gmail.com>, Artyom Tarasenko <atar4qemu@gmail.com>, Andrzej Zaborowski <balrogg@gmail.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Sagar Karandikar <sagark@eecs.berkeley.edu>, Collin Walling <walling@linux.ibm.com>, Christian Borntraeger <borntraeger@de.ibm.com>, David Hildenbrand <david@redhat.com>
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[Qemu-devel] [PATCH 29/36] s390x/tcg: Fix length calculation in probe_write_access()
Posted by Richard Henderson 5 years, 7 months ago
From: David Hildenbrand <david@redhat.com>

Hm... how did that "-" slip in (-TAGRET_PAGE_SIZE would be correct). This
currently makes us exceed one page in a single probe_write() call,
essentially leaving some memory unchecked.

Fixes: c5a7392cfb96 ("s390x/tcg: Provide probe_write_access helper")
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190826075112.25637-3-david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/s390x/mem_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 7819aca15d..4b43440e89 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -2623,7 +2623,7 @@ void probe_write_access(CPUS390XState *env, uint64_t addr, uint64_t len,
 #else
     /* test the actual access, not just any access to the page due to LAP */
     while (len) {
-        const uint64_t pagelen = -(addr | -TARGET_PAGE_MASK);
+        const uint64_t pagelen = -(addr | TARGET_PAGE_MASK);
         const uint64_t curlen = MIN(pagelen, len);
 
         probe_write(env, addr, curlen, cpu_mmu_index(env, false), ra);
-- 
2.17.1